Scalable synthesis of perimorphic carbons

Abstract

The name of the invention is scalable synthesis of coated carbon. The present disclosure relates to scalable synthesis of carbonaceous coating materials, including carbonaceous coating frameworks, on recyclable templates and using recyclable process liquids. The present disclosure also shows a novel envelope architecture. In particular, a coating framework is presented that includes a synthetic anthracite network. Using these methods, three-dimensional architectures constructed from graphene carbon can be produced in a scalable manner.

Description

(19) State Intellectual Property Office (12) Invention Patent Application (10) Application Publication Number (43) Application Publication Date (21) Application Number 202511533001.7 (22) Application Date 2021.09.07 (30) Priority Data 63 / 075,918 2020.09.09 US (62) Divisional Application Data 202180075447.3 2021.09.07 (71) Applicant Dickinson Company Address USA (72) Inventors M. Bishop D. Brill C. Carstens A. Thomas A. West (74) Patent Agency Beijing Zhucheng Law Firm 11313 Patent Attorneys Chen Yanjuan Wang Yanbo (51) Int.Cl. C01B 32 / 184 (2017.01) C01B 32 / 186 (2017.01) C01B 32 / 194 (2017.01) B82Y 40 / 00 (2011.01) C01B 32 / 15 (2017.01) (54) Invention Title: Scalable Synthesis of Coated Carbon (57) Abstract: The invention title is Scalable Synthesis of Coated Carbon. This disclosure relates to the scalable synthesis of carbonaceous coated materials, including carbonaceous coated frameworks, on recyclable templates and using recyclable process liquids. This disclosure also demonstrates novel coated architectures. In particular, coated frameworks comprising synthetic anthracite networks are demonstrated. Using these methods, three-dimensional architectures constructed from graphene carbon can be produced in a scalable manner. Claims 4 pages, Description 55 pages, Drawings 34 pages, CN 121536914 A 2026.02.17 CN 1 21 53 69 14 A 1. A method for generating a carbonaceous coated framework by: I. obtaining a precursor material and a mother liquor from a first reserve solution by solvent-free precipitation; and II. heating the precursor material to form a template material; and III. adsorbing the carbonaceous coated material onto the template material; and IV. reacting the template material with an extractant solution comprising the mother liquor to form a carbonaceous coated framework and a second reserve solution, the second reserve solution and the first reserve solution sharing a similar chemical composition. 2. A method for generating a carbonaceous coated framework by: I. obtaining a precursor material and a mother liquor from a first reserve solution by solvent-free precipitation; and II. heating the precursor material to form a template material; and III. adsorbing the carbonaceous coated material onto the template material; and IV. reacting the template material with an extractant solution comprising the mother liquor to form a carbonaceous coated framework and a reconstructed reserve solution, the first reserve solution and the reconstructed reserve solution sharing a similar chemical composition; and V. repeating cycles of I to IV to form an additional coated framework, wherein the reconstructed reserve formed in each cycle...The solution includes a first reserve solution used in subsequent cycles. 3. A method for generating a carbonaceous coated framework by: I. forming, by solvent-free precipitation from a first reserve solution comprising ions dissolved in a process liquid: a precursor material comprising a solid precipitate; and a mother liquor comprising an unprecipitated portion of the ions dissolved in the process liquid; and II. treating the precursor material to form a template material, the treatment comprising at least one of: decomposing a portion of the precursor material, altering the morphology of the precursor material, activating the precursor material, and heating the precursor material; and III. adsorbing a carbonaceous coated material onto the template material to form a coated composite material; and IV. exposing the coated composite material to an extractant solution comprising an extractant and the mother liquor; and V. extracting the template material from the coated composite material to form: a second reserve solution having a composition similar to the first reserve solution; and a carbonaceous coated framework comprising carbonaceous coated walls and pores formed by the extraction of the template material; and VI. The carbonaceous coated framework is separated from the second reserve solution. 4. A method for generating a hollow carbonaceous coated framework by: I. atomizing and evaporating a first stock solution comprising ions dissolved in a process liquid to form: a precursor material comprising hollow precursor particles; and a vapor comprising evaporated process liquid; and II. condensing the evaporated process liquid in the vapor to form a stored process liquid; and III. processing the precursor material to form a template material comprising hollow template particles and the processing comprising at least one of: decomposing a portion of the precursor material, altering the morphology of the precursor material, activating the precursor material, and heating the precursor material; and IV. adsorbing a carbonaceous coating material onto the template material to form a coated composite material comprising hollow coated composite particles; and V. forming an extractant solution by adding an extractant to the stored process liquid; and VI. exposing the coated composite material to the extractant solution; and VII. extracting the template material from the coated composite material to form: A second reserve solution having a composition similar to the first reserve solution; and a hollow carbonaceous coated framework comprising carbonaceous coating walls and pores formed through the extraction of the template material; and VIII. separating the hollow carbonaceous coated framework from the second reserve solution. 5. A method for generating a carbonaceous coated framework by: I.A precursor material comprising magnesium carbonate precipitate is formed from a first stock solution comprising aqueous magnesium bicarbonate by solvent-free precipitation: I. A precursor material comprising magnesium carbonate precipitate; a mother liquor comprising an unprecipitated portion of the first stock solution having a reduced concentration of magnesium bicarbonate; and a vapor comprising at least one of a first portion of process water vapor and a first portion of CO2 process gas; II. The precursor material is treated to form: A template material comprising porous magnesium oxide particles; and a vapor comprising at least one of a second portion of process water vapor and a second portion of CO2 process gas; III. A carbonaceous coating material is adsorbed onto the template material to form a coated composite material; IV. Optionally, at least one of the first and second portions of process water vapor is condensed to form preserved process water; V. The coated composite material is exposed to an extractant solution comprising aqueous H2CO3, the extractant solution optionally comprising at least one of the first and second portions of CO2 process gas and the preserved process water; VI. The template material is extracted from the coated composite material to form: A second reserve solution comprising magnesium bicarbonate and having a composition similar to the first reserve solution; and a carbonaceous coated framework comprising carbonaceous coated walls and pores formed by the extraction of the template material; and VII. separating the carbonaceous coated framework from the second reserve solution. 6. A method for generating a hollow carbonaceous coated framework by: I. atomizing and evaporating a first reserve solution comprising magnesium bicarbonate dissolved in process water to form: a precursor material comprising hollow magnesium carbonate precursor particles; and vapor comprising a first portion of process water vapor and a first portion of CO2 process gas; and II. condensing the first portion of process water vapor to form a first portion of stored process water; and III. processing the precursor material to form: a template material comprising hollow magnesium oxide particles; and vapor comprising at least one of a second portion of process water vapor and a second portion of CO2 process gas; and IV. optionally, condensing the second portion of process water vapor to form a second portion of stored process water; and V. adsorbing a carbonaceous coating material onto the template material to form a coated composite material comprising hollow coated composite particles; and VI. In at least one of the process water stored in the first and second portions, at least one of the CO2 process gases in the first and second portions is dissolved to form an extractant solution comprising H2CO3; and VII.VIII. Exposing the coated composite material to the extractant solution; and VIII. Extracting the template material from the coated composite material to form: a second reserve solution comprising magnesium bicarbonate and having a composition similar to the first reserve solution; and a hollow carbonaceous coated framework comprising carbonaceous coating walls and pores formed through the extraction of the template material; and IX. Separating the hollow carbonaceous coated framework from the second reserve solution. 7. A method for generating a carbonaceous coated framework by: I. forming, by solvent-free precipitation from a first stock solution comprising aqueous magnesium bicarbonate: a precursor material comprising magnesium carbonate precipitate; and a mother liquor comprising an unprecipitated portion of the first stock solution having a reduced concentration of magnesium bicarbonate; and a vapor comprising at least one of a first portion of process water vapor and a first portion of CO2 process gas; and II. processing the precursor material to form: a template material comprising porous dehydrated magnesium carbonate particles; and a vapor comprising at least one of a second portion of process water vapor and a second portion of CO2 process gas; and III. adsorbing a carbonaceous coating material onto the template material to form a first coated composite material; and IV. optionally condensing at least one of the first and second portions of process water vapor to form stored process water; and V. decomposing the template material to form a second coated composite material comprising the carbonaceous coating material and content magnesium oxide; VI. The second coated composite material is exposed to an extractant solution comprising aqueous H2CO3, the extractant solution optionally comprising at least one of the first and second portions of CO2 process gas and the stored process water; and VII. The content magnesium oxide is extracted from the coated composite material to form: a second reserve solution comprising magnesium bicarbonate and having a composition similar to the first reserve solution; and a carbonaceous coated framework comprising carbonaceous coated walls and pores formed by the extraction of the template material; and VIII. The carbonaceous coated framework is separated from the second reserve solution. 8. The method according to any one of claims 1 to 7, further comprising: annealing at least one of the coated composite material and the carbonaceous coated framework. Claims 3 / 4 pages 4 CN 121536914 A 9. The method according to any one of claims 1 to 8, wherein the carbonaceous coated material comprises a synthetic anthracite network. 10. The method according to any one of claims 1 to 8, wherein the carbonaceous coated material comprises a graphene monolayer.11. The method of any one of claims 1 to 10, wherein the carbonaceous coating material comprises a maximum thickness of 100 nm. 12. The method of any one of claims 1 to 11, wherein the template material comprises a porous network of joint subunits. 13. The method of any one of claims 1 to 12, wherein the template material comprises a Brunauer–Emmett–Teller (BET) surface area between 10 m² / g and 100 m² / g. 14. The method of any one of claims 1 to 12, wherein the template material comprises a BET surface area between 100 m² / g and 400 m² / g. 15. The method of any one of claims 1 to 14, wherein the template material comprises at least one of a Group I metal cation, a Group II metal cation, an oxoanion, and an oxoanion. 16. The method of any one of claims 1 to 15, wherein the extractant solution is formed by dissolving CO₂ in water at a CO₂ pressure greater than 1 atm. 17. The method of any one of claims 1 to 16, wherein the precursor material comprises a carbonate of a Group I or Group II metal. 18. The method according to any one of claims 1 to 17, wherein the precursor material comprises a magnesium salt of a weak acid. 19. The method according to any one of claims 17 to 18, wherein the precursor material comprises hydrated magnesium carbonate. 20. The method according to any one of claims 1 to 19, wherein the precursor material comprises a hierarchical isometric morphology. Claims 4 / 4 Page 5 CN 121536914 A Scalable Synthesis of Coated Carbon

[0001] This application is a divisional application of the Chinese national phase patent application No. 202180075447.3, filed on May 8, 2023, after the international application No. PCT / US2021 / 049195, international application date September 7, 2021, entitled "Scalable Synthesis of Coated Carbon".

[0002] Cross-Reference to Related Applications:

[0003] This application claims priority to U.S. Provisional Patent Application No. 63 / 075,918, filed September 9, 2020, entitled “SCALABLE SYNTHESIS OF PERIMORPHIC CARBONS,” the entire contents of which are incorporated herein by reference. The following applications are hereby incorporated in their entirety by reference for all purposes: U.S. Provisional Patent Application 63 / 075,918 ('918 application); U.S. Provisional Patent Application 63 / 121,308 ('308 application); U.S. Utility Model Application 16 / 758,580 ('580 application); U.S. Utility Model Application 16 / 493,473('473 application); PCT / US17 / 17537 ('17537 application); PCT / US21 / 37435 ('37435 application); and US Patent 10,717,843 B2 ('843B2 patent). Technical Field

[0004] This disclosure relates to a method for the scalable production of carbonaceous coated materials. More specifically, this disclosure relates to a low-cost, waste-reducing method for producing carbonaceous coated materials, wherein process materials are recyclable. Background Art

[0005] Nanostructured materials can possess superior properties compared to bulk materials. The construction of three-dimensional ordered architectures from block structures by nanostructures facilitates the realization of these superior properties in bulk material forms. These "frameworked" materials can be produced by synthesizing nanoscale or microscale blocks and arranging them into fine assemblies. In particular, porous materials with frameworked porous structures are favored due to their low density, high specific surface area, and potential mechanical properties.

[0006] Existing methods exist for constructing three-dimensional porous assemblies from nanostructured blocks. The preparation of three-dimensional aerogels can involve dispersing nanostructured ions in a liquid matrix. At sufficient concentrations, the nano-ions can self-assemble into a gel-like network that can serve as the basis for the aerogel. For example, three-dimensional aerogels constructed from carbon or silica can be formed by freeze-drying self-assembling hydrogels. However, non-directed self-assembly techniques can produce disordered architectures with micropores. While these aerogels may have impressively low densities, their disorder and pore size make them unsuitable for many applications.

[0007] Theoretical models indicate a need for porous architectures with controllable compaction and order. For example, the Buehler group imposed a high level of compaction, i.e., reduced pore size, when modeling the mechanical properties of theoretical helices constructed from continuous monolayer graphene. When the quasi-segmented spaces within the helical architecture are sufficiently small, the predicted mechanical properties of the framework outperform certain steels. This can likely be attributed to the compaction and order of the architecture.

[0008] To impart order, directed synthesis techniques have been used. One approach to guided synthesis involves using another structure as a sacrificial template, thereby endowing the templated structure with the desired three-dimensional morphology. The template is then removed. This method is essentially a mimicry of geography; natural “crust pseudo-contents,” also known as “coating bodies,” are formed by mineralization around a sacrificial scaffold that dissolves later. For this reason, we describe templated materials as coating bodies and refer to them as coated in this paper. In some template techniques, a porous template is required. The pores are filled and replicated by the coating material; these techniques are described as “negative replication.” In other template techniques, the coating material does not fill the pores of the template but only covers the surface of the template, similar to specification page 1 / 55 6 CN 121536914 A.Concrete paper is conformally applied onto the molded body. These techniques are described herein as “surface replication.”

[0009] Template-directed deposition techniques (such as chemical vapor deposition (“CVD”) can conformally replicate the surface of a template. CVD decomposes gaseous reactants at elevated temperatures; for this reason, the template compound used in conjunction with the CVD procedure is often a thermally stable metal oxide. Template-directed CVD is commonly used to synthesize graphene carbon, which has a two-dimensional molecular structure suitable for fine applications. Surface defects of the metal oxide can catalyze the nucleation of the graphene lattice. Subsequent extraction of the template can leave a porous framework comprising thin nanostructured walls. These frameworks are described herein as “coated frameworks,” or simply “frameworks.”

[0010] Compared to other compounds with lower thermal stability, metal oxides have the disadvantage of being insoluble or only minimally soluble. For this reason, they are often reacted with strong acids to form soluble salts that can subsequently be extracted into solution. One notable exception is the use of cubic NaCl templates, which have been used for template-directed CVD synthesis of hollow carbon cubes. NaCl crystals are readily extracted by dissolution in water. For lower-temperature template-directed methods (such as liquid-phase coating), a wider range of template compounds with better solubility can be used.

[0011] Another important factor in surface replication is whether the template is porous. Replicating the surface of a non-porous template produces hollow coated frameworks. Shi has demonstrated the synthesis of cubic frameworks on non-porous NaCl cubic templates. Tian has demonstrated the synthesis of inorganic frameworks with tubular and cubic morphologies on non-porous magnesium carbonate rod and cubic templates. Hollow frameworks formed by templates with non-porous templates may be morphologically regular, but are typically macroporous and lack compaction. In addition, the sizable non-porous templates have little surface area to replicate, meaning that the coating mass produced by surface replication techniques is small compared to the mass of template consumed.

[0012] In contrast, surface replication with porous templates can be used to create more ordered and compact coated frameworks than those synthesized on aerogels or on non-porous templates. Cui describes a template-directed CVD procedure that uses a porous magnesium oxide (MgO) template derived from magnesium carbonate precursor crystals to synthesize mesoporous graphene fibers. Each mesoporous fiber comprises a coated framework with a labyrinthine pore structure inherited from the porous structure of the template's combined nanocrystalline subunits, consisting of bonded nanocrystalline subunits. Workers have produced porous metal oxide templates derived from metal hydroxide or metal carbonate precursors.

[0013] Currently, the use of surface replication techniques on porous metal oxide templates represents a powerful means of synthesizing three-dimensional porous architectures constructed from nanostructured blocks. However, industrial-scale processes using porous metal oxide templates remain uniquely challenging due to the large number of inputs and outputs associated with the products produced. Although associated with these porous templatesThe product yields of the combined products may be higher than those associated with non-porous, lower surface area templates, but they may still be lower.

[0014] Cui's work on mesoporous graphene fibers provides an example. Despite the relatively high surface area of ​​36 m²g⁻¹ and mesoporous features of 10–30 nm that should increase the product yield of the porous MgO template used, the mass of MgO consumed is still more than 30 times that of the coated product produced. The MgO template is then dissolved in a 1 mol / L aqueous hydrochloric acid (HCl) solution, resulting in another 50-fold increase in mass. Without any rinsing, this synthesis process will produce three orders of magnitude (OOM) more diluted magnesium chloride (MgCl₂) liquid waste than the coated product. Even with the use of fuming HCl, the aqueous waste stream will be 200M more than the coated product before rinsing, and the concentrated MgCl₂ brine waste may then require treatment and further input. In addition, more intensive rinsing of the coated product is required, resulting in even more diluted waste.

[0015] When these materials are produced on an industrial scale, cleaning the coated framework, which has a high specific porosity, can be problematic. To illustrate this, we note that even after filtration, the mass of water retained within the pores of the coated product (such as Cui's graphene nanofibers) can easily exceed the template mass by 200M. This is due to the latter's higher specific porosity. Assuming a difference of 200M, even if the MgCl2 concentration in the retained water is 0.1% (by weight), upon drying, a residual MgCl2 mass equivalent to approximately 10% of the coated mass will remain. This level of impurity can make the coated product unacceptable for many applications, including electrochemical applications, such as those described in the manual 2 / 55 page 7 CN 121536914 A, where carbon frameworks (produced at high purity on a laboratory scale) have proven to be superior.

[0016] It is also noted that rinsing and purification problems will be more severe compared to coated frameworks produced by surface replication on a non-porous template (given that their hollow interiors are typically large pores). However, for frames produced on porous templates, they remain problematic, and for these frames to be highly useful industrially, they should be able to be produced on an industrial scale at a reasonable level of purity. To achieve this purity, rinsing with water produces significantly more rinsing fluid than with conventional materials, exacerbating the aforementioned problem of large inputs and outputs.

[0017] Some of these challenges can be addressed by recycling the template and the process liquids used to extract the template from the coating material. This could potentially reduce the inputs and outputs associated with template synthesis and removal. Recycling the template involves harvesting the template compound by extracting ions of the template compound from the encapsulated coating phase, and then reconstructing the template to the desired chemical and morphological specifications from the harvested ion library. Recycling the process liquids used means reusing a considerable portion of the process liquids without requiring energy-intensive distillation.

[0018] Recycled templates or template-like materials have been demonstrated. Of particular note, Tian demonstrated the recycling of a non-porous crystalline metal carbonate template. This procedure involves: (i) applying an inorganic compound liquid to the surface of a magnesium carbonate template; (ii) dissolving the magnesium carbonate template in carbonic acid to form a diluted metastable magnesium bicarbonate (Mg(HCO3)2) solution; and (iii) using an ethanol antisolvent to destabilize the metastable bicarbonate solution and precipitate new magnesium carbonate crystals. In another work, Tian utilized a similar method to recycle porous MgO adsorbent materials derived from thermally decomposed magnesium carbonate precursor crystals. Similar porous MgO materials form templates for synthesizing subcrystalline frameworks. This recycling procedure involves: (i) dissolving the porous MgO material in carbonic acid to form a diluted metastable Mg(HCO3)2 solution; (ii) using an ethanol antisolvent to destabilize the bicarbonate solution and precipitate magnesium carbonate crystals; and (iii) thermally decomposing the magnesium carbonate crystals to reconstruct the porous MgO adsorbent material. In a subsequent step, it was noted that ethanol was used to accelerate precipitation and also to control the morphology of the precipitated magnesium carbonate; this is likely the case in both of Tian's processes. It was further noted that, without solvent, the precipitate was agglomerated and irregular in morphology.

[0019] Tien noted that while the template compound can be recycled without antisolvent, the template (including its chemical and morphological specifications) cannot be recycled. Although the template or template-like material is ultimately recycled in both methods, the use of antisolvent not only requires a large solvent input but also generates a diluted solvent waste stream that cannot be recycled without distillation. The resulting solvent waste may be worse than brine waste when the template is recycled. Therefore, this approach may exacerbate the liquid waste problem. Summary of the Invention

[0020] It is desirable to use a method that recycles both the template and the process liquid to produce carbonaceous coated materials. This method will reduce the required material input and input, thereby reducing costs and waste. The template can be extracted from the encapsulating phase of the carbonaceous coated material and then reconstituted to the desired chemical and morphological specifications. It is particularly desirable to develop a method for recovering or using metal oxide templates or metal oxide-containing templates (including Group I and II metal oxides, such as MgO) without consuming strong acids or solvents. This has not been demonstrated in the prior art.

[0021] It is also desirable to produce carbonaceous coated materials using methods that retain a significant portion of the process liquids used in extraction and precipitation. This method will reduce liquid consumption and waste. It is particularly desirable to preserve process liquids without requiring large-scale distillation of miscible solutions.

[0022] It is also desirable to produce carbonaceous coated materials using methods that avoid retaining large amounts of water within their porous architecture. This will eliminate...In addition to the need for excessive rinsing of the templated carbonaceous product and avoiding the generation of large amounts of diluted liquid filtrate, it will also improve the purity of the templated carbonaceous product.

[0023] Furthermore, it is desirable to develop carbonaceous coated materials with novel architectural features. This may include novel particle geometries, sizes, and aspect ratios that have not yet been synthesized, as well as rationally designed tunable pore structures. In particular, it is desirable to develop carbonaceous coated frameworks with regular equiaxed particle geometries using methods combined with template recycling. It is also desirable to develop carbonaceous coated frameworks with hierarchical equiaxed particle geometries using methods combined with template recycling.

[0024] It is also desirable to synthesize carbonaceous coated materials such as those described in '308 application, '580 application, '473 application, '37435 application, and '843B2 patent using recycled templates.

[0025] This disclosure demonstrates an industrially scalable method for synthesizing carbonaceous coated materials. The general method is described according to four stages (precursor stage, template stage, replication stage, and separation stage) combining template and liquid cycles, in which a portion of the template material is preserved for reuse, and in the liquid cycle, a portion of the process liquid is preserved for reuse. While many potential variations of the general method exist, a notable variation is the preferred method in which a solvent-free precipitation technique is used to precipitate the magnesium carbonate template precursor and a carbon-coated framework is prepared using the MgO template. The preferred method also incorporates gas circulation, in which a portion of the CO2 process gas is preserved for reuse.

[0026] The methods disclosed herein can be used in conjunction with a variety of industrial separation techniques. Techniques that may be particularly useful in separating hydrophobic carbonaceous coated products from a stock solution include foam flotation and liquid-liquid separation. Therefore, it is contemplated that the methods disclosed herein can be extended to include the use of known industrial separation techniques.

[0027] This disclosure also illustrates novel coated material frameworks and variations of novel methods that can be used to manufacture them. In particular, equiaxed carbonaceous coated frameworks and graded equiaxed carbonaceous coated frameworks are shown.

[0028] The object of the present invention is to improve the scalability and economy of producing carbonaceous coated frameworks by providing a method for recycling template materials and process liquids. Another object of the present invention is to provide a method for minimizing the waste stream generated by template recycling. In particular, the object of the present invention is to provide a scalable method for creating three-dimensional, controllable, compact architectures constructed from graphene carbon.

[0029] Another object of the present invention is to broaden the range of synthesizable template morphologies and provide techniques for controlling architecture characteristics. This allows for the rational design of template materials based on the requirements of specific applications. Brief Description of the Drawings

[0030] FIG1 is a cross-sectional view illustrating surface replication and the formation of a coated framework.

[0031] FIG2 is a cross-sectional view illustrating the formation of a coated framework using a porous template.

[0032] Figure 3 is a cross-sectional view showing the differences between the primary and non-primary morphological states of the coated framework.

[0033] Figure 4A is a cross-sectional view showing the synthetic labyrinthine framework. Figure 4B is a SEM micrograph of the labyrinthine framework.

[0034] Figure 5A is a TEM micrograph of (top) PC particles including layered carbonaceous coated phase and MgO content phase and (bottom) the coated framework after content extraction. Figure 5B is an HRTEM micrograph showing the disordered nematic graphene layers including coated wall segments of the synthetic anthracite network.

[0035] Figure 6 is a cross-sectional view showing the different types of superstructure shapes that can be formed. Cross-hatching indicates smaller-scale cellular substructures.

[0036] Figure 7 is a cross-sectional view showing the formation of labyrinthine frameworks under confined and unconfined diffusion conditions.

[0037] Figure 8 is a cross-sectional view depicting four coated frameworks with similar overall volume but different compaction.

[0038] Figure 9 is an illustration of the shuttle technique, in which the dissolution of the contents, the formation of the stock solution, and the precipitation from the stock solution outside the coating framework are shown to occur simultaneously. Specification 4 / 55 pages 9 CN 121536914 A

[0039] Figure 10 is an illustration of a general method. Template circulation and liquid circulation are marked.

[0040] Figure 11 is an illustration of a general method with gas circulation. Process gas is used to generate the extractant in the separation stage and is recaptured during the precursor stage and / or template stage.

[0041] Figure 12 is an illustration of a preferred method. In the preferred method, the stock solution comprises a Mg(HCO3)2 solution, the template precursor comprises magnesium carbonate, the template comprises MgO, and the coating material is carbonaceous.

[0042] Figure 13A is an illustration of a sequence incorporating shuttle, concentration of the stock solution by increasing CO2 pressure, and solvent-free precipitation by decreasing CO2 pressure. Figure 13B is an illustration of the use of a pressurized reactor for obtaining content extraction and concentration of Mg(HCO3)2 stock solution.

[0043] Figure 14 includes a SEM micrograph of template precursor particles (N1), which comprises magnesite particles with elongated superstructures obtained from an aqueous Mg(HCO3)2 stock solution.

[0044] Figure 15 includes a SEM micrograph of template precursor particles (H1), which comprises magnesite particles with isometric, hierarchical isometric superstructures obtained from an aqueous Mg(HCO3)2 stock solution.

[0045] Figure 16 includes a SEM micrograph of template precursor particles (H2), which comprises magnesite particles with elongated hierarchical superstructures obtained from an aqueous Mg(HCO3)2 stock solution.

[0046] Figure 17 is a SEM micrograph of template precursor particles (H3), which comprises magnesite particles with elongated hierarchical superstructures obtained from an aqueous Mg(HCO3)2 stock solution.

[0047] Figure 18 is a SEM micrograph of template precursor particles (L1), which include hydrated magnesite particles with an isometric superstructure obtained from an aqueous Mg(HCO3)2 reserve solution.

[0048] Figure 19 is a SEM micrograph of template precursor particles (M1), which include magnesite particles with an isometric superstructure.

[0049] Figure 20 is a SEM micrograph of template precursor particles (M2), which include magnesite particles with an isometric superstructure.

[0050] Figure 21 includes a SEM micrograph of template precursor particles (A1), which include amorphous magnesium carbonate particles with a hollow hierarchical isometric superstructure obtained from an aqueous Mg(HCO3)2 reserve solution. Some particles include thin fragments of hollow spherical shells.

