Method capable of regulating and controlling pore diameter of aerogel and application
By soaking the hydrogel in the pore-ablative solution and performing freeze-drying treatment, the problem of difficulty in controlling the aerogel pore size in the prior art is solved, efficient and simple aerogel pore size control is achieved, and adsorption rate and efficiency are improved.
Patent Information
- Application Number
- CN202411468857.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-21
- Publication Date
- 2025-02-14
AI Technical Summary
The prior art is difficult to effectively regulate the aerogel pore size, resulting in difficulty in improving adsorption rate and efficiency, and cumbersome operation, relying on complex equipment and pore-making agents.
By soaking the hydrogel in the pore reaming solution and lyophilizing the treatment, the aerogel pore size is controlled. This method is simple and easy to operate, suitable for various hydrogel systems, can dynamically adjust the pore size and increase the adsorption rate.
It realizes flexible control of aerogel pore size, improves adsorption rate and efficiency, simplifies process flow, reduces costs, and has good repeatability and biocompatibility.
Smart Images
Figure CN119431873A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of aerogel preparation, and particularly relates to a method and application for adjusting the pore size of aerogel. Background Art
[0002] Aerogel is a low-density and high-porosity polymer material with hemostatic, non-toxic, antibacterial, and biocompatible properties. It is widely used in different fields such as medicine, environment, construction, pharmaceuticals, food, cosmetics, and wastewater. Hydrogel molding is an essential step in the preparation of aerogels. The liquid part in the hydrogel is replaced by gas through freeze-drying technology, leaving a porous scaffold structure without collapse. Hydrogel is a gel preparation with a solvent as a continuous phase that can absorb a large amount of water or other liquids. The raw materials for preparing hydrogels currently include organic or inorganic compounds such as silica, cellulose, metal oxides, and biochar, as well as composites. The polymer chains dispersed in the aqueous medium are cross-linked through various mechanisms to form a hydrogel. Its three-dimensional network structure is formed by physical or chemical cross-linking, and these cross-linking mechanisms include physical entanglement, ionic reaction, and chemical cross-linking.
[0003] Aerogels have abundant N, O, S, P and other functional groups on their surfaces, and exhibit high specific surface area, low density and adjustable surface chemical properties, making them particularly suitable for adsorbing water pollutants, gases and biomacromolecules. The adsorption mechanisms of aerogels mainly include electrostatic interactions, surface complexation, chelation, diffusion, coordination interactions, ion exchange, hydrogen bonds and van der Waals forces at the microscopic level, as well as capillary forces at the macroscopic level.
[0004] The structural properties of aerogels (such as pore size and density) are often restricted by the hydrogel raw materials and their processing technology. Although the preparation methods of hydrogels and aerogels are relatively mature, there is still a gap in the technology of effectively regulating the hydrogel and then controlling the pore size of the aerogel. Current research on regulating the pore size of aerogels mainly focuses on the following ways: adjusting the diameter of hydrogel fibers through production equipment, and then controlling the pore size of aerogels by electrospinning and other methods; by adding pore-forming agents or foaming agents to the hydrogel, and regulating the size of the hydrogel pores by particle degradation or reaction. Existing aerogel preparation technologies focus on regulating the pore size of aerogels by controlling the porous scaffold structure of hydrogels, but these methods rely on complex equipment and pore-forming agents, are cumbersome to operate, and have limited precision in pore size regulation. In addition, these approaches usually cannot achieve dynamic pore size regulation, especially ignoring the regulation ability of the liquid in the hydrogel, resulting in the swelling and deswelling behavior of the hydrogel being regarded as an unfavorable factor when preparing aerogels. For this reason, the adsorption rate and efficiency of traditional aerogels are difficult to be further improved. Summary of the invention
[0005] In view of this, the purpose of the present invention is to provide a method and application of adjustable aerogel pore size with low cost, easy operation, safety and environmental protection, and significantly improved adsorption rate. The method is universal and applicable to various hydrogel systems. The aerogel pore size can be regulated by simple immersion and freeze-drying processes to prepare aerogel materials with high adsorption rate. The preparation method is not only simple and easy to operate, but also has good repeatability. The prepared aerogel can be widely used in the fields of pollutant adsorption, biomedical dressings, and drug carriers.
[0006] The object of the present invention is to achieve the following:
[0007] The present invention provides a method for adjusting the pore size of aerogels, comprising the following steps:
[0008] (1) Preparation of hydrogel: preparing a three-dimensional hydrogel using one or a combination of two or more of cellulose and its derivatives, hemicellulose and its derivatives, gelatin and its modifications, chitosan and its derivatives, collagen, alginate, hyaluronic acid, polyethylene glycol, polyurethane, polylactic acid, polyvinyl pyrrolidone, polyvinyl alcohol, polyacrylic acid, polyacrylamide, (poly)acrylic acid and its derivatives, carbomer, silicon dioxide, agar, starch and its derivatives, and pectin as main components;
[0009] (2) Hydrogel pore expansion: The prepared hydrogel is immersed in a pore expansion solution with a concentration of 0 wt% to 100 wt%, a solution pH controlled at 1 to 14, an immersion temperature of 10°C to 100°C, and a time of 10 to 1440 min to ensure that the solution enters the interior of the hydrogel; after the immersion, the hydrogel is taken out and placed at the same temperature, without direct sunlight and wind for 0 to 24 h to ensure the stability of the hydrogel structure and the uniform expansion of the pore size, and then washed with a washing solution to remove the residual pore expansion solution;
[0010] (3) Aerogel preparation: The obtained hydrogel is immediately freeze-dried in a vacuum oven at a freezing temperature of -10°C to -80°C and a drying time of 12h to 48h to obtain an aerogel.
