A preparation method for constructing an indium germanium ion channel adsorbent material based on a template method

Abstract

The application relates to the technical field of adsorbing material preparation, and discloses a preparation method of an indium germanium ion channel adsorbing material based on a template method, which comprises the following steps: impregnating a diatomite hard template with an imprinting polymerization precursor solution without an additional crosslinking agent to graft functional monomers on the surface of the template channel; treating with hydrofluoric acid to use soluble silicon species released in situ by etching the template as a crosslinking agent to copolymerize with the grafted monomers to form a functional polymer skeleton; eluting target template ions to solve the problem of functional plugging of the mass transfer channel by copying the template channel, realize the unity of selective sites and high-efficiency mass transfer channels, and couple etching and polymerization to improve atomic economy and process efficiency.

Description

Technical Field

[0001] This invention relates to a method for preparing indium-germanium ion channel adsorbent materials based on template method, belonging to the field of adsorbent material preparation technology. Background Technology

[0002] In the semiconductor and new energy industries, indium and germanium are key rare metals. Recovering these metals from industrial wastewater is of great significance for resource recycling and environmental protection. Adsorption, as a chemical or physical method, is considered an effective way to treat low-concentration indium and germanium-containing wastewater. Among them, natural mineral adsorbents, such as diatomaceous earth, are widely available, inexpensive, and have naturally formed multi-level interconnected pore structures, providing good mass transfer conditions, and are considered ideal adsorbent carriers. However, natural mineral materials like diatomaceous earth themselves have almost no selective adsorption capacity for indium and germanium ions. The usual approach to improvement in this field is to use chemical methods, such as ion imprinting technology, to polymerize a layer of functional polymer in situ on the pore surface of the diatomaceous earth carrier in order to introduce highly selective recognition sites.

[0003] This technical approach of modifying the surface of existing carriers faces constraints between process and performance. The polymerization process necessary for constructing selective sites results in polymers that easily cover and block the original multi-level mass transfer channels of the diatomaceous earth carrier. This channel blockage leads to increased mass transfer resistance and decreased adsorption kinetics of the final material, causing the original structural advantages of the diatomaceous earth carrier to be lost due to the modification process. To avoid the blockage problem caused by polymerization within the pores of inorganic carriers like diatomaceous earth, other technical approaches have been explored in this field, using organic polymer gels themselves as adsorbent matrices and functionalizing them. For example, the method described in publication number CN102872838A... A Chinese invention patent discloses a composite adsorbent material for removing germanium ions from natural water bodies and its preparation method. It uses agarose gel as a matrix and introduces thiol (-SH) groups on its framework to selectively complex germanium ions. However, the mechanical strength and structural stability of this type of adsorbent material, which is mainly composed of organic gel, are often difficult to meet the requirements in industrial applications such as packed column operation. It is prone to compression, breakage or blockage. More importantly, the pore structure of this type of gel material (mainly relying on the network of the gel itself) is different from the regular multi-level interconnected pores of materials such as diatomaceous earth in terms of mass transfer efficiency. It fails to solve the problem of unifying high selectivity sites and efficient mass transfer channels.

[0004] Therefore, the technical problem to be solved by this invention is to provide a novel preparation method that can fundamentally decouple the constraints between selective site construction and efficient mass transfer channel maintenance, obtain highly selective imprinted sites, and retain an efficient multi-level pore structure similar to natural diatomaceous earth. Summary of the Invention

[0005] To address the problems mentioned in the background art, the technical solution of the present invention is as follows: A method for preparing indium-germanium ion channel adsorbent materials based on template method, comprising the following steps:

[0006] Step 101: Prepare an imprinted polymerization precursor solution. The imprinted polymerization precursor solution contains target template ions of indium or germanium and organosilane functional monomers. The organosilane functional monomers are silane coupling agents containing at least one functional group of a amine oxime group, mercapto group, carboxyl group or amino group.

[0007] Step 102: Use natural diatomaceous earth or bentonite as a rigid template, and use imprinted polymerization precursor liquid to impregnate and fill the pores of the rigid template.

[0008] Step 103: Chemically graft organosilane functional monomers onto the pore surface of the hard template to form a hard template grafted with functional monomers.

[0009] Step 104: Hydrofluoric acid or a mixture of hydrofluoric acid and inorganic acid is used to perform etching-induced self-crosslinking treatment on the hard template grafted with functional monomers formed in step 103; wherein, in step 104, the etching of the hard template by hydrofluoric acid or its mixture releases soluble silicon species in situ; and the soluble silicon species released in situ act as siloxane crosslinking agents, undergoing copolymerization reaction with the grafted organosilane functional monomers, and simultaneously forming a functional polymer backbone on the etching reaction front;

[0010] Step 105: Use a non-hydrofluoric acid acidic solution to elute the functional polymer backbone, remove the target template ions, and form ion-imprinted channels in the functional polymer backbone.

[0011] Preferably, in step 101, the imprinting polymerization precursor solution does not contain any added siloxane crosslinking agent; the organosilane functional monomer and the target template ion are premixed in the imprinting polymerization precursor solution to form an imprinting precursor complex.