[0051] Figure 22 includes SEM micrographs (images A to D) of template precursor particles with hollow hierarchical isometric superstructures, and TEM micrographs (image E) of carbon-coated frameworks with hollow hierarchical isometric superstructures. In image A, type A2 precursor particles are shown. In image B, type A3 precursor particles are shown. In image E, the coated framework synthesized on a template obtained from type A2 particles is shown.

[0052] Figure 23 includes SEM micrographs of template precursor particles (C1), which comprise magnesium citrate particles with hollow hierarchical isometric superstructures obtained from an aqueous magnesium citrate stock solution.

[0053] Figure 24 is an optical micrograph of template precursor particles (E1), which comprise esperidone salt (magnesium sulfate heptahydrate) with an elongated superstructure obtained from an aqueous magnesium sulfate stock solution.

[0054] Figure 25 includes a SEM micrograph of template precursor particles (H4), which comprises hydromagnesite particles obtained from an aqueous Mg(HCO3)2 stock solution containing dissolved lithium carbonate at a concentration of 2.71·10⁻³ mol kg⁻¹ Li.

[0055] Figure 26 includes a SEM micrograph of template precursor particles (H5), which comprises hydromagnesite particles with a hierarchical isometric superstructure obtained from an aqueous Mg(HCO3)2 stock solution containing dissolved lithium carbonate at a concentration of 2.74·10⁻² mol kg⁻¹ Li.

[0056] Figure 27 includes a SEM micrograph of template precursor particles, which comprises magnesite particles with an isometric superstructure obtained from an aqueous Mg(HCO3)2 stock solution. Figure 27A includes M3 type precursor particles. Figure 27B includes M4 type precursor particles. Figure 27C includes M5 type precursor particles.

[0057] Figure 28 includes an optical micrograph of template precursor particles (N2), which comprise trihydrate magnesite particles with elongated superstructures. This precursor material was obtained from an aqueous Mg(HCO3)2 stock solution, which was first used to precipitate hydrated magnesite. The hydrated magnesite was then recrystallized into trihydrated magnesite.

[0058] Figure 29 includes an optical micrograph of template precursor particles (N3), which comprise trihydrate magnesite particles with elongated superstructures. This precursor material was obtained from an aqueous Mg(HCO3)2 stock solution, which was first used to precipitate hydrated magnesite. The hydrated magnesite was then recrystallized into trihydrated magnesite in the presence of sodium dodecyl sulfate as a surfactant.

[0059] Figure 30 includes an optical micrograph of template precursor particles, which comprise trihydrated magnesite particles precipitated from hydrated magnesite. Image A is a micrograph of trihydrated magnesite particles precipitated without a surfactant. Image B is a micrograph of precipitated magnesite trihydrate particles in the presence of surfactant.

[0060] Figure 31 includes an SEM micrograph of template precursor particles (Li1), which comprises lithium carbonate particles with a hollow hierarchical isometric superstructure obtained from an aqueous Li2CO3 stock solution. Colored arrows indicate various observable features such as pinholes (red), cracks (blue), and wrinkled (yellow) spheres.

[0061] Figure 32 includes an SEM micrograph of porous MgO template particles (N1T1) made from N1 template precursor particles. The template particles have inherited the elongated superstructure of the precursor.

[0062] Figure 33 includes an SEM micrograph of porous MgO template particles (H1T1) made from H1 template precursor particles. The template particles have inherited the hierarchical isometric superstructure of the precursor.

[0063] Figure 34 includes an SEM micrograph of porous MgO template particles (H2T1) made from H2 template precursor particles. The template particles have inherited the hierarchical equiaxed superstructure of the precursor.

[0064] Figure 35 includes an SEM micrograph of porous MgO template particles (H1T2) made from H1 template precursor particles. Due to sintering, most of the hierarchical equiaxed superstructure of the precursor has been lost.

[0065] Figure 36 includes an SEM micrograph of porous MgO template particles (M1T1) made from M1 template precursor particles. The template particles have inherited the equiaxed superstructure of the precursor.

[0066] Figure 37 includes an SEM micrograph of porous MgO template particles (M1T2) made from M1 template precursor particles. The template particles have inherited the equiaxed superstructure of the precursor.

[0067] Figure 38 includes an SEM micrograph of porous MgO template particles (M1T3) made from M1 template precursor particles. The template particles have inherited the equiaxed superstructure of the precursor.

[0068] Figure 39 includes an SEM micrograph of porous MgO template particles (M1T4) made from M1 template precursor particles. The template particles have inherited the isometric superstructure of the precursor.

[0069] Figure 40 includes an optical micrograph of porous MgSO4 template particles (E1T1) made from E1 template precursor particles. The template particles have inherited the elongated superstructure of the precursor.

[0070] Figure 41 includes an SEM micrograph of porous MgO template particles. In image A, the porous MgO template particles are made from undoped hydromagnesite particles. The joint subunits average 50 nm to 60 nm. In image B, the porous MgO template particles (H4T1) are made from Li-doped hydromagnesite particles. The template particles include joint subunits averaging 80 nm to 100 nm, with some subunits up to 200 nm. The template particles have inherited the plate-like morphology of the precursor. In image C, the porous MgO template particles (H5T1) are made from Li-doped hydromagnesite particles. The average wavelength of the joint subunits is 100 nm to 300 nm. The template particles have inherited the thin plate-like morphology of the precursor.

[0071] Figure 42 includes SEM micrographs of porous MgO template particles (H6T1) made from H6 template precursor particles. Template specification 6 / 55 pages 11 CN 121536914 A The particles have inherited the elongated superstructure of the precursor.

[0072] Figure 43 is a set of SEM micrographs comparing carbon-coated frameworks. In image A, a P1 type framework is shown, which is made from M3T1P1 PC particles. In image B, a P19 type framework is shown, which is made from M4T1P19 PC particles. In image C, a P20 type framework is shown, which is made from M5T1P20 PC particles.

[0073] Figure 44 includes SEM micrographs of porous MgO template particles (M1T4) made from M1 template precursor particles. The template particles have inherited the isometric superstructure of the precursor.

[0074] Figure 45 includes a SEM micrograph of PC particles (N2T1P21). The template particles (N2T1) were made by treating N2 template material with heat and steam.

[0075] Figure 46 shows the TGA mass loss rate (% / ℃) of the N2 template precursor material. In frame A, the mass loss rate is shown at a sample heating rate of 5℃ / min and 20℃ / min under flowing Ar at 100 sccm. In frame B, the mass loss rate is shown at a sample heating rate of 5℃ / min and 20℃ / min under flowing CO2 at 100 sccm.

[0076] Figure 47 includes a SEM micrograph of porous MgO template particles (N2T4) made from N2 template precursor particles. The N2 template precursor material was heated at a rate of 5℃ / min under flowing Ar.

[0077] Figure 48 includes an SEM micrograph of porous MgO template particles (N2T5) made from N2 template precursor particles. The N2 template precursor material was heated in flowing Ar at a step rate of 20 °C / min. In image A, red arrows indicate the expansion regions of the elongated superstructures characteristic of these template particles. The expansion regions are associated with the internal macropores generated during heat treatment. In image B, the internal macropores are shown.

[0078] Figure 49 includes an SEM micrograph of porous MgO template particles (N2T6) made from N2 template precursor particles. The N2 template precursor material was heated to a temperature of 350 °C in flowing CO2 at a heating rate of 20 °C / min, and then further heated at a heating rate of 5 °C / min.

[0079] Figure 50 includes an SEM micrograph of porous MgO template particles (N2T7) made from N2 template precursor particles. Red arrows indicate the ruptures associated with the formation and expansion of internal macropores in the template particles.

[0080] Figure 51 includes an SEM micrograph of a carbon-coated framework fabricated on porous MgO template particles (L2T1). Due to uncontrolled localized recrystallization during the template stage, the framework comprises features that are both elongated and thin. The elongated and thin features are indicated by red arrows.

[0081] Figure 52 includes an SEM micrograph of a PC structure and a carbon-coated framework fabricated on porous MgO template particles (L3T1).

[0082] Figure 53 includes an SEM micrograph of PC particles obtained from L3T1 template particles. Images A and B show typical superstructures associated with the PC structure. Image C shows a magnified surface.

[0083] Figure 54 includes an SEM micrograph of porous MgO template particles (A1T1) fabricated from A1 template particles. The yellow box and magnified inset show the porous substructure of the shell of the hollow spherical particles.

[0084] Figure 55 includes an SEM micrograph of porous MgO template particles (A3T1) fabricated from A3 template particles. The shell contains macropores, which are inherited features also present in the superstructure of the A3 template precursor. Several macropores are circled in yellow dashed circles. In addition, the shell contains mesopores generated by the decomposition of the A3 template precursor.

[0085] Figure 56 is a SEM micrograph of a carbon-coated framework (P17) generated by content extraction from Ca1T1P17 PC material. The framework retains almost its original morphology and reflects the template surface of the template material Ca1T1.

[0086] Figure 57 is a SEM micrograph of a carbon-coated framework (P18) generated by content extraction from Li1T1P18 PC material. The framework retains its original morphology and reflects the template surface of the removed template particles. Specification 7 / 55 pages 12 CN 121536914 A

[0087] Figure 58 includes an optical micrograph of a mixture generated by content extraction via shuttle technology. PictureThe micrograph in A reveals two distinct phases: magnesite trihydrate particles and a carbon-coated framework. The framework is sometimes deformed, as indicated by the yellow arrows. The micrograph in B reveals one of the carbon-coated frameworks. The area in the yellow square is magnified in the micrograph in C.

[0088] Figure 59 includes SEM micrographs of the spray-dried MgSO4 template precursor (in A) and SEM micrographs of the carbon-coated framework obtained from these precursor particles (in B and C). The cellular substructure of the framework indicates the formation of a porous template by the MgSO4 precursor during the template stage.

[0089] Figure 60 is a photograph of the liquid-liquid separation results in which hexane is blended into an aqueous mixture of the carbon-coated framework and magnesite trihydrate. The carbon-coated framework migrates to the black hexane phase at the top of the scintillation vial, while the magnesite trihydrate remains in the aqueous phase at the bottom, appearing mostly white (although some carbon particles are mixed in and adhere to the sides of the scintillation vial).

[0090] Figure 61 is a photograph showing the initial mixing and subsequent flotation of the carbon-coated framework when the flask is placed under partial vacuum.

[0091] Figure 62 includes SEM micrographs of the carbon-coated framework generated by surface replication on pre-trihydrate magnesite template particles followed by content extraction. The substructures include mesoporous cellular subunits with a consistent isometric morphology and size throughout the superstructure. Image A shows the particles imaged at 250,000x magnification. Image B shows the particles at 100,000x magnification. Image C shows the particles at 25,000x magnification.

[0092] Figure 63 includes SEM micrographs of the carbon-coated framework generated from pre-trihydrate magnesite and porous MgO template particles. The framework includes fibrous and tubular elongated superstructures and cellular substructures, which include conjoint subunits, mesoporous subunits, and macroporous subunits.

[0093] Figure 64 includes an SEM micrograph of a carbon-coated framework generated from pre-magnesia ore and porous MgO template particles. The framework comprises both thin and hierarchical equiaxed superstructures and mesoporous cellular substructures.

[0094] Figure 65 includes an SEM micrograph of a carbon-coated framework generated from pre-magnesia ore template particles. Mechanical agitation during content extraction has produced individualized thin particles stacked on top of each other.

[0095] Figure 66 includes an SEM micrograph of a carbon-coated framework generated from pre-magnesia ore template particles. Long-term heat treatment during the template stage and mechanical agitation during content extraction have produced smaller subunit clusters without obvious higher-order structures.

[0096] Figure 67 includes an SEM micrograph of a carbon-coated framework generated from pre-magnesia ore and sintered MgO template particles. The framework comprises quasi-polyhedral cellular subunits with a diameter greater than 100 nm.

[0097] Figure 68 includes an optical micrograph of a carbon-coated framework that springs back from a non-primary shrinkage state produced by evaporation drying to its primary architecture.

[0098] Figure 69 includes SEM micrographs of carbon-coated frameworks generated from elongated template particles (N2T4). These carbon frameworks comprise flexible porous carbon fibers, as shown in image A. Due to deformation of the thin coating walls, the cellular substructure is blurred, as shown in image B.

[0099] Figure 70 includes SEM micrographs of carbon-coated frameworks generated from elongated template particles (N2T8). These carbon frameworks show damage and fuzzing.

[0100] Figure 71 includes SEM micrographs of carbon-coated frameworks (P21) generated by content extraction from N2T1P21 PC particles. The frameworks wrinkle and cohede together through van der Waals interactions between the coating walls. The N2T1 template particles are made by treating the N2 template material with heat and steam.

[0101] Figure 72 includes SEM micrographs of carbon-coated frameworks. Image A shows a framework generated on porous MgO template particles (N2T4). Image B shows a framework generated on porous MgO template particles (N2T1). The N2T1 template particles were generated after heat and steam treatment, resulting in an increased subunit size relative to the N2T4 subunits. This difference in the template can be observed after content extraction based on the smoother appearance of the frame in image A and the wrinkled appearance of the frame in image B.

[0102] Figure 73 includes SEM micrographs of the template precursor particles and the carbon-coated frames obtained from them. In image A, precipitated calcium carbonate (CaCO3) template precursor particles are shown. In image B, the carbon frames from which templates were obtained are shown.

[0103] Table summary (at the end of the specification):

[0104] Table 1 is a collection of samples discussed in this disclosure. Table 1 is arranged to show the progress of the materials in four stages of the general approach.

[0105] Table 2 is a collection of Raman peak positions obtained by the average Raman spectrum and theoretical TGA mass loss of the hydrated magnesium carbonate template precursor.

[0106] Table 3 is an overview of the N2 adsorption analysis of the template particles of the Na-doped magnesite template precursor. It shows the template material, the template precursor material used to generate the template material, the Na wt. molar concentration of the stock solution used to generate the template precursor material, and the furnace scheme and temperature used to convert the template precursor material into the template material. The Brunauer–Emmett–Teller (BET) surface area, BJH pore volume, template space (%), and template porosity (%) of the template material are shown.

[0107] Table 4 is an overview of the N2 adsorption analysis of the template material generated from the N2 template precursor material with and without H2O during heat treatment. It shows the template material, the template precursor material used to generate the template material, the furnace scheme and temperature used to convert the template precursor material into the template material, and the treatment atmosphere. The BET surface area and BJH pore volume of the template material are shown.Volume, template space (%), and template porosity (%).

[0108] Table 5 is an overview of exemplary template stage procedures and materials for understanding the pod structure during the thermal decomposition of template precursor particles in Ar and CO2 atmospheres.

[0109] Table 6 is an overview of the template stage processing protocol for generating all templates used as templates in the replication stage embodiments. It lists the template precursors, furnace schemes, and temperature-time-gas conditions for each stage.

[0110] Table 7 is an overview of the CVD synthesis protocol for generating all PC materials used as templates in the replication stage embodiments. It lists the templates, furnace schemes, and temperature-time-gas conditions for each stage.

[0111] Table 8 is an overview of the Raman data for the carbon framework and the relevant CVD parameters for all replication stage carbons. The CVD parameters include the temperature-gas type-yield for each replication stage carbon. The Raman data includes the laser power used and the ID / IG-ITr / IG peak intensity ratio, G peak position, D peak position, and G-D peak wavenumber span. Detailed Description

[0112] The detailed description begins with the initial section on “Terminology and Concepts,” which provides the language and concepts used to describe and understand the invention. Subsequent sections are organized according to four methodological phases: “Precursor Phase,” “Template Phase,” “Replication Phase,” and “Separation Phase.” Several exemplary procedures and materials relating to each of the four phases are shown. Numerous potential variations of each phase can be readily conceived by those skilled in the art and can be combined to form numerous variations without departing from the method.

[0113] The detailed description is organized according to the following sections:

[0114] I. Terms and Concepts

[0115] II. Description of General Methods and Variations

[0116] III. Furnace Scheme, Analytical Techniques and Material Nomenclature

[0117] IV. Precursor Stage – Examples 9 / 55 pages 14 CN 121536914 A

[0118] V. Template Stage – Examples

[0119] VI. Replication Stage – Examples

[0120] VII. Separation Stage – Examples

[0121] VIII. Encapsulation Framework Examples

[0122] I. Terms and Concepts

[0123] As defined herein, a “template” is a potential sacrificial structure that imparts a desired morphology to another material formed therein or on. Related to surface replication techniques are the positively replicated surface of the template (i.e., the “template surface”) and its negatively replicated bulk phase (i.e., the “template body”). Templates may also play other roles, such as catalyzing the formation of encapsulated materials. A “template-based” structure is a structure that replicates a feature of the template.

[0124] A “coated” or “coated” material is a material formed within or on a solid or “hard” template material.

[0125] As defined herein, “surface replication” includes template techniques in which the surface of a template is used to guide the adsorbed material.The formation of a thin coating wall of material, which substantially encapsulates and replicates the template surface formed thereon. Subsequently, upon removal, the template body is negatively replicated by the intracellular space within the coating wall. Surface replication produces a coated framework with a templated porous wall architecture.

[0126] As defined herein, a “coated framework” (or “frame”) is a nanostructured coating body formed during surface replication. A coated framework comprises a nanostructured “coated wall” (or “wall”) with a thickness ranging from less than 1 nm to 100 nm, but preferably between 0.6 nm and 5 nm. Because the coating wall substantially encapsulates and replicates the template surface, the coating wall can be described as “conformal”. Coated frameworks can be fabricated with diverse architectures, ranging from simple hollow architectures formed on non-porous templates to labyrinthine architectures formed on porous templates. They may also include different chemical compositions. Typical frameworks may be constructed of carbon and may be referred to as “carbon coated frameworks”.

[0127] As defined herein, “contents” includes the template because it is present within the substantially encapsulated coating phase. Therefore, after a coating phase has been formed around the template, the template can be described as the contents or "content-based".

[0128] As defined herein, a "coated composite" or "PC" material is a composite structure comprising a contents and a coating body. A PC material may be represented as x@y, where x is the coating element or compound and y is the contents element or compound. For example, a PC structure comprising a carbon coating body on MgO contents may be represented as C@MgO.

[0129] The term "positive" is used herein to describe space occupied by a solid mass. The space occupied by the contents in a coated composite (i.e., "content space") is an example of a positive space. A non-porous template comprises only positive space. A coated frame does not include positive space except for the space occupied by its thin walls.

[0130] The term "negative" is used herein to describe space not occupied by a solid or liquid mass. A negative space may be empty, gas-filled, or liquid-filled. The pores inside an unimpregnated porous template comprise negative space. A porous template comprises both positive and negative space. Apart from the space occupied by its thin walls, the coating framework comprises only negative space.

[0131] The term “cellular” is used herein to describe the pore wall morphology associated with the coating framework. “Cell” or “cell subunit” includes the region specifying the intracellular pores and the coating walls surrounding the pores.

[0132] The term “intracellular” is used herein to describe the negative space in the coating framework, which is formed by removing contents from the coating composite. As it is acquired from the contents, the intracellular space is essentially enclosed by the coating walls.

[0133] The term “extracellular” is used herein to describe the negative space in the coating framework, which is inherited from the pore space of the coating composite, which in turn is inherited from the pore space of the porous template. We note that although there is a “-extra” before it,However, the extracellular space may be substantially located within the coating framework.

[0134] The intracellular and extracellular spaces of the coating framework are substantially separated by coating walls. However, the ability to remove contents from the template composite means that the walls are open or incomplete barrier layers at some point, as perfectly encapsulated contents cannot be removed. Therefore, although the coating body is described herein as substantially encapsulating the template surface, the encapsulation may still be incomplete or have gaps.

[0135] The term “native” is used herein to describe the morphological state of the coating structure in the coating composite. “Native” features include features that are substantially in their native state, and we may refer to the structure as having certain features “natively” (e.g., natively 1 nm thick coating walls). After the contents are removed from the coating composite, the coating body may substantially retain its native properties or may be altered.

[0136] The term “non-native” is used herein to describe a morphological state of a coated structure that has significantly changed from its native morphological state (i.e., its original state within the coated composite). This change can occur at the substructure or superstructure level. For example, during the evaporation and drying of the internal liquid, the coated walls can be pulled inward by the liquid, causing a portion of the intracellular space to collapse. The deformation of the framework to a non-native collapsed morphology can be reversible—that is, the framework can be substantially restored to its native morphology.

[0137] The terms “labyrinth” or “labyrinthine” are used herein to describe a network of interconnected pores in a template or coated framework. The labyrinth can be intracellular or extracellular. Coated frameworks formed on porous templates can natively include intracellular and extracellular labyrinths; therefore, frameworks formed on porous templates can be described as “labyrinthine frameworks.” The intracellular and extracellular labyrinths of a labyrinthine framework, while not overlapping, can be interwoven. Labyrinthine frameworks include a preferred class of coated frameworks.

[0138] As defined herein, a “template precursor” or “precursor” is a material from which a template is obtained through some process that may include decomposition, grain growth, and sintering. The template may retain a pseudomorphological similarity to the template precursor; thus, engineering the precursor provides a way to engineer the template. The precursor is formed in a process liquid and is obtained from a stock solution.

[0139] The term “superstructure” is defined herein as the overall size and geometry of a porous template or coated framework. The superstructure of a coated framework may be inherited from the morphology of the template precursor. The superstructure of a coated framework is important because the overall size and geometry of the framework will affect its properties, including how it interacts with other particles. Some superstructures may facilitate the drying of a wet paste of a coated framework into a fine powder, while others may cause the wet paste to dry into macroscopic particles that may require subsequent grinding. Superstructures may include the following shapes:

[0140] •"Equiaxed" is defined herein as a shape that is similar in size (size difference less than 5 times) along its long axis, central axis, and short axis.

[0141] • "Elongated" is defined herein as a shape whose size along its long axis is significantly larger than its size along its central axis and short axis (5 to 50 times).

[0142] • "Thin" is defined herein as a shape whose size along its long axis and central axis is more than 5 times that along its short axis.

[0143] • "Graded" is defined herein as an equiaxed or elongated shape having a thin feature.

[0144] The term "substructure" is defined herein as a local morphology of a porous template or coated framework—that is, the internal architecture. Some porous templates or coated frameworks have substructures comprising repeating joint substructure bases or "subunits". Different substructures may be characterized by subunits of different shapes, sizes, and spacing from each other.

[0145] The term "amorphous cell" is used herein to describe the negative space inside which is not considered templated herein, nor is it considered part of the coated framework, but it is still substantially surrounded by and located within the framework. Amorphous space is not a templated space because it does not strictly correspond to the positive space, negative space, or surface of the template, and it only occurs when surface replication cannot occur on a portion of the template surface (typically an inaccessible internal region).

[0146] Amorphous space may be desirable for density reduction in some applications and can be engineered using a combination of reasonable template engineering and diffusion-constrained synthesis techniques. In particular, large template precursors can be used to produce large templates that combine long diffusion paths with small pores with minimal sintering. Reasonable design of surface replication parameters can also be helpful. For example, in CVD, low concentrations of carbonaceous vapor can be more easily removed from reaction sites and prevented from permeating into the entire porous substructure of the porous template.

[0147] Another way to achieve density reduction is by using porous template precursor materials. This produces extracellular and internal porosity superior to amorphous space because it is more engineerable and does not require diffusion constraints. Porous template precursors can be made by using a blowant (e.g., hollow microspheres produced during spray drying) or by using a sacrificial material during the preparation of the template precursor (e.g., around sacrificial micelles or polymer-synthesized template precursors).

[0148] The concept of “compaction” herein refers to the area of ​​the coating walls contained within a given volume of a coated framework – i.e., the volumetric surface area. A framework with a more compact substructure will have a finer, denser arrangement of coating walls within a given volume, while a framework with a less compact substructure will have a coarser, more spatially diffuse arrangement of coating walls within a given volume. Porous templates and labyrinthine frames formed thereon can be engineered to have different degrees of compaction. Compaction includesThe measure of the framework's mesoscale crosslinking—that is, crosslinking at a higher scale than the molecular scale—is that the crosslinking originates from the topology of the template surface.

[0149] The compaction of the coated framework and the porous phase can be tuned by engineering the positive and negative spaces of the template. For example, a porous MgO structure produced by decomposing a magnesium carbonate precursor has a positive space comprising a network of interconnected MgO microcrystals. Its negative space comprises a porous network extending between and throughout the MgO microcrystals. It is known that microcrystals can grow at elevated temperatures, thereby roughening the grain structure. The same process can also lead to the growth and roughening of pores. This roughening of the positive and negative spaces will reduce the surface area of ​​the porous MgO template and thus reduce the compaction of the coated framework formed on the template. While the template is roughened, it will become denser, and its denserness will reduce the amount of extracellular space in the coated framework formed on the template.

[0150] The roughness of the template may be important for many reasons. For example, increasing the pore size of the template and reducing its surface area allows reactive vapors to diffuse more quickly and deeply throughout the pores of the template during CVD. If sufficient diffusion kinetics can be achieved, the coated walls synthesized in such processes can be more uniform in thickness.

[0151] The compaction of the coated framework and the porous phase can also be tuned by selecting different template precursors. Different precursors will have different proportions of variability mass. The negative space of the template will depend on the extent to which the initial mass of the template precursor is lost during its decomposition. Calcination of template precursors containing a large proportion of variability material (e.g., highly hydrated salts) can produce porous templates with high specific porosity that are more open to diffusion flow during CVD. Such templates may also be desirable if a larger extracellular space is desired in the coated framework.

[0152] The term “recycled” is used herein to describe the use of process materials previously used in a given step of the production process. Due to the actual loss of process materials that may occur during the production of the coated product (e.g., process liquid loss due to evaporation or filtration), these losses can be compensated using pure raw process materials, and “recycled” process materials may partially include pure raw materials.

[0153] As defined herein, “process materials” include potentially recyclable non-coating materials used to generate the coated material. Process materials may include process liquids, process gases, extractants, template precursor materials, and template materials.

[0154] As defined herein, a “stock solution” contains solvated cations and anions as well as process liquids, with the solvated ions carried by the process liquid (which may be referred to herein as the “host”). The stock solution is formed during the separation stage. The precursor is obtained from the stock solution through one or more precipitation, dissolution, or decomposition reactions.

[0155] As defined herein, “process liquid” is liquid water (“process water”) used in the precursor stage and separation stage.The raw material for the solvent (“process solvent”). The process liquid can play several different roles in these stages. In the precursor stage, the formation of the template precursor is carried by the process liquid, and the precursor can bind the process liquid into its crystal – for example, hydrated salts can be formed in process water and some of the process water can be bound into their crystal structure. In the separation stage, the extractant is carried by the process liquid, and the solvated ions generated by the reaction between the template, the process liquid, and the extractant are carried by the process liquid. The process liquid can participate in the generation of the extractant and can itself react with the template during the separation stage.

[0156] As defined herein, “residual liquid” is a portion of the process liquid that may or may not carry solvated ions, which remains inseparable from the solid (e.g., precursor or coated product) when the solid is separated from the main portion of the process liquid. The residual liquid may be contained within the coated product or wetted onto its surface. The residual liquid may constitute a very small portion of the total process liquid. If a dry solid is desired, the retention of residual liquid by the solid may require further separation.

