Composites containing non-impregnated cellular carbon nanostructures

Abstract

To provide a novel class of composite materials incorporating unimpregnated cellular carbons with templated cavity morphology.SOLUTION: There is provided a composite comprising a binder and nanostructured carbons, wherein the binder comprises one or more of polymeric, metallic, or ceramic, or pyrolytic carbon binder and the nanostructured carbon has a cellular structure. The cellular structure comprises one or more cell walls having a structure formed by a template and one or more cavities. Each cavity is substantially enclosed by the one or more cell walls and substantially unimpregnated by a liquid or solid.SELECTED DRAWING: Figure 2C

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. Provisional Patent Application No. 62 / 471,711, filed March 15, 2017. This provisional application claims priority to US Provisional Application No. 2004 / 0109994, filed on May 1, 2004, which is hereby incorporated by reference in its entirety for all purposes. This application is incorporated herein by reference in its entirety. Provisional Patent Application No. 62 / 448,129 (now PCT / US18 / 14549), and Regarding U.S. Provisional Patent Application No. 62 / 294,751 (now PCT / US17 / 17537) Both of these provisional applications are incorporated herein by reference in their entirety for all purposes. It is incorporated for this purpose. [Background technology]

[0002] Nanocomposites have been proposed in which nanostructured carbon is arranged within larger heterogeneous structures. In particular, various types of sp 2 -Hybrid carbon nanoparticles are used in structures, batteries and displays Due to its potential to improve the structural and electronic properties of composites used in spray technology, "Zero-dimensional" carbon nanostructures, such as Buckminster Fuller Ferroelectric and carbon quantum dots have been the subject of intense research activity for the past few decades. So-called "one-dimensional" carbon nanostructures, such as carbon nanotubes and carbon nanotubes, Fibers have been studied more recently, and "two-dimensional" carbon nanostructures, e.g. For example, graphene nanoplatelets. Studies of (D or 2D) carbon reveal its extraordinary strength-to-weight ratio and electronic properties. By distributing this carbon in other materials, composites with desirable properties can be created. However, for particles with low-dimensional geometries, many fields This presents challenges compared to particles with three-dimensional geometries. Particles with such a property tend to aggregate or entangle and cannot be uniformly dispersed throughout the matrix. can be difficult.

[0003] On the other hand, in carbons with porous structures, the favorable attributes of low-dimensional particles are It has the potential to be incorporated without the problems associated with the geometry of the child. In particular, the estimated modeling of 3D objects constructed from these materials shows an outstanding compressive strength-to-weight ratio. One of them is a hollow 3D sphere formed by 2D graphene as a spherical surface. Examples include self-assembled graphene aerogels. D-graphene assemblies are difficult to synthesize and have controllable pore morphology. Furthermore, such assemblies, due to their porosity and electrical conductivity, It may be particularly well suited for electrochemical applications. Summary of the Invention [Problem to be solved by the invention]

[0004] Described herein are non-impregnated ceramics having templated cavity morphology. Some embodiments are polymer-based, A binder containing one or more of the following binders: metal-based, ceramic-based, or pyrolytic carbon-based. The composite material includes a binder and nanostructured carbon, the nanostructured carbon being attached to a template. One or more cell walls and one or more cavities having a structure formed therewith Each cavity may be substantially surrounded by one or more cell walls and may contain a liquid or The majority of the one or more walls may be 100 The majority of the cavities may have diameters of 10 nm or more and thicknesses of 10 nm or less. and may have an aspect ratio substantially less than 10:1. The majority of the composites may have a diameter of 1 mm or less. It can be formed by directed chemical vapor deposition.

[0005] In some embodiments, the polymeric binder may be a thermoplastic. The polymeric materials are: Poly(methyl methacrylate), Acrylonitrile butadiene styrene , polyamide, polylactic acid, polybenzimidazole, polycarbonate, polyethers sulfone, polyoxymethylene, polyether ether ketone, polyetherimide, poly Ethylene, polyphenylene oxide, polyphenylene sulfonate Fido, polypropylene, polystyrene, polyvinyl chloride, polytetrafluoroethylene or copolymers thereof. The binder may comprise a thermosetting polymer. Bottom: Polyester, polyurethane, polyurea, phenol-formaldehyde, urea-formaldehyde Formaldehyde, epoxy, benzoxazine, polyimide, bismaleimide, polythiophene at least one of urate, polysiloxane, vinyl ester, or blends thereof It may include types.

[0006] In some embodiments, the nanostructured carbon comprises 1%, 10%, 50% or more of the composite by weight. The nanostructured carbon may be non-covalently bonded to the binder. The carbon can be electrically conductive.

[0007] In some embodiments, the composite may be a powder. The composite may have a density greater than that of the binder. The composite may have a density of 0.80 g / cm 3 Density below The composite may have a density of 0.50 g / cm 3 and has a density of obtain.

[0008] In some embodiments, the composite has a compressive strength at 10% strain that is 140% greater than the compressive strength of the binder. The composite may have an ultra-high compressive strength at 10% strain. It has a compressive strength at 10% strain that is more than 600% greater than the compressive strength at 0% strain. The composite has an ultimate tensile strength that is more than 140% greater than the ultimate tensile strength of the binder. The composite may have a compressive modulus greater than 640% of the compressive modulus of the binder. The composite may have a specific strength at 10% strain of the binder that is 400% greater than the specific strength at 10% strain of the binder. The composite may have a specific strength at 10% strain greater than 10% of the binder. and a specific strength at 10% strain that is more than 790% greater than the specific strength at 10% strain. The composite has a specific maximum compressive strength that is more than 400% greater than the specific maximum compressive strength of the binder. The composite may have a specific maximum compressive strength that is greater than 790% of the specific maximum compressive strength of the binder. The composite may have a high compressive strength, and the specific modulus of the composite may be more than 470% greater than the specific modulus of the binder. The composite may have a specific modulus that is 810 times greater than the specific modulus of the binder. % or more.

[0009] Some embodiments include polymer-based, metal-based, ceramic-based, or pyrolytic carbon-based biomass. and a film or coating comprising nanostructured carbon and a binder comprising one or more of the binders. The nanostructured carbon includes one or more templated structures. The cavity may comprise a wall and one or more cavities, each cavity comprising one or more of the It may be substantially surrounded by a wall and not substantially impregnated with liquid or solid matter. The majority of the one or more cell walls may have a thickness of 100 nm or less. The majority of the voids have diameters greater than 10 nm and aspect ratios substantially smaller than 10:1. The majority of the cellular structures may have a diameter of 1 mm or less. obtain.