[0012] Preferably, the impregnation filling in step 102 adopts the vacuum impregnation method, the vacuum degree of the vacuum impregnation method is 10 Pa to 500 Pa, and the impregnation time is 2 h to 12 h.

[0013] Preferably, the chemical grafting in step 103 is carried out under controlled pressure, maintaining the solvent in the imprinted polymerization precursor solution at a boiling reflux; by adjusting the control pressure, the boiling point of the solvent is maintained at the temperature required for the chemical grafting reaction, which is 60°C. Up to 90 The latent heat of vaporization of the solvent is used to absorb the heat released by the chemical grafting reaction, thus maintaining a constant temperature inside the hard template channel.

[0014] Preferably, before step 102, the method further includes step 501: depositing a porous, hydrofluoric acid-resistant inert reinforcing layer on the surface of the pores of the hard template by chemical vapor deposition or impregnation pyrolysis; wherein the imprinted polymerization precursor solution in step 102 impregnates and fills the pores covered by the inert reinforcing layer; in step 104, the hard template is etched away, and the inert reinforcing layer and the functional polymer skeleton together constitute a composite skeleton.

[0015] Preferably, the inert reinforcement layer is a carbon layer or a silicon carbide layer, and the thickness of the inert reinforcement layer is 5 nm to 50 nm, and the pore size is 2 nm to 100 nm.

[0016] Preferably, in step 104, the mass percentage concentration of hydrofluoric acid or a mixture thereof is 5% to 20%; the temperature of the etching-induced self-crosslinking treatment is 10°C. Up to 40 The processing time is 12 to 48 hours.

[0017] Preferably, in step 101, the imprinted polymerization precursor solution further includes an initiator; in step 103, the chemical grafting reaction is initiated or accelerated by applying microwave radiation to a hard template impregnated with the imprinted polymerization precursor solution; wherein the frequency of the microwave radiation is 2450MHz, and the power of the microwave radiation is 300W to 800W; the imprinted polymerization precursor solution is used as a microwave absorbing medium for volume heating, and the hard template is used as a poor microwave conductor.

[0018] Preferably, in step 101, the chemical structural formula of the organosilanes functional monomer is as follows: ;in Functional groups that can coordinate with target template ions; It is a hydrocarbon group; The molar concentration of the organosilane functional monomer in the imprinted polymerization precursor solution is methyl or ethyl. molar concentration of the target template ion Between, satisfy The relationship.

[0019] Preferably, in step 105, the acidic solution for non-hydrofluoric acid is a hydrochloric acid solution or a nitric acid solution, the concentration of the acidic solution is 0.5 mol / L to 2.0 mol / L, and the elution is carried out using a dynamic cross-flow elution method.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. By using natural diatomaceous earth as a hard template, a chemical etching step is used to selectively remove the diatomaceous earth template through in-situ polymerization of functional monomers inside the pores. The resulting functional polymer skeleton completely replicates the original multi-level mass transfer channels of diatomaceous earth in terms of structure. This process unifies the highly selective imprinting sites and efficient mass transfer channels of the material in terms of structure. The imprinting sites are located within the skeleton of the mass transfer channels, avoiding the technical problems of functional coatings covering and clogging the original pores of diatomaceous earth in the prior art.

[0022] 2. In the polymerization step, a chemical-physical method of maintaining solvent boiling and reflux by microwave radiation or pressure regulation is adopted. By utilizing the differences in physical properties, such as dielectric properties or thermal conductivity, between the precursor liquid and the diatomaceous earth as a template, the energy of the precursor liquid inside the pores can be applied directly or homogenized. This avoids the problem of uneven polymerization heat caused by the poor thermal conductivity of the diatomaceous earth template. This mild and uniform polymerization condition ensures the stability of the coordination structure between the template ions and functional monomers during the polymerization and curing process. Finally, the ion-imprinted channels formed after elution have high fidelity and consistency in three-dimensional configuration and functional group arrangement.

[0023] 3. The present invention provides a process improvement method in which no crosslinking agent is added to the precursor solution. In the subsequent etching step, the silicon species generated in situ by the etching and dissolution of the diatomaceous earth template acts as the crosslinking agent. The two independent chemical steps, the construction of the polymer network and the etching and removal of the template, are coupled into a synergistic chemical process. By reusing the function of the diatomaceous earth template from a structural mold to an in-situ reservoir for chemical reactions, the process step of adding an external crosslinking agent is eliminated. The decomposition process of the template and the synthesis process of the polymer are unified, thereby improving atom economy and process efficiency. Attached Figure Description

[0024] Figure 1 This is a flowchart illustrating the preparation process of the indium-germanium ion channel adsorbent material of the present invention.

[0025] Figure 2 This is a graph showing the effect of grafting temperature on grafting rate and selectivity coefficient in this invention.