[0157] As defined herein, an “extractant” includes an acid carried by a process liquid, the two phases together constituting an “extractant solution.” The extractant may be present in an extractant solution at a very dilute concentration. In some cases, the extractant may be generated from (and within) the process liquid. For example, a carbonic acid (H2CO3) extractant may be generated from (and within) process water according to the reaction H2O(l) + CO2(aq) → H2CO3(aq).

[0158] As defined herein, “content extraction” includes the selective removal of a portion of the contents from a content complex. Content extraction includes a reaction between the contents and the extractant solution that produces solvated ions that efflux from the surrounding contents, resulting in the simultaneous removal of the contents, consumption of the extractant from the extractant solution, and the formation of a reserve solution. Typically, it is desirable to remove substantially all contents. Sometimes, it may be desirable to partially remove contents, or only partial removal of contents may be achievable.

[0159] As defined herein, “coating separation” includes separating the coated product from the uncoated, preserved process material after content extraction. The preserved uncoated phase may include process liquids, stock solutions, and precipitates of the stock solutions. Coating separation may include many different industrial separation techniques (e.g., filtration, centrifugation, foam flotation, solvent-based separation, etc.).

[0160] As defined herein, “solvent-free precipitation” includes precipitation of template precursors in the precursor stage, wherein the precipitation is substantially driven by a solution instability mechanism that does not require the introduction of miscible antisolvents into the process liquid. As a first example of a solvent-free precipitation technique, the stock solution may be spray-dried. As a second example of a solvent-free precipitation technique, metastable gold may be...The bicarbonate stock solution is depressurized to reduce CO2 solubility, resulting in the release of CO2 gas and precipitation of metal carbonates. We note that the term "solvent-free precipitation" does not mean that there is absolutely no miscible solution or solvent during precipitation, but rather indicates that precipitation is not primarily driven by mixing miscible solutions into the stock solution. One conceivable scenario is that the miscible solution mixed with the process liquid maintains substantially the same concentration throughout the liquid cycle.

[0161] As defined herein, "shuttle" includes content extraction techniques that can be used during the separation phase, wherein simultaneously: (i) an extractant is generated by the reaction of the process gas with the process liquid; (ii) the contents are reacted with the extractant solution; (iii) the extractant is consumed; (iv) solvated ions in the stock solution are expelled from the contents; and (v) a precipitate is formed from the stock solution outside the contents. For example, shuttle may include simultaneously: (i) forming an H2CO3 extractant by dissolving CO2 in process water; (ii) reacting MgO contents with the H2CO3 extractant solution; (iii) consuming H2CO3; (iv) forming Mg2+ and (HCO3)− ions that permeate from the coating; and (v) precipitating magnesium carbonate in the surrounding process water.

[0162] “MgCO3·xH2O” is used herein to describe magnesium carbonate. It may include any hydrated or anhydrous magnesium carbonate, as well as basic magnesium carbonate, such as hydromagnesite.

[0163] As defined herein, “template circulation” includes a circulation loop in which a template is formed, utilized, and reconstituted.

[0164] As defined herein, “liquid circulation” includes a circulation loop in which liquid-phase extraction of contents and liquid-phase formation of precursors are carried out using process liquids.

[0165] As defined herein, “gas circulation” includes a circulation loop in which process gases are dissolved in process liquids to produce an extractant solution, and then subsequently released and recaptured. Release may be associated with the template precursor or the forming phase of the template, page 13 / 55, 18 CN 121536914 A.

[0166] The “yield” of the coating material or the process used to prepare the coating material is defined herein as the coating mass divided by the sum of the content mass and the coating mass. The yield can be used to understand the amount of template material required to produce a given amount of coating material.

[0167] FIG1 is a cross-sectional view illustrating surface replication. The first structure in the sequence represents a simple non-porous template comprising a template body and a template surface. The second structure in the sequence represents a PC structure comprising contents and a coating body. This composite is formed by applying conformal coating walls to the template surface. The third structure in the sequence comprises a coating framework in a liquid. This represents the framework after the contents have been removed by liquid-phase extraction. The fourth structure in the sequence represents the framework in its native state after drying. The walls of the coating framework substantially replicate the template surface, and its pores substantially replicate the template body.

[0168] FIG2 is a cross-sectional view showing the formation of a coated framework using a porous template. The first structure in the sequence represents a template having a plurality of pores leading to a central pore. The entire pore space is not occupied by solid or liquid material blocks and includes negative space. The second structure in the sequence represents a PC structure including contents and a coating body. This composite is formed by applying a conformal coating body to the surface of the template. The PC structure includes positive space associated with the contents and negative space associated with the pores of the porous template. The third structure in the sequence represents a coated framework formed by removing the contents. The framework includes negative intracellular space corresponding to the contents of the PC structure and negative extracellular space corresponding to the pores of the PC structure. Both the intracellular and extracellular spaces are located inside the coated framework.

[0169] FIG3 is a cross-sectional view showing the difference between the coated framework in native and non-native morphological states. The first structure in the sequence represents a PC structure including contents and a coating body. The morphology of the coating body in the PC structure represents its native morphology. The second structure in the sequence represents a coated framework formed by removing the contents. The morphology of the framework has not changed significantly from its original form in the PC structure, and therefore the framework is in its native state. The third structure in the sequence represents a deformed and collapsed encapsulated framework. In this non-native state, the walls no longer represent a replica of the template surface, and the intracellular space no longer represents a negative replica of the contents. If elastic deformation occurs, the framework may reversibly deform back to its native form.

[0170] Figure 4A is a cross-sectional view showing the synthesis of the labyrinthine framework. From left to right, the first structure in the sequence represents the template precursor. The second structure represents the porous template. The porous template includes a labyrinth of interconnected template pores (but their connectivity is not shown in the cross-section). The surface of this porous structure guides the formation of the encapsulated body. The third structure in the sequence represents a PC structure including the contents and the encapsulated body. The labyrinth of template pores in the template is inherited from the PC structure. The fourth structure in the sequence represents a labyrinthine framework formed by removing the contents. The framework natively includes an intracellular labyrinth reflecting the positive space of the template and an extracellular labyrinth reflecting its negative space. Although the intracellular and extracellular labyrinths do not overlap, they can permeate the volumetric interweaving of the framework.

[0171] Figure 4B is a SEM micrograph of the labyrinthine carbon framework synthesized on a porous MgO template. The contents have been removed, and the framework retains its original morphology. From the main image, we can see that the framework includes a rhombohedral superstructure. This superstructure is inherited from the rhombohedral magnesite precursor. From the magnified inset, we can see the cellular substructure of the combined cellular subunits. Two such subunits are outlined and marked in the magnified inset. Each cellular subunit includes an intracellular pore and an encapsulated portion of the encapsulated wall. We can also see the extracellular pores in the magnified inset, and two such pores are marked. The extracellular labyrinth traverses the interior of the framework and interweaves with the intracellular labyrinth.

[0172] Figure 5A is a TEM micrograph of PC particles (top) including a graphene-coated phase and an MgO content phase, and a graphene-coated framework (bottom) after content extraction. Figure 5B is an HRTEM micrograph showing a disordered nematic graphene layer including segments of the coating wall.

[0173] Figure 6 is a cross-sectional view showing four types of superstructure shapes: elongated, thin, equiaxed, and hierarchical equiaxed. Cross-hatching indicates smaller-scale cellular substructures present throughout the superstructure. The exemplary “hierarchical equiaxed” superstructure shown in Figure 6 is a hollow sphere with a thin shell. Specification 14 / 55 pages 19 CN 121536914 A

[0174] Figure 7 shows how density reduction of the coating framework can be achieved through hierarchical porosity engineering. This is a cross-sectional representation, so the template subunits, although appearing disconnected, are actually connected. Figure 7A shows the generation of density-reduced non-cellular spaces within the coating framework through a diffusion-limited surface replication procedure. In this case, the template precursor can be non-porous. Diffusion restriction prevents the adsorbate material from being uniformly distributed throughout the porous substructure. This can facilitate the creation of coating walls with a certain thickness and integrity gradient, and in some cases, it can even create hollow acellular spaces within the coating framework, as shown in Figure 7A. Figure 7B shows the creation of a reduced-density extracellular space within the coating framework by porous template precursor material generated around the trapped gas region. This can occur due to the effect of internal blow-up bodies or due to the formation around the bubbles. Figure 7C shows the creation of a reduced-density extracellular space within the coating framework by porous template precursor material generated around the sacrificial material that is subsequently removed.

[0175] Figure 8 is a cross-sectional view showing three labyrinthine frameworks with different substructures. The substructure shown on the left side of the diagram is the least compact of the three. Its volume is similar to the others, but it contains less coating area within this volume. The substructure shown in the center of the diagram is slightly more compact than the substructure on the left because its volume contains a larger coating area. The substructure shown on the right side of the diagram is the most compact - its volume is similar to the other two substructures, but it contains the largest coating area. This diagram illustrates that the compaction of the coated frame is determined by the volumetric surface area of ​​the porous template—that is, the total internal and external surface area per unit template volume—where the template volume includes both the positive and negative spaces of the template.

[0176] Figure 9 is a cross-sectional view showing the shuttle. The first image in the sequence represents PC material immersed in the extractant solution. The second image in the sequence represents the coated frame containing incompletely extracted contents. In this second image, the reaction between the contents and the extractant solution is underway. The solvated ions formed by this reaction are diffusely effluxing from the coated frame, as indicated by the arrows, and precipitating in the surrounding process liquid. In other words, the contents are being dissolved in the form of solvated ions.The coated product “shuttles” out, a portion of the solvated ions are then reprecipitated outside the framework. We note that the precipitate and contents may not include the same compounds.

[0177] II. Description of General Methods and Variations

[0178] The “general method” is the most basic form of the method. It includes methods for synthesizing coated products in which a large portion of the template material and process liquid is preserved and reused. Thus, the general method can be performed cyclically. All variations of the methods disclosed in this disclosure include some variation of the general method.

[0179] The general method includes a series of steps presented herein in four stages (i.e., precursor stage, template stage, replication stage, and separation stage) for ease of description. Each stage is defined according to one or more steps as follows:

[0180] Precursor stage: Obtaining the precursor material from the stock solution by solvent-free precipitation. A portion of the process liquid is preserved.

[0181] Template stage: Processing the precursor material formed in the precursor stage in one or more procedures to form the template material.

[0182] Replication stage: Adsorbing the adsorbate material onto the template surface of the template to form the PC material.

[0183] Separation Stage: Perform content extraction and coating separation. Content extraction produces a stock solution. Coating separation separates the coated product from the preserved process material.

[0184] In practice, each step within these stages may itself include multiple subsidiary steps. Furthermore, each of these steps may occur simultaneously with a step from another stage, such that different stages may overlap in time sequence in practice. This is particularly anticipated in variations employing a one-pot technique. As a hypothetical example of this, the stock solution may be continuously injected into the furnace along with the adsorbent material. In this hypothetical furnace, precursor particles may be precipitated from the stock solution continuously and simultaneously, template particles may be formed by heating the precursor particles, and the coating material may be adsorbed onto the template particles. This corresponds to the steps in specification 15 / 55, 20 CN 121536914 A, which are respectively attributed to the precursor stage, template stage, and replication stage herein.

[0185] Similarly, it is contemplated that, in practice, many variations of the general method may incorporate the steps described in the four stages in different orders. Moreover, in some variations, steps that, by definition, belong to one of the four stages described herein may instead occur in different stages. Such variations are contemplated herein and do not depart from the method of the invention, which, for the sake of describing the entire cycle, is presented herein only as a discrete sequence of four stages.

[0186] Auxiliary processing steps (e.g., rinsing, drying, blending, condensing, spraying, stirring, etc.) may also be incorporated into each stage of the method. As a hypothetical example of this, the replication stage may involve coating a template with a coating material via a liquid-phase adsorption procedure.The material is then filtered, rinsed, and dried to obtain the PC material. These processing steps, incorporated into many variations, will be apparent to those skilled in the art, and therefore are not enumerated herein.

[0187] The inputs and outputs of the general method are shown in Figure 10. The general method includes a template cycle by which template material can be preserved and reused, and a liquid cycle by which process liquids can be preserved and reused.

[0188] Variations of the General Method

[0189] The following discussion enumerates various ways in which the general method can be implemented differently. Variations omitted in this discussion should not be construed as limiting, as an exhaustive list of ways in which the general method can be implemented is impractical.

[0190] The general method is intended to provide a way to circulate the production of the coated product while preserving the process material. In each cycle of the general method, a portion of the process material used is preserved and reused. In some variations, essentially all of the process material used is preserved and reused. In other variations, a portion of the process material may be lost. A hypothetical example of this is the loss of process liquid through evaporation from an open tank or wet filter.

[0191] In some variations of the general method, the process steps may correspond to a batch process. In other variations, the process steps may correspond to a continuous process.

[0192] In some variations of the general method, solvent-free precipitation may include at least one of the following techniques: heating or cooling the stock solution to change the solubility of the solute in the stock solution; evaporating dissolved gases in the stock solution; depressurizing the stock solution; atomizing the stock solution; spray drying the stock solution or spray pyrolysis.

[0193] In some variations of the general method, the precursor structure may include at least one of the following: elongated, thin, equiaxed or hierarchically equiaxed superstructures; elongated superstructures with an aspect ratio greater than 200:1; elongated superstructures with an aspect ratio between 50:1 and 200:1; spherical or spherical superstructures; hollow superstructures; fragmented superstructures comprising fragments of another parent superstructure; and bent fragmented superstructures comprising fragments of hollow superstructures.

[0194] In some variations of the general method, the precursor structure may precipitate around one or more other sacrificial structures, which may exist as inclusions in the precursor structure after precipitation. In some variations, these inclusions in the precursor structure may subsequently be removed, thereby creating voids.

[0195] In some variations of the general method, the measurement along the long axis of the precursor structure may be less than 1 μm. In some variations, the measurement along the long axis of the precursor may be between 1 μm and 100 μm. In some variations, the measurement along the long axis of the precursor may be between 100 μm and 1,000 μm.

[0196] In some variations of the general method, the precursor material may comprise at least one of the following: hydrate; metal carbonate.Hydrogen salts or carbonates; Group I or Group II metal bicarbonates or carbonates; mixtures of salts. In some variations, the precursor may comprise MgCO3·xH2O in the form of at least one of the following: hexahydrate, hydrous magnesite, trihydrate magnesite, hydrous magnesite, spheroidal magnesite, magnesite, and nanocrystalline or amorphous MgCO3·xH2O.

[0197] In some variations of the general method, the stock solution may comprise at least one of the following: metal cations and oxygen-containing anions; aqueous solutions of metal bicarbonates; Group I or Group II metal bicarbonates; organic salts; Mg(HCO3)2. In some variations of the specification 16 / 55 pages 21 CN 121536914 A, the stock solution may comprise at least one of dissolved gases, acids, and bases. In some variations, the stock solution may be metastable.

[0198] In some variations of the general method, the process liquid preserved in the precursor stage may include distillates. In some variations, the distillate may be formed by condensing process liquid vapors formed during spray drying or spray pyrolysis. In some variations, the process liquid preserved in the precursor stage may carry solvated ions, with the process liquid and ions together constituting the mother liquor.

[0199] In some variations of the general method, the treatment performed on the precursor material in the template stage may include at least one of the following: decomposing the precursor; partially or partially decomposing the precursor; decomposing the precursor surface; thermal decomposition; and oxidizing the organic phase present within the precursor structure. In some variations, the treatment may include flash drying, spray drying, spray pyrolysis, vacuum drying, rapid heating, slow heating, and sublimation. In some variations, vapors released during the treatment may be preserved. In some variations, the released vapors may include at least one of CO2 and H2O. In some variations, the treatment may include at least one of the following: roughening the grain structure of the precursor or the decomposition products of the precursor; exposing to reactive vapors; exposing to water vapor; sintering; and sintering with the assistance of a dopant.

[0200] In some variations of the general method, the template material may include at least one of the following: metal carbonates, metal oxides, Group I or II metal oxides, transition metals, and MgO. In some variations, the template structure may include at least one of the following: macropores, mesopores, hierarchical porosity, subunits greater than 100 nm, subunits between 20 nm and 100 nm, and subunits between 1 nm and 20 nm.

[0201] In some variations of the general method, the template structure may include at least one of the following: elongated, thin, equiaxed or hierarchically equiaxed superstructures; elongated superstructures with an aspect ratio greater than 200:1; elongated superstructures with an aspect ratio between 50:1 and 200:1; spherical or spherical superstructures; hollow superstructures; fragmented superstructures comprising fragments of another parent superstructure; and bent fragmented superstructures comprising fragments of hollow superstructures.

[0202] In some variations of the general method, adsorbing the coating material onto the template surface may include at least one of the following: coating techniques, physical vapor deposition, and chemical vapor deposition. In some variations, the coating technique may include applying a liquid or solid organic coating onto the template surface, followed by the formation of a carbon coating from the master coating. In some variations, deposition may include the pyrolytic decomposition of a vapor-phase organic compound at a temperature between 350°C and 950°C. In some variations, the coated carbon may be annealed after adsorption onto the template surface.

[0203] In some variations of the general method, content extraction may utilize an extractant solution containing a weak acid as an extractant. In some variations, the extractant solution may be formed by dissolving a process gas in process water. In some variations, the extractant solution may be an aqueous solution of H2CO3 formed by dissolving liquid or gaseous CO2 in process water. In some variations, content extraction may include a shuttle technique. In some variations, content extraction may be performed under elevated pressure or temperature conditions.

[0204] In some variations of the general method, coating separation may include at least one of the following: decanting, hydrocyclone, settling, sedimentation, flotation, foam flotation, centrifugation, filtration, and liquid-liquid extraction. In some variations, coating separation may separate the coated product from substantially all process liquids. In some variations, the coated product may retain a residual portion of the process liquid. In some variations, the coated product may float naturally due to the retention of its internal gas. In some variations, the internal gas of the coated product may expand by reducing the pressure of the surrounding process liquid, increasing the buoyancy of the coated product, and causing flotation. In some variations, a portion of the internal gas of the coated product may permeate by reducing the pressure of the surrounding process liquid and then repressurizing the surrounding process liquid, such that hydrostatic pressure causes the process liquid to permeate into the coated product.

[0205] In some variations of the general method, the coating framework may include at least one of the following: carbonaceous material, carbon, anthracite network of carbon, SPX network of carbon, and helical network of carbon.

[0206] In some variations of the general method, under 532 nm excitation, the carbonaceous coating framework may include at least one of the following: Raman spectral ID / IG ratio between 4.0 and 1.5; Raman spectral ID / IG ratio between 1.5 and 1.0; Raman spectral ID / IG ratio between 1.0 and 0.1; Raman spectral ITr / IG ratio between 0.0 and 0.1; Raman spectral ITr / IG ratio between 0.1 and 0.5; Raman spectral ITr / IG ratio between 0.5 and 1.0; Raman spectral ITr / IG ratio between 0 and 0.15.Raman spectral I²D / IG ratio; Raman spectral I²D / IG ratio between 0.15 and 0.3; and Raman spectral I²D / IG ratio between 0.30 and 2.0.

[0207] In some variations of the general method, under 532 nm excitation, the carbonaceous coated framework may include at least one of the following: an unfitted Raman spectral D peak located between 1345 and 1375 cm⁻¹; an unfitted Raman spectral D peak located between 1332 and 1345 cm⁻¹; an unfitted Raman spectral D peak located between 1300 and 1332 cm⁻¹; an unfitted Raman spectral G peak located between 1520 cm⁻¹ and 1585 cm⁻¹; an unfitted Raman spectral G peak located between 1585 cm⁻¹ and 1600 cm⁻¹; and an unfitted Raman spectral G peak located between 1600 cm⁻¹ and 1615 cm⁻¹.

[0208] In some variations of the general method, the coated product may include a coated framework. In some variations, the coated framework may include at least one of the following: native morphology, non-native morphology, internal gas, hydrophobic surface, hydrophilic surface, mesopore, one or more macropores, hierarchical porosity.

[0209] In some variations of the general method, the measured value of the coated framework along its long axis may be less than 1 μm. In some variations, the measured value of the coated framework along its long axis may be between 1 μm and 100 μm. In some variations, the measured value of the coated framework along its long axis may be between 100 μm and 1,000 μm. In some variations, the coated framework may include an elongated, thin, isometric, or hierarchically isometric superstructure. In some variations, the elongated coated framework may include an aspect ratio between 50:1 and 200:1. In some variations, the isometric superstructure of the coated framework may be spherical or globular. In some variations, the equiaxed superstructure of the coating framework may be hollow. In some variations, the coating framework may include fragments of hollow shells. In some variations, the coating framework may include acellular space.

[0210] In some variations of the general method, the coating framework may include a BET surface area of ​​1,500 to 3,000 m² / g. In some variations of the general method, the coating framework may include a BET surface area of ​​10 to 1,500 m² / g.

[0211] In some variations of the general method, the coating product may undergo further processing after coating separation. In some variations, further processing after coating separation may include at least one of the following: flash drying, spray drying, spray pyrolysis, decomposition, chemical reaction, annealing, and chemical functionalization.

[0212] In some variations of the general method, liquid recycling may also incorporate the recapture and preservation of process liquids released or evaporated (possibly in vapor phase) during the template stage, although this is not reflected as an output in Figure 10. It is not shown in Figure 10.This is reflected in the fact that, in most (but not all) variations of the conceived general method, the amount of process liquid retained during the template stage will be significantly less than the amount retained during the precursor stage.

[0213] In some variations of the general method, gas recycling may be incorporated into the method. The inputs and outputs of a general method with gas recycling are shown in Figure 11. In gas recycling, process gas is released during the precursor stage and / or template stage. This released gas is retained. Then, during the separation stage, the retained process gas can be dissolved in the retained process liquid to generate an extractant solution.

[0214] The preferred method described below includes variations of the general method in which MgCO3·xH2O template precursor material is obtained from an aqueous Mg(HCO3)2 stock solution, and a portion of the CO2 process gas is retained by gas recycling. The inputs and outputs of the preferred method are shown in Figure 12. The preferred method includes:

[0215] Precursor stage: Obtaining MgCO3·xH2O precursor material from an aqueous Mg(HCO3)2 stock solution, wherein the acquisition includes solvent-free precipitation of MgCO3·xH2O and emission of CO2 process gas. A portion of the released CO2 process gas is preserved. The MgCO3·xH2O precursor material and process water are separated. The process water is preserved.

[0216] Template stage: Thermally decomposing the MgCO3·xH2O precursor material formed in the precursor stage in one or more procedures to form a porous MgO template material. The released CO2 process gas can be preserved.

[0217] Replication stage: Adsorbing an organic or carbonaceous coating material onto the template surface of the porous MgO template to form a PC material.

[0218] Separation stage: Dissolving the preserved CO2 process gas into the preserved process water to form an aqueous H2CO3 extractant solution. Content extraction involves a reaction between the content MgO and an aqueous H2CO3 extractant solution to generate an aqueous Mg(HCO3)2 stock solution. Coating separation may include techniques to remove process water from the coated product to minimize residual process water. Foam flotation, liquid-liquid separation, or other techniques based on hydrophobicity can be used to separate the carbon coatings.

[0219] Certain variations of the preferred method may employ pressure regulation to form a concentrated stock solution and improve the precipitation process. Concentrated stock solutions can be associated with many benefits, including superior precipitation kinetics, reduced process water consumption, smaller containers, and improved energy efficiency. Two exemplary ways to do this are shown in Figure 13 and described below.

[0220] In the first frame of Figure 13A, a shuttle technique has been used to achieve content extraction. The shuttle technique produces a mixture comprising an aqueous Mg(HCO3)2 stock solution, one or more coated frames, and a MgCO3·xH2O precipitate. This precipitate is shown in Figure 13A.The first image of Figure 13A shows a mixture of trihydrate magnesite rods and needle-like trihydrate magnesite agglomerates. Next, the coated product is separated from other process liquids and solids. Following this, the MgCO3·xH2O precipitate is dissolved by increasing the CO2 pressure, which increases the concentration of dissolved CO2, H2CO3, and HCO3−, thus forming a concentrated stock solution, as shown in the second image of Figure 13A. Finally, as shown in the third image, the MgCO3·xH2O precursor can be rapidly nucleated and precipitated from the concentrated stock solution by decreasing the CO2 pressure (and optionally the total pressure).

[0221] Another way to obtain a concentrated stock solution is to perform content extraction in a pressurized reactor. A schematic diagram illustrating this approach is shown in Figure 13B. Similar to the procedure shown in Figure 13A, the procedure shown in Figure 13B uses increased CO2 pressure to increase the concentration of dissolved CO2, H2CO3, and HCO3−. In Figure 13B, PC material, CO2, and H2O (possibly, aqueous Mg(HCO3)2 mother liquor) are fed into a pressurized reactor. Content extraction and formation of a concentrated stock solution occur within the pressurized reactor. The mixture of the coated product and the concentrated stock solution is discharged from the pressurized reactor, where coating separation can then occur. Separation can advantageously be achieved using liquid-liquid separation that eliminates the need for rinsing. The MgCO3·xH2O precursor can be rapidly nucleated and precipitated from the concentrated stock solution by reducing the CO2 pressure (and optionally the total pressure).

[0222] III. Furnace Schemes, Analytical Techniques, and Material Nomenclature

[0223] Certain furnace schemes have been detailed in the process of describing the procedures for generating exemplary materials as described in the following sections. These schemes can be used in the exemplary template stage procedures detailed in Part V and the exemplary replication stage procedures detailed in Part VI.

[0224] Scheme A: In Scheme A, a Thermcraft tube furnace modified into a rotary furnace with a quartz tube can be used. The furnace has a clamshell design including a cylindrical heating chamber with a diameter of 160 mm and a heating length of 610 mm. The furnace has a wattage of 6800 W and a maximum operating temperature of 1100°C. The quartz tube may be a 60 mm OD quartz tube containing an extended intermediate section (“belly”) of a 130 mm OD tube positioned within the heating zone of the furnace. The tube is rotatable. Quartz baffles inside the belly facilitate agitation of the powder sample during rotation. The furnace can be kept horizontal (i.e., not tilted). A template powder sample can be placed inside the belly in the heating zone, and ceramic blocks are inserted outside the belly on each side of the heating zone of the furnace. Glass wool can be used to secure the position of the ceramic blocks.

[0225] For an exemplary procedure performed using scheme A, a material sample can be placed inside the belly such that it is in the reaction specification 19 / 55 pages 24 CN 121536914 AThe material is stirred inside the vessel. Loose-fitting ceramic blocks located on the outside of the belly section on each side of the furnace's heating zone allow gas flow and block the powder. Glass wool filling can be used to fix the position of the ceramic blocks while also acting as a permeable layer. The end of the tube can be fitted with two stainless steel flanges to allow gas flow through the system.

[0226] Option B: An MTI rotary tube furnace with a quartz tube can be used. The furnace has a clamshell design including a cylindrical heating chamber with dimensions of 120 mm in diameter and 440 mm in heating length. The furnace has a wattage of 2500 W and a maximum operating temperature of 1150°C. The OD of the quartz tube can be 60 mm. The tube can be substantially horizontal. For an exemplary procedure performed using Option B, a material sample can be placed in a ceramic boat. It can then be placed in the quartz tube within the heating zone, after which heating can begin. Loose-fitting ceramic blocks located outside the furnace's heating zone allow gas flow. Glass wool filling can be used to fix the position of the ceramic blocks while also acting as a permeable layer. The end of the tube can be fitted with two stainless steel flanges.