[0010] Still further embodiments are polymer-based, metal-based or ceramic-based or pyrolytic carbon-based. and a nanostructured carbon having a structure. The nanostructured carbon includes a molded casting comprising a template-formed structure. Each cavity may have one or more walls and one or more cavities. The body is substantially surrounded by the one or more walls and is substantially impregnated with a liquid or solid. The majority of the one or more cell walls may have a thickness of 100 nm or less. The majority of the cavities may be 10 nm or larger in diameter and substantially smaller than 10:1. The majority of the cellular structures may have a diameter of 1 mm or less. It may have the following structure:

[0011] The related PCT / US18 / 145 application describes the use of template carbon morphology to produce two 3D carbon nanotubes with both 2D and 3D features, with controllable spacing between the features. Nanocomposite networks have been described. Such structures include those that have been synthesized using template-directed synthesis. The term "cell" refers to a carbon material having a cell and a cavity formed therein. " is used to denote a templated carbon structure containing an internal cavity. The cell is , inclusions in carbon powders (e.g., S1-S3) or composite (e.g., C1 and C2) materials The cells are generally used to form The nanocomposite nanoparticles inherit the morphological characteristics of the template into which they are embedded. The composite is referred to herein as a "cellular carbon" nanocomposite. In PCT / US18 / 145, cells are provided with: It is "impregnated" or filled with liquid or solid materials that modify the properties of the composite. The impregnation of the cells with solid or liquid material can be intentional, or it can occur accidentally. For example, the cells may be filled by infiltration of liquid into pores or crevices in the cell walls. This may result in an impregnated state.

[0012] "Unimpregnated" cellular composites, or those filled with gas rather than solid or liquid materials Composites with thin or highly voided cells offer even more favorable strength-to-weight ratios. Specifically, in non-impregnated cellular composites, the cellular carbon frame The structural rigidity of the structure can be provided while the gas-filled or voided cells The construction reduces weight and density.

[0013] The composite materials described herein may be made of a material having a range of carbon weight fractions (e.g., from less than 1% to more than 50%). The cells may be dispersed throughout the matrix, or The composite material may also be in the form of a powder, granules, or the like, densely packed throughout the matrix. The composite may be in the form of a powder, pellets, or liquid dispersion. The composite may be molded, coated, or printed. It is possible.

[0014] In one embodiment, the present invention provides a method for manufacturing a semiconductor device having improved physical, mechanical, electrical and thermal properties. The present invention provides a new class of composite materials from which components can be fabricated using the method.

[0015] In addition to the reduced density, non-impregnated cellular carbon has a higher thermal conductivity than impregnated cellular carbon, especially in nanocomposites. For example, non-impregnated cellular carbons can be used in nanocomposites with impregnated cellular structures. may have greater freedom to bend and absorb kinetic energy than composites Also, the unimpregnated carbon may exhibit a low electron scattering profile and low electrical resistivity, resulting in electrical nanostructures. Highly porous, non-impregnated cellular carbons may offer advantages for composite applications, where thermal insulation is desired. The thermal conductivity can be engineered to be low in desired applications. Further advantages and applications will become readily apparent from the detailed description.

[0016] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate examples. and, together with the general description given above and the detailed description given below, the systems and methods of the present disclosure This helps explain the features of [Brief explanation of the drawings]

[0017] [Figure 1A] FIG. 1A is a scanning electron microscopy (SEM) micrograph of the nesquehonite template precursor. [Figure 1B] Figure 1B is an SEM micrograph of the MgO template obtained by calcination of nesquehonite powder. [Figure 1C] Figure 1C is an SEM micrograph of a cellular carbon structure grown on a nesquehonite-derived MgO template. [Figure 2A] FIG. 2A is an SEM micrograph showing the cellular carbon particles of S1 carbon powder. [Figure 2B] FIG. 2B is a close-up of the S1 particle 100 shown in FIG. 1D to allow calculation of the particle's aspect ratio. [Figure 2C] FIG. 2C is a high magnification SEM micrograph showing the cellular carbon particles of S1 carbon powder. [Figure 2D] FIG. 2D is a high magnification view of a portion of FIG. 2B showing cell wall 120a. [Figure 3A] Figure 3A is an SEM micrograph of the cellular carbon particles of S2 carbon powder. [Figure 3B] Figure 3B is a high magnification of a portion of Figure 3A showing unextracted MgO template material trapped within the minor phase of cellular carbon particles. Such impregnated cells appear less transparent. [Figure 4] Figure 4 shows an SEM micrograph of a single carbon cell in which the lateral pores in the cell wall are covered with a nearly transparent carbon sheet. [Figure 5] Figure 5 is an SEM micrograph of the cellular carbon particles of S3 carbon powder. [Figure 6] Figure 6 shows an SEM micrograph of the C1 composite powder before densification. [Figure 7] Figure 7 shows an SEM micrograph of the cryo-ion beam milled cross section of the compression molded C1 sample specimen. Large, irregular micron-scale voids are distributed throughout the composite. [Figure 8]Figure 8 shows an SEM micrograph of the cryo-ion beam milled cross section of the compression molded C1 sample specimen. Intracellular or intrinsic porosity corresponding to the S1 cell cavity, as well as larger intercellular voids, can be observed. [Figure 9A] Figure 9A is an SEM micrograph of the cryo-ion beam milled cross section of the compression molded C1 sample specimen. Clusters of pseudo-reticulated cells can be observed. [Figure 9B] FIG. 9B is a magnified image of one of the cells in FIG. 9A. [Figure 10] Figure 10 shows an SEM micrograph of a cryo-ion beam milled cross section of a compression molded composite composed of 10% cellular carbon and 90% CPO by weight. The image contrasts the appearance of the impregnated and unimpregnated cells. [Figure 11] Figure 11 is an SEM micrograph of cellular carbon after being subjected to uniaxial compression at 250,000 psi. Linear buckling patterns are evident. [Figure 12] FIG. 12 is an SEM micrograph of collapsed spheroidal cell carbon with a crystal lattice. [Figure 13] FIG. 13 is an SEM micrograph of a composite coating composed of spheroidal cells coated with CPO. [Figure 14] FIG. 14 is an SEM micrograph of a composite particle scraped from the dried C3 coating. DETAILED DESCRIPTION OF THE INVENTION

[0018] The examples and descriptions herein are to be considered illustrative in nature and not restrictive. Specific exemplary methods for preparing cellular carbon powder precursor materials and composites are provided herein. Although described, it should be understood that the present disclosure is not limited to such preparation methods. The material can be prepared by any of the methods disclosed herein, as well as by the methods described in PCT / US18 / 14549 and PCT / US18 / 14549. No. PCT / US17 / 17537 (both of which are incorporated by reference). It is understood that the composition may be prepared according to any of the methods.