[0026] Figure 3 This is a schematic diagram illustrating the evolution of key states of the material during the preparation process of this invention. Detailed Implementation

[0027] To make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention will be further described in conjunction with specific embodiments. It should be noted that the embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0028] This invention provides a method for preparing indium-germanium ion channel adsorbent materials based on a template method. In step 101, an imprinted polymerization precursor solution is prepared, which contains indium (In(III)) ions or germanium (Ge(IV)) ions as target template ions, and an organosilane functional monomer capable of coordinating with the target template ions. The chemical structural formula of the organosilane functional monomer can be as follows: ,in, The functional group is capable of coordinating with the target template ion and can be one of the following: a metalloxime group, a mercapto group, a carboxyl group, or an amino group. It is a hydrocarbon group. The monomer is methyl or ethyl; during preparation, the organosilane functional monomer and the target template ion are pre-mixed in a solvent to form an imprinted precursor complex; the imprinted polymerization precursor solution does not contain added siloxane crosslinking agents; to ensure effective formation of imprinted sites and stability of the polymer backbone, the molar concentration of the organosilane functional monomer is... molar concentration of the target template ion Between satisfy The relationship is such that if the ratio is less than 2, the number of functional monomers is insufficient, resulting in a decrease in the fidelity of the imprinted sites and insufficient subsequent crosslinking density. If it is greater than 8, it may lead to too many non-specific adsorption sites, reducing selectivity. In step 102, the hard template is preferably natural diatomaceous earth or bentonite with a multi-level through-pore structure. It usually needs to be purified and dried before use. The impregnation and filling adopts the vacuum impregnation method. The dried hard template is placed in a vacuum impregnation device with a vacuum degree of 10 Pa to 500 Pa. The imprinting polymerization precursor liquid prepared in step 101 is introduced to fully immerse the hard template. The impregnation time is 2 h to 12 h. This vacuum impregnation process is used to remove residual air inside the template pores, so that the precursor liquid can fully penetrate and fill the template pores.

[0029] The natural diatomaceous earth or bentonite rigid template used in step 102 preferably undergoes a surface standardization pretreatment procedure before impregnation and filling. This procedure includes: placing the rigid template material in a 1.0 mol / L to 3.0 mol / L hydrochloric acid or nitric acid solution at 80°C. Up to 100 The raw material is stirred for 4 to 8 hours to remove metal oxides and carbonate impurities. The acid-treated hard template is then repeatedly filtered and washed with deionized water until the pH of the filtrate is constant at 6.5 to 7.0. Finally, the washed hard template is placed in a vacuum oven at 105°C. Up to 120 The material is dried at a temperature of 6 to 12 hours. This step removes physically adsorbed water while maximally preserving the surface-active silanol groups required for subsequent chemical grafting in step 103. In step 103, organosilane functional monomers are chemically grafted onto the pore surface of the hard template to form stable chemical bonds. To initiate or accelerate this chemical grafting reaction, one of two homogenization energy application methods can be used: The first method is microwave radiation, where the imprinted polymerization precursor liquid also contains an initiator. In step 103, microwave radiation is applied to the hard template impregnated with the precursor liquid. The microwave frequency can be 2450 MHz, and the power can be 300 W to 800 W. The precursor liquid is used as a microwave absorption medium for volumetric heating, and the diatomaceous earth hard template is used as a poor microwave conductor to homogenize the pores. The second method is pressure-controlled boiling reflux, where the chemical grafting is carried out under controlled pressure to maintain the solvent in the precursor liquid in boiling reflux. By adjusting the control pressure, the boiling point of the solvent is maintained at the temperature required for the chemical grafting reaction, which can be 60°C. Up to 90 The latent heat of vaporization of the solvent absorbs the heat released during the grafting reaction, maintaining a constant temperature inside the pores. This avoids uneven heat transfer caused by the poor thermal conductivity of the diatomaceous earth template, ensuring a gentle and uniform grafting reaction. Step 104 is an etching-induced self-crosslinking treatment. The hard template grafted with functional monomers formed in step 103 is immersed in hydrofluoric acid or a mixture thereof. The mass percentage concentration of hydrofluoric acid or a mixture thereof can be 5% to 20%, and the treatment temperature is controlled at 10°C. Up to 40 The processing time is 12 to 48 hours. In this step, two chemical processes occur in tandem: hydrofluoric acid chemically etches the hard template of diatomaceous earth or bentonite, dissolving it, while the etching process releases soluble silicon species in situ at the reaction interface. These in-situ released soluble silicon species act as siloxane crosslinking agents, undergoing copolymerization reactions with organosilane functional monomers grafted onto the pore surface, and simultaneously forming a functional polymer backbone on the etching reaction front. The template removal is coupled with polymer synthesis, using the template itself as a source of crosslinking agents, eliminating the need for the step of adding external crosslinking agents.