[0227] Option C: A Lindberg Blue-M tube furnace with a quartz tube can be used. The OD of the quartz tube can be 150 mm. The furnace has a clamshell design with a cylindrical heating chamber having dimensions of 190 mm in diameter and 890 mm in heating length. The furnace has a wattage of 11,200 W and a maximum operating temperature of 1200°C. The tube can be substantially horizontal. For an exemplary procedure performed using Option C, the sample can be placed in a ceramic boat. It can then be placed in the quartz tube within the heating zone, after which heating can begin. A loosely fitted ceramic block located outside the heating zone of the furnace allows gas flow. The ends of the tube can be fitted with two aluminum flanges to allow gas flow through the system.

[0228] Option D: A Vulcan 3-550 muffle furnace can be used. The furnace has a rectangular heating chamber having dimensions of 190 mm x 240 mm x 228 mm. The furnace has a wattage of 1440 W and a maximum operating temperature of 1100°C. For the exemplary procedure performed using scheme D, the material sample may be placed in a ceramic boat. It may then be placed inside a muffle furnace, after which heating may begin.

[0229] Scheme E: A TA Instruments Q600 TGA / DSC may be used. For the exemplary procedure performed using scheme E, a 90 µL alumina dish may be used to hold the material sample. Unless otherwise specified, the gas flow may be a specified gas at 100 sccm. The heating rate may be mentioned in the exemplary procedure using scheme E.

[0230] Various analytical techniques are used to characterize the procedures and materials presented herein. These are detailed below.

[0231] Solution concentration is measured using electrolytic conductivity (“conductivity”). Conductivity is a measured response of the solution’s electrical conductance. SolutionThe electrical response can be correlated with the concentration of ions dissolved in the solution, and the conductivity value decreases as ions in the solution precipitate. A similar measurement is total dissolved solids (“TDS”), which correlates conductivity measurements with a reference ion concentration (typically potassium chloride), which depends on the dissolved salt compound.

[0232] Thermogravimetric analysis (TGA) was used to analyze the thermal stability and composition of the materials. All TGA characterizations were performed on a TA Instruments Q600 TGA / DSC. Samples were held in 90 µL alumina disks during TGA analysis. Unless otherwise specified, all TGA procedures were performed at 20 °C / min. Unless otherwise specified, air or Ar (Ar) was used as the carrier gas during TGA procedures.

[0233] Raman spectroscopy was performed using a ThermoFisher DXR Raman microscope equipped with a 532 nm excitation laser. For each sample analyzed, a 16-point spectrum was generated using measurements performed on a 4 x 4 point rectangular grid with a point-to-point spacing of 5 μm. The 16-point spectra were then averaged to produce an average spectrum. The Raman peak intensity ratio and Raman peak position reported for each sample were derived from the average spectrum of the sample. No linear fitting software was used, therefore the reported peak intensity ratio and peak position are related to unfitted peaks associated with the overall Raman linearity.

[0234] Gas adsorption measurements were performed using Micromeritics Tristar II Plus. Nitrogen adsorption was measured across a pressure (p) range at a temperature of 77 K, where the pressure increment range is up to page 20 / 55 of the specification, 25 CN 121536914 A. The BET specific surface area was calculated using Micromeritics MicroActive software, which assumed a cross-sectional area derived from the BET monolayer capacity. Samples were pretreated by degassing with a continuous flow of dry nitrogen at 100 °C prior to analysis.

[0235] Pore size distribution (PSD) and pore volume accumulation are another technique that can be performed based on gas adsorption data to gain a deeper understanding of the sintering behavior of the particles. Data were collected by Micromeritics Tristar II Plus, which measures nitrogen adsorption and desorption at 77 K in increments up to the range of pressure. Samples were pretreated by degassing with a continuous flow of dry nitrogen at 100 °C prior to analysis.

[0236] The adsorption-desorption PSD and pore volume accumulation were calculated using Micromeritics MicroActive software by applying the Barrett, Joyner, and Halenda (BJH) method. This method provides the mesopore size distribution of the gas adsorption data.Comparative evaluation. For all BJH data, Faas correction and Harkins and Jura thickness curves can be applied. Pore cumulative volume can be measured for both the adsorption and desorption portions of the isotherm.

[0237] A variety of exemplary materials are described in this disclosure. To help identify and track these exemplary materials, a material naming system has been adopted and is described below. All names of exemplary materials are in bold; in this document, N2 describes the exemplary material and N2 refers to nitrogen.

[0238] Exemplary types of template precursor materials are designated as Sx, where S specifies the first one or two letters of the template precursor material (i.e., N represents trihydrate magnesite, L represents polyhydrate magnesite, Li represents lithium carbonate, C represents magnesium citrate, A represents amorphous or non-crystalline MgCO3·xH2O, H represents hydromagnesite, M represents magnesite, E represents esperidium salt, Ca represents calcium carbonate), and where x specifies different types of precursor compounds (e.g., H1 and H2 represent two different types of hydromagnesite precursors).

[0239] Exemplary types of template materials are named in the format SxTy. The Sx name component specifies the precursor type used to produce the template type SxTy, and the Ty name component specifies the specific treatment used to produce the template type SxTy. For example, N1T1 and N1T2 indicate two different template types formed by two different treatments of the precursor type N1. It should be noted that while the full SxTy name represents a specific template type, the Ty name component itself is specific only to a given Sx precursor type. For example, the treatments used to make template types N1T1 and N2T1 are different, although these template types share the same T1 name component.

[0240] Exemplary types of PC materials are named in the format SxTyPz, where the SxTy name component specifies the template type, and the Pz name component specifies the specific carbon encapsulation type. For example, M3T1P1 and M3T1P2 indicate two different PC materials formed from the same M3T1 template material. The Pz name components within the SxTyPz name are unique—that is, each Pz name component specifies a unique coating body type, regardless of the SxTy template type used to prepare the coating body.

[0241] Exemplary types of coating frames (i.e., porous coating products generated through content extraction) are named in the format Pz, where the Pz name components do not begin with the SxTy template type. The Pz name components used to name the frame type match the Pz name components of the SxTyPz PC material type from which the frame type is derived.

[0242] Exemplary types of template precursor materials, template materials, coating composites, and coating materials in this disclosure are enumerated in Table 1. Table 1 is arranged to show the progress of synthesized materials starting from the template precursor material. While not every exemplary material is tracked in all four stages, it should be understood that any exemplary material may be tracked if desired. Table 1 also follows the material naming system described above.

[0243] IV. Precursor Stage – Examples

[0244] This section details the small-scale production of exemplary template precursor materials using exemplary procedures. Therefore, these procedures include partial implementations of the general method. Thus, it should be understood that these procedures must be combined with other procedures described in the specification 21 / 55 pages 26 CN 121536914 A in full implementation of the general method. Additionally, it should be understood that these procedures only demonstrate similar, larger-scale procedures that will be used for industrial-scale manufacturing.

[0245] Precipitation of the precursor material can be performed using various techniques. For example, a stock solution can be heated to evaporate the process liquid, thereby causing the stock solution to become supersaturated and precipitate the precursor material. This can be combined with techniques for controlling the shape and size of the precipitated template precursor particles. For example, the stock solution can be spray-dried to produce discrete spheres or hollow spheres. Other techniques that will be apparent to those skilled in the art can be utilized.

[0246] Example N1: In an exemplary precursor stage procedure, elongated trihydrate magnesite (MgCO3·3H2O) template precursor material can be obtained from an aqueous Mg(HCO3)2 stock solution.

[0247] To demonstrate this acquisition on a small scale, a representative stock solution can be prepared first. This stock solution represents the stock solution that can be generated during the separation stage of a full implementation of a general method. For this example, water, CO2 gas, and MgO can be used to generate a representative aqueous Mg(HCO3)2 stock solution.

[0248] First, a 0.24 mol kg⁻¹ Mg mixture comprising deionized water and the commercial magnesium oxide (MgO) product Akrochem Elastomag 170 can be prepared. This mixture can be carbonated in a circulating tank using a jet tube that bubbles CO2 to generate carbonic acid. After the MgO has completely dissolved to form the stock solution, the CO2 bubbling can be interrupted. The stock solution can be at approximately 14.5°C.

[0249] Next, air bubbling can be initiated in the stock solution in the circulation tank through the jet pipe at an air flow rate of approximately 12 scfm. This bubbling can lead to the precipitation of magnesite particles and the associated emission of CO2 process gas. Bubbling and circulation can continue until the conductivity of the solution stabilizes. At this point, the aqueous mixture of magnesite particles can be filtered to separate the particles from the aqueous Mg(HCO3)2 filtrate. This filtrate contains mother liquor and substantially all of the process water. In a full implementation of the general method, the separated process water can be preserved for reuse, as shown in Figure 12. In addition, in a full implementation of the general method, conventional techniques can be used to preserve the emitted CO2 process gas for reuse.

[0250] The type of magnesite template precursor particles generated by this procedure can be identified herein as N1 and can be seen in the SEM micrograph of Figure 14. This is due to the elongated morphology and a TGA mass loss of 70.4% (which is consistent with the values ​​shown in Table 2).The expected mass loss of 70.9% of MgO is very consistent, confirming that the template precursor is MgO.

[0251] Apart from the presence of some small debris, the crystals have a smooth, thin surface. The elongated shape of these crystals may be valuable. In applications requiring interlocking particles (such as filter membranes), the elongated shape may be useful. In applications requiring the assembly of percolation networks (such as for electron transport), elongated particles can achieve percolation with fewer particles compared to equiaxed particle morphologies. In applications requiring mechanical reinforcement, elongated particles can provide excellent tensile properties.

[0252] Example H1: In another exemplary precursor stage procedure, graded equiaxed MgO (Mg5(CO3)4(OH)2·4H2O) template precursor material can be obtained from an aqueous Mg(HCO3)2 stock solution.

[0253] To demonstrate this acquisition on a small scale, a representative stock solution can first be prepared. This stock solution represents the stock solution that can be generated in the separation stage of a full implementation of a general method. For this embodiment, an aqueous Mg(HCO3)2 stock solution with an approximate weight molar concentration of 0.14 mol kg⁻¹ Mg(aq) can be prepared first as a representative stock solution.

[0254] Next, the stock solution can be placed in a 1 L Buchi rotary evaporator container and then rotated in a 100°C water bath at 280 RPM. Crystallization can be allowed to continue until most of the Mg ions have precipitated as hydromagnesite precursor particles. Accompanying this precipitation, CO2 process gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during precipitation.

[0255] The resulting hydromagnesite mixture can then be filtered to separate the solids from the aqueous Mg(HCO3)2 filtrate. This filtrate contains the mother liquor and substantially all of the process water. In a full implementation of the general method, the separated mother liquor can be preserved for reuse.

[0256] The type of hydromagnesite template precursor particles generated by this procedure are identified herein as H1 and can be seen in the representative SEM micrograph of Figure 15. The TGA mass loss of these particles is 56.6%, which is very consistent with the expected mass loss of 56.9% for hydromagnesia magnesia (Table 2), pages 22 / 55 of CN 121536914 A. Thin (thickness < 100 nm) hydromagnesia slabs are arranged in a hierarchical equiaxed superstructure. This template precursor morphology is of interest due to the combination of thin morphological features and equiaxed morphological features. In applications requiring high surface area, the hierarchical equiaxed morphology prevents the surface of thin crystals from being obscured, whereas simple planar particles tend to stack on top of each other and obscure each other's surfaces.

[0257] Example H2: In another exemplary precursor stage procedure, elongated slabs can be obtained from an aqueous Mg(HCO3)2 stock solution.Graded hydromagnesite (Mg5(CO3)4(OH)2·4H2O) template precursor material.

[0258] To demonstrate this acquisition on a small scale, trihydrate magnesite can first be precipitated from a representative aqueous Mg(HCO3)2 stock solution. This stock solution represents the stock solution that can be generated during the separation phase of a full implementation of a general method. For this embodiment, the representative stock solution and an aqueous mixture of precipitated trihydrate magnesite can be obtained using the procedure described in Example N1. Accompanying this trihydrate magnesite precipitation, CO2 process gas can be released. In a full implementation of a general method, conventional techniques can be used to preserve the released CO2 process gas.

[0259] Next, the trihydrate magnesite mixture can be heated to 100°C and maintained at said temperature until recrystallization into hydromagnesite is complete. In this exemplary procedure, the process water can be completely evaporated, thereby separating it from the solid residue of elongated hydromagnesite particles. In a full implementation of a general method, conventional techniques can be used to preserve the released process water.

[0260] The type of hydromagnesite template precursor particles generated by this procedure are designated H2 herein and can be seen in the representative SEM micrograph of Figure 16. This template precursor material combines the advantages of the aforementioned elongated and thin morphologies.

[0261] Example H3: In another exemplary precursor stage procedure, plate-like hydromagnesite (Mg5(CO3)4(OH)2·4H2O) template precursor material can be obtained from an aqueous Mg(HCO3)2 stock solution.

[0262] To demonstrate this acquisition on a small scale, graded hydromagnesite can first be obtained from a representative aqueous Mg(HCO3)2 stock solution. This stock solution represents the stock solution that can be generated during the separation stage of a full implementation of the general method. For this example, the representative stock solution and precipitated hydromagnesite can be obtained using the procedure described in Example H2. Along with the precipitation, CO2 process gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the released CO2 process gas. Additionally, in a full implementation of the general method, the separated process water can be preserved.

[0263] Next, the graded magnesite particles can be mechanically broken up. This can be achieved in various ways using known milling techniques. For illustrative purposes, the particles can be slurried in process water. The mixture can then be agitated using high-shear techniques to break down the finely graded magnesite particles into their constituent individualized plates. The plate-like magnesite particles can then be filtered out from the process water. In a full implementation of the general method, the separated process water can be preserved for reuse.

[0264] The type of magnesite template precursor particles generated by this procedure are designated H3 herein and can be seen in the representative SEM micrographs of Figure 17. These particles have a TGA mass loss of 56.6%, which is very consistent with the expected magnesite mass loss of 56.9% as seen in Table 2.

[0265] Example L1: In another exemplary precursor stage procedure, equiaxed hydrated magnesite (MgCO3·5H2O) template precursor material can be obtained from an aqueous Mg(HCO3)2 stock solution.

[0266] To demonstrate this acquisition on a small scale, a representative stock solution can first be prepared. This stock solution represents the stock solution that can be generated in the separation stage of a full implementation of the general method. For this example, a representative aqueous Mg(HCO3)2 stock solution with a concentration of approximately 0.25 mol kg⁻¹ Mg(aq) can be prepared and cooled to 2°C.

[0267] The cooled stock solution can then be subjected to N₂ bubbling at a flow rate of 4 scfh air. The resulting precipitation can cause CO₂ process gas to be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO₂ process gas released during precipitation. Instructions 23 / 55 pages 28 CN 121536914 A

[0268] After 67 minutes, N2 bubbling can be interrupted. After the N2 bubbling is interrupted, the formed crystals can be stirred for another 50 minutes, and then the mixture can be filtered to separate the solids from the mother liquor. The solids can be washed with 5°C deionized water. In a full implementation of the general method, the separated mother liquor can be preserved for reuse.

[0269] The type of hydrous magnesite template precursor particles generated by this procedure are designated L1 herein and can be seen in the representative SEM micrograph of Figure 18. The template precursor particles have the characteristic prismatic isometric morphology of hydrous magnesite, and these particles have a TGA mass loss of 76.4%, which is very consistent with the expected hydrous magnesite mass loss of 76.9% as seen in Table 2. The prismatic isometric morphology may be desirable for applications where the coated product must be bound to a liquid and the viscosity effect must be minimized. Furthermore, due to the relatively high hydration state of hydrous magnesite, for a given mass of Mg, the generated template precursor volume is greater than that obtainable using MgCO3·xH2O with lower hydration, and more template pore volume is obtained upon decomposition of the precursor material. This can be used to generate a coated framework with more extracellular space.

[0270] Raman spectroscopy can be used to characterize the chemical composition of the template precursor material. Applying this Raman spectroscopy produces a peak position matching consistent with hydrous magnesite at 1083 cm⁻¹, as seen in Table 2.

[0271] Example L2: In another exemplary precursor stage procedure, equiaxed hydrous magnesite (MgCO3·5H2O) template precursor material can be obtained from an aqueous Mg(HCO3)₂ stock solution.

[0272] To demonstrate this acquisition on a small scale, a representative stock solution can first be prepared. This stock solution represents the stock solution that can be generated in the separation stage of a full implementation of a general method. For this example, a representative stock solution can be obtained as follows.Reserve solution. First, an aqueous mixture of precipitated hydrated magnesite can be obtained using the procedure described in Example N1. The concentration of this mixture can be adjusted to 0.62 mol kg⁻¹ Mg. The mixture can then be added to a high-pressure baffle reactor equipped with a self-priming stirrer. The system can be stirred at 700 RPM and cooled to 5°C while CO2 process gas is injected into the top space of the reactor until a pressure of 850 psi is reached, or until all solids have dissolved, thereby producing a representative pressurized reserve solution.

[0273] When depressurizing the reserve solution to atmospheric pressure, the stirring rate can be reduced to 500 RPM, and the solution can be maintained at 12°C while air flows through the top space. The resulting precipitation of hydrated magnesite particles can cause the CO2 process gas to be released. In a full implementation of the general method, conventional techniques can be used to retain the CO2 process gas released during precipitation.

[0274] After 228 minutes, the mixture of hydrated magnesite particles can be discharged from the reactor and then filtered to separate the hydrated magnesite solids from the mother liquor. In a full implementation of the general method, the separated mother liquor can be preserved for reuse. For analytical purposes, the hydrous magnesite solid can be washed with deionized water, resuspended in ethanol, filtered again, and dried in a vacuum oven at room temperature up to 29 inHg.

[0275] The hydrous magnesite template precursor particles of this type generated by this procedure are designated L2 herein. Raman spectroscopy analysis confirmed that the products of this reaction matched those of hydrous magnesite (as seen in Table 2).

[0276] Hydrous magnesite is significantly more industrially scalable and less expensive than other isometric MgCO3·xH2O type precursors (e.g., magnesite). For applications where the coated product must be bound to a liquid and viscosity effects must be minimized, prismatic isometric morphology may be desirable. Furthermore, due to the relatively high hydration state of hydrated magnesite, the generated template precursor volume for a given mass of Mg is greater than that obtainable using MgCO3·xH2O with lower hydration, and more template pore volume can be obtained upon decomposition of the precursor material. This can be used to generate a coated framework with more extracellular space.

[0277] Example L3: In another exemplary precursor stage procedure, equiaxed partially dehydrated template hydrated magnesite (MgCO3·5H2O) template precursor material can be obtained from an aqueous Mg(HCO3)2 stock solution.

[0278] To demonstrate this acquisition on a small scale, an aqueous hydrated magnesite mixture can first be obtained from a representative aqueous Mg(HCO3)2 stock solution. This stock solution represents a stock solution that can be generated during the separation stage of a full implementation of a general method. For this example, the representative stock solution and aqueous hydrated magnesite can be obtained using the procedure described in Example L2.Mineral mixture. As described in Example L2, precipitation of hydrated magnesite particles can result in the release of CO2 process gas. In a full implementation of the general method, conventional techniques can be used to retain the CO2 process gas released during precipitation.

[0279] The concentration of the hydrated magnesite mixture can be adjusted to a solid concentration of 7% by weight. The mixture can then be spray-dried, resulting in partial dehydration of the hydrated magnesite material. To demonstrate this on a small scale, spray drying can be performed using a Sinoped LPG-5 spray dryer. The hydrated magnesite particles in the 7% by weight mixture can be kept continuously suspended by stirring in the container. The mixture can be pumped from the container into the BETE XAER250 air atomizing nozzle of the spray dryer at a rate ranging from 116 mL / min to 162 mL / min. Compressed air can also be delivered to the nozzle at a flow rate ranging from 1.2 scfm air at 20 psig to 3.6 scfm air at 59 psig. The inlet temperature of the spray dryer can be set to 300°C, resulting in an outlet temperature ranging between 111°C and 123°C.

[0280] The dried, partially dehydrated magnesite particles can be collected by a cyclone particle separator. In a full implementation of the general method, conventional techniques can be used to preserve the process water vapor generated by the spray drying.

[0281] The type of partially dehydrated magnesite template precursor particles generated by this procedure are designated L3 herein. The process liquids and gases can be recovered by typical industrial methods for reuse in the separation stage.

[0282] A 67.1% TGA mass loss of the L3 template precursor material generated according to the above procedure confirms that partial dehydration has occurred (the theoretical mass loss for magnesite is 76.9%, as shown in Table 2). This partial dehydration is due to the increased temperature experienced during the spray drying process.

[0283] Example M1: In another exemplary precursor stage procedure, equiaxed magnesite (MgCO3) template precursor material can be obtained from an aqueous Mg(HCO3)2 stock solution.

[0284] To demonstrate this acquisition on a small scale, a representative stock solution can first be prepared. This stock solution represents the stock solution that can be generated during the separation phase of a full implementation of a general method. For this example, a representative aqueous Mg(HCO3)2 stock solution with a concentration of 0.25 mol kg⁻¹ Mg(aq) can be prepared. This stock solution can then be slurried with additional MgO to provide more Mg ions. In a full implementation of a general method, additional Mg ions can be provided using MgCO3·xH2O precipitated from the stock solution. However, for the purposes of this demonstration, the additional MgO may include a commercially available MgO product (Elastomag 170) that has been calcined at 1050°C for 1 hour. By additionally loading Mg ions, the total Mg present in the stock solution mixture can be 1.5mol kg⁻¹ Mg.

[0285] Next, this stock solution-mixture can be placed in a pressure vessel with magnetic stirring, a high-pressure gas inlet, and a purge needle valve. CO₂ can be flowed for 2 minutes to purge the air in the vessel, after which it can be completely sealed and pressurized with CO₂ to 725 psi at 14.4°C. The vessel can be heated on a heating stir plate. With magnetic stirring and heating, the vessel can reach 193.7°C and 975 psi after 291 minutes. Inside the vessel, magnesite precipitates during this heat treatment, and CO₂ process gas can be vented into the top space of the vessel. The vessel can then be depressurized and cooled over a 30-minute process, thereby continuously releasing vapors and CO₂. In a full implementation of the general method, conventional techniques can be used to preserve the CO₂ process gas released during precipitation and subsequent depressurization.

[0286] The mixture of magnesite particles can then be discharged from the reactor and filtered to separate the magnesite solids from the mother liquor. In the full implementation of the general method, the separated mother liquor can be preserved for reuse in the separation stage. Magnesite can be dried at 100°C.

[0287] The type of magnesite template precursor particles generated by this procedure are designated as M1 herein. The particles exhibit an isometric rhombohedral morphology and are shown in the SEM micrograph of Figure 19. Thermogravimetric analysis of the samples shows the magnesite composition due to the absence of any thermal decomposition prior to the decarboxylation stage at 400°C. The TGA mass loss of these particles is 52.2%, which matches the expected magnesite mass loss of 52.2% as seen in Table 2. Raman spectroscopy analysis also confirms that the particles are magnesite, as seen in Table 2. This experiment demonstrates the production of isometric magnesite template precursor particles using a Mg(HCO3)2 stock solution enriched with additional Mg2+ and HCO3− ions, respectively, by passing MgO and CO2 gases.

[0288] Example M2: In another exemplary precursor stage procedure, equiaxed magnesite (MgCO3) template precursor material can be obtained from an aqueous Mg(HCO3)2 stock solution.

[0289] To demonstrate this acquisition on a small scale, trihydrate magnesite can be generated from an aqueous Mg(HCO3)2 stock solution using the procedure described in Example N1. This precipitation can cause CO2 process gas to be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during precipitation. Similarly, in a full implementation of the general method, the separated mother liquor can be preserved.

[0290] In this exemplary procedure, the multihydrate magnesite can then be combined with water to prepare a mixture with a concentration of 1.5 mol kg⁻¹ Mg. The mixture can be placed in a pressure vessel with a magnetic stirrer, a high-pressure gas inlet, and a purge needle valve. PressureThe top space of the container may contain ambient pressure air, with no additional gas input. The pressure vessel can then be sealed.

[0291] The mixture can be magnetically stirred in the container for 10 minutes. The container can then be heated to 175°C over 68 minutes. During this heat treatment, the reaction temperature can fluctuate, reaching a maximum temperature of 180°C and a maximum pressure of 1190 psi, under which any CO2 released from the trihydrate magnesite in the reaction can become supercritical. The pressure vessel can then be cooled for 199 minutes.

[0292] The resulting magnesite particle mixture can be discharged from the reactor and then filtered to separate the magnesite solids from the mother liquor. In a full implementation of the general method, the separated mother liquor can be preserved for reuse in the separation stage. The magnesite can be dried at 100°C.

[0293] The type of magnesite template precursor particles generated by this procedure are designated M2 herein. The particles exhibit an isometric rhombohedral morphology and are shown in the SEM micrograph of Figure 20. Raman spectroscopy analysis confirmed that the products of this reaction matched those of magnesite, as shown in Table 2.

[0294] Example A1: In another exemplary precursor stage procedure, hollow, non-crystalline MgCO3·xH2O template precursor material can be obtained from an aqueous Mg(HCO3)2 stock solution.

[0295] To demonstrate this acquisition on a small scale, a representative stock solution can be prepared first. This stock solution represents the stock solution that can be generated in the separation stage of a full implementation of a general method. For this example, a representative aqueous Mg(HCO3)2 stock solution with a concentration of 0.43 mol kg⁻¹ Mg(aq) can be prepared. This can be done by mixing a commercial MgCO3·xH2O product (“light magnesium carbonate” supplied by Akrochem Corporation) in water at a solid concentration equivalent to 0.43 mol kg⁻¹ Mg. This mixture can be carbonated using pressurized CO2 gas in a circulating pressure vessel. The system can be pressurized to a total pressure of 555 psi by injecting CO2 gas into the vessel. This can be maintained at 34°C for 2 hours and 13 minutes, or until all solids dissolve. At this point, the container can be depressurized and stored at atmospheric pressure at 4°C.

[0296] The cooled stock solution can then be spray-dried. To demonstrate this, the stock solution can be pumped at a rate of 35 mL / min through the BETE XAER150 air atomizing nozzle of the Sinoped LPG-5 spray dryer. Compressed air can be delivered into the nozzle at a flow rate of 2.8 scfm at 45 psig. The inlet temperature of the spray dryer can be set to 165°C, resulting in an outlet temperature of 110°C.

[0297] The particles generated by spray drying the stock solution can be collected by a cyclone particle separator. In generalIn the full implementation of the method, conventional techniques can be used to preserve both process water vapor and CO2 process gas discharged through spray drying. Specification 26 / 55 pages 31 CN 121536914 A

[0298] The type of MgCO3·xH2O template precursor material produced by this process is identified herein as Al. SEM image analysis of Al particles, as shown in the SEM micrograph in Figure 21, indicates that the amorphous MgCO3·xH2O particles produced by spray drying consist of generally hollow multi-level equiaxed particles with smooth outer surfaces. Shell fragments are also present. Shell fragments indicate that there are large pores within the shell.