[0019] The following disclosure describes embodiments of composites and exemplary methods for manufacturing cellular carbon powders. The cellular carbon powder was placed in a stainless steel furnace with an outer diameter ("OD") of 100 mm. Template in an MTI rotary tube furnace equipped with a gas inlet and one gas outlet. The process gases can be synthesized by gas-directed chemical vapor deposition ("CVD"). It may be manufactured by Praxair, Inc.

[0020] Although CVD is presented herein as an exemplary growth method, CVD may be used in the manner described. It will be appreciated that this is only one example of many ways in which templated carbons can be made. Other exemplary methods that can be used include, for example, grafting the template onto an organic or polymeric After coating with a polymer precursor shell, the precursor shell is either pyrolyzed or converted into graphite oxide nanoparticles. The platelets can be attached to a template in either a solid or liquid state. In this case, the use of a template determines the cellular carbon around which it is synthesized. It provides a fixed structure.

[0021] As noted above, CVD growth of cellular carbon structures such as those described herein involves the use of templates. The use of templates to form the carbon powders of various embodiments can be directed. This allows the creation of cellular carbons with different particle and cell structures. Examples include MgO powder, which is described in more detail below. The disclosure also relates to the use of such templates and other specific templates described herein. It should be understood that the present invention is not limited to the following. Other exemplary templates include, but are not limited to: However, oxides other than MgO (e.g., mixed oxides such as silicates), carbonates, halides, etc. These include nitrates, sulfates, phosphates, polymers, droplets in emulsions, and air bubbles. An exemplary method for growing cellular carbon, as well as additional template materials The fees are described in further detail in PCT / US17 / 17537.

[0022] Other differences in the morphology of cellular carbons can be attributed to specific process parameters, e.g. This can be achieved by varying the rate of pre-CVD heating. It is understood that all such applications, whether expressly described or not, are within the scope of this disclosure. I want to be done that.

[0023] In a first embodiment, the carbon powder sample is "nesquehonite" (N-MgCO Hydrated magnesium carbonate (MgCO3) in the form of rods was used as the template precursor. The CVD procedure used to create the powder according to the first embodiment Before this, nesquehonite can be "calcined" or heated to the point of decomposition, producing CO2 and H2O. A MgO template can be obtained by using a propylene / argon mixture as the CVD feed gas. It can be used as follows.

[0024] 1A-1B show the structure of the template at various stages of this embodiment. Figure 1A shows the structure of nesquehonite template precursor T1. The particles are rod-shaped and have a high "aspect ratio" of substantially greater than 10:1. It can be easily observed that the length of the The aspect ratio of the nesquehonite particles is greater than 50:1. Figure 1B shows the calcined nesquehonite. In particular, FIG. 1B shows the MgO template T2 obtained by The resulting MgO microstructure T2_FS is shown in Figure 1, which shows discrete features with a rhombic habit. Although not shown in Figure 1B, the MgO template was prepared from the nesquehonite precursor shown in Figure 1A. The rod-like grain structure with a high aspect ratio is maintained. A molecular structure is imparted to the cellular carbon structure, which is described in more detail below.

[0025] According to a first embodiment, the procedure for making S1 can be as follows: N- MgCO3 was measured by the spat of room temperature air into a magnesium bicarbonate (Mg(HMgCO3)2) solution. The N-MgCO3 can be prepared by filtering from the solution and evaporating. The dried N-MgCO3 can be subjected to ball milling and then dried for 30 After drying overnight at 0°C, it can be used as a substrate for carbon fabrication. O3 can be loaded into a quartz tube (OD 100 mm) inside the heating zone of the furnace. During the linear ramp, growth and cooling stages, the reaction may be rotated at a speed of 2.5 rpm. The temperature of the vessel was increased linearly from room temperature to the set temperature of 750°C over 30 minutes. The temperature was maintained at 500 sccm for 30 min under Ar flow to fabricate the MgO template. Next, a C3H6 flow of 165 sccm was started while the Ar flow was kept unchanged. This may continue for 30 minutes. Then the C3H6 flow may be discontinued and the reactor may continue at 200°C. The mixture is allowed to cool to room temperature under a stream of water.

[0026] During the linear ramp and hold of the temperature, MgCO3 acts as an MgO template for carbon growth. After carbon growth, the MgO template can be converted into a substrate by acid etching with hydrochloric acid (HCl). The carbon can be extracted by mixing in a brine of aqueous magnesium chloride (MgCl2). The carbon can then be filtered from the brine and washed three times with deionized water. The water can then be extracted using a solvent exchange method. This can then be replaced with acetone to give an acetone / carbon paste. The paste is dried by evaporation to obtain the dried carbon powder (S 1) can be formed.

[0027] The cells or cavities of the porous powder according to the first embodiment are formed by a secondary CVD process. The cell walls may then be sealed with a thin carbon sheet, in which case they will further grow by autocatalysis. Further details regarding this procedure and the mechanisms involved are set out in PCT / US17 / 175 Approximately 4.8 g of dry carbon powder was placed in a quartz tube (e.g., The quartz tube can then be placed in a tube having an outer diameter (OD) of 60 mm. During the linearly incremental heating (described below) and growth and cooling phases, the rotor was rotated at a speed of 10 rpm. The CVD reactor was heated from room temperature to a set temperature of 750°C in a linear ramp over 30 minutes. The temperature can then be raised to 750°C for 30 minutes under an Ar flow of 500 sccm. Next, while the Ar flow is kept constant at 500 sccm, the A C3H6 flow may be initiated. This may continue for 2 minutes. The C3H6 flow is then stopped. The reactor is then allowed to cool to room temperature under a continuous Ar flow. 1 shows the carbon powder according to the first embodiment obtained after a secondary CVD process.