[0030] The process window for the etching-induced self-crosslinking treatment in step 104 is determined by a calibration procedure that includes process monitoring. This procedure clarifies the concentration of hydrofluoric acid or its mixed acids and the treatment time. The determination is based on the synergistic achievement of complete template removal and complete backbone crosslinking. The template removal process is monitored by periodically sampling and measuring the silicon concentration in the etching acid solution using inductively coupled plasma mass spectrometry (ICP-MS). When the silicon concentration no longer increases with continuous sampling and remains constant, the template etching is considered complete. The crosslinking integrity of the functional polymer backbone is verified by examining the structural integrity of products treated at different times. The dried product is treated in a 100W, 40kHz ultrasonic cleaner for 10 minutes. Samples with no obvious backbone breakage or disintegration are considered to have achieved effective crosslinking at the corresponding treatment time. The hydrofluoric acid treatment in step 104 is performed in a closed reactor made of corrosion-resistant materials such as polytetrafluoroethylene (PTFE) or perfluoroalkoxy (PFA). This reactor is equipped with a circulating water bath jacket to precisely maintain the temperature of the reaction system at the specified 10°C. Up to 40 Within the process zone; simultaneously, the exhaust port of the reactor is connected to an alkaline absorption tower containing sodium hydroxide or calcium hydroxide solution, used to neutralize and absorb hydrogen fluoride (HF) vapor or silicon tetrafluoride (SiF4) that may be released during the etching process. The gas is used to maintain a stable pressure and operating environment inside the reactor; in step 105, the functional polymer framework obtained in step 104 is eluted to remove the target template ions; this step uses a non-hydrofluoric acid acidic solution to avoid damaging the newly formed polysiloxane framework, and the acidic solution can be hydrochloric acid solution or nitric acid solution; the concentration of the acidic solution can be 0.5 mol / L to 2.0 mol / L; the elution method can adopt a dynamic cross-flow elution method to improve mass transfer efficiency; after the template ions are removed, ion-imprinted channels are formed in the functional polymer framework, and the material has the specific adsorption capacity for indium or germanium ions; to further improve the mechanical strength and structural stability of the final adsorbed material, this invention also provides In an improved embodiment, prior to step 102, the method further includes step 501: depositing a porous, hydrofluoric acid-resistant inert reinforcement layer on the surface of the pores of the hard template by chemical vapor deposition or immersion pyrolysis; the inert reinforcement layer is preferably a carbon layer or a silicon carbide layer, with a thickness controlled between 5 nm and 50 nm and a pore size between 2 nm and 100 nm, to provide support without obstructing the immersion channels of the subsequent precursor liquid; the imprinted polymerization precursor liquid in step 102 is impregnated and filled into the pores covered by the inert reinforcement layer; in the subsequent etching step 104, the diatomaceous earth hard template is etched away, while the inert reinforcement layer is retained, forming a composite skeleton with enhanced mechanical properties together with the functional polymer skeleton.

[0031] Example 1: In a typical scenario of treating indium-containing wastewater from the semiconductor industry, the concentration of indium (In(III)) ions in the wastewater is low, requiring high recovery efficiency and processing speed. Existing adsorption materials, which coat functional polymers onto the surface of diatomaceous earth carriers, generally suffer from problems such as blocked mass transfer channels leading to slow adsorption kinetics and insufficient volume capacity due to functional sites being limited to the surface, failing to meet the needs of continuous industrial processing. In this example, the imprinted polymerization precursor liquid prepared in step 101 contains In(III) ions as the target template ion and organosilicon functional monomers containing a methylamine oxime group that can coordinate with it, without containing any added siloxane crosslinking agents. In step 102, natural diatomaceous earth is selected as the hard template, and the precursor liquid is filled into the pores using a vacuum impregnation method. In step 103, a pressure-controlled boiling reflux method is used to heat the precursor liquid at 75°C. The impregnated template is then chemically grafted to bond functional monomers to the inner wall of the diatomaceous earth pores; step 104, corrosion-induced self-crosslinking treatment, involves placing the grafted hard template in a 15% hydrofluoric acid solution at 25°C. The process is carried out for 24 hours; unlike traditional preparation methods where polymerization and etching are separated, they are coupled; hydrofluoric acid etches the diatomaceous earth template, releasing soluble silicon species in situ at the reaction front. These soluble silicon species immediately act as siloxane crosslinking agents not added in step 101, undergoing in-situ copolymerization with the functional monomers already grafted onto the pore surface. This makes the template dissolution process the same as the crosslinking synthesis process of the polymer skeleton, transforming the template from a structural mold into a chemical reactant, achieving simultaneous template removal and skeleton formation; in step 105, 1.5 mol After dynamic cross-flow elution with a hydrochloric acid solution of / L to remove In(III) template ions, the resulting product is a functional polymer framework that is structurally identical to the multi-level interconnected channels of diatomaceous earth, consisting entirely of functional polymers. This avoids the technical problems of functional coatings covering and blocking mass transfer channels in existing technologies. Ion-imprinted channels are formed inside the polymer framework rather than attached to the surface, so that highly selective sites and efficient mass transfer channels are structurally unified. The density of functional sites is no longer limited by the specific surface area of ​​the carrier, resulting in an adsorbent material with both high adsorption capacity and fast adsorption kinetics.