[0299] Raman spectroscopy analysis shows that the product of this reaction does indeed have a Raman peak at 1106 cm⁻¹ that can be associated with crystalline carbonates. However, it does not match any typical MgCO3·xH2O peaks (Table 2). In addition, TGA analysis of the template precursor failed to match the common crystalline form of MgCO3·xH2O with a mass loss of 66.3%, as seen in Table 2. Therefore, it is considered amorphous.

[0300] Example A2: In another exemplary precursor stage procedure, hollow fractionated equiaxed amorphous MgCO3·xH2O template precursor material can be obtained from an aqueous Mg(HCO3)2 stock solution.

[0301] To demonstrate this acquisition on a small scale, a representative stock solution can be prepared first. This stock solution represents the stock solution that can be generated in the separation stage of a full implementation of a general method. For this example, a representative aqueous Mg(HCO3)2 stock solution with a concentration of 1.39 mol kg⁻¹ Mg(aq) can be prepared. This can be done by mixing a commercial Mg(OH)2 product (“Versamag” supplied by Akrochem Corporation) in water at a solid concentration equivalent to 1.49 mol kg⁻¹ Mg. This mixture can be carbonized using pressurized CO2 gas in a circulating pressure vessel. The system can be pressurized to a total pressure of 700-800 psig by injecting CO2 gas into the vessel. This can be maintained at 10°C for 2 hours, or until all (i.e., >90%) solids dissolve. At this point, the contents can be depressurized and stored at atmospheric pressure at 4–10°C.

[0302] The stock solution can then be spray-dried. To demonstrate this, the stock solution can be pumped at a rate of 2.7 mL / min through a 0.7 mm Buchi B-290 dual-fluid air atomizing nozzle in a Buchi B-191 spray drying system. Compressed air can be delivered to the nozzle at a flow rate of 0.6 scfm at 88 psig. The inlet temperature of the spray dryer can be set to 130°C, resulting in an outlet temperature between 85–89°C. The aspirator can be set to 18 scfm air.

[0303] The particles generated by spray drying of the stock solution can be collected by a cyclotron particle separator. In a full implementation of the general method, conventional techniques can be used to preserve both the process water vapor and CO2 process gas discharged by spray drying.

[0304] The type of MgCO3·xH2O template precursor material produced by this process is designated as A2 herein. SEM image analysis of A2 particles, as shown in the SEM micrographs in Figures 22A and 22B, indicates that the amorphous MgCO3·xH2O particles generated by spray drying consist of generally hollow, multi-level equiaxed particles with smooth outer surfaces. Shell fragments are also present. The shell fragments indicate that, in addition to the central cavity, the shell also has a closed-pore macroporous structure. Compared to the shell of A1 particles, the shell of A2 particles is thicker due to its increased shell porosity. The spheres are also smaller, with 95% or more of the population having a diameter of less than 10 μm.

[0305] Raman spectroscopy analysis shows that the MgCO3·xH2O spheres do not have obvious Raman peaks that can be associated with crystalline carbonates. Furthermore, the TGA analysis of the template precursor failed to match the common crystalline form of MgCO3·xH2O with a mass loss of 68.4%, as seen in Table 2. Therefore, it was considered amorphous.

[0306] Example A3: In another exemplary precursor stage procedure, hollow hierarchical equiaxed amorphous MgCO3·xH2O template precursor material can be obtained from an aqueous Mg(HCO3)2 stock solution.

[0307] To demonstrate this acquisition on a small scale, a representative stock solution can be prepared first. This stock solution represents the stock solution that can be generated in the separation stage of a full implementation of a general method. For this example, a representative aqueous Mg(HCO3)2 stock solution with a concentration of 1.08 mol kg⁻¹ Mg(aq) can be prepared. This can be done by mixing a commercial Mg(OH)2 product (“Versamag” supplied by Akrochem Corporation) in water at a solid concentration equivalent to 1.12 mol kg⁻¹ Mg. This mixture can be carbonized using pressurized CO2 gas in a circulating pressure vessel. The system can be pressurized to a total pressure of 700-800 psig by injecting CO2 gas into the container. This can be maintained at 10°C for 2 hours, or until substantially all (i.e., >90%) of the solids dissolve. At this point, the contents can be depressurized and stored at atmospheric pressure at 4-10°C.

[0308] The stock solution can then be spray-dried. To demonstrate this, the stock solution can be pumped at a rate of 2.7 mL / min through a 0.7 mm Buchi B-290 dual-fluid air atomizing nozzle in the Buchi B-191 spray drying system. It can be sprayed at 88 psig with 0.6 scfm of air.The flow rate delivers compressed air into the nozzle. The inlet temperature of the spray dryer can be set to 90°C, resulting in an outlet temperature between 56 and 58°C. The air intake can be set to 18 scfm air.

[0309] The particles generated by spray drying of the stock solution can be collected by a cyclone particle separator. In a full implementation of the general method, conventional techniques can be used to preserve both the process water vapor and CO2 process gas discharged by spray drying.

[0310] The type of MgCO3·xH2O template precursor material produced by this process is designated as A3 herein. SEM image analysis of A3 particles, as shown in the SEM micrographs in Figures 22C to 22D, indicates that the amorphous MgCO3·xH2O particles generated by spray drying consist of generally hollow, multi-level equiaxed particles with smooth outer surfaces. Shell fragments are also present. The shell fragments indicate that, in addition to the central cavity, the shell also has a closed-pore macroporous structure. Compared to the shells of A1 and A2 particles, the shell of A3 is thicker due to its increased shell porosity. These indicate that the average aspect ratio of the particle radius to the shell thickness is also low. The particles circled in solid yellow have an aspect ratio of approximately 5:1, while the particles circled in dashed yellow have an aspect ratio of approximately 2:1.

[0311] Macropores are present throughout the shell, which can be seen in the carbon-coated framework grown thereon. Figure 22E is a TEM image of the carbon-coated framework grown on a template obtained from A3 particles. The mottled appearance of the shell, corresponding to its porosity, extends throughout the shell. The macropores of the shell are sandwiched between two surface layers—an outer surface layer and an inner surface layer (which represent the inner and outer surfaces of the shell, respectively). These surface layers appear darker in TEM. The macroporous shell is part of the coated superstructure; the cellular substructure is more refined, as shown in the inset of Figure 22E (i.e., a TEM micrograph showing the mesoporous cellular substructure).

[0312] Raman spectroscopy analysis shows that the MgCO3·xH2O spheres do not have obvious Raman peaks that can be associated with crystalline carbonates. Additionally, the TGA analysis of the template precursor failed to match the common crystalline form of MgCO3·xH2O with a mass loss of 72.9%, as seen in Table 2. Therefore, it was considered amorphous.

[0313] Example C1: In another exemplary precursor stage procedure, hollow fractionated equiaxed magnesium citrate template precursor material can be obtained from an aqueous magnesium citrate stock solution.

[0314] To demonstrate this acquisition on a small scale, a representative stock solution can first be prepared. This stock solution represents the stock solution that can be generated in the separation stage of a full implementation of a general method. For this example, a 0.52 mol kg-1 Mg(OH)2 (Versamag, supplied by Akrochem) aqueous mixture can be prepared by reacting citric acid (supplied by Sigma Aldrich) with 0.52 mol kg-1 Mg(OH)2 (Versamag, supplied by Akrochem).A representative aqueous magnesium citrate stock solution of (aq).

[0315] The stock solution can then be spray-dried. To demonstrate this, the stock solution can be pumped at a rate of 3.75 mL / min through a Buchi B-290 two-fluid nozzle of a Buchi B-191 spray dryer. Compressed air can be delivered to the nozzle at a flow rate of 0.6 scfm at 88 psig with the getter air flow rate set to 18 scfm air. The inlet temperature can be set to 220°C, resulting in an outlet temperature of 110°C.

[0316] The particles generated by spray drying the stock solution can be collected by a cyclone particle separator. In a full implementation of the general method, conventional techniques can be used to preserve the process water vapor discharged by spray drying.

[0317] The type of magnesium citrate template precursor material produced by this process is designated C1 herein. SEM analysis of the C1 particles, as shown in the SEM micrograph in Figure 23, indicates that the magnesium citrate particles generated by spray drying consist of generally hollow multi-level equiaxed particles. Most comprise a solid shell and a hollow interior, with a wrinkled spherical superstructure, as seen in Figure 23. Some particles comprise a smooth, unwrinkled spherical superstructure; these particles may have a thicker and more rigid shell compared to the wrinkled particles. Spray-dried magnesium citrate precursor particles rarely break or fracture, although pinholes may be observed, as indicated in Figure 23.

[0318] Raman spectroscopy analysis confirmed that the products of this reaction matched those of magnesium citrate, as shown in Table 2.

[0319] Example E1: In another exemplary precursor stage procedure, an elongated template precursor material of esperidone salt (magnesium sulfate heptahydrate MgSO4·7H2O) can be obtained from an aqueous stock solution of magnesium sulfate.

[0320] To demonstrate this acquisition on a small scale, a representative stock solution can first be prepared. This stock solution represents the stock solution that can be generated in the separation stage of a full implementation of the general method. For this embodiment, a representative aqueous magnesium sulfate stock solution with a concentration of 4.06 mol kg⁻¹ Mg(aq) can be prepared by dissolving zapek salt in water at room temperature. This can be done in a glass beaker with magnetic stirring at 700 RPM.

[0321] Once dissolved, 410.86 g of acetone can be added dropwise through a separatory funnel, which can result in the immediate formation of crystals in the solution. While this represents an antisolvent precipitation that is generally undesirable, solvent-free precipitation of zapek salt can be easily achieved by cooling or spray drying the stock solution. The procedure of Example E1 is more for the purpose of precipitating zapek salt, rather than demonstrating a precursor morphology for engineering design or a scalable procedure, so that the precipitation from zapek salt can be demonstrated and analyzed in subsequent sections of this disclosure.Template and coating materials obtained from salt precursor compounds. In a full implementation of the general method, the mother liquor separated after solvent-free precipitation can be preserved for reuse in the separation stage.

[0322] After 22 minutes, precipitation of esperidone salt can be completed. The resulting mixture can be collected and filtered. The particles can be dried.

[0323] The type of esperidone salt template precursor material produced by this process is designated E1 herein. The particles can be observed as slender rods with a hexagonal cross-section by optical microscopy, as shown in Figure 24.

[0324] Raman spectroscopy analysis confirmed that the product of this reaction matches the product of esperidone salt (as seen in Table 2).

[0325] Example H4: In another exemplary precursor stage procedure, Li-doped hydrated magnesite (Mg5(CO3)4(OH)2·4H2O) template precursor material can be obtained from an aqueous stock solution of Mg(HCO3)2 that also contains a low concentration of aqueous Li2CO3.

[0326] To demonstrate this acquisition on a small scale, a representative stock solution can first be prepared. This stock solution represents the stock solution that can be generated during the separation phase of a full implementation of a general method. For this example, a representative aqueous Mg(HCO3)2 stock solution can be prepared, with the additional step of adding lithium carbonate (Li2CO3). This can be done as follows. First, MgO powder (Akrochem Elastomag 170 calcined at 1050°C for 1 hour) can be slurried in water at a solid concentration of 0.23 mol kg⁻¹ Mg. This can be done in a glass beaker with magnetic stirring. Li2CO3 (Sigma Aldrich) can be added to this mixture at a solid concentration of 2.71 × 10⁻³ mol kg⁻¹ Li. The mixture can be carbonated using a jet tube that bubbles CO2 gas to generate aqueous H₂CO3. After the MgO and Li₂CO3 are completely dissolved, the CO2 flow can be interrupted. The Mg(HCO3)2 stock solution can then be filtered to remove any residual undissolved impurities.

[0327] Next, the stock solution can be heated to 100°C in an open glass beaker with magnetic stirring. This condition can be maintained for 2 hours, during which time hydrated magnesite particles can precipitate. After 2 hours, the resulting mixture can be filtered, and the solid hydrated magnesite can be dried in a forced air circulation at 100°C.

[0328] The type of Li-doped hydrated magnesite template precursor material produced by this process is designated herein as H4. The particles are shown in the SEM micrograph of Figure 25. They are thin (< 100 nm along their short axis) and flat, and have a smooth surface.

[0329] Example H5: In the exemplary precursor stage procedure, Li-doped hydrated magnesite (Mg5(CO3)4(OH)2·4H2O) template precursor material can be obtained from an aqueous stock solution of Mg(HCO3)2 that also contains a medium concentration of Li2CO3.

[0330] To demonstrate this acquisition on a small scale, a representative stock solution can first be prepared. This stock solution represents the stock solution that can be generated during the separation phase of a general implementation of the method. For this example, a representative aqueous Mg(HCO3)2 stock solution can be prepared, with the additional step of adding lithium carbonate (Li2CO3). This can be done as follows. Specification 29 / 55 pages 34 CN 121536914 A

[0331] First, MgO powder (Akrochem Elastomag 170 calcined at 1050°C for 1 hour) can be slurried into water at a solid concentration of 0.23 mol kg⁻¹ Mg. This can be done in a glass beaker with magnetic stirring. Li2CO3 (Sigma Aldrich) can be added to this mixture at a solid concentration of 2.74·10⁻² mol kg⁻¹ Li. The mixture can be carbonated using a jet tube that bubbles CO2 gas to generate aqueous H2CO3. After MgO and Li2CO3 are completely dissolved, the CO2 flow can be interrupted. The Mg(HCO3)2 stock solution can then be filtered to remove any residual undissolved impurities.

[0332] Next, the stock solution can be heated to 100°C in an open glass beaker with magnetic stirring. This condition can be maintained for 1 hour, during which time hydromagnesite particles can precipitate. After 1 hour, the resulting mixture can be filtered, and the solid hydromagnesite can be dried in a forced air circulation at 100°C.

[0333] The type of Li-doped hydromagnesite template precursor material produced by this process is designated as H5 herein. The particles are shown in the SEM micrograph of Figure 26. Their plates are thin (along their short axis < 120 nm) and the surface is rougher than the surface of the plates shown in Figure 25. This roughness can indicate the increased Li doping due to the higher concentration of Li2CO3 in the aqueous stock solution.

[0334] Example M3: In another exemplary precursor stage procedure, equiaxed magnesite (MgCO3) template precursor material can be obtained from an aqueous Mg(HCO3)2 stock solution.

[0335] To demonstrate this acquisition on a small scale, a representative stock solution can first be prepared. This stock solution represents the stock solution that can be generated during the separation phase of a full implementation of a general method. For this embodiment, the stock solution can be generated in a high-pressure reactor. First, commercial magnesite product (Akrochem light magnesium carbonate) can be slurried in water at a solid concentration of 0.74 mol kg⁻¹ Mg. This mixture can be placed in a circulating pressure vessel. The sealed vessel can then be heated to 145 °C, at which temperature, ~800 psi of gaseous CO₂ can be introduced into the system. This reaction can be continued at 145 °C for a duration of 139 minutes, thereby reaching a maximum pressure of 900 psi. During this heat treatment, the magnesite can dissolve, thereby formingAqueous Mg(HCO3)2 is formed, and magnesite can precipitate from Mg(HCO3)2. At this point, the container can be depressurized to release CO2 process gas. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during precipitation and subsequent depressurization.

[0336] The resulting magnesite particle mixture can be discharged from the reactor and then filtered to separate the magnesite solids from the mother liquor. In a full implementation of the general method, the separated mother liquor can be preserved for reuse in the separation stage. Magnesite can be dried at 100°C.

[0337] The type of magnesite template precursor material produced by this process is designated as M3 herein. Isometric magnesite particles can be seen in the SEM micrograph of Figure 27A. Based on a TGA mass loss of 51.7% (which closely matches the theoretical expectation of 52.2% in Table 2), the structure indicates magnesite.

[0338] Example M4: In another exemplary precursor stage procedure, equiaxed magnesite (MgCO3) template precursor material can be obtained from an aqueous Na-rich Mg(HCO3)2 stock solution.

[0339] To demonstrate this acquisition on a small scale, a representative stock solution can be prepared first. This stock solution represents the stock solution that can be generated in the separation stage of a full implementation of a general method. For this example, the stock solution can be generated in a high-pressure reactor. First, a commercially available hydromagnesite product (Akrochem light magnesium carbonate) can be slurried in water at a solid concentration of 0.74 mol kg⁻¹ Mg. A commercially available NaHCO3 product (Arm & Hammer) can be added to this mixture at a concentration of 2.17 × 10⁻³ mol kg⁻¹ Na. This mixture can be placed in a circulating pressure vessel. The sealed vessel can then be heated to 145 °C, at which temperature ~800 psi of gaseous CO2 can be introduced into the system. This reaction can be continued at 145°C for a duration of 135 minutes, thereby reaching a maximum pressure of 840 psi. During this heat treatment, hydromagnesite can dissolve to form aqueous Mg(HCO3)2, and magnesite can precipitate from the aqueous Mg(HCO3)2. At this point, the container can be depressurized to release CO2 process gas. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during precipitation and subsequent depressurization.

[0340] The resulting mixture of magnesite particles can be discharged from the reactor and then filtered to separate the magnesite solids from the mother liquor. In a full implementation of the general method, the separated mother liquor can be preserved for reuse in the separation stage. Magnesite can be dried at 100°C.

[0341] The type of magnesite template precursor material produced by this process is designated M4 herein. Isometric magnesite particles can be seen in the SEM micrograph of Figure 27B. Based on 51A 0.6% TGA mass loss (which closely matches the theoretical expectation of 52.2% in Table 2) indicates magnesite.

[0342] Example M5: In another exemplary precursor stage procedure, equiaxed magnesite (MgCO3) template precursor material can be obtained from an aqueous Na-rich Mg(HCO3)2 stock solution.

[0343] To demonstrate this acquisition on a small scale, a representative stock solution can be prepared first. This stock solution represents the stock solution that can be generated in the separation stage of a full implementation of a general method. For this example, the stock solution can be generated in a high-pressure reactor. First, a commercially available hydromagnesite product (Akrochem light magnesium carbonate) can be slurried in water at a solid concentration of 0.74 mol kg⁻¹ Mg. A commercially available NaHCO3 product (Arm & Hammer) can be added to this mixture at a concentration of 0.19 mol kg⁻¹ Na. This mixture can be placed in a circulating pressure vessel. The sealed vessel can then be heated to 145°C, at which temperature ~800 psi of gaseous CO2 can be introduced into the system. This reaction can be continued at 145°C for a duration of 137 minutes, thereby reaching a maximum pressure of 850 psi. During this heat treatment, hydromagnesite can dissolve to form aqueous Mg(HCO3)2, and magnesite can precipitate from the aqueous Mg(HCO3)2. At this point, the container can be depressurized to release CO2 process gas. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during precipitation and subsequent depressurization.

[0344] The resulting mixture of magnesite particles can be discharged from the reactor and then filtered to separate the magnesite solids from the mother liquor. In a full implementation of the general method, the separated mother liquor can be preserved for reuse in the separation stage. Magnesite can be dried at 100°C.

[0345] The type of magnesite template precursor material produced by this process is designated M5 herein. The isometric magnesite particles can be seen in the SEM micrograph of Figure 27C as rhombohedral crystals of magnesite. Based on a 51.9% TGA mass loss (which closely matches the theoretical expectation of 52.2% in Table 2), the structure indicates magnesite.

[0346] Comparing M3, M4, and M5, there are no obvious morphological differences that can be easily identified based on SEM analysis.

[0347] Example N2: In another exemplary precursor stage procedure, elongated trihydrate magnesite (MgCO3·3H2O) template precursor material can be obtained from an aqueous Mg(HCO3)2 stock solution.

[0348] To demonstrate this acquisition on a small scale, multihydrate magnesite can be generated from an aqueous Mg(HCO3)2 stock solution using the procedure described in Example L2. This precipitation can cause CO2 process gas to be vented. In a full implementation of the general method,Conventional techniques are used to preserve the CO2 process gas released during precipitation. Similarly, in a full implementation of the general method, the separated mother liquor can be preserved.

[0349] Next, water can be heated to 35°C in a glass beaker. Once the water reaches the temperature, hydrated magnesite can be added to produce a mixture with a concentration of 0.74 mol kg⁻¹ Mg. The mixture can be magnetically stirred at 600 RPM and maintained at 35°C for 100 minutes. During this heat treatment, hydrated magnesite can dissolve and trihydrated magnesite can precipitate. The mixture can then be filtered to separate the mother liquor from the hydrated magnesite. In a full implementation of the general method, the separated mother liquor can be preserved.

[0350] The type of trihydrated magnesite template precursor material produced by this process is designated herein as N₂. An optical micrograph is shown in Figure 28. The trihydrated magnesite particles are mostly individualized, thus forming a fine powder. Instructions for Use, Pages 31 / 55, 36, CN 121536914 A

[0351] Example N3: In another exemplary precursor stage procedure, elongated trihydrate magnesite (MgCO3·3H2O) template precursor material can be obtained from an aqueous Mg(HCO3)2 stock solution.

[0352] To demonstrate this acquisition on a small scale, hydrated magnesite can be generated from an aqueous Mg(HCO3)2 stock solution using the procedure described in Example L2. This precipitation can cause CO2 process gas to be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during precipitation. Similarly, in a full implementation of the general method, the separated mother liquor can be preserved.

[0353] Next, a 10.84 mM aqueous solution of SDS (TCI Chemical) can be heated to 35°C in a glass beaker. Once the water reaches the temperature, hydrated magnesite can be added to produce a mixture with a concentration of 0.74 mol kg⁻¹ Mg. The mixture can be magnetically stirred at 600 RPM and maintained at 35°C for 100 minutes. During this heat treatment, hydrated magnesite can dissolve and trihydrated magnesite can precipitate. The mixture can then be filtered to separate the mother liquor from the hydrated magnesite. In a full implementation of the general method, the separated mother liquor can be preserved.

[0354] The type of trihydrated magnesite template precursor material produced by this process is identified herein as N3. An optical micrograph is shown in Figure 29. Comparison of the optical micrographs of N2 in Figure 30A and N3 in Figure 30B shows that N3 particles are on average longer and have a smaller diameter. This demonstrates that the presence of surfactant during precipitation can be used to control the size of the template precursor particles.

[0355] Example Li1: In another exemplary precursor stage procedure, hollow fractionated equiaxed Li2CO3 template precursor material can be obtained from an aqueous Li2CO3 stock solution.

[0356] To demonstrate this acquisition on a small scale, a representative stock solution can be prepared first. This stock solution represents the availableThe stock solution is generated during the separation phase of a general implementation of the method. For this example, a representative aqueous Li2CO3 stock solution can be prepared as follows. First, a commercial Li2CO3 product (supplied by FMC) can be slurried in water at a concentration of 0.54 mol kg⁻¹ Li. This mixture can be carbonized in a top-stirred reactor equipped with gas dispersion blades and a jet nozzle. CO2 gas can be introduced into the mixture at a rate of 9 sfch air for 175 minutes or until the solid is completely dissolved. At this point, the solution can be diluted with water to adjust the concentration to 0.27 mol kg⁻¹ Li (aq).

[0357] This representative stock solution can then be spray-dried. To demonstrate this, the stock solution can be pumped at a rate of 7 mL / min through the Buchi B-290 two-fluid nozzle of a Buchi B-191 spray dryer. With the getter air flow rate set to 18 scfm air, compressed air can be delivered to the nozzle at a flow rate of 0.6 scfm air at 88 psig. The inlet temperature can be set to 170°C, resulting in an outlet temperature of 100°C.

[0358] The particles generated by spray drying of the stock solution can be collected by a cyclone particle separator. In a full implementation of the general method, conventional techniques can be used to preserve both the CO2 process gas and the process water vapor discharged by spray drying.

[0359] The type of lithium carbonate template precursor material produced by this process is identified herein as Li1. The particles are hollow hierarchical isometric structures, as seen in the SEM micrograph of Figure 31. The hollow structures can be identified at different survival stages. The shells exhibit pinholes between the Li2CO3 subunits, indicated by red arrows in Figure 31A. In some shells, fragmentation and larger pores or cracks can be observed (indicated by blue arrows in Figure 31A). Wrinkled shells are present in the sample (indicated by yellow arrows in Figure 31A). In Figure 31B, the substructure of the loosely packed subunits of the particles can be identified. Their sizes are mainly between 200 and 700 nm, and the larger particles obviously include larger subunits. Raman peaks around 1091 cm⁻¹, 195 cm⁻¹, and 158 cm⁻¹ confirm the structure as Li₂CO₃.

[0360] V. Template Stage - Examples

[0361] This section details the small-scale production of exemplary template materials using exemplary procedures. Therefore, these procedures include partial implementations of a general method as described on pages 32 / 55 of this specification, 37 CN 121536914 A. Therefore, it should be understood that these procedures must be combined with other procedures in the full implementation of the general method. In addition, it should be understood that these procedures only demonstrate similar larger-scale procedures that will be used for industrial-scale manufacturing.

[0362] This section describes several exemplary procedures for preparing template materials. In some exemplary procedures, the template precursor material may be processed in separate and distinct template stage procedures to form the template material, and the resulting template material may then be used in separate and distinct replication stage procedures. In other cases, both the template stage and replication stage procedures may be performed in the same reactor. Some of these exemplary template stage procedures use template precursor materials previously named and described in Part V. Additionally, new template precursor materials are used.

[0363] Example N1T1: In an exemplary template stage procedure, a magnesite template precursor material may be heat-treated to form a porous MgO template material.

[0364] To demonstrate this, N1-type magnesite particles may first be generated using the procedure described in Example N1. This material represents a template precursor material that may be generated in the precursor stage of a full implementation of the general method.

[0365] Next, the template precursor material may be heat-treated. This may be performed in a TGA instrument under an Ar inert gas flow, as described in Scheme E in Part III. A sample of N1-type trihydrate magnesite particles can be heated from room temperature to a final temperature of 1,000°C at a rate of 10°C / min under Ar gas. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. The sample can be cooled back to room temperature upon reaching 1,000°C.

[0366] The type of porous MgO template material produced by this process is designated herein as N1T1. The template particles retain the elongated superstructure of the precursor particles, as shown in the SEM micrograph of Figure 32. The length of the particles ranges from 20 µm to 100+ µm. Unbroken rods can exhibit an average aspect ratio of approximately 15:1. Due to the porous substructure of the nanocrystalline MgO subunits, the ends of the particles have a brittle appearance.

[0367] Example H1T1: In another exemplary template stage procedure, a trihydrate magnesite template precursor material can be heat-treated to form a porous MgO template material.

[0368] To demonstrate this, H1-type hydrated magnesite particles can first be generated using the procedure described in Example H1. This material represents a template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0369] Next, the template precursor material can be heat-treated. This can be performed in a TGA instrument under an inert Ar gas flow, as described in Scheme E in Part III. A sample of H1-type hydrated magnesite particles can be heated from room temperature to a final temperature of 1,000°C at a rate of 10°C / min under Ar gas. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. Upon reaching 1,000°C, the sample can be cooled back to room temperature.