[0028] In a second embodiment, the template used in CVD to form the carbon powder is Elastomag 170 "EL-170" MgO manufactured by Akrochem, Inc. The propylene / argon mixture was used as the feed gas during CVD. It can be used as such.

[0029] The procedure for making the exemplary powder (S2) according to the second embodiment is as follows: The as-received EL-170 can be used after being fired at 900°C for 15 hours. A 500 g sample of EL-170 can be loaded into a quartz tube inside the heating zone of the furnace. The tube may be rotated at a speed of 10 rpm during the linear ramp, growth and cooling steps. The reactor was heated linearly from room temperature to a set temperature of 750°C over 30 minutes, and then heated for 50 minutes. The temperature can be maintained at 750°C for 30 minutes under 0 sccm Ar flow. Then, without changing the Ar flow, While still held, a 1050 sccm C3H6 flow can be started. This is continued for 30 minutes. The C3H6 flow can then be discontinued and the reactor allowed to cool to room temperature under a continuous Ar flow. .

[0030] The MgO can then be extracted by acid etching with HCl, leaving an aqueous MgCl2 brine. A slurry containing carbon in the brine can be obtained. The carbon is then filtered from the brine and deionized. The solution can be collected as an aqueous paste by rinsing three times with ethanol and then using a solvent exchange method. The water can then be replaced with acetone to give an acetone / carbon paste. The paste can be dried by evaporation to form a dry carbon powder.

[0031] The cells or cavities of the porous S2 powder are filled with a thin carbon sheet by a secondary CVD process. The cells may be sealed with a sealant, in which case the cell walls grow further by autocatalysis. The sequence and mechanisms involved are discussed in PCT / US17 / 17537. 0.8 g of dry carbon powder can be loaded into a quartz tube inside the heating zone of the furnace. The tube is straight. During the incremental heating, growth and cooling stages, the reactor can be rotated at a speed of 10 rpm. The temperature was increased linearly from 0°C to the set temperature of 750°C over 30 minutes, and 500 sccm The temperature can be maintained for 30 minutes under a constant Ar flow. Then, a flow of 85 sccm of C3H6 can be started. This can be continued for 3 minutes. The 3H6 flow can be discontinued and the reactor allowed to cool to room temperature under a continuous Ar flow. In the specification, the exemplary carbon according to the second embodiment obtained after this secondary CVD process is Powder is shown.

[0032] In a third embodiment, the template used in CVD to form the carbon powder is The template was prepared using EL-170, the same template source material as used in the second embodiment. A propylene / argon mixture was used as the feed gas during CVD. It can be done.

[0033] The procedure for making the powder according to the third embodiment may be as follows: A sample of El-170 can be loaded into a quartz tube inside the heating zone of the furnace. The temperature was increased linearly from room temperature to the set temperature of 1050°C over 30 minutes, and the The reactor can then be maintained at that temperature for 30 minutes under an Ar flow of 75 cm. The mixture was cooled to 0°C and allowed to equilibrate at 750°C for 30 minutes. At 750°C, the Ar flow was not changed. While maintaining this temperature, a 250 sccm C3H6 flow can be initiated. This is continued for 60 minutes. The C3H6 flow can then be discontinued and the reactor allowed to cool to room temperature under a continuous Ar flow. .

[0034] The MgO can then be extracted by acid etching with HCl, leaving an aqueous MgCl2 brine. A slurry containing carbon in the brine can be obtained. The carbon is then filtered from the brine and deionized. The solution can be collected as an aqueous paste by rinsing three times with ethanol and then using a solvent exchange method. The water can then be replaced with acetone to give an acetone / carbon paste. The resulting carbon powder according to this third embodiment can be obtained by evaporation. The end is referred to as "S3" in this specification.

[0035] Comparison of the structures of S1, S2 and S3 powders For the powders prepared according to the procedures of the first, second and third embodiments, the nanostructure SEM micrographs were analyzed to understand the structure and microstructure.

[0036] FIG. 2A shows a powder sample (S1) fabricated according to the first embodiment. In this case, some individual particles, such as particle 100, are nesquehonite tenonite shown in FIG. The plate particles appear to have a rod-like structure similar to the individual particles of t100. However, However, the use of ball milling to generate S1 allows for a relatively high aspect ratio. ratio (i.e., greater than 10:1) of cleavage of nesquehonite template precursor particles. At first glance at Figure 2A, the average particle size of S1 is smaller than 10:1. It is clear that the crystal has a high aspect ratio.

[0037] FIG. 2B is a close-up of the particle 100 of FIG. 2A. FIG. 2B shows an aspect of the exemplary particle 100. The a / b ratio is close to 3:1, and the microstructure of the nesquehonite-derived MgO template is inherited. However, in Figures 2C and 2D, the fine structure (Figure 1 Cavities formed by T2_FS of nesquehonite-derived MgO as shown in B It can be observed that the aspect ratio of the exemplary particle 100 is smaller than the 3:1 ratio of the exemplary particle 100. As shown in C, the particles are made up of multi-cellular clusters of individual cells 120. The individual cells 120 are smaller than 100 nm in diameter. The image shows some transparency. Cell 120 contains part of the template or liquid filler. Therefore, cell 120 in FIG. 2C appears transparent. This means that the MgO template that formed the cell has been removed and other solids have been added to the cell. Or indicates that the liquid is not impregnated.

[0038] The gas filling the cell 120 is typically the atmosphere present when the template is extracted. The ambient gas. However, it should be understood that the gas may be any suitable gas. For example, it may be desirable to flood the cell 120 with an inert gas to retard chemical reactions. It may be desirable to fill the cell 120 with gas at atmospheric pressure. However, the cell 120 can be filled with gas at any suitable pressure. For example, the cells 120 may be heated to a temperature within an atmosphere within the environment in which the carbon or composite material containing the cells 120 is placed. It may be desirable to fill the space with gas at a pressure higher than the ambient pressure. This allows a positive pressure to be applied to the interior walls of the cells 120, increasing the stiffness and / or Alternatively, shape memory could potentially be improved.

[0039] FIG. 2D is an enlargement of the portion shown in FIG. 2C showing cell wall 120a. As can be seen, the cell wall 120a is relatively clear in the SEM due to the high contrast image. 2C / 2D show that the thickness of the cell wall 120a is only a few nanometers. Indicates that.