[0032] Example 2: This example objectively verifies the technical effect of the etching-induced self-crosslinking method in step 104 without adding an external crosslinking agent. It is compared with a coating method (representing the prior art) that does not etch the template, and a conventional method that uses a template but adds an external crosslinking agent. The test materials in this example include: a hard template made of natural diatomaceous earth (specific surface area 25.5). (Average pore size 2.2 μm), pre-washed with acid and 120 mL before use. Drying treatment; the target template ion was Ge(IV) ions, prepared by dissolving GeCl4 in hydrochloric acid solution; the functional monomer was (3-aminopropyl)triethoxysilane (APTES), chemically pure; the added crosslinking agent (used in the control group) was tetraethoxysilane (TEOS), chemically pure; the etching solution was 10% (mass percentage) hydrofluoric acid (HF) solution; the eluent was 1.0 mol / L hydrochloric acid (HCl) solution; the experimental equipment included a vacuum impregnation drying oven (vacuum degree <100 Pa) and a pressure-controlled boiling reflux device (temperature control accuracy ±1... ), temperature-controlled oscillator (25) Temperature control accuracy ±0.5 ), and inductively coupled plasma mass spectrometry (ICP-MS, used to determine germanium ion concentration); simulated waste liquid: initial concentration of Ge(IV) ions The concentration was set at 100.5 mg / L, and the solution pH was 2.0. Three sample groups were prepared for comparison: Sample group of the present invention (IS): prepared according to the method of the present invention, in step 101, an imprinted polymerization precursor solution without added TEOS was prepared, wherein the molar ratio of APTES to Ge(IV) ions was... The control is set to 4; step 102, the diatomaceous earth hard template is impregnated using the vacuum impregnation method (500 Pa, 4 h); step 103, the pressure-controlled boiling reflux method is used to impregnate the template at 80°C. Chemical grafting was performed for 6 hours; in step 104, the grafted template was immersed in a 10% HF solution at 25°C. Etching-induced self-crosslinking for 24 h; Step 105, dynamic cross-flow elution with 1.0 mol / L HCl solution, followed by drying to obtain the final product; Control group A (CA, simulating existing coating methods): using the same diatomaceous earth hard template, preparations were made containing Ge(IV) ions and APTES ( ) and the precursor solution with added crosslinking agent TEOS (TEOS to APTES molar ratio of 1:2); using the same vacuum impregnation and 80 Heat treatment (6 h) allows the functional monomers and crosslinking agents to polymerize in situ on the pore surface to form a functional coating; the key difference is that the HF etching process in step 104 is not used, and the template ions are eluted with a 1.0 mol / L HCl solution; Control group B (CB, template method simulating the addition of an external crosslinking agent): the preparation method is basically the same as that of control group A, and the precursor solution also contains the external crosslinking agent TEOS; but at 80 After heat treatment polymerization, an additional step is performed using a 10% HF solution (25). The diatomaceous earth template was removed by etching (24h), and finally eluted with 1.0 mol / L HCl solution. The adsorption performance test procedure was as follows: 0.1g of the above three dried sample groups (IS, CA, CB) were added to 100mL of initial concentration. The simulated waste liquid was placed at 25°C with a concentration of 100.5 mg / L. The reaction mixture was shaken in a constant-temperature shaker. Samples were taken at 10 min, 30 min, 60 min, and 120 min. Another set of samples was shaken for 24 h to determine equilibrium adsorption. After centrifugation, the supernatant of all samples was collected, and the residual concentration of germanium ions was determined by ICP-MS. (120 min) or equilibrium concentration (24h), calculate the adsorption rate (%) = Calculate the equilibrium adsorption capacity (mg / g)= ,in This is the solution volume (0.1L). The value represents the mass of the adsorbent (0.1 g); test results are shown in Table 1.

[0033] Table 1: Comparison of adsorption kinetics and equilibrium adsorption capacity of germanium ions in simulated waste liquids of different pairs.

[0034]

[0035] The data analysis in Table 1 is as follows: The adsorption kinetics of control group A (coating method) were slow (adsorption rate of only 38.8% at 120 min) and the lowest equilibrium adsorption capacity (44.7 mg / g). This is attributed to the fact that its polymerization process blocked the mass transfer channels of diatomaceous earth, and the functional sites were limited to the surface of the material. Both the sample group (IS) of this invention and the control group B (with added crosslinking agent) used the template method, and their equilibrium adsorption capacities (95.5 mg / g and 92.3 mg / g, respectively) were higher than those of control group A, indicating that the template method, which replicates the channels and functionalizes the entire material, has an advantage in terms of capacity. Both the sample group (IS) of this invention and the control group B (with added crosslinking agent) replicated the channel structure. The sample group of this invention showed better adsorption kinetics (adsorption rate of 94.7 mg / g at 120 min). The results show advantages in both 0.1% (vs. 86.0%) and equilibrium adsorption capacity (95.5 mg / g vs. 92.3 mg / g). The data indicate that the specific chemical mechanism of etching-induced self-crosslinking used in step 104 of this invention achieves higher adsorption efficiency and capacity compared to the external crosslinking agent method in control group B. This may be because the externally added TEOS in control group B undergoes a certain degree of prepolymerization in the precursor solution, resulting in uncontrollable density of the polymer skeleton formed by subsequent etching. In contrast, the sample group of this invention utilizes highly active soluble silicon species released in situ from the etching front as a crosslinking agent, which polymerizes synchronously with the grafted functional monomers. The resulting polymer skeleton is more uniform in structure, achieving higher accessibility of imprinted sites and adsorption performance.