[0370] The porous MgO template material produced by this process is designated herein as H1T1. The template particles retain the hierarchical equiaxed rose superstructure of the precursor particles, as shown in the SEM micrograph of Figure 33. The diameter of individual plates typically ranges from 1 µm to 3 µm, with an average size between these values. The diameter of the particles typically ranges from 4 µm to 10 µm, with an average size between these values. The average plate thickness is less than 100 nm and structurally corresponds to a monolayer of laterally networked nanocrystalline subunits. The plates exhibit high thickness uniformity. The brittle appearance of the plate edges reflects the porous substructure of the nanocrystalline MgO subunits.

[0371] Example H2T1: In another exemplary template stage procedure, the hydromagnesite template precursor material can be heat-treated to form a porous MgO template material.

[0372] To illustrate this, H2-type hydromagnesite particles can first be generated using the procedure described in Example H2. This material represents a template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0373] Next, the template precursor material can be heat-treated. This can be performed in a tube furnace according to scheme B, as detailed in Part A of Section III, page 33 / 55 of the specification, CN 121536914. A sample of H2-type hydromagnesite particles can be placed in a ceramic boat and introduced into the tube furnace at room temperature. The furnace can then be heated to 1050°C at a heating rate of 20°C / min under an Ar flow of 2000 sccm. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. The sample can then be maintained at 1050°C for two hours, after which the furnace can be cooled to room temperature.

[0374] The type of porous MgO template material produced by this process is designated herein as H2T1. The template particles retain the elongated rosette superstructure of the precursor particles, as shown in the SEM micrograph of Figure 34. The lengths of the particles range from 10 µm to 100 µm, with some particles having aspect ratios exceeding 5:1. The diameters of the plates range from 0.5 µm to 1.5 µm. Compared to the H1T1 plates, the H2T1 plates have a coarser substructure, comprising more discrete subunits and larger pores between them. The subunits comprise cubic or polyhedral nanocrystals ranging in size from ~40 nm to ~100 nm with an average size between these values. The coarsening of the substructure can be attributed to the more intense heat treatment used to prepare the H2T1 template material.

[0375] Some of the subunits observed in Figure 34 are laterally bonded to their nearest neighbors without any visible interstitial pores. These bonds can form grain boundaries. Other subunits are more discrete and, while still bonded to the overall network, they...Separated from their neighbors by pores. Since the plate is typically only one subunit in thickness, the gaps between the subunits penetrate the thickness of the plate. These through-pores are an important and desirable structural feature in thin template structures because they generate more crosslinks in the coating framework formed by the template.

[0376] During the heat treatment in Example H2T1, the porous MgO template material obtained by the decomposition of the template precursor can undergo grain growth and sintering due to atomic diffusion. The distance at which diffusion can occur can be a function of temperature. Therefore, adjusting the temperature and duration of the template stage treatment can be useful for the fine engineering design of the template substructure (and correspondingly, the coating framework substructure).

[0377] During roughening, the porous substructure of the template material can also be densified. This can affect the fractional composition of the positive and negative template spaces. In extreme cases, the densification of the porous substructure can continue until the negative space (i.e., the pore structure of the template) is eliminated. Higher order porosity can be obtained through the pores between these previously discrete particles when the particles are sintered together. Workers have used this technology to produce template structures comprising a macroscopic porous network of sintered metal oxide particles. Such macroscopic monolithic template structures can be formed during the template stage and recycled using general methods.

[0378] Example H1T2: In another exemplary template stage procedure, the magnesite template precursor material can be heat-treated to form MgO template material.

[0379] To demonstrate this, H1-type magnesite particles can first be generated using the procedure described in Example H1. This material represents the template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0380] Next, the template precursor material can be heat-treated. This can be performed in the TGA according to scheme E, as detailed in Part III. A sample of H1-type magnesite particles can be heated from room temperature to a final temperature of 1200°C at a heating rate of 10°C / min under Ar gas, during which CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. The sample can be held at 1200°C for 10 minutes and then cooled.

[0381] The type of MgO template material produced by this process is designated herein as H1T2. The type of template particles produced by this procedure are shown in the SEM micrograph of Figure 35. The heat treatment not only transforms the subunits but also transforms the template superstructure, which no longer appears hierarchical. Thus, the gradual aggregation of nanoscale subunits and pores at the substructural level can ultimately lead to the superstructural transformation of the template, and individual particles can be sintered together to form larger (even macroscopic) template structures.

[0382] Example N1T2: In another exemplary template stage procedure, the magnesite template precursor material can be heat-treated. (Pages 34 / 55, CN)121536914 A Processing to form MgO template material.

[0383] To demonstrate this, N1-type trihydrate magnesite particles can first be generated using the procedure described in Example N1. This material represents a template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0384] Next, the template precursor material can be heat-treated. This can be done in a TGA according to Scheme E under Ar gas at a heating rate of 10°C / min from room temperature to a final temperature of 1200°C. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. The sample can be held at 1200°C for 10 minutes and then cooled.

[0385] The type of MgO template material produced by this process is designated herein as N1T2. Due to gradual sintering at high temperatures, the template particles have lost the porous substructure that evolved during thermal decomposition.

[0386] Example N1T3: In another exemplary template stage procedure, the magnesite template precursor material can be heat-treated to form a porous MgO template material.

[0387] To illustrate this, N1-type magnesite particles can first be generated using the procedure described in Example N1. This material represents the template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0388] Next, the template precursor material can be heat-treated. This can be performed in a tube furnace according to Scheme B, as detailed in Part III. The sample can be heated from room temperature to 460°C under an Ar gas flow of 1271 sccm. At this time, acetylene (C2H2) gas can be introduced into the system to begin carbon deposition on the template surface. During this replication stage procedure, the template, which may not have completed its thermal decomposition, can continue to decompose in a high-temperature environment, and CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. This condition can be maintained for 3 hours. The acetylene flow can be stopped, and the furnace can then be cooled to room temperature under a continuous Ar flow.

[0389] The type of porous MgO template material produced by this process is designated N1T3 herein.

[0390] Example M1T1: In another exemplary template stage procedure, the magnesite template precursor material can be heat-treated to form a porous MgO template material.

[0391] To demonstrate this, the procedure described in Example M1 can be used first to generate M1 type magnesite particles. This material represents the template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0392] Next, the template precursor material can be heat-treated. This can be performed in the TGA according to scheme E, as in Part III.The details are as follows. The sample can be heated from room temperature to 1050°C at a rate of 50°C / min under an Ar flow. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. The sample can be held at 1050°C for 1 minute and then allowed to cool.

[0393] The type of porous MgO template material produced by this process is designated herein as M1T1. The template particles retain the isometric superstructure of the precursor particles, as shown in the SEM micrograph of Figure 36. The diameter of the template particles ranges from 5 µm to 20 µm. At lower magnifications, the surface appears substantially smooth and continuous. At higher magnifications, the surface appears rougher due to the porous substructure. Due to the ~5 nm iridium particles used to coat the surface for imaging, it is difficult to clearly resolve the precise nanoscale substructure, but the regular, rugged appearance indicates the underlying MgO subunits.

[0394] Example M1T2: In another exemplary template stage procedure, the magnesite template precursor material may be heat-treated to form a porous MgO template material.

[0395] To illustrate this, the procedure described in Example M1 may be used first to generate M1 type magnesite particles. This material represents the template precursor material that can be generated in the precursor stage in a full implementation of the general method.

[0396] Next, the template precursor material may be heat-treated. This may be performed in a tube furnace according to Scheme B, as detailed in Part III. The sample may be heated from room temperature to a final temperature of 1050°C at a heating rate of 20°C / min and under an Ar flow of 2360 sccm. During this heat treatment, CO2 gas may be released. In a full implementation of the general method, conventional techniques may be used to preserve the CO2 process gas released during the decomposition of the template precursor material. The sample may be held at 1050°C for 4 hours and then cooled.

[0397] The type of MgO template material produced by this process is designated herein as M1T2. The template particles retain the isometric superstructure of the precursor particles, as shown in the SEM micrograph of Figure 37. The diameter of the template particles ranges from 5 µm to 20 µm. At low magnification, the surface appears substantially smooth and continuous. At higher magnification, the surface appears rougher due to the porous substructure. Due to the ~5 nm iridium particles required for imaging the coated surface, it is difficult to clearly resolve the precise nanoscale substructure, but the regular, rugged appearance indicates the underlying MgO subunits.

[0398] Example M1T3: In another exemplary template stage procedure, the magnesite template precursor material may be heat-treated to form a porous MgO template material.

[0399] To demonstrate this, M1-type magnesite particles can first be generated using the procedure described in Example M1. This material represents a template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0400] Next, the template precursor material can be heat-treated. This can be performed in the TGA according to Scheme E, as detailed in Part III. The sample can be heated from room temperature to a final temperature of 1200°C at a rate of 50°C / min in flowing Ar. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. The sample can then be held at 1200°C for 1 minute and then cooled.

[0401] The type of MgO template material produced by this process is designated herein as M1T3. The template particles retain the isometric superstructure of the precursor particles, as shown in the SEM micrograph of Figure 38. The diameter of the template particles in the template sample ranges from 5 µm to 20 µm. At low magnification, the surface appears substantially smooth and continuous. At higher magnification, the surface appears rougher due to the porous substructure. It is difficult to clearly distinguish the precise nanoscale substructure due to the ~5 nm iridium particles used to coat the surface, but its regular, rugged appearance indicates the underlying MgO subunits. Although the substructure cannot be easily distinguished from comparable samples treated at only 1050°C (described in Example M1T1 and shown in Figure 37), the subunits appear to begin agglomeration via sintering.

[0402] Example M1T4: In another exemplary template stage procedure, the magnesite template precursor material can be heat-treated to form a porous MgO template material.

[0403] To illustrate this, the procedure described in Example M1 can be used first to generate M1-type magnesite particles. This material represents the template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0404] Next, the template precursor material can be heat-treated. This can be performed in a tube furnace according to scheme B, as detailed in Part III. The sample can be heated from room temperature to a final temperature of 1200°C at a heating rate of 20°C / min in an Ar flow of 2000 sccm. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. The sample can be held at 1200°C for 4 hours and then allowed to cool.

[0405] The type of MgO template material produced by this process is designated herein as M1T4. The template particles retain the equiaxed superstructure of the precursor particles, as shown in the SEM micrograph of Figure 39. The diameter of the template particles ranges from 5 µm to 20 µm.Compared to comparable samples treated at 1050°C (as described in Example M1T1 and shown in Figure 37) or comparable samples treated at 1200°C for only 1 minute (as described in Example M1T2 and shown in Figure 38), the particles of the samples appear to have a rougher surface at low magnification. At higher magnification, it can be seen that the grains have grown significantly during the 1200°C isotherm. The porosity that evolved during thermal decomposition also appears to have been eliminated, which is similar to other exemplary template samples (e.g., H1T2 and N1T2) treated at 1200°C for a long time.

[0406] Example E1T1: In another exemplary template stage procedure, the esperidone salt template precursor material may be heat-treated to form a dehydrated alkaline MgSO4 template material.

[0407] To demonstrate this, esperidone salt particles may be generated first. The esperidone particles used in this exemplary procedure are generated as described in Example E1. This material represents a template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0408] Next, the template precursor material can be heat-treated. This can be performed in a forced air circulation oven. The sample can be heated from room temperature to a final temperature of 215°C. During this heat treatment, the aqueous esperidone particles can be dehydrated. The sample can be held at 215°C for 2 hours and then allowed to cool.

[0409] The resulting porous dehydrated MgSO4 sample is shown in Figure 40A as an optical micrograph. In Figure 40A, the smooth facets that can be observed in the E1 crystal (see Figure 24) have been replaced by rougher surfaces due to the evacuation of crystalline H2O.

[0410] If the dehydrated MgSO4 material is used in the high-temperature replication stage procedure, the MgSO4 can initially undergo further thermal effects and sintering, and this can be considered as part of the heat treatment for generating the template material. This procedure can be performed in a tube furnace according to scheme B, as detailed in Section III. This part of the heat treatment may include heating a sample of dehydrated MgSO4 material from room temperature to 580°C under Ar gas flowing at 1102 sccm. During this heat treatment, the MgSO4 may continue to roughen, and a portion may decompose into MgO.

[0411] The type of MgSO4 template material produced by this process is referred to herein as E1T1. Next, propylene (C3H6) gas may be introduced into the furnace to begin surface replication. The template stage and replication stage may overlap as long as the MgSO4 template material is still roughening. At some point, the pyrolysis formation of carbon-coated material on the E1T1 template material may stabilize the latter, thereby preventing further roughening and indicating the true completion of the template stage. CVD can continue for 2 hours, after which the furnace may be cooled under a continuous flow of Ar.

[0412] After the furnace has cooled to room temperature, the PC material (E1T1P16) is collected. This PC material is shown in the SEM micrograph of Figure 40B. From this, we can see that the E1T1 type template particles retain the superstructure of the Epsom salt precursor particles, although cracks are observed. Figures 40C and 40D are SEM micrographs of the P16 type carbon-coated framework formed on the E1T1 type template particles. In Figure 40D, the cellular substructure indicates the porous substructure of the template.

[0413] Example H4T1: In another exemplary template stage procedure, the Li-doped hydromagnesite precursor material can be heat-treated to form a porous MgO template material.

[0414] To illustrate this, the procedure described in Example H4 can be used first to generate H4 type hydromagnesite particles. This material represents the template precursor material that can be generated in the precursor stage in a full implementation of the general method.

[0415] Next, the template precursor material can be heat-treated. This can be performed in a tube furnace under an Ar flow of 2000 sccm according to scheme B, as detailed in Part III. The sample can be heated from room temperature to a temperature of 1050°C at a heating rate of 20°C / min. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. The sample can be held at 1050°C for 20 minutes, after which the furnace can be cooled.

[0416] The type of porous MgO template material produced by this process is designated herein as H4T1. The template particles retain the plate-like superstructure of the precursor particles, as shown in the SEM micrograph of Figure 41B. The diameter of the individual plates ranges from approximately submicrometers to several micrometers, with an average size of about 1 μm. The average plate thickness ranges from approximately 80 nm to 100 nm and structurally corresponds to a monolayer of transversely networked subunits with an average diameter between 80 nm and 100 nm. The plates exhibit high thickness uniformity between particles. The subunits are discrete, with numerous pores separating the individual nanocrystals. Specification 37 / 55 pages 42 CN 121536914 A

[0417] At diameters of 80 nm to 100 nm, the subunits of the template particles in H4T1 are considerably larger than the 50 nm to 60 nm subunits shown in the SEM micrograph of Figure 41A. These subunits were obtained from undoped hydromagnesite particles that underwent the same template stage procedure. As an approximation, the 90 nm subunit is 1.5 times larger in diameter than the 60 nm subunit and more than 3 times larger in volume.

[0418] Example H5T1: In another exemplary template stage procedure, Li-doped hydromagnesite precursor material can be heat-treated to form a porous MgO template material.

[0419] To demonstrate this, H5-type hydromagnesite particles can first be generated using the procedure described in Example H5.The material represents a template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0420] Next, the template precursor material can be heat-treated. This can be performed in a tube furnace at an Ar flow of 2000 sccm according to Scheme B, as detailed in Part III. The sample can be heated from room temperature to a temperature of 1050°C at a heating rate of 20°C / min. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. The sample can be held at 1050°C for 20 minutes, after which the furnace can be cooled.

[0421] The type of porous MgO template material produced by this process is designated herein as H5T1. The template particles retain the plate-like superstructure of the precursor particles but have much larger interstitial gaps between the subunits, as shown in the SEM micrograph of Figure 41C. The plate particles range in lateral dimension from 2 µm to 8 µm and in thickness from 100 nm to 300 nm. As with other Li-doped and pure magnesite-derived MgO templates, the thickness of the plate is typically a single subunit.

[0422] Compared to H4T1 type template particles (see Figure 41B) produced by the same heat treatment, H5T1 type template particles exhibit much larger subunits with lateral diameters ranging from 150 nm to 500 nm. The subunits can be 1 to 200 nm larger in volume than the subunits of undoped pre-magnesite MgO templates (see Figure 41A). In addition, the subunits are not cubic like the undoped subunits and exhibit increased elongation along the plane of the plate. This indicates that increasing the dopant concentration enhances the roughening effect during heat treatment and also alters the geometry of the subunits. Given these results, doping with a variety of heteroatoms is expected to be useful for template engineering design.

[0423] Example H6T1: In another exemplary template stage procedure, magnesite template precursor materials can be heat-treated to form porous MgO template materials.

[0424] To demonstrate this, a commercially available magnesite product consisting primarily of plate-like particles (“light magnesium carbonate” supplied by Akrochem Corporation) can be used. This commercial product was chosen because it provides chemical and morphological properties similar to those of the magnesite template precursor; for this reason, the precursor material is described herein as H6. This material represents the template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0425] Next, the template precursor material can be heat-treated. This can be performed in a muffle furnace according to scheme D, as detailed in Part III. The sample can be placed in a ceramic boat within the muffle furnace. The sample can be heated from room temperature to 750°C at a heating rate of 5°C / min. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional...A technique is used to preserve the CO2 process gas released during the decomposition of the template precursor material. The sample can be held at 750°C for 1 hour and then cooled to room temperature.

[0426] The type of porous MgO template material produced by this process is designated herein as H6T1. The template particles retain the plate-like superstructure of the precursor particles, as shown in the SEM micrograph of Figure 42. Individual plates range from approximately 0.5 µm to 2 µm along their principal and intermediate axes, with an average diameter between these values. The average plate thickness is less than 100 nm and structurally corresponds to a monolayer of transversely networked subunits. The plates exhibit high thickness uniformity across particles.

[0427] Examples M3T1, M4T1, M5T1: In another set of exemplary template stage procedures, magnesite template precursor materials can be heat-treated to form porous MgO template materials.

[0428] To demonstrate this, M3 type magnesite particles can first be generated using the procedures described in Examples M3, M4, and M5. This material represents a template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0429] Next, the template precursor material can be heat-treated. This can be performed in a muffle furnace according to Scheme D, as detailed in Part III. The sample (M3, M4, or M5) can be placed in a ceramic boat in the muffle furnace. The sample can be heated from room temperature to 580°C at a heating rate of 5°C / min. The sample can then be maintained at up to 580°C for 1 hour. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. Next, the sample can be heated from 580°C to 1050°C at a heating rate of 5°C / min and maintained at this temperature for 3 hours. Then, it can be cooled to room temperature.

[0430] The porous MgO template materials of this type produced by this process are identified herein as M3T1, M4T1, and M5T1 (corresponding to variants based on M3, M4, and M5 template precursor materials). The M3T1, M4T1, and M5T1 template materials can be compared to demonstrate the use of dopants in enhancing the roughening effect during heat treatment. It is enlightening to observe the carbon-coated frameworks formed on these templates, as the frameworks in their native morphology are replicas of the template surface (and negative replicas of the template body). In addition, the carbon frameworks are also partially electronically transparent, thus allowing visualization of the internal substructure of the template.

[0431] PC materials made using the M3T1, M4T1, and M5T1 template materials are identified herein as M3T1P2, M4T1P19, and M5T1P20, respectively (these exemplary replication stage procedures are described in Part VI). They can then be dissolved in an aqueous H2CO3 extractant.The MgO content in these PC materials is extracted, leaving carbon-coated products P1, P19, and P20. These coated materials can be examined to determine the substructure of the template.

[0432] The P1, P19, and P20 coated materials are shown in SEM micrographs of Figures 43A, 43B, and 43C, respectively. The cell subunits of the carbon-coated framework (P20) fabricated on the template material with the highest Na doping degree (M5T1) can be 1 to 200 M larger in volume than the cell subunits of the framework (P1) fabricated on the undoped template material (M3T1). Therefore, the framework fabricated on the doped template material is significantly less compact than the framework fabricated on the undoped template.

[0433] The PC material (M5T1P20) made from M5T1 is shown in Figure 44. These particles retain the equiaxed superstructure of the precursor particles, and the particle size is typically about 1 µm to 5 µm. The substructure of the particles is very coarse, including subunits ranging from 100 nm to 400 nm.

[0434] Table 3 summarizes the N2 gas adsorption analysis of template materials M3T1, M4T1, and M5T1. After heat treatment at 1050 °C on M3T1, M4T1, and M5T1, the BET surface area of ​​the Na-doped template materials decreased by 31% (M4T1) and 57% (M5T1) compared to the undoped template material (M3T1). Moreover, after heat treatment at 1050 °C, the Na-doped samples had porosity that was 13% (M4T1) and 30% (M5T1) lower than that of the undoped template material (M3T1). Roughening and densification increased with increasing dopant levels in the template materials.

[0435] Similar to the observations made on Li-doped magnesite template precursors, this suggests that Na doping can help roughen the template and reduce the compaction of the coated framework. Other dopants may have similar effects.

[0436] Examples M3T2, M4T2, M5T2: In another set of exemplary template stage procedures, magnesite template precursor materials may be heat-treated to form porous MgO template materials.

[0437] To demonstrate this, the procedures described in Examples M3, M4, and M5 may be used first to generate M3, M4, and M5 type magnesite particles. This material represents template precursor materials that can be generated in the precursor stage of a full implementation of the general method.

[0438] Next, the template precursor material may be heat-treated. This may be performed in a muffle furnace according to Scheme D, as detailed in Part III. Samples (M3, M4, or M5) may be placed in ceramic boats within the muffle furnace. The samples may be heated from room temperature to 580°C at a heating rate of 5°C / min. The samples may then be maintained at up to 580°C for 1 hour. During this heat treatment, the specification may be described on pages 39 / 55, 44 CN 121536914 A.CO2 gas is released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. Next, the sample can be heated from 580°C to 900°C at a heating rate of 5°C / min and maintained at this temperature for 1 hour. It can then be cooled to room temperature.

[0439] The porous MgO template materials of the type produced by this process are identified herein as M3T2, M4T2 and M5T2 (corresponding to variants based on M3, M4 and M5 template precursor materials).

[0440] Table 3 summarizes the N2 gas adsorption analysis of template materials M3T2, M4T2 and M5T2. After heat treatment at 900°C, the surface area of ​​the Na-doped template materials decreased by 8% (M4T2) and 78% (M5T2) compared to the undoped material (M3T1). Their reduced surface area is consistent with the relatively rougher substructure of the Na-doped template materials relative to the undoped template materials.

[0441] For this N2 gas adsorption method, the BJH results are limited to pore size ranges of 1.70 nm and 300 nm. The porosity of the template particles can be determined using the calculated BJH cumulative pore volume. Porosity can be defined as the ratio of specific pore volume to specific template volume, and can be considered as the percentage of the total space occupied by pores relative to the entire particle. The BJH desorption cumulative pore volume can be used as a measure of the specific pore volume of the template particles. Specific MgO volume can be the specific volume of the MgO component of the porous MgO template - i.e., the reciprocal of the theoretical density of MgO. Specific template volume can be the sum of specific pore volume and specific MgO volume. The porosity of the template particles can be determined using the following formula:

[0442]

[0443]

[0444] After heat treatment at 900 °C, the doped sample has a porosity that is 1.5% (M4T2) and 58% (M5T2) lower than that of the undoped template material (M3T2). As in the previous exemplary procedures, this demonstrates that the level of dopant in the template material can be used to influence roughening and densification effects. Combined with the Li doping results already described, this demonstrates the ability to adjust the compaction of the coated framework, the size and morphology of its cell subunits, and the ratio of its intracellular space to its extracellular space.

[0445] Example M3T3: In another exemplary template stage procedure, a magnesite template precursor material may be heat-treated to form a porous MgO template material.

[0446] To demonstrate this, M3-type magnesite particles may first be generated using the procedure described in Example M3. This material represents a template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0447] Next, the template precursor material may be heat-treated. This may be performed in a muffle furnace according to scheme D, as detailed in Part III. A template precursor sample may be placed in a ceramic boat in a muffle furnace. The sample may be heated at 5°C / min.The sample is heated from room temperature to 580°C. It can then be maintained at 580°C for up to 13.5 hours. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. Next, the sample can be heated from 580°C to 1050°C at a heating rate of 5°C / min and maintained at this temperature for 1 hour. It can then be cooled to room temperature.

[0448] The type of porous MgO template material produced by this process is designated herein as M3T3.

[0449] Example N2T1: In another exemplary template stage procedure, a magnesite template precursor material can be heat-treated to form a porous MgO template material.

[0450] To illustrate this, N2 type magnesite particles can first be generated using the procedure described in Example N2. This material represents a template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0451] Next, the template precursor material can be heat-treated using steam as a roughening aid. This can be performed in a rotary tube furnace according to scheme A, as detailed in Part III. The quartz tube can be rotated at 1 rpm. Under a dry Ar flow, the N2 sample (page 40 / 55 of the specification, CN 121536914 A) can be heated in the furnace from room temperature to 450°C at a heating rate of 5°C / min. Once the furnace reaches 450°C, an Ar flow can be started through the bubbler at a flow rate of 2360 sccm. The bubbler chamber can be maintained at a slight positive pressure of 0.23 psig, and an external temperature of 100°C can be maintained to fill the top space of the bubbler with water vapor. The furnace can be maintained at 450°C for 1 hour, and then heated to 500°C at a heating rate of 5°C / min. After 1 hour at 500°C, the furnace can be heated to a final temperature of 1000°C at a heating rate of 5°C / min and held at 1000°C for 1 hour. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. At this time, the dry Ar flow can be restored, and the sample can be cooled to room temperature under the flowing dry Ar.

[0452] The type of porous MgO template material produced by this process is referred to herein as N2T1. The template particles retain the elongated superstructure of the precursor particles. This can be observed in the SEM micrograph of an exemplary PC material (N2T1P21) made by surface replication on N2T1 template particles. The N2T1P21 PC material, comprising a thin electron-transparent carbon coating phase and an N2T1 content phase, is shown in the SEM micrograph of Figure 45. Imaging the PC material is possible when the carbon coating wall is thin enough to understand the template.A good way to achieve plate substructures and superstructures is because the PC material includes content template particles coated with a conformal conductive layer.

[0453] In Figure 45, it is evident that the N2T1 template material is rougher than the N1T1 template material (see Figure 32). The size of the subunits ranges from 50 to 400 nm. This demonstrates the use of water vapor during heat treatment to enhance roughening during the template stage. Of particular note is that the porosity of the template appears to be significantly reduced, and the small slit-like morphology of the pores between the subunits is evident.

[0454] Example N2T2: In another exemplary template stage procedure, the magnesite template precursor material can be heat-treated to form a porous MgO template material.

[0455] To illustrate this, N2-type magnesite particles can first be generated using the procedure described in Example N2. This material represents the template precursor material that can be generated in the precursor stage in a full implementation of the general method.

[0456] Next, the template precursor material can be heat-treated. This can be performed in a rotary tube furnace according to scheme A, as detailed in Part III. The quartz tube can be rotated at 1 rpm. Under a dry Ar flow, the N2 sample can be heated in the furnace from room temperature to 450°C at a heating rate of 5°C / min. Once the furnace reaches 450°C, a dry Ar flow can be started through the bubbler at a flow rate of 2360 sccm. The furnace can be maintained at 450°C for 1 hour, followed by heating to 500°C at a heating rate of 5°C / min. After 1 hour at 500°C, the furnace can be heated to a final temperature of 1000°C at a heating rate of 5°C / min and maintained at 1000°C for 1 hour. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. At this point, the dry Ar flow can be resumed, and the sample can be cooled to room temperature under flowing dry Ar.