[0040] Figure 3A shows particles 200 of a powder (S2) prepared according to the second embodiment. 2A, cells 220 of S2 are more discrete than cells 120 of S1. 3A shows that the diameter of the cells 220 of this powder is 200 nm (e.g., the diameter of an exemplary cell is approximately 400 nm). a).

[0041] Figure 3B shows residual MgO template as a result of incomplete or incomplete acid extraction of the template. 3B is an enlargement of the indicated portion of FIG. 3A showing minority phase cellular carbon particles impregnated with a cellulose material. The impregnated cellular carbon particles appear opaque compared to the non-impregnated cells due to the presence of the template.

[0042] FIG. 4 shows a S2 pore structure in which the horizontal pores 230 in the cell walls are covered with a nearly transparent carbon sheet 240. One cell 220a of powder is shown. Carbon sheet 240 is formed by the secondary CVD process described above. The sheet 240 grows during the process, forming a "patch" that covers the lateral cavity 230. This is because the cells 220a are permeated when they come into contact with a liquid polymer or resin. Thus, the secondary CVD process can reduce the MgO (or other) The holes in the cell walls created by the extraction of the plates have the potential to seal.

[0043] Figure 5 shows particles 300 of a powder (S3) prepared according to the third embodiment. and particles prepared according to the second embodiment (S1 and S2 shown in Figures 2A and 3, respectively). Unlike S2), the particles prepared according to the third embodiment (S3) are roughly spheroidal. Since S2 and S3 were grown in EL170, this difference in morphology is due to the template provided. The difference in morphology is not due to the feedstock. Instead, the difference in morphology is due to the temperature of the pre-CVD heat treatment. This is due to the difference in temperature (1050°C for S3 and 750°C for S2). Higher temperatures in this case result in more sintering and smoother / larger grains. As shown in Figure 1, most cells 320 in S3 have "bridge" connections with one or more neighboring cells 320. The cells 320 are connected by "edges" 340, i.e., connecting carbon pieces. The wall is also shown to have unpatched holes 350 (as opposed to the patched holes shown in FIG. 4). ), this is because a secondary CVD process to patch the holes was not applied. However, such a process may be applied to, among other things, seal holes 350 in cells 320. It will be understood that it would be better to

[0044] Preparation of carbon / polymer composites In a fourth embodiment, one or more of the powders S1 and S2 are selected from the exemplary polymers "Battery Polyolefin 164-1 (100% solids) or "CPO" By combining the two composite powders, a carbon / polymer composite can be created. C1 and C2 are powders made according to the first and second embodiments, respectively (e.g., Other powder combinations are within the scope of this disclosure. Please understand that.

[0045] As used herein, the term "binder" generally refers to a carbon powder (e.g., S1 to S 3) refers to the additives used to create composite materials. "Binder" refers to carbon Alternatively, the "binder" can be chemically bonded to the powder. The binder may, for example, merely provide structure to the resulting composite. Although a CPO is shown as an exemplary binder, multiple binders may be used. It is understood that any binder suitable for providing the desired properties to the mix may be used. Other exemplary binders include other suitable polymeric materials. The binder may also include metallic materials, ceramics or other carbon materials. The carbon-based binder is functionalized with metal oxides and then sintered to form a or can be produced by the thermal decomposition of inorganic polymer precursors such as polysiloxanes. Examples of other carbon materials that can be used as underlayers include, but are not limited to, polymer-based precursors. Another example is pyrolytic carbon materials produced by the thermal decomposition of the body. thermoplastics, e.g., poly(methyl methacrylate), acrylonitrile butadiene Styrene, polyamide, polylactic acid, polybenzimidazole, polycarbonate, polyethylene Polyethersulfone, polyoxymethylene, polyetheretherketone, polyetherimide Polyethylene, polyphenylene oxide, polyphenylene sulfide, polypropylene Polystyrene, polyvinyl chloride, polytetrafluoroethylene, or copolymers thereof The binder may also include a thermosetting polymer, such as polyester. , polyurethane, polyurea, phenol-formaldehyde, urea-formaldehyde, Epoxy, benzoxazine, polyimide, bismaleimide, polycyanurate, polysilane Also included may be hydroxyl groups, vinyl esters, or blends thereof.

[0046] CPO binder was obtained from Eastman Chemical Company. The control sample (C0) may have a chlorine content of 17.5% to 23%. One example was made with only CPO binder and no cellular carbon.

[0047] To make composite powders (e.g., C1 and C2) according to this embodiment, Two toluene solutions can be first made. Each solution contains 2.4 grams of CPO powder in 40 mL of toluene. Each solution can be prepared by dissolving 1000 mg of toluene in 1000 mg of toluene. Each solution is stirred magnetically for 30 minutes. 1.6 grams of carbon S1 can then be added to one of the melts used to make C1. 1.6 grams of carbon S2 can be added to the other solution used to make C2. Each solution can be magnetically stirred for 10 minutes to wet the carbon surface. Each CPO / toluene solution was subjected to 30-minute heating using a Branson 8510DTH. The mixture may be subjected to bath sonication to disperse the carbon throughout.

[0048] The CPO in each solution can then be coated onto the surface of the dispersed carbon particles. To achieve this, each solution may be subjected to a destabilization treatment to remove the CPO from the solution phase. Destabilization was achieved by adding 120 grams of isopropyl alcohol (IPA) dropwise to each solution. This can be achieved by adding IPA, which aids in the complete removal of CPO from the solution. The CPO coated carbon particles can then be added to each solution at a rate of about 15 g / min under stirring. The resulting CPO-carbon retentate can be filtered from the solution and rinsed with IPA. The carbon nanotubes can be dried overnight at 250 K and then ground in a mortar and pestle to give cellular carbons S1 and S2, respectively. Two samples of corresponding fine composite powders C1 and C2 can be obtained.

[0049] Two exemplary composite powder samples C1 and C2 according to this embodiment were prepared in the manner described above. A control powder sample, C0, was also prepared using only the CPO binder.

[0050] Composites according to this embodiment can be compression molded as follows: The sample is screwed The material can be loaded into a cylindrical compression mold designed to be compressible by fastening the material. Once the powder is loaded, the mold can be placed in a furnace preheated to 150°C. The mold can be left in the oven for 20 minutes to allow the CPO to soften. The mold can then be removed from the oven. The sample can be compressed by tightening the mold screws with a torque wrench. The shrunk mold can be placed back into the 150°C oven for another 20 minutes, and then once again The sample specimen is then removed from the mold at room temperature. The flat surface of the sample specimen may be polished to provide a uniform surface for compression testing. obtain.