[0036] Example 3: This example combines Figures 1 to 3 This describes a method for preparing an indium-germanium ion channel adsorbent material based on a template method, such as... Figure 1As shown, starting with a hard template made of natural diatomaceous earth or bentonite, the process can proceed through step 501: depositing an inert reinforcing layer to improve the mechanical strength of the final framework; step 101: preparing an imprinted polymerization precursor solution containing target ions and functional monomers, but without added crosslinking agents; the two are combined in step 102: impregnation and filling, where the precursor solution impregnates the pores of the hard template; step 103: chemical grafting, where functional monomers are grafted onto the surface of the pores; followed by step 104: etching-induced self-crosslinking, using hydrofluoric acid treatment, with simultaneous etching and polymerization. The key mechanism is that the coupling between etching and polymerization lies in the soluble silicon species released in situ during etching acting as crosslinking agents; then step 105: elution, using non-hydrofluoric acid to remove target template ions, yielding an indium germanium ion channel adsorbent material, forming a functional polymer framework for ion-imprinted channels.

[0037] like Figure 2 As shown, the horizontal axis represents the grafting temperature. The range is from 50 to 100. The left vertical axis represents the grafting rate (%), ranging from 50 to 100, and the right vertical axis represents the selectivity coefficient, ranging from 0 to 8. The graph contains two curves, with the grafting rate curve showing that the grafting rate increases with temperature from 50°C. The percentage rose from 60.2% to 80%. 90% of the time, in 90 Up to 100 The selectivity remains above 90%. Another selectivity coefficient curve shows that the selectivity coefficient increases with temperature from 50°C. The number of times rose from 3 to 80 The peak value was 7 at 90. It then dropped sharply, to 100 The value dropped to 2.1; Figure 3 As shown, the initial state is that the raw materials are ready and the template and precursor solution have been prepared. Step 102: impregnation and filling transforms the state into a pore-filled state, and the hard template pores are impregnated with the precursor solution. Step 103: chemical grafting transforms the state into a monomer-grafted state, and the functional monomer is bonded to the pore surface. Step 104: etching-induced self-crosslinking transforms the state into a functional backbone containing template ions, and the polymer backbone is formed and the template is encapsulated. Finally, step 105: template ion elution transforms the state into the final ion-imprinted channel product state, and the template ions are eluted to form imprinted sites.

[0038] Example 4: This example discloses a calibration method for determining the etching-induced self-crosslinking process parameters in step 104. The parameters include hydrofluoric acid concentration and processing time. This method is used to determine a parameter window that achieves complete removal of the hard template, intact functional polymer backbone structure, and high process efficiency. The initial material used in the calibration method is a batch of homogeneous hard template intermediates grafted with functional monomers, which are prepared according to steps 101 to 103. In step 101, the molar ratio of organosilane functional monomers to target template ions in the imprinted polymerization precursor solution is... The value is set to 4, and this selection is based on the following understanding: When When the number is below 2, the number of functional units is insufficient to form a stable network in subsequent steps, making the framework prone to breakage. Above 8, excessive functional monomers lead to an increase in non-specific adsorption sites and reduced selectivity; all intermediates underwent the same vacuum drying treatment before calibration; three standards were set to determine whether the process parameters were qualified: first, the completeness of hard template removal, judged by the final product being dried at 800°C in air. Thermogravimetric analysis (TGA) showed that the residual ash (SiO2) was less than 1.0% (mass percentage); secondly, the structural integrity of the functional polymer framework was judged by the absence of obvious breakage or disintegration of the dried product after treatment in an ultrasonic cleaner for 5 minutes; thirdly, the retention of adsorption performance was judged by the equilibrium adsorption capacity of the product for the target ion. Not less than 90% of the benchmark value of 95.5 mg / g.

[0039] The calibration method employs a gradient experiment, dividing the aforementioned intermediates into 25 equal groups and placing them at 25°C. In a constant temperature environment, samples were immersed in hydrofluoric acid (HF) solutions with different parameter combinations for treatment. The HF mass percentage concentration gradient was set at 2%, 5%, 10%, 15%, 20%, and 25%, and the treatment time gradient was set at 6h, 12h, 24h, 48h, and 60h. After reaching the preset time points, the samples were removed, washed until neutral, and eluted and dried according to step 105. All 25 groups of samples were then subjected to the three standard tests mentioned above. The test results showed that: in the 2% HF concentration group (all time points), the residual ash content of TGA was higher than 5%, failing to meet standard one; in the 25% HF concentration group (all time points), the skeleton did not pass the ultrasonic treatment of standard two; in the 6h time group (all concentrations), the residual ash content of TGA was higher than 3%, failing to meet standard one; in the 60h time group (5% to 20% concentrations), although the samples met the three standards, their adsorption capacity... There was no improvement compared to the 48h group, so from the perspective of process efficiency, 48h is the effective upper limit; finally, when the HF mass percentage concentration is in the range of 5% to 20% and the processing time is in the range of 12h to 48h, all the samples obtained can simultaneously meet the above three criteria, and the optimized process parameter window of step 104.