[0457] The type of porous MgO template material produced by this process is identified herein as N2T2. N2 gas adsorption can be performed on these templates using the previously described methods. As seen in Table 4, the N2T1 template material produced by steam-assisted treatment of the N2-type precursor material at 1000°C has a 59% smaller surface area compared to the N2T2 template material produced by drying the N2-type precursor material at 1000°C. This indicates that roughening can be enhanced by utilizing water vapor.

[0458] Examples N2T3, N2T4, N2T5, and N2T6: In another set of exemplary template stage procedures, the trihydrate magnesite template precursor material can be heat-treated to form a porous MgO template material.

[0459] To demonstrate this, N2-type trihydrate magnesite particles can first be generated using the procedure described in Example N2. This material represents a template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0460] Next, the template precursor material can be heat-treated in several ways outlined in Table 5. Each of these heat treatments can be performed in a tube furnace according to scheme B, as detailed in Part III. In short, all procedures involve initiating a carrier gas flow of the desired flow rate and treating the template precursor sample under the desired thermal conditions. Each heat treatment may involve a single isothermal section 41 / 55, CN 121536914 A, or multiple isothermal sections. During this heat treatment, CO2 gas may be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. The template precursor material, carrier gas, furnace scheme, heating rate, temperature setting, and isothermal duration of each section are specified in Table 5. After all sections related to the heat treatment have passed, the furnace can be cooled to room temperature under a continuous carrier gas flow.

[0461] The types of porous MgO template materials produced by these processes are identified herein as N2T3, N2T4, N2T5, and N2T6. These variations were performed to test how the heat treatment parameters affected the resulting template morphology.

[0462] During the heat treatment of the hydrated MgCO3·xH2O template precursor material, H2O and CO2 were the two main gases released. The thermogravimetric mass loss curve of the N2-type template precursor material in Ar is shown in Figure 46A. This graph shows the mass loss derivative (% / ℃) of the N2-type template precursor material at heating rates of 5 °C / min and 20 °C / min. Dehydration can be substantially completed at 300–350 °C. Decarboxylation can be substantially completed at 500–550 °C, resulting in MgO. At the faster heating rate of 20 °C / min, the mass loss curve shifts to higher temperatures. Figure 46B shows the thermogravimetric mass loss curve of the N2-type template precursor material in CO2. Compared to the mass loss in Ar, the mass loss in CO2 is delayed until higher temperatures and occurs more abruptly, as indicated by the height of the derivative curve.

[0463] The N2T3 type template material is shown in the SEM micrograph of Figure 47. This template material, generated by heating from room temperature to 640°C at a heating rate of 5°C / min under Ar flow, retains the elongated superstructure of the N2 type precursor particles. The porous substructure comprises uniformly repeating subunits and has no obvious macropores.

[0464] The N2T4 type template material is shown in the SEM micrograph of Figure 48. This template material, generated by heating from room temperature to 640°C at a heating rate of 20°C / min under Ar flow, retains the elongated superstructure of the N2 type precursor particles. In addition to the mesopores between subunits, the porous substructure also includes macropores. These macropores are internal and visible as bulbous protrusions, except where the template particles break down to allow the interior to be seen. These protrusions create a wavy surface, as indicated by the red arrows in Figure 48.These cavities are formed by the expansion of volatile CO2 gas produced during thermal decomposition. This gas acts as a blower, thereby creating macropores and plastically deforming the surrounding phase of amorphous MgCO3·xH2O.

[0465] The N2T5 type template material is shown in the SEM micrograph of Figure 49. This template material, generated by heating from room temperature to 350°C at a heating rate of 20°C / min under Ar flow, and then from 350°C to 640°C at a heating rate of 5°C / min, does not form internal macropores and associated bulbous protrusions. Instead, the template particles retain the prismatic superstructure of the elongated magnesite precursor particles. The substructure includes regular repeating subunits and mesopores. The absence of macropores indicates that the increased heating rate during decarboxylation exacerbates the accumulation of CO2 trapped in the particle bulk.

[0466] The PC particles generated in the replication stage and the coating framework generated in the separation stage inherit the internal macropores of the template particles. These internal macropores are clearly observed in the mesoporous graphene fibers of Cui. The elimination of these macropores in the template material results in the absence of macropores in the coating material, as shown in the SEM micrographs of Figures 69A and 69B. The presence of these uncontrolled macropores may be undesirable in many applications; therefore, the N2T3 and N2T5 template materials without these internal macropores represent preferred variants for obtaining porous MgO template materials from trihydrate magnesite.

[0467] The PC material (N2T6P22) prepared on the N2T6 template material is shown in the SEM micrograph of Figure 50. Imaging the PC material provides a good representation of the template morphology when the carbon coating wall is sufficiently thin, as the PC material comprises content template particles coated with a conformal conductive layer. Based on this, it can be concluded that the N2T6 template particles generated by heating from room temperature to 640°C at a heating rate of 5°C / min under a CO2 flow undergo catastrophic fracture during the template stage. These fractures are indicated by red arrows in Figure 50. This embodiment highlights the role that heating rate and gas environment can play during the template stage process.

[0468] Embodiment L2T1: In another exemplary template stage procedure, the hydrous magnesite template precursor material can be thermally treated according to the specification page 42 / 55 47 CN 121536914 A to form a porous MgO template material.

[0469] To demonstrate this, L2-type hydrous magnesite particles can first be generated using the procedure described in Embodiment L2. This material represents the template precursor material that can be generated in the precursor stage in a full implementation of the general method.

[0470] Next, the template precursor material can be heat-treated. This can be performed in a tube furnace according to Scheme B, as described in Part III. The L2-type sample can be placed in the tube furnace. Heating can be performed at 20°C / min under an Ar flow of 1220 sccm.The furnace was heated from room temperature to 640°C and maintained at 640°C for 2 hours. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. The furnace can then be cooled to room temperature under a continuous Ar flow.

[0471] The type of porous MgO template material produced by this process is designated herein as L2T1. The morphology of the L2T1 type template particles can be identified from the native morphology of the carbon-coated framework synthesized thereon. Such frameworks are shown in the SEM micrograph of Figure 51. The carbon frameworks indicate that the hydrous magnesite template precursor material undergoes recrystallization during the template stage procedure, forming hydrous magnesite and trihydrate magnesite phases before the formation of the L2T1 template material. The recrystallization of the precursor during this period can be attributed to the large amount of water released in the early stages of the heat treatment.

[0472] Example L3T1: In another exemplary template stage procedure, partially dehydrated hydrous magnesite template precursor material may be heat-treated to form porous MgO template material.

[0473] To illustrate this, the procedure described in Example L3 may be used first to generate L3-type partially dehydrated hydrous magnesite particles. This material represents the template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0474] Next, the template precursor material may be heat-treated. This may be performed in a tube furnace according to Scheme B, as described in Part III. The L3-type template precursor material may be placed in a tube furnace. The furnace may be heated from room temperature to 640°C at 20°C / min under an Ar flow of 1220 sccm and maintained at 640°C for 2 hours. During this heat treatment, CO2 gas may be released. In a full implementation of the general method, conventional techniques may be used to preserve the CO2 process gas released during the decomposition of the template precursor material. Following this heat treatment, the furnace can be cooled to room temperature under a continuous Ar flow.

[0475] The porous MgO template material produced by this process is designated herein as L3T1. The morphology of the L3T1 type template particles can be identified from the native morphology of the carbon-coated framework synthesized thereon. Figure 52 shows a SEM micrograph of a mixture of C@MgO PC particles and a carbon-coated framework made from L3T1 type template particles. These particles do not show any indication of recrystallization into hydromagnesite or trihydrate magnesite, from which we can infer that the L3 template precursor material did not undergo sufficiently extensive recrystallization during the aforementioned heat treatment. This suggests that, like the L3 template precursor material, their superstructures can be better preserved if rapid techniques such as flash drying or spray drying are used to partially or completely dehydrate hydromagnesite and other highly hydrated template precursor materials.

[0476] Example L3T2: In another exemplary template stage procedure, partially dehydrated hydrous magnesite template precursor material may be heat-treated to form porous MgO template material.

[0477] To demonstrate this, L3-type partially dehydrated hydrous magnesite particles may first be generated using the procedure described in Example L3. This material represents template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0478] Next, the template precursor material may be heat-treated. This may be performed in a tube furnace according to Scheme B, as described in Part III, with some modifications. The furnace may be heated to 540°C and maintained at said temperature when a CO2 flow of 815 sccm is applied. Prior to the heat treatment, the L3-type sample may be temporarily stored inside a quartz tube, but outside the heating zone. The template precursor material may then be rapidly introduced into the preheating zone via a propulsion mechanism and maintained at 540°C for 30 minutes. During this heat treatment, CO2 gas may be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material (pages 43 / 55, CN 121536914 A). Finally, the treated template can be removed from the heating zone and cooled to room temperature under a continuous CO2 flow.

[0479] The type of porous MgO template material produced by this process is designated L3T2 herein. The C@MgO PC material made by forming a thin carbon coating on the L3T2 type template material is shown in the SEM micrograph of Figure 53. Imaging the PC material provides a good representation of the template morphology when the carbon coating wall is thin enough, since the PC material comprises content template particles coated with a conformal conductive layer. Based on this, it can be concluded that the L3T2 type template particles did not undergo sufficiently extensive recrystallization during heat treatment to degrade their superstructure.

[0480] Example A1T1: In another exemplary template stage procedure, a spray-dried MgCO3·xH2O template precursor material comprising hollow spherical particles can be heat-treated to form a porous MgO template material.

[0481] To illustrate this, the procedure described in Example A1 can be used first to generate A1-type spray-dried MgCO3·xH2O particles. This material represents a template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0482] Next, the template precursor material can be heat-treated. This can be performed in a tube furnace at a tube rotation speed of 1 RPM according to Scheme A, as detailed in Part III. A sample can be placed in the tube furnace. When under an Ar flow of 1271 sccm, the furnace can be heated from room temperature to 100°C at a heating rate of 20°C / min and maintained at 100°C for 1 hour. Then, the furnace can be heat-treated at 20°C / min.The furnace is heated to 500°C at a heating rate of 20°C / min and maintained at 500°C for 1 hour. Finally, the furnace can be heated to 640°C at a heating rate of 20°C / min and maintained at 640°C for 3 hours. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. The furnace can then be cooled to room temperature under a continuous Ar flow.

[0483] The type of porous MgO template material produced by this process is designated herein as AlT1. The template particles retain the hollow hierarchical equiaxed superstructure of the precursor particles, and some particles include shell fragments, as shown in the SEM micrograph of Figure 54. At higher magnification, a porous MgO substructure including joint subunits can be identified. This porous substructure is clearly visible in the enlarged inset of Figure 54.

[0484] Example A3T1: In another exemplary template stage procedure, a spray-dried MgCO3·xH2O template precursor material comprising hollow spherical particles may be heat-treated to form a porous MgO template material.

[0485] To illustrate this, the procedure described in Example A3 may be used first to generate A3-type spray-dried MgCO3·xH2O particles. This material represents a template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0486] Next, the template precursor material may be heat-treated. This may be performed in a tube furnace according to scheme A, as detailed in Part III. The sample may be placed in a ceramic boat in the tube furnace. The furnace may be heated from room temperature to 200°C at a heating rate of 20°C / min and maintained at 200°C for 1 minute under a N2 flow of 2408 sccm. The furnace may then be heated to 500°C at a heating rate of 5°C / min and maintained at 500°C for 1 minute. Finally, the furnace can be heated to 900°C at a heating rate of 20°C / min and maintained at 900°C for 15 minutes. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. The furnace can then be cooled to room temperature under a continuous flow of N2.

[0487] The type of porous MgO template material produced by this process is designated herein as A3T1. The template particles retain the hollow hierarchical equiaxed superstructure of the precursor particles (as shown in Figure 55A) and their macroporous shell structure (as shown in Figure 55B). At higher SEM magnification, porous MgO substructures including joint subunits can be identified.

[0488] Example C1T1: In another exemplary template stage procedure, a spray-dried template precursor material including hollow hierarchical equiaxed particles can be heat-treated to form a porous MgO template material.

[0489] To illustrate this, the C1 type spray-dried particles can be generated first using the procedure described in Example A1. This explanationPages 44 / 55, CN 121536914 A. The material represents a template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0490] Next, the template precursor material can be heat-treated. This can be performed in a muffle furnace according to scheme D, as detailed in Part III. The C1 type template precursor material can be placed in a ceramic boat in the muffle furnace. The sample can then be heated from room temperature to 650°C at a heating rate of 5°C / min. The sample can then be maintained at 650°C for 3 hours. During this heat treatment, CO2 gas can be released. In a full implementation of the general method, conventional techniques can be used to preserve the CO2 process gas released during the decomposition of the template precursor material. The furnace can then be cooled to room temperature.

[0491] The type of porous MgO template material produced by this process is designated herein as C1T1.

[0492] Example Ca1T1: In another exemplary template stage procedure, precipitated CaCO3 template precursor material (Albafil) (described herein as Ca1) may be heat-treated to form a porous MgO template material.

[0493] The precipitated Ca1-type particles represent template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0494] Next, the template precursor material may be heat-treated. This may be performed in a tube furnace according to scheme C, as detailed in Part III. The Ca1-type sample may be placed in a ceramic boat within the tube furnace. The furnace may be heated to 1050°C at a flowing Ar at 1102 sccm. During this heat treatment, CO2 gas may be released. In a full implementation of the general method, conventional techniques may be used to preserve the CO2 process gas released during the decomposition of the template precursor material. When the furnace reaches 1050°C, methane (CH4) gas may be introduced into the system to begin forming a carbon coating on the template surface. Although this surface replication step can be considered part of the replication stage, the template material can continue to be roughened simultaneously until the carbon coating stabilizes it. The system can be maintained at 1050°C for 15 minutes with flowing CH4 and Ar, then the CH4 flow can be interrupted and the furnace can be cooled to room temperature with a continuous Ar flow.

[0495] The type of calcium oxide (CaO) template material produced by this process is designated Ca1T1 herein, and the PC material made using the Ca1T1 template material is designated Ca1T1P17 herein. Observing the P17 type carbon-coated material after extracting the Ca1T1 template material is enlightening, as the framework in its native morphology is a copy of the template surface (and a negative copy of the template body). In addition, the carbon framework is also partially electronically transparent, thus allowing visualization of the internal substructure of the template.

[0496] Figure 56 is a SEM micrograph of the P17 type carbon-coated material after extracting the Ca1T1 template material. 1050°CThe thermal decomposition can cause individual CaCO3 or CaO particles to sinter together, resulting in the formation of a template with a cluster morphology. The P17 type carbon envelope, which appears to be essentially in its original morphology except for some damage, is framed to retain this cluster geometry.

[0497] Example Li1T1: In another exemplary template stage procedure, a spray-dried lithium carbonate template precursor material comprising hollow hierarchical equiaxed particles can be heat-treated to form a porous Li2CO3 template material.

[0498] To illustrate this, the Li1 type spray-dried particles can first be generated using the procedure described in Example Li1. This material represents a template precursor material that can be generated in the precursor stage of a full implementation of the general method.

[0499] Next, the template precursor material can be heat-treated. This can be performed in a tube furnace according to scheme C, as detailed in Part III. A Li1 type sample can be placed in a ceramic boat within the tube furnace. The furnace can be heated to 580°C at a flowing Ar at 1271 sccm. At this point, C3H6 gas can be introduced into the system to begin forming a carbon coating on the template surface. While this surface replication step can be considered part of the replication phase, the template material can simultaneously continue to be roughened until the carbon coating stabilizes it. The system can be maintained at 580°C for 870 minutes with flowing C3H6 and Ar, then the C3H6 flow can be interrupted and the furnace can be cooled to room temperature with a continuous Ar flow.

[0500] The type of Li2CO3 template material produced by this process is referred to herein as Li1T1, and the PC material made using the Li1T1 template material is referred to herein as Li1T1P18. It is enlightening to observe the P18 type carbon coating material after extracting the Li1T1 template material, as the framework in its original form is a copy of the template surface (and a negative copy of the template body, pages 45 / 55, 50 CN 121536914 A). In addition, the carbon framework is also partially electronically transparent, thus allowing visualization of the internal substructure of the template.

[0501] Figure 57 is a SEM micrograph of a P18-type carbon-coated framework generated on Li1T1 template particles. The porous carbon framework largely retains its native morphology. In addition to intact unit cell subunits, extracellular pores are identifiable, indicating that the Li1T1 template particles (such as the Li1 precursor particles shown in Figure 31) comprise a porous shell. Typical liquid-phase precipitation of crystalline Li2CO3 produces non-porous, anhydrous crystals. However, the spray-drying process promotes the formation of porous template precursors, and the template can retain these pores.

[0502] VI. Replication Stage – Examples

[0503] To demonstrate the general applicability of the replication stage to a variety of template materials, several exemplary replication stage procedures are presented below. For illustrative purposes, each exemplary procedure includes CVD growth of the carbon coating on selected template particles. However, it should be noted that…Note that other procedures and alternative compositions of the coating will be apparent to those skilled in the art.

[0504] In some exemplary replication stage procedures, the template material may be formed from the template precursor material in separate and different template stages occurring in different reactors. In other cases, both the template stage procedure and the replication stage procedure may be performed in the same reactor.

[0505] Some exemplary replication stage procedures presented in this section use template materials that have been previously named and described. In addition, some exemplary template stage procedures describe new template materials, and for this reason, we describe the synthesis of these new templates in this section. Table 6 is an overview of all template materials used in the following exemplary replication stage procedures. The table includes basic parameters for manufacturing the template material, including the template precursor material, the furnace scheme for the template stage treatment, and the temperature, time, heating rate, carrier gas, and gas flow rate associated with the template stage treatment. Some treatments include multiple stages, as shown in Table 6. There are special cases where the heating rate is described as “Max” in Table 6, indicating that the furnace is not heating at a fixed rate, but rather at the furnace’s maximum power setting. Typically, the heating rate in such cases is around 40°C / min. There is another special case where the heating rate is described as “Flash” in Table 6, indicating that the template precursor material is introduced into the preheating furnace and heated extremely quickly.

[0506] Table 7 is an overview of the CVD parameters used in the exemplary replication stage procedures. Table 7 lists templates that can be used to demonstrate various replication stage procedures. Table 7 also lists furnace schemes that can be used for each replication stage procedure as previously described in Part III. Each replication stage procedure outlined in Table 7 may consist of one or more segments. Each segment has a target temperature associated with the segment. The target temperature is represented by Tn in Table 7, where n' represents the segment number. Each segment also has a target holding time at the target temperature Tn. The holding time is represented by tn in Table 7, where 'n' also represents the segment number. Each segment also has a target heating time to reach Tn. The heating time is represented by Rn in Table 7, where 'n' also represents the segment number. There is a special case where Rn is described as 'max' in Table 7. This indicates that the furnace is not heating at a fixed rate, but rather at a fixed maximum power setting. Typically, the heating rate for this type of case is around 40°C / min.

[0507] In some procedures, the replication phase immediately follows the template phase. In this case, Rn is described as 'Not Applicable' in Table 7. This indicates that the heating rate is not applicable because the replication phase initiates immediately after the template phase and continues from the same temperature used in the template phase procedure.

[0508] Table 7 lists the hydrocarbon gases (“HC type”) and flow rates (“HC flow”) used in the replication phase. Table 7 also lists CVD replication...The type and flow rate of the carrier gas used in the preparation stage are indicated by “CR type” and “CR flow” for each segment, respectively.

[0509] VII. Separation Stage - Example

[0510] The separation stage includes content extraction and coating separation. In some variations, this may occur in an integrated one-pot technology. In other variations, the separation stage may occur in two or more separate and distinct stages. For example, content extraction may involve mixing PC material in a stored process liquid and dissolving the content material inside the coating material. The coating material may then be separated from the stock solution. The stock solution may then be precipitated at atmospheric pressure. The precipitate may then be slurried into process water at a higher solids concentration. By adjusting the temperature or pressure, the solids in this concentrated mixture may then be redissolved at a higher concentration to produce a concentrated stock solution that can be used in the precursor stage.

[0511] Example VIIa: In an exemplary content extraction procedure, MgO contents can be extracted from the carbon-coated body by dissolving MgO in an extractant solution containing aqueous H2CO3.

[0512] First, approximately 12.5 g of C@MgO PC powder (containing approximately 94.75% MgO contents and 5.25% carbon-coated body (grown by CVD) by weight) can be slurried in 2.5 L of deionized water in a 3 L round-bottom flask. This water represents the preserved process water obtained from the precursor stage in a full implementation of the general method. A gas line containing 0.5 μm diffuser stones (to reduce CO2 bubble size and improve reaction efficiency) can be fed into the bottom of the flask, and the water can be stirred with a magnetic stir plate. CO2 gas can be continuously bubbled into the flask at a flow rate of 4 scfh air for 141 minutes. This CO2 represents the preserved process gas obtained from the precursor or template stage in a full implementation of the general method. The dissolution of CO2 and its reaction with process water generate an aqueous H2CO3 extractant solution. The reaction of the aqueous H2CO3 extractant solution with the content MgO results in content extraction and the generation of a new aqueous Mg(HCO3)2 reserve solution outside the carbon-coated framework.

[0513] The carbon-coated framework is separated from the coating of the aqueous Mg(HCO3)2 reserve solution by filtering the mixture. The carbon-coated framework can be rinsed and dried, and an ash content test can be performed. The carbon-coated framework may contain approximately 9.49% MgO, which represents a 99.5% removal efficiency of the MgO template material. The remaining unextracted MgO can be hermetically encapsulated within certain carbon frameworks. Higher extraction efficiencies can be obtained using higher-energy agitation techniques that can promote the cracking of the hermetically encapsulated walls.

[0514] In a full implementation of the general method, the separated aqueous Mg(HCO3)2 reserve solution can then be preserved for use in the precursor stage.

[0515] Example VIIb: In another exemplary content extraction procedure, MgO contents can be extracted from the carbon-coated body using a shuttle technique.

[0516] First, 500 mL of water can be magnetically stirred at 700 RPM in a 1 L glass beaker. This water represents the preserved process water obtained in the precursor stage of a full implementation of the general method. Next, CO2 process gas can be continuously bubbled through the process water from a dropper at 3–5 scfh air to form an aqueous H2CO3 extractant solution. This CO2 represents the preserved process gas obtained in the precursor or template stage of a full implementation of the general method. Approximately 10 g of C@MgO PC material containing elongated particles (yield 3.5%) can be gradually introduced into the extractant solution. When the C@MgO PC material is fully integrated into the solution, the mixture may be black and have a pH of 9. The beaker can be covered to maintain a CO2-rich atmosphere.

[0517] After a 24-hour reaction, the conductivity of the mixture was measured at 19.7 mS / cm at 19.6°C, the pH was 8, and it was gray. This mixture contains the coated product and a fresh aqueous Mg(HCO3)2 stock solution, which can be used in the precursor stage of a full implementation of a general method. The solids can then be separated from the stock solution using conventional techniques.

[0518] The solids from this mixture can be seen in the optical micrograph of Figure 58A and the SEM micrographs of Figures 58B and 58C. Two distinct phases are present in the sample. The first phase comprises precipitated magnesite particles, which appear as transparent, elongated crystals in Figure 58A. The second phase comprises the coated product containing a carbon-coated framework, which appears as black particles in Figure 58A. Some of the frameworks appear to be curved, indicating their flexibility when extracting rigid contents. The aqueous H2CO3 extractant solution reacts with the content MgO to form solvated Mg2+ ions and HCO3- ions, which efflux from the carbon coating. During efflux from the carbon coating, some of these ions precipitate as trihydrate magnesite. The dissolution and precipitation mechanisms occur simultaneously.

[0519] In Figure 58B, the carbon-coated framework is shown. The framework has been deformed into a non-primary morphology, demonstrating both its flexibility and rigidity in the extraction of the content MgO. Content solids are clearly present, but they are not the original MgO content. Instead, they are the residual aqueous Mg(HCO3)2 reserve solution precipitated from the interior of the framework, which has never been rinsed during the drying of the high-porosity coated framework. In other words, the framework is essentially free of content solids prior to drying. The residual reserve solution can be replaced using a liquid-liquid separation technique, in which case such a shuttle technique would result in the removal of 10% of the content solids from the framework using only 500 mL of water.g of MgO. This is approximately twice the maximum concentration of MgO that can dissolve in an aqueous H2CO3 extractant solution at atmospheric pressure.

[0520] The mechanism is likely that CO2 nanobubbles preferentially adsorb and nucleate within the hydrophobic carbon framework, thereby increasing the internal CO2 pressure within the framework and thus increasing the solubility of Mg(HCO3)2 within the framework. This creates a concentration gradient that drives solvated ions to the surrounding process water, where these ions precipitate due to the lower external CO2 pressure. Thus, shuttles reduce the amount of process water required for content extraction, as well as the required container size.

[0521] Example VIIc: Content extraction of certain metal oxides or metal carbonate compounds can be facilitated by making CO2 supercritical. In an exemplary procedure, 3.007 g of MgO (Elastomag 170 calcined at 1050°C for 1 hour) was slurried with 100.00 g of DI water, resulting in a solution conductivity of 340 μS / cm at 12.4°C. This translates to a mixture concentration of 30 g / L MgO. The mixture can be poured into a 1L pressure vessel equipped with a magnetic stirrer and heating mantle. Approximately 600 g of dry ice (solid CO2) can be added to the reactor, and the reactor is sealed. After heating for 101 minutes, the minimum conditions for supercritical CO2 are exceeded at 31.4 °C and 1,125 psi. After a total of 144 minutes, the reactor conditions reach 36.2 °C and 1200 psi. The reactor can then be actively cooled with cooling coils for 74 minutes, after which its conditions reach 18.3 °C and 675 psi. The pressure in the reactor can then be slowly released, and after 6 minutes, due to pressure release, the reactor can be equilibrated to atmospheric pressure with a temperature probe reading of -5.0 °C. Approximately 23 minutes after pressure release, a sample can be removed from the solution, which has a conductivity of 30.2 mS / cm at 4.5 °C. The solution is likely to be clear, without any signs of particles or precipitation. The template precursor material can then be crystallized using this higher concentration solution.

[0522] Example VIId: In another exemplary separation stage procedure, the content extraction of the water-soluble content template material can be obtained by simply dissolving it in water. This can be demonstrated by mixing the C@MgSO4 PC material, as shown in the SEM micrograph of Figure 59A, in process water. In a full implementation of the general method, this process water may include the preservation process water from the precursor stage. The MgSO4 content material block can be dissolved in the process water at room temperature. Content extraction can be confirmed by SEM image analysis, as shown in Figures 59B to 59C. The aqueous MgSO4 template precursor material can then be crystallized using a novel aqueous reserve solution of solvated Mg2+ and SO4 2− ions in a full implementation of the general method. The resulting solution can be alkaline, whichThe indicator is the trace decomposition of MgSO4 to MgO during the template or replication stage. The alkaline stock solution can be neutralized with a small amount of sulfuric acid (H2SO4). The coated product can then be separated by filtration or some other separation technique. In a full implementation of the general method, the stock solution can be preserved for reuse in the precursor stage.