[0051] Each of the samples C0, C1 and C2 was prepared in the above manner, and then the compressive strength and compressive elasticity were measured. The test was carried out according to ISO 844 using cylindrical specimens. The crosshead speed of the testing machine was set to 1.0 mm / min.

[0052] Comparison of compression molded test pieces The dimensions of the sample specimen were evaluated using a Mitutoyo digital caliper as follows: Four separate diameter measurements (D1-D4) and three separate height measurements (H1-H4) were taken. H3) was obtained along with the specimen weight.

[0053] The results are summarized in Table 1. As shown in Table 1, the diameter and height of the specimens were The ranges were 12.0-13.0 mm and 14.0-18.0 mm. [Table 1]

[0054] The above dimensional measurements are then used in conjunction with the weight measurements to determine the density of the test specimen. Table 2 reports the average dimensions of the specimens and the associated volumes and densities. [Table 2]

[0055] Table 2 shows that the carbon-containing composites C1 and C2 were significantly better than the polymer control C0. This indicates low density. Solid carbon is denser than CPO. The results are probably explained by the high degree of porosity of the C1 and C2 samples. The density is extremely low, less than 50% of that of C0 and only just over 50% of that of Cl. Note that there was no significant difference in the porosity of C2. This suggests that the degree of porosity of C2 is relatively high. .

[0056] To investigate the results of the CPO coating treatment on carbon particles, C1 composite powder and C1 compact were used. The structure of the specimen was evaluated using SEM.

[0057] Figure 6 shows the SEM micrograph of the C1 composite powder before densification in the mold. Some features of the S1 powder, including 20, as well as intercellular voids 160, are visible in FIG. Figure 6 shows that CPO is virtually indistinguishable from carbon (S1) in SEM images. No clear CPO phase was observed in the whole sample. This suggests that the carbon was uniformly wetted by the

[0058] Figure 7 shows an SEM micrograph showing the structure of C1 after densification in a compression mold, and then By heating, the CPO melts together with the carbon cell to form a cylindrical composite specimen. More specifically, FIG. 7 shows a cryo-ion milled cross section of such a specimen.

[0059] As shown in Figure 7, the large and irregular micron-scale intercellular voids shown in Figure 6 Pores 160 remain distributed throughout the molded C1 composite specimen after densification, indicating incomplete densification. The pores 160 reflect the size and morphology of the carbon cells 120 of C1 / S1. Rather, the voids 160 are not shown in FIG. Although the porosity is not clearly shown, it appears to be large enough to be between the cells. This is due to the limited packing efficiency of the carbon nanostructures represented by C1, and the insufficient compaction due to insufficient compression. Densification, lack of sufficient free-flowing CPO to fill these spaces, and / or cooling The C1 composite specimen was removed from the mold, and the CPO / S1 (carbon) interface was formed. This could be due to potential cavitation in the

[0060] Figure 8 shows a high-magnification SEM micrograph of the cryo-ion milled cross section of the C1 pellet in Figure 7. At the magnification level shown in FIG. 8, the intracellular voids 160 shown in FIG. Alternatively, a second type of pore 180 of intrinsic porosity may be observed. This second type of void 180 is visible throughout the cross section. It is clear that the voids 180 of this type appear to correspond to the cavities of the S1 structure cell. (See, for example, cell 120 in FIGS. 2C and 8).

[0061] Figure 9A is an SEM image of another cross section of Cl. Figure 9A shows a cluster of cells 120. Within the cluster, there are gas-filled carbon cells (also referred to herein as "intrinsic voids"). Both the cell-cell gap 120 and the inter-cell gap 180 are present. The porosity of the composite also reduces the density of the composite, resulting in the density of the C1 sample being lower than that of the C0 sample (Table 2) is explained.

[0062] FIG. 9B is an inset of an enlarged portion of FIG. 9A showing one cell 120. As can be seen, the cell wall and CPO adsorption layer 121a appear to be approximately 30 nm thick, which is The average thickness of the cell walls 121 of nanostructured carbon ranges from a few nanometers to It can vary up to 100 nm.

[0063] For comparison, Figure 10 shows the composites with higher CPO content than either C1 or C2. Figure 10 shows an SEM image of a cryo-ion milled cross section of a compression molded composite. The composite material used is 90% CPO and 10% cellular carbon by weight. The force is due to the porous cell walls and high CPO content of the composite in Figure 10. In fact, in the image, there are very few unimpregnated cells 420. 8-9, the unimpregnated cell 420 in FIG. The figure shows the effect of charging the relatively dark unimpregnated cell cavity as well as the cell walls surrounding the cavity. The non-impregnated cells 420 can be identified by their lighter color. It certainly looks like it.

[0064] Conductivity Testing The sheet electrical resistivities of C0, Cl, and C2 were measured using a Keithly 2400 Source The measurement was carried out using a 4-terminal meter probe. This measurement confirmed that C0 is an insulator. C1 had an average sheet resistance of 1.58 Q / sq and 1.46 Q C2 had the lowest sheet resistance of 2.51 Q / sq. The lowest sheet resistance was 2.46 Q / sq. Each reported sheet resistance was measured using three separate This is the average of the measurements.

[0065] These results indicate that each sample is significantly better than the typical insulating polymer material, e.g., C0. This indicates that the sheet resistance of the film is relatively low, even though the carbon is coated with a polymer. This suggests that a conductive network is formed throughout the composite. Composites reinforced with carbon-type materials, such as S1 to S3, are suitable for applications where lightweight, electrically conductive materials are required. It is suggested that this may be desirable for applications such as piezoresistive sensing. Examples include "smart" composite materials that contain functionalities.

[0066] Mechanical Testing The mechanical properties of the C1 and C2 specimens were measured using a compression subpress fixture (W Yoming Test Fixtures) and 30001b (13345N) The test was carried out on a hydraulic universal testing system with a load cell. The test system was operated at a constant rate of 1 mm / min. The crosshead speed was 100 Hz. The data was transmitted to a Windows PC in real time. National Instruments USB-6341 data acquisition system Strain data was recorded using a strain gauge. The measurements were carried out using a deflectometer (Model 3540) manufactured by Ration.