[0040] Example 5: This example discloses a preparation method that solves the technical problem that the pure polymer skeleton is easily compacted or broken when the adsorbent material is used in large industrial column beds under high pressure drop and high flow rate conditions, such as when subjected to continuous fluid pressure above 0.5 MPa. Before step 102 impregnation and filling, step 501, namely the deposition step of the inert reinforcement layer, is added. This step 501 adopts the impregnation pyrolysis method, in which the dried natural diatomaceous earth hard template is completely immersed in a 15% (w / v) furfuryl alcohol acetone solution, maintained for 12 hours, and then taken out and heated to 80°C. After drying and curing, place the product in a tube furnace and heat it at 5°C under a nitrogen protective atmosphere. Heating to 350°C at a rate of / min Keep warm for 2 hours, then use 2 Heating to 700 at a rate of / min After being kept at a high temperature for 3 hours and allowed to cool naturally, a porous carbon layer with a thickness of approximately 20 nm is uniformly deposited on the surface of the pores of the diatomaceous earth template. This carbon layer serves as an inert reinforcing layer resistant to hydrofluoric acid corrosion. After obtaining this composite hard template with the deposited inert reinforcing layer, a new technical problem arises during the chemical grafting process in step 103. The thermal conductivity uniformity of this composite hard template is worse than that of a pure diatomaceous earth template. Using conventional pressure-controlled boiling reflux methods can easily lead to uneven heat distribution within the pores, affecting the uniformity of the grafting reaction. In this embodiment, step 103 uses microwave radiation to treat the composite hard template, and in step 102, it is vacuum impregnated (100 Pa, 8 hours) and filled with an imprinted polymerization precursor solution containing an initiator. Subsequently, the composite hard template was placed in a 2450MHz microwave reactor with a microwave power of 500W. Radiation was performed using a pulsed pattern of 30s on and 30s off, for a total radiation time of 15 minutes. Utilizing the physical differences between the hard template (diatomaceous earth and carbon layer) as a poor microwave conductor and the imprinted polymerization precursor liquid inside the pores as a microwave absorption medium, direct and homogenized volumetric heating of the precursor liquid inside the pores was achieved, ensuring the uniformity of the grafting reaction. Steps 104 and 105 were performed using conventional methods. The resulting composite skeleton exhibited improved mechanical stability compared to the sample group that did not undergo step 501, showing no significant compaction or breakage under 1.0MPa pressure.

[0041] Example 6: This example discloses a standardized engineering calibration procedure for determining the key process parameter, namely the temperature required for the chemical grafting reaction, when using the pressure-controlled boiling reflux method for chemical grafting in step 103. It addresses the technical problem of determining a temperature that ensures effective chemical grafting between the functional monomer and the hard template pore surface under different solvent systems, while avoiding thermal decomposition or rearrangement of the imprinted precursor complex before polymerization due to excessively high temperatures. The initial state of this procedure is defined as preparing a batch of imprinted polymerization precursor solution (using Ge(IV) as the template ion and APTES as the functional monomer) impregnated with ethanol as the solvent, according to steps 101 and 102. =4) homogeneous diatomaceous earth hard template; the pressure-controlled boiling reflux device is a reactor with precise pressure control (control accuracy ±1.0kPa) and condensation reflux function. By adjusting the internal pressure, at 30 Up to 100 The boiling point of the ethanol solvent can be set arbitrarily within the range; the process judgment criteria of this procedure are set as two: first, the grafting efficiency, which is calculated by measuring the concentration of APTES remaining in the precursor solution after the reaction, and the value should be higher than 85%; second, the fidelity of the imprinted site, which is determined by selective adsorption test on the finally prepared adsorbent material (following the subsequent steps according to the parameters of Example 4), and the selectivity coefficient of Ge(IV) (relative to the coexisting Ga(III) ions) should not be less than 5.0.

[0042] This calibration procedure employs a gradient experiment: the impregnated hard template is divided into several groups and placed in a pressure-controlled boiling reflux apparatus; the boiling point of the ethanol solvent is maintained constant at 50°C by adjusting the internal pressure of the reactor. 60 70 80 90 100 At six temperature gradients, each group of temperatures was maintained at boiling reflux for 6 hours. After the reaction, each group of samples was tested according to the two process judgment criteria mentioned above. The test results and parameter ranges were determined as follows: Analytical data showed that at 50... At that time, the grafting rate was only 60.2%, failing to meet standard one; at 100 At that time, the grafting rate reached 91.5%, but the final material selectivity coefficient was only 2.1, failing to meet standard two, indicating that excessively high temperatures caused the coordination structure of the imprinted precursor complex to be destroyed during the grafting process; when the boiling point temperature was controlled at 60... Up to 90 When the sample is within the specified range, it can simultaneously meet the criteria of grafting rate higher than 85% and selectivity coefficient higher than 5.0, thus determining the optimized process temperature window for step 103 under this specific system.