[0523] Coating Separation

[0524] A variety of conventional techniques can be used to separate the coated product. In one technique, liquid-liquid separation can be used. This can be demonstrated by taking the mixture produced by the shuttle process described above and blending it with an immiscible solvent (such as hexane). The carbon coated framework migrates into the solvent phase, while magnesite trihydrate remains in the aqueous phase. This results in phase separation and two different slurries, as shown in Figure 60, which is a photograph taken after hexane has been blended into the mixture produced by the shuttle process described above. The black mixture contains the solvent and the carbon coated framework. The mixture below contains water and magnesite trihydrate and appears to contain mainly white magnesite trihydrate particles (although some carbon particles are mixed in and adhere to the sides of the scintillation vial).

[0525] Separation of carbon-coated frames can also be easily achieved using flotation. In some carbon-coated frames, air bubbles can be retained trapped in the extracellular pores during liquid-phase content extraction. This allows the frames to float or quasi-float during content extraction. Furthermore, subjecting the mixture of these bubble-injected frames to partial vacuum increases their buoyancy as the internal bubbles expand and expel water from the porous frames. Gradual flotation and separation of carbon-coated frames under partial vacuum is shown in Figure 61. This partial vacuum flotation is achieved without the use of solvents used in bubbling or typical foam flotation procedures.

[0526] Various variations and improvements to these separation techniques can be readily envisioned. Flotation can be improved by using solvents that would be typical in conventional foam flotation processes. Frames made on template materials with greater particle porosity retain more air and are more buoyant. Hollow spheres, in particular, can contain more trapped air and are more buoyant.

[0527] Concentrated Stock Solution

[0528] In some cases, it may be desirable to produce a concentrated stock solution after separating the coated product. Mixtures of precipitated particles (such as magnesite trihydrate precipitated during the shuttle process described above) can be redissolved under conditions allowing for higher solution concentrations. For example, an aqueous mixture of precipitated MgCO3·xH2O particles can be subjected to higher CO2 pressure to prepare a concentrated stock solution, as shown in Figure 14. This concentrated stock solution can be used in the precursor stage.

[0529] Example VIIe: In an exemplary procedure, MgO can be dissolved at a higher concentration under pressure. To demonstrate this, 15 g of MgO (Elastomag 170) template can be slurried together with 750 g of deionized water, the deionized...The sub-water can represent the preservation process water retained from the precursor stage. The water can be cooled to 5°C. The solids concentration of the mixture can be 20 g / L MgO, or approximately twice the maximum concentration of MgO soluble in an aqueous H₂CO₃ extractant solution at atmospheric pressure. The mixture can have a solution pH of approximately 10.5 and a resulting solution conductivity of 146 μS / cm. The mixture can be poured into a 1 L pressure vessel equipped with a magnetic stirrer, a high-pressure gas inlet, and a purge needle valve. The reactor can be sealed and purged by opening the high-pressure gas inlet via the purge needle valve, allowing pressurized CO₂ gas (representing the preservation CO₂ process gas recaptured in the precursor and template stages) to flow into the vessel for 2 minutes to remove any air. The purge valve can then be closed, and the reactor pressurized to 125 psi with CO₂. After 65 minutes, the conductivity measured at 16.3°C and pH 8.5 is approximately 15.6 mS / cm. This conductivity represents the equivalent concentration of Mg(HCO3)2 solution of 10 g / L dissolved MgO, which would likely require a reaction time of an order of magnitude longer at atmospheric pressure. After 290 minutes, the conductivity measured at 19.5°C and pH 7.5 is approximately 27.8 mS / cm. The conductivity and pH measurements at 290 minutes represent a Mg(HCO3)2 solubility greater than the possible approximately 10 g / L MgO at atmospheric pressure.

[0530] Increased CO2 pressure can also be used to produce concentrated stock solutions from MgCO3·xH2O solutes (such as those produced via shuttle processes). These concentrated stock solutions can be produced via a multi-step separation stage process, where the stock solution is used to precipitate solids that would redissolve under conditions allowing for higher solubility. Alternatively, coating extraction using an aqueous H2CO3 extractant solution can be performed at increased CO2 pressure, allowing for higher concentrations to be obtained without precipitation and redissolution at increased CO2 pressure.

[0531] VIII. Coated Frame Examples

[0532] In a preferred method, carbon coated frames are synthesized using MgO templates obtained from MgCO3·xH2O precursors. While roughening can reduce the fine structure of these MgO templates, typical MgO templates comprise a porous substructure of coupled nanocrystals. This produces a labyrinthine frame with intracellular and extracellular mazes. This labyrinthine structure is not specific to the carbon frames formed on these templates—that is, any frame will have the same native morphology. However, carbon frames with thin conformal coating walls can be used to study these structures because they are capable of producing fine electronically translucent replicas of the template.

[0533] As an example, Figure 62A is a SEM micrograph taken at high magnification, showing a labyrinthine carbon frame that retains its native morphology. The nanocellular subunits are quasi-discrete but coupled to each other. This is similar to the discrete structures synthesized on them.MgO subunits, whose cells are monodisperse, exhibit a consistent equiaxed morphology and size throughout the superstructure. This consistency and their filling regularity are best observed at different magnifications. Figure 62 includes SEM micrographs of the same carbon framework imaged at magnifications of 25,000x (Figure 62A), 100,000x (Figure 62B), and 250,000x (Figure 62C). Highly regular cell morphology and compaction are observed throughout the framework. The labyrinthine framework in Figure 62 was constructed on pages 49 / 55 of the specification for pre-trihydrate magnesite MgO templates, 54 CN 121536914 A.

[0534] Although the subunits are uniformly equiaxed, the superstructures of the frameworks obtained from porous MgO templates exhibit diverse geometries relative to the various precursors from which the MgO templates are derived. For example, frameworks formed on MgO templates made from magnesite template precursors impart elongated fibrous superstructures, as shown in the labyrinthine frameworks in Figures 63A to 63C. Frameworks formed on templates made from hydromagnesite or spheroidal magnesite template precursors impart thin superstructures (Figures 64A to 64B, where Figure 64B shows an enlarged view of the area indicated by the yellow square in Figure 64A) or hierarchical superstructures (Figure 64C). The labyrinthine framework shown in Figure 64C was formed on a hierarchical isometric hydromagnesite template.

[0535] In addition to these diverse architectures, the fragmentation and deformation of frameworks can originate from mechanical agitation, such as multilayer stacks of thin pseudomorphs as shown in Figure 65. Unlike stacks of monolayer materials (e.g., graphene), these thin mesoporous stacks should have high specific porosity, retain most of their surface area, and be relatively easy to exfoliate due to the limited contact area between their surfaces. Small subunit clusters can also be generated by agitation. Figure 66 is an SEM image showing a carbon framework that has been decomposed by agitation to form smaller polycrystalline clusters.

[0536] If the template precursor or some decomposition product of the template precursor is roughened during the template stage, the resulting coated framework becomes less compact. In one experiment, an MgO template was sintered at 1,000 °C for 2 hours before the replication stage. The resulting MgO template was quasi-polyhedral and typically had a diameter greater than 100 nm. Figure 67 is an SEM image of the less compact frameworks formed on these roughened templates. Roughening by sintering and coalescence of particles can degrade the inherited superstructure, resulting in particles with irregular geometries rather than particles with regular pseudocrystalline geometries.

[0537] Although these less compact, less regular frameworks are not as ordered as the more compact frameworks with more regular geometries, they can still be combined to form polycrystalline clusters with attractive functional properties as described in U.S. Patent Application 62 / 448,129. One benefit of less compact frameworks with flexible coating walls is their increased pseudoelasticity—That is, the originally rough collapsed framework, although densified due to its collapse, can still retain the ability to expand back to its original size without covalent failure.

[0538] The elasticity is shown in the optical image sequence in FIG68. In the first sequence (1-4), elongated carbon-coated frameworks are shown drying on a glass slide. These frameworks first shrink and deform as the surface tension of the reduced residual water inside them deforms the flexible coating walls, and then expand back to their original geometry as the deformed walls locally spring back to their original shape. This elastic response eventually restores the original superstructure geometry. In the first sequence, two frameworks (labeled A and B) progress from their most contracted non-original state back to their original expanded state. The outline of framework A is drawn in frame 1, and this outline is applied to frames 2-4 for comparison. Eventually, both framework A and framework B recover to their straight original superstructure. In the second sequence (I-IV), hollow spherical carbon-coated frameworks are shown drying on a glass slide. These frameworks progress from their most contracted, non-primitive state back to their primordial, extended state. The outlines of representative frameworks are drawn in picture I, and this outline is applied to pictures II-IV for comparison.

[0539] Figure 69 includes SEM micrographs of carbon-coated frameworks grown on an elongated template (N2T4) as described in Part V. The frameworks are flexible (Figure 69A) but remain relatively intact under high shear agitation. The surfaces of the porous carbon particles appear uniform and blurred due to the fine collapsed cellular substructure (Figure 69B).

[0540] Figure 70 includes SEM micrographs of carbon-coated frameworks grown on an elongated template (N2T8) as described in Part V. Templates N2T4 and N2T8 were generated from the same sample template precursor material (N2) through different treatments during the template stage. Compared to the frameworks shown in Figure 69, the carbon frameworks in Figure 70 are still flexible, but they exhibit damage and pitting after high shear agitation.

[0541] Figure 71 includes SEM micrographs of carbon-coated frameworks grown on an elongated template (N2T1) as described in Part V, page 50 / 55, CN 121536914 A. These frameworks represent the coated products generated by content extraction and coating separation of the N2T1P21 PC material. The frameworks are both flexible and highly wrinkled, as shown in Figure 71. They are compared with more compact frameworks synthesized on N2T4 in Figure 72. Figure 72A shows the more compact frameworks synthesized on N2T4, while Figure 72B shows the less compact cellular substructure of the frameworks synthesized on N2T4. Frameworks with different compaction degrees can be obtained from a common template precursor material by changing the processing procedure of the template stage.

[0542] Figure 73A is a carbon-coated framework obtained from a PC material (Ca1T1P17) prepared on a calcium oxide (CaO) template material (Ca1T1).SEM micrograph of the frame (P17). The replication stage is discussed in Part 5. Although some fragmentation is observed, the frames largely retain their original morphology after content extraction and separation. Figure 73B is an SEM micrograph of the template precursor material (Ca1) used to prepare the CaT1 template material, namely the commercial product of precipitated calcium carbonate (CaCO3) (Albafil). The average size of the precursor particles is 0.7 micrometers. These precursor particles were heated to 1050°C, thereby decomposing them into CaO and sintering individual particles.

[0543] Raman spectroscopy is commonly used to characterize carbon and is a key means of characterizing the lattice structure of the exemplary carbon-coated materials in this disclosure. Details of the equipment and techniques used for Raman analysis are described in Part III.

[0544] Three main spectral features are generally associated with sp2-bonded carbon: the “G band” (typically at or around 1585 cm⁻¹), the “2D band” (typically between 2500 and 2800 cm⁻¹), and the “D band” (typically between 1200 and 1400 cm⁻¹). The G band is associated with sp2-hybridized carbon. The D band is associated with radial breathing mode phonons in polycyclic sp2-hybridized carbon and is activated by defects. Therefore, the D band is associated with disorder, and the peak intensity ratio of the D band to the G band provides a measure of disorder. Another feature associated with disorder is the interband region located between the D band and the G band. The presence of broad peaks in this interband region increases the height of the valley between the D band and the G band, and therefore, this height can be used as a measure of disorder, where a higher valley is associated with greater disorder. For this reason, this disclosure utilizes the height of this valley to characterize disorder. The valley height is defined herein as the local minimum intensity value that appears between the wavenumber associated with the D peak and the wavenumber associated with the G peak. The intensity value at this wavenumber is then compared with the G peak intensity to characterize disorder.

[0545] To avoid resorting to subjective line-fit judgments, this disclosure analyzes the unfitted Raman spectra of the carbon-coated materials presented herein. Therefore, all references to peak positions and intensities are related to unfitted peak positions and are derived without line-fitting. Furthermore, all reported peak positions and intensities were measured at 532 nm excitation. The intensities of G, 2D, D, and valley are labeled as I1G, I2D, I1D, and I1Tr, respectively, herein.

[0546] Table 8 summarizes the Raman spectra of the carbon frameworks generated in this disclosure. Table 8 details the sample names of the template precursors, templates, and PC materials from which the frameworks were generated. The CVD growth temperatures, hydrocarbons used, and program times during the replication phase are detailed. The yields obtained from TGA analysis of PC are also detailed in Table 8. The Raman laser power used for the spectroscopic measurements is also listed in Table 8. The Raman indices presented in Table 8 include the ID / IG and ITr / IG peak ratios, as well as the G peak, D peak, and the span between the G and D peaks.Degree. These Raman indices, when combined, convey information about the degree of order and disorder in the samples.

[0547] The ID / IG peak intensity ratio of the carbon coating in PC materials ranges from 0.78 to 1.27, indicating that these samples contain disordered carbon. This disorder is confirmed by the typically high ITr / IG peak intensity ratio, which ranges from 0.17 to 0.64, as shown in Table 8. This is also confirmed by the nonplanarity of the graphene lattice, which can be discerned in high-resolution TEM micrographs (such as the enlarged inset of Figure 5B).

[0548] For crystalline sp2 hybrid carbon such as graphite, the center of the G band is expected to be around ~1580 cm⁻¹. It has also been shown that for carbon, the G band can redshift under compressive strain and blueshift under tensile strain. For sp2 carbon, the center of the D band (if present) should be around ~1350 cm⁻¹ (for a 532 nm laser). As seen in some samples, the redshift of the D band position indicates the presence of sp3 defect states in disordered sp2 carbon.

[0549] For the samples described herein, the range of the G band peak position is between 1581 and 1609 cm⁻¹, and the range of the D band peak position is between 1324 and 1358 cm⁻¹, as shown in Table 8. The span between the G and D band peak positions can be between 239 and 279 cm⁻¹, and the wider the span, the greater the strain and the more disordered the sample. Some samples have been annealed, and annealing may be desirable to reduce this disorder.

[0550] Table 1

[0551]

[0552] Table 2

[0553] Specification 52 / 55 pages 57 CN 121536914 A

[0554] Table 3

[0555]

[0556] Table 4

[0557]

[0558] Table 5

[0559]

[0560] Table 6 Specification 53 / 55 pages 58 CN 121536914 A

[0561]

[0562] Table 7

[0563]

[0564] Table 8 Specification 54 / 55 pages 59 CN 121536914 A

[0565] Specification 55 / 55 pages 60 CN 121536914 A Figure 1 Figure 2 Specification Figure 1 / 34 pages 61 CN 121536914 A Figure 3 Figure 4 Specification Figure 2 / 34 pages 62 CN 121536914 A Figure 5 Figure 6 Appendix 3 / 34 of the instruction manual Page 63 CN 121536914 A Figure 7 Figure 8 Appendix 4 / 34 of the instruction manual Page 64 CN 121536914 A Figure 9 Figure 10 Appendix 5 / 34 of the instruction manual Page 65 CN121536914 A Figure 11 Figure 12 Appendix to the Instruction Manual Page 6 / 34 66 CN 121536914 A Figure 13 Figure 14 Appendix to the Instruction Manual Page 7 / 34 67 CN 121536914 A Figure 15 Figure 16 Appendix to the Instruction Manual Page 8 / 34 68 CN 121536914 A Figure 17 Figure 18 Appendix to the Instruction Manual Page 9 / 34 69 CN 121536914 A Figure 19 Appendix to the Instruction Manual Page 10 / 34 70 CN 121536914 A Figure 20 Figure 21 Appendix to the Instruction Manual Page 11 / 34 71 CN 121536914 A Figure 22 Figure 23 Appendix to the Instruction Manual Page 12 / 34 72 CN 121536914 A Figure 24 Figure 25 Appendix to the Instruction Manual Page 13 / 34 73 CN 121536914 A Figure 26 Figure 27 Figure 28 Instruction Manual Figures 14 / 34, Page 74, CN 121536914 A, Figures 29, 30, and 31; Instruction Manual Figures 15 / 34, Page 75, CN 121536914 A, Figures 32 and 33; Instruction Manual Figures 16 / 34, Page 76, CN 121536914 A, Figures 34 and 35; Instruction Manual Figures 17 / 34, Page 77, CN 121536914 A, Figures 36 and 37; Instruction Manual Figures 18 / 34, Page 78, CN 121536914 A, Figures 38 and 39; Instruction Manual Figures 19 / 34, Page 79, CN 121536914 A, Figures 40 and 41; Instruction Manual Figures 20 / 34, Page 80, CN 121536914 A, Figures 42, 43, and 44; Instruction Manual Figures 21 / 34, Page 81, CN 121536914 A, Figures 45 and 46; Instruction Manual Figures 22 / 34 Page 82 CN 121536914 A Figure 47 Figure 48 Instruction Manual Drawings 23 / 34 Page 83 CN 121536914 A Figure 49 Figure 50 Instruction Manual Drawings 24 / 34 Page 84 CN 121536914 A Figure 51 Figure 52 Figure 53 Instruction Manual Drawings 25 / 34 Page 85 CN 121536914 A Figure 54 Figure 55 Instruction Manual Drawings 26 / 34 Page 86 CN 121536914 A Figure 56 Figure 57 Instruction Manual Drawings 27 / 34 Page 87 CN 121536914 A Figure 58 Figure 59 DescriptionFigures 28 / 34, page 88, CN 121536914 A, Figures 60 and 61; Figures 29 / 34, page 89, CN 121536914 A, Figures 62, 63, and 64; Figures 30 / 34, page 90, CN 121536914 A, Figures 65 and 66; Figures 31 / 34, page 91, CN 121536914 A, Figures 67 and 68; Figures 32 / 34, page 92, CN 121536914 A, Figures 69, 70, and 71; Figures 33 / 34, page 93, CN 121536914 A, Figures 72 and 73; Figures 34 / 34, page 94, CN 121536914 A. Abstract: The name of the invention is the scalable synthesis of coated carbon. The present disclosure relates to the scalable synthesis of carbonaceous coated materials, including carbonaceous coated frameworks. on recyclable templates and using recyclable process liquids. The present disclosure also demonstrates a novel envelope architecture. In particular, a coating framework including a synthetic anthracite network is shown. Using these methods, three-dimensional architectures constructed from graphene carbon can be produced in a scalable manner.

Claims

1. A method for generating a carbonaceous coated framework by: I. Obtaining precursor materials and mother liquor from the first stock solution by solvent-free precipitation; as well as II. Heating the precursor material to form a template material; as well as III. Adsorbing the carbonaceous coating material onto the template material; as well as IV. React the template material with an extractant solution including the mother liquor to form a carbonaceous coated framework and a second reserve solution, the second reserve solution and the first reserve solution sharing a similar chemical composition.

2. A method for generating a carbonaceous coated framework by: I. Obtaining precursor materials and mother liquor from the first stock solution by solvent-free precipitation; as well as II. Heating the precursor material to form a template material; as well as III. Adsorbing the carbonaceous coating material onto the template material; as well as IV. React the template material with an extractant solution including the mother liquor to form a carbonaceous coated framework and a reconstructed reserve solution, wherein the first reserve solution and the reconstructed reserve solution share a similar chemical composition; as well as V. Another coating framework is formed by repeating cycles I through IV, wherein the reconstructed reserve solution formed in each cycle includes the first reserve solution used in subsequent cycles.

3. A method for generating a carbonaceous coated framework by: I. Formed by solvent-free precipitation from a first stock solution containing ions dissolved in the process liquid: Precursor materials, said precursor materials comprising solid precipitates; and Mother liquor, the mother liquor comprising the unprecipitated portion of the ions dissolved in the process liquid; as well as II. Processing the precursor material to form a template material, the processing comprising at least one of the following: decomposing a portion of the precursor material, altering the morphology of the precursor material, activating the precursor material, and heating the precursor material; as well as III. Adsorbing carbonaceous coating material onto the template material to form a coated composite material; as well as IV. Expose the coated composite material to an extractant solution, the extractant solution comprising an extractant and the mother liquor; as well as V. Extracting the template material from the coated composite material to form: A second reserve solution having a composition similar to that of the first reserve solution; as well as A carbonaceous coated framework, the carbonaceous coated framework comprising a carbonaceous coating wall and pores, the pores being formed by the extraction of the template material; as well as VI. Separate the carbonaceous coated framework from the second reserve solution.

4. A method for generating a hollow carbonaceous coated framework in the following manner: I. Atomize and evaporate a first reserve solution containing ions dissolved in the process liquid to form: Precursor materials, said precursor materials comprising hollow precursor particles; as well as Steam, including evaporated process liquid; as well as II. Condensing the evaporated process liquid in the vapor to form a preserved process liquid; as well as III. Processing the precursor material to form a template material, the template material comprising hollow template particles, and the processing comprising at least one of the following: decomposing a portion of the precursor material, altering the morphology of the precursor material, activating the precursor material, and heating the precursor material; as well as IV. Adsorbing a carbonaceous coating material onto the template material to form a coated composite material, the coated composite material comprising hollow coated composite particles; as well as V. An extractant solution is formed by adding the extractant to the preserved process liquid; as well as VI. Expose the coated composite material to the extractant solution; as well as VII. Extracting the template material from the coated composite material to form: A second reserve solution having a composition similar to that of the first reserve solution; as well as A hollow carbonaceous coated framework, the hollow coated framework comprising a carbonaceous coated wall and pores formed by the extraction of the template material; as well as VIII. Separate the hollow carbonaceous coated framework from the second reserve solution.

5. A method for generating a carbonaceous coated framework by: I. Formed by solvent-free precipitation from a first stock solution comprising aqueous magnesium bicarbonate: Precursor materials, said precursor materials comprising magnesium carbonate precipitate; and The mother liquor comprises the unprecipitated portion of the first reserve solution having a reduced concentration of magnesium bicarbonate; as well as Steam, the steam comprising at least one of a first portion of process water vapor and a first portion of CO2 process gas; as well as II. Process the precursor material to form: Template material, wherein the template material comprises porous magnesium oxide particles; as well as Steam, said steam including at least one of the second part process water steam and the second part CO2 process gas; as well as III. Adsorbing carbonaceous coating material onto the template material to form a coated composite material; as well as IV. Optionally, at least one of the process water vapor in the first and second portions is condensed to form stored process water; as well as V. Exposing the coated composite material to an extractant solution comprising aqueous H2CO3, the extractant solution optionally comprising at least one of the first and second portions of CO2 process gas and the preserved process water; VI. Extract the template material from the coated composite material to form: A second reserve solution, comprising magnesium bicarbonate and having a composition similar to the first reserve solution; and A carbonaceous coated framework, the carbonaceous coated framework comprising a carbonaceous coating wall and pores formed by the extraction of the template material; as well as VII. Separate the carbonaceous coated framework from the second reserve solution.

6. A method for generating a hollow carbonaceous coated framework in the following manner: I. Atomize and evaporate a first stock solution, including magnesium bicarbonate dissolved in process water, to form: Precursor materials, said precursor materials comprising hollow magnesium carbonate precursor particles; as well as Steam, comprising a first portion of process water steam and a first portion of CO2 process gas; and II. Condense the first portion of process water vapor to form the first portion of preserved process water; as well as III. Process the precursor material to form: Template material, wherein the template material comprises hollow magnesium oxide particles; as well as Steam, said steam including at least one of the second part process water steam and the second part CO2 process gas; as well as IV. Optionally, the process water vapor in the second portion is condensed to form the process water stored in the second portion; as well as V. Adsorbing a carbonaceous coating material onto the template material to form a coated composite material, the coated composite material comprising hollow coated composite particles; as well as VI. Dissolve at least one of the CO2 process gases in the first and second portions in at least one of the process water stored in the first and second portions to form an extractant solution comprising H2CO3; as well as VII. Expose the coated composite material to the extractant solution; as well as VIII. Extracting the template material from the coated composite material to form: A second reserve solution comprising magnesium bicarbonate and having a composition similar to that of the first reserve solution; as well as A hollow carbonaceous coated framework, the hollow carbonaceous coated framework comprising a carbonaceous coated wall and pores formed by the extraction of the template material; as well as IX. Separate the hollow carbonaceous coated framework from the second reserve solution.

7. A method for generating a carbonaceous coated framework by: I. Formed by solvent-free precipitation from a first stock solution comprising aqueous magnesium bicarbonate: Precursor materials, said precursor materials comprising magnesium carbonate precipitate; and The mother liquor comprises the unprecipitated portion of the first reserve solution having a reduced concentration of magnesium bicarbonate; as well as Steam, the steam comprising at least one of a first portion of process water vapor and a first portion of CO2 process gas; as well as II. Process the precursor material to form: Template material, wherein the template material comprises porous dehydrated magnesium carbonate particles; as well as Steam, said steam including at least one of the second part process water steam and the second part CO2 process gas; as well as III. Adsorbing carbonaceous coating material onto the template material to form a first coated composite material; as well as IV. Optionally, at least one of the process water vapor in the first and second portions is condensed to form stored process water; as well as V. Decompose the template material to form a second coated composite material, the second coated composite material comprising the carbonaceous coating material and magnesium oxide; VI. Exposing the second coated composite material to an extractant solution comprising aqueous H2CO3, said extractant solution optionally comprising at least one of the first and second portions of CO2 process gas and the preserved process water; as well as VII. Extract the content magnesium oxide from the coated composite material to form: A second reserve solution, comprising magnesium bicarbonate and having a composition similar to the first reserve solution; and A carbonaceous coated framework, the hollow carbonaceous coated framework comprising a carbonaceous coating wall and pores formed through the extraction of the template material; as well as VIII. Separate the carbonaceous coated framework from the second reserve solution.

8. The method according to any one of claims 1 to 7, further comprising: At least one of the coated composite material and the carbonaceous coated framework is annealed.

9. The method according to any one of claims 1 to 8, wherein the carbonaceous coating material comprises a synthetic anthracite network.

10. The method according to any one of claims 1 to 8, wherein the carbonaceous coating material comprises a graphene monolayer.

11. The method according to any one of claims 1 to 10, wherein the carbonaceous coating material comprises a maximum thickness of 100 nm.

12. The method according to any one of claims 1 to 11, wherein the template material comprises a porous network of joint subunits.

13. The method according to any one of claims 1 to 12, wherein the template material comprises between 10 μm 2 / g and 100 m 2 Brunauer–Emmett–Teller (BET) surface area between / g.

14. The method according to any one of claims 1 to 12, wherein the template material comprises between 100 m 2 / g and 400 m 2 BET surface area between / g.

15. The method according to any one of claims 1 to 14, wherein the template material comprises at least one of group I metal cations, group II metal cations, oxyanions, and oxyanions.

16. The method according to any one of claims 1 to 15, wherein the extractant solution is formed by dissolving CO2 in water under a CO2 pressure greater than 1 atm.

17. The method according to any one of claims 1 to 16, wherein the precursor material comprises a carbonate of a Group I or Group II metal.

18. The method according to any one of claims 1 to 17, wherein the precursor material comprises a magnesium salt of a weak acid.

19. The method according to any one of claims 17 to 18, wherein the precursor material comprises hydrated magnesium carbonate.

20. The method according to any one of claims 1 to 19, wherein the precursor material comprises a graded equiaxed morphology.

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