[0067] Table 3 shows the measured compressive strengths of C0, C1 and C2. The compressive strengths were measured at 10% strain. The maximum compressive strength was not reached during the measurement. The compressive strength is the maximum compressive strength. Table 3 also shows the compressive modulus of elasticity for samples C0 to C2. vinegar. [Table 3]

[0068] Both the compressive strength and modulus of the porous composites C1 and C2 were significantly higher than those of the porous composites C1 and C2 without any carbon addition. This result is much higher than that of the C0 sample, which is a CPO polymer without carbon materials. It is shown that adding to CPO strengthens and reinforces the composite. [Table 4]

[0069] As shown in Table 4, which shows the specific strength and modulus of elasticity of C0, Cl, and C2, the composites The effect of carbon addition on mechanical properties is even more dramatic. It shows that the addition of S1 to CPO improves the specific strength and specific modulus by almost 800%.

[0070] The improvement in mechanical properties is probably due to the distribution of loads within the composite. For example, the improved strength comes from improved stress transfer from the polymer to the cellular carbon reinforcement phase. Due to the improved modulus, the C1 composite absorbs the compressive load through both the encapsulated voids and the inter-cell voids. It is suggested that the voids in non-rigid polymers such as CPO are effectively distributed around the Yielding before the matrix and significant consolidation (e.g., compressive strain without significant stress increase) This tends to result in a lower compressive modulus (increased compressive strength) and a correspondingly lower compressive modulus.

[0071] The C1 and C2 composite specimens also showed improvements when compared to comparable composites during compression testing. It also showed improved shape retention. Specifically, the compressive force applied by the test frame was released. The C1 and C2 specimens were relaxed to within a few percent of the pre-test dimensions shown in Table 1. The same results were obtained from the strain test. The specimens were compressed multiple times with increasing amounts of force and strain. Sample dimensions were measured after each individual compression test. The dimensional measurements were then used to calculate the stress and strain at the next iteration.

[0072] The results reported in Table 5 were as follows: Diameter of four measurements made by caliper The diameter and height measurements were averaged before each test. Based on the average diameter and height, Based on a specimen mass of 0.687 grams (consistent across all seven tests), Densification was tracked along with the applied force, resulting strain, and compressive stress. [Table 5]

[0073] The relatively low strain values ​​shown in Table 5 indicate that these composite materials are particularly susceptible to stresses applied. If it is relatively small, it is suggested that it has a certain amount of "shape memory" (i.e., the applied (When the force is less than 1600N, the shape is maintained within 10%). C1 is typically a typical rigid foam, e.g., syntactic foam, which exhibits very little elasticity. It is distinct from the check form or CPO itself.

[0074] Table 6 shows how composite C1 maintains this "shape memory" even at relatively high strains. Indicates whether to keep the [Table 6]

[0075] In particular, Table 6 shows that the specimens retained 90% of their original height even when subjected to strains of nearly 40%. This extraordinary shape shows a recovery of just over 5% (less than 5% height deformation). The shape retention is likely due to the ability of the carbon cells to deform under high stress and then return to their original dimensions. is.

[0076] The cellular carbons described herein are characterized by their defect-engineering PCT can be particularly effective at recovering shape after deformation due to its carbon lattice structure. As described in US Pat. No. 1,753,787, for example, the one used in this disclosure is a cell wall This can lead to the formation of lattice defects in the solid. Theoretical models suggest that topological defects It is predicted that the defective lattice will be more ductile than crystalline graphene. There are sp between the lattices that make up the wall 3 -Hybrid bonds are formed, preventing lattices from shearing against each other. Interlaminar shear occurs when the wall is relaxed during compression. This is a mechanism that may be in place.

[0077] Figure 11 shows the results for the cellular carbon sample S3 at a pressure of approximately 250,000 psi. The results of the axial compression test are shown. The effect of compression of the cell 320 was confirmed by linear buckling 395. The linear buckle 395 reflects the yielding caused by stress concentration during compressive deformation of the cell 320. Despite the buckling of the cell walls, the cells 320 remain roughly spherical after flattening. The shape clearly recovered, which is due to the storage and release of potential energy by elastic forces. This demonstrates the cell's ability to resist stress relaxation due to interlaminar shear. This suggests that...

[0078] Crystalline cellular carbon, in contrast, undergoes irreversible fracture after compression at 250,000 psi. Defective engineered cellular carbon powders, e.g., powders up to 250,000 psi Unlike S1-S3, which were not pelletized by the compression, the crystalline cellular carbon powder The powder was easily compressed into pellets, forming dense pellets. sp after being subjected to uniaxial compression at 000 psi 2 -SEM micrograph of hybrid crystalline cellular carbon Specifically, this image shows that the cellular carbon was subjected to the same compression process as shown in Figure 11. The carbon in Figure 12 is grown by CVD at high temperatures. (1050°C), while the cell 320 shown in Figure 11 was grown by CV at low temperature. The carbon in Figure 12 was irreversibly fractured and probably Instead, the cells flattened into a lattice with cell walls shearing against each other. After the force was removed, the cell did not retain its shape or porosity. This shows more wrinkles and folds than the cell 320 of FIG. 12, which was subjected to the same uniaxial compression. is the topological mismatch between the flat graphitic cell walls and the curved template surface. This can be attributed to

[0079] Composite materials as coating materials In yet another embodiment, the composite material of the above embodiment may be used as a coating material. To produce the composite coating of the embodiment, carbon powder was mixed with CPO and toluene (10 The S3 powder can be slurried and dispersed in a solution of toluene (1:1). The liquid composite is then applied as a thin coating onto a metal substrate. 13 and 14 show the coating application of non-impregnated cellular carbon composites. The powder used in this experiment was S3, which The resulting coating material is called "C3."

[0080] Figure 13 shows an SEM micrograph of composite coating C3. As shown in Figure 13, The covering material C3 is densely packed with syntactic structure and CPO binder 360 (mainly cluster The aligned spheroidal cells 320 are covered with a thin film (visible as a connecting layer between adjacent cells 320 within the film). 20. If the CPO binder 360 were not present, each cell 320 would contain, e.g. They would have been more distinct and spaced apart, such as cells 320 shown in FIG.