[0043] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing indium-germanium ion channel adsorbent materials based on template method, characterized in that, Includes the following steps: Step 101: Prepare an imprinted polymerization precursor solution. The imprinted polymerization precursor solution contains target template ions of indium or germanium and organosilane functional monomers. The organosilane functional monomers are silane coupling agents containing at least one functional group of a amine oxime group, mercapto group, carboxyl group or amino group. Step 102: Use natural diatomaceous earth or bentonite as a rigid template, and use imprinted polymerization precursor liquid to impregnate and fill the pores of the rigid template. Step 103: Chemically graft organosilane functional monomers onto the pore surface of the hard template to form a hard template grafted with functional monomers. Step 104: Hydrofluoric acid or a mixture of hydrofluoric acid and inorganic acid is used to perform etching-induced self-crosslinking treatment on the hard template grafted with functional monomers formed in step 103; wherein, in step 104, the etching of the hard template by hydrofluoric acid or its mixture releases soluble silicon species in situ; and the soluble silicon species released in situ act as siloxane crosslinking agents, undergoing copolymerization reaction with the grafted organosilane functional monomers, and simultaneously forming a functional polymer backbone on the etching reaction front; Step 105: Use a non-hydrofluoric acid acidic solution to elute the functional polymer backbone, remove the target template ions, and form ion-imprinted channels in the functional polymer backbone. Furthermore, in step 101, the imprinting polymerization precursor solution does not contain any added siloxane crosslinking agent; the organosilane functional monomer and the target template ion are premixed in the imprinting polymerization precursor solution to form an imprinting precursor complex. The chemical structural formula of organosilane functional monomers is as follows: ;in Functional groups that can coordinate with target template ions; It is a hydrocarbon group; The molar concentration of the organosilane functional monomer in the imprinted polymerization precursor solution is methyl or ethyl. molar concentration of the target template ion Between, satisfy The relationship.

2. The method for preparing an indium-germanium ion channel adsorbent material based on template method according to claim 1, characterized in that, The impregnation filling in step 102 adopts the vacuum impregnation method, with a vacuum degree of 10 Pa to 500 Pa and an impregnation time of 2 h to 12 h.

3. The method for preparing an indium-germanium ion channel adsorbent material based on template method according to claim 1, characterized in that, The chemical grafting in step 103 is carried out under controlled pressure, maintaining the solvent in the pre-imprinted polymerization solution at a boiling reflux. By adjusting the control pressure, the boiling point of the solvent is maintained at the temperature required for the chemical grafting reaction, which is 60°C. Up to 90 The latent heat of vaporization of the solvent is used to absorb the heat released by the chemical grafting reaction, thus maintaining a constant temperature inside the hard template channel.

4. The method for preparing an indium-germanium ion channel adsorbent material based on template method according to claim 1, characterized in that, Before step 102, the method further includes step 501: depositing a porous, hydrofluoric acid-resistant inert reinforcing layer on the surface of the pores of the hard template by chemical vapor deposition or impregnation pyrolysis; wherein the imprinted polymerization precursor solution in step 102 impregnates and fills the pores covered by the inert reinforcing layer; in step 104, the hard template is etched away, and the inert reinforcing layer and the functional polymer skeleton together constitute a composite skeleton.

5. The method for preparing an indium-germanium ion channel adsorbent material based on template method according to claim 4, characterized in that, The inert reinforcement layer is a carbon layer or a silicon carbide layer, with a thickness of 5 nm to 50 nm and a pore size of 2 nm to 100 nm.

6. The method for preparing an indium-germanium ion channel adsorbent material based on template method according to claim 1, characterized in that, In step 104, the mass percentage concentration of hydrofluoric acid or a mixture thereof is 5% to 20%. The temperature for etching-induced self-crosslinking treatment is 10°C. Up to 40 The processing time is 12 to 48 hours.

7. The method for preparing an indium-germanium ion channel adsorbent material based on template method according to claim 1, characterized in that, In step 101, the imprinted polymerization precursor solution also contains an initiator; in step 103, the chemical grafting reaction is initiated or accelerated by applying microwave radiation to a hard template impregnated with the imprinted polymerization precursor solution; wherein the frequency of the microwave radiation is 2450MHz and the power of the microwave radiation is 300W to 800W; the imprinted polymerization precursor solution is heated by volume as a microwave absorbing medium, and the hard template is a poor microwave conductor.

8. The method for preparing an indium-germanium ion channel adsorbent material based on template method according to claim 1, characterized in that, In step 105, the non-hydrofluoric acid acidic solution is a hydrochloric acid solution or a nitric acid solution, and the concentration of the acidic solution is from 0.5 mol / L to 2.0 mol / L.

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