[0081] Figure 14 shows a high magnification micrograph of a composite particle scraped from the dry C3 coating shown in Figure 13. The non-impregnated cavity structure of cell 320 is observed in the ruptured cell 321. Other non-impregnated cavity structures embedded just below the surface of the CPO binder 360 It is possible to observe that CPOs are deposited on both the extrinsic and intrinsic cell surfaces, This results in the presence of lateral pores in the S3 cell walls. Nevertheless, the cells are still viable for volumetric analysis. 14 shows that the size scale of the cells 320 is 1 micron. The size scale of this cavity is clearly shown to be a fractional diameter, e.g. Traditional material "foaming" methods by blowing air bubbles into the material to create foam For example, a 100 nm diameter cellular carbon sphere , has a volume one million times smaller than a 10 μm diameter gas bubble. The cladding material can hold not just a few but many cellular carbon spheres. Therefore, thin coatings of cellular carbon composites, especially those with a syntactic structure, are preferred. This may be the case.

[0082] Availability The above-mentioned cellular carbon composite materials have several uses other than those explicitly mentioned herein. It should be understood that the present invention may have other uses. Lightweight coatings that provide electrical or thermal conductivity properties. , damage or fatigue sensors and / or damage to vehicles, e.g., aircraft or automobiles Other applications include, for example, when the composite material is used in body armor, military equipment, and the like. ballistic detection when incorporated into products or other objects that may be exposed to ballistic impact Also, for example, actuators or actuators for measuring motion or trajectory. Molded composite and / or cladding composite applications in velocimeters may also be mentioned.

[0083] Controlling the cell morphology of unimpregnated cellular carbon allows for engineering of composite properties. In manufacturing and application, typical foam forming means (e.g., glass bead templates) This allows for greater versatility than the use of The unimpregnated cells are in a syntactic configuration, e.g., packed densely enough to touch each other. Possible sizes and geometries of unimpregnated cellular carbons can be formed. The structures are numerous and varied, ranging from spheroids to complex multicellular sheets and Small diameter particles with nanostructured carbon walls are used in hollow glass and Non-impregnated cellular carbon can provide lower density and superior mechanical properties compared to non-impregnated cellular carbon. To create highly electrically conductive syntactic architectures for applications that benefit from multifunctionality, Such composites may also be useful for electromagnetic shielding, resistive heating, and piezoresistive sensing. Non-impregnated cellular carbon nanostructures can also be used to improve resistance to compression. Internal pressure may be applied for this purpose.

[0084] The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the embodiments of the present invention. Various modifications of these examples will be apparent to those skilled in the art. It will be readily apparent that the general principles set forth herein are within the spirit and scope of the description. The present disclosure may be applied to several embodiments without departing from the spirit and scope of the present invention. It is not intended that the present invention be limited to the illustrated embodiments, but rather to the scope of the following claims. and to be accorded the widest scope consistent with the principles and novel features disclosed herein. Let's say.

Claims

1. a matrix comprising a polymeric binder material; and nanostructured carbon particles having a multicellular structure comprising a network of interconnected bridge cells, The network comprises: Walls having a templated morphology, the walls being 100 nm thick or less and having sp ２ - walls containing a composite layer; and cell cavities having a template-type morphology, wherein a majority of the cell cavities have a diameter of 10 nm or greater, are substantially surrounded by the wall, and are not substantially impregnated with a liquid or solid; and A composite material having a density substantially less than the density of said binder material.

2. The composite of claim 1 , wherein the wall is formed by template-directed chemical vapor deposition.

3. The composite of claim 1 , wherein the polymeric binder is a thermoplastic.

4. 4. The composite of claim 3, wherein the thermoplastic material comprises at least one of the following: poly(methyl methacrylate), acrylonitrile butadiene styrene, polyamide, polylactic acid, polybenzimidazole, polycarbonate, polyethersulfone, polyoxymethylene, polyetheretherketone, polyetherimide, polyethylene, polyphenylene oxide, polyphenylene sulfide, polypropylene, polystyrene, polyvinyl chloride, polytetrafluoroethylene, or copolymers thereof.

5. The composite of claim 1 , wherein the polymeric binder is a thermosetting polymer.

6. 6. The composite of claim 5, wherein the thermoset polymer comprises at least one of the following: polyester, polyurethane, polyurea, phenol-formaldehyde, urea-formaldehyde, epoxy, benzoxazine, polyimide, bismaleimide, polycyanurate, polysiloxane, vinyl ester.

7. 10. The composite of claim 1, wherein the nanostructured carbon particles comprise 1% or less of the composite by weight.

8. 10. The composite of claim 1, wherein the nanostructured carbon particles comprise 10% or less of the composite by weight.

9. 10. The composite of claim 1, wherein the nanostructured carbon particles comprise up to 50% of the composite by weight.

10. The composite of claim 1 , wherein the nanostructured carbon particles are non-covalently bonded to the binder.

11. 10. The composite of claim 1, wherein the composite is a powder.

12. 10. The composite of claim 1, wherein the nanostructured carbon particles are electrically conductive.

13. 0.80 g / cm ３ 10. The composite of claim 1 having a density:

14. 0.50 g / cm ３ 10. The composite of claim 1 having a density:

15. 10. The composite of claim 1, having a compressive strength at 10% strain that is more than 140% greater than the compressive strength at 10% strain of the binder.

16. 10. The composite of claim 1, having a compressive strength at 10% strain that is more than 600% greater than the compressive strength at 10% strain of the binder.

17. 10. The composite of claim 1 having a compressive modulus that is greater than 640% greater than the compressive modulus of the binder.

18. 10. The composite of claim 1, having a specific strength at 10% strain that is more than 400% greater than the specific strength at 10% strain of the binder.

19. 10. The composite of claim 1, having a specific strength at 10% strain that is greater than 790% greater than the specific strength at 10% strain of the binder.

20. 10. The composite of claim 1 having a specific maximum compressive strength that is more than 400% greater than the specific maximum compressive strength of the binder.

21. 10. The composite of claim 1 having a specific maximum compressive strength that is greater than 790% greater than the specific maximum compressive strength of the binder.

22. 10. The composite of claim 1, having a specific modulus that is greater than 470% greater than the specific modulus of the binder.

23. 10. The composite of claim 1, having a specific modulus that is greater than 810% greater than the specific modulus of the binder.

24. The composite of claim 1 comprising a membrane or coating.

25. The composite of claim 1 comprising a molded casting.

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