[0011] Based on the above technical scheme, further, the specific process of step (1) is as follows: 1-2 g of hemicellulose xylan is dissolved in deionized water, and then sodium periodate is added at a molar ratio of 1:1-1:2, and the reaction is stirred for 20-30 hours at 35-45°C in complete darkness; 5-20 mL of ethylene glycol is added to the reaction mixture, and dialyzed to remove oligomers and impurities, and the dialyzed solution is precipitated and filtered, and dried at a temperature below 40°C for 20-48 hours to obtain dialdehyde hemicellulose. The invention discloses a method for preparing a hydrogel comprising the steps of: dissolving chitosan in a 1.0-3.0 wt% acetic acid aqueous solution to prepare a chitosan acetic acid aqueous solution with a concentration of 0.01-0.05 g / mL; dissolving dialdehyde hemicellulose powder in deionized water to prepare a dialdehyde hemicellulose powder aqueous solution with a concentration of 0.01-0.05 g / mL; uniformly mixing the dialdehyde hemicellulose powder aqueous solution and the chitosan acetic acid aqueous solution in a volume ratio of 1:1, pouring the mixture into a mold, and maintaining the mixture at 15-25°C for 10-20 hours to obtain a hydrogel.
[0012] Based on the above technical scheme, further, the pore expansion solution described in step (2) includes but is not limited to water, methanol, ethanol, propanol, acetone, ethyl acetate, dimethyl sulfoxide, N,N-dimethylformamide, tetrahydrofuran, acetonitrile, dichloromethane, chloroform, and carbon tetrachloride; the anions in the solution are one of tartrate, acetate, phosphate, citrate, sulfate, sulfate oxide, carbonate, carbonate cyanide, dioxyphosphate, thiosulfate, and chloride ions; and the cations in the solution are one of ammonium ions, lithium ions, potassium ions, sodium ions, manganese ions, calcium ions, and barium ions.
[0013] Based on the above technical solution, further, the washing solution described in step (2) includes but is not limited to water.
[0014] The present invention also provides an aerogel with adjustable pore size prepared by the above method.
[0015] Based on the above technical solution, further, the pore size of the aerogel is 1nm to 10mm.
[0016] The present invention also provides the application of the above-mentioned aerogel with adjustable pore size in medical equipment, environmental pollutant adsorption, sanitary products, cosmetics, fertilizers, food and medicine.
[0017] The beneficial effects of the present invention compared with the prior art are as follows:
[0018] 1. The present invention breaks through the limitations of traditional technology, focuses on the liquid area of the hydrogel, and realizes the control of the aerogel pore size by dynamically adjusting the pore size enlargement and reduction through an innovative method of dynamic regulation of the front pore size caused by solution penetration and flow.
[0019] 2. The hydrogel of the present invention has the highest water content, transparency and hardness after soaking for 1440 minutes, and has stable performance.
[0020] 3. The aerogel prepared by the present invention has certain compression performance, stable structure, higher efficiency of adsorbing target objects than that of non-expanded aerogel, and greatly shortens the adsorption equilibrium time.
[0021] 4. The pore size regulator used in the present invention is a common solvent, which is biocompatible, safe and environmentally friendly.
[0022] 5. The present invention has low cost for adjusting the pore size, easy raw material acquisition, no need for additional complex equipment, simple operation and strong repeatability.
[0023] 6. Compared with similar material preparation processes, the pore size control method provided by the present invention not only simplifies the process flow, but also achieves a qualitative leap in performance, bringing a more efficient, stable and reliable solution for the adsorption application of aerogels (such as water pollution treatment and biomedical fields). BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order to more clearly illustrate the embodiments of the present invention, the drawings related to the embodiments are briefly introduced below.
[0025] Figure 1 Figure 2 shows the hydrogel before freeze-drying (a) and the aerogel after freeze-drying (b), where (a) is the hydrogel after being soaked in the solution for 0 min, 5 min, 15 min, 30 min, 60 min, 120 min, 240 min, 480 min, and 1440 min, and (b) is the upward straight line corresponding to the aerogel after freeze-drying in Figure (a).
[0026] Figure 2 SEM images of the corresponding aerogels after freeze-drying of the hydrogels after being immersed in the solution for 0 min (a), 5 min (b), 15 min (c), 30 min (d), 60 min (e), 120 min (f), 240 min (g), 480 min (h), and 1440 min (i), respectively (scale bar 1 mm).
[0027] Figure 3 N2 adsorption-desorption isotherms (a) and corresponding BJH pore size distribution diagrams (b) of DHC-5, DHC-60, DHC-240 and DHC-1440 aerogels.
[0028] Figure 4 This is the compressive stress-strain curve of the aerogel under different strain conditions obtained after immersion in the solution for 240 minutes in the hydrogel state.
[0029] Figure 5The state and transparency of the hydrogel after immersion in the solution for 1440 min.
[0030] Figure 6 These are the adsorption curves of DHC-0, DHC-5, DHC-15, DHC-30, DHC-60, DHC-120, DHC-240, DHC-480, and DHC-1440 aerogels.
[0031] Figure 7 The diagrams are of the swelling and deswelling of the hydrogel after soaking in the solution for 30 minutes, wherein the left diagram is of the hydrogel after soaking in the solution for 30 minutes deswelling for 60 minutes, and the right diagram is of the hydrogel after soaking in the solution for 30 minutes swelling for another 210 minutes.
[0032] Figure 8 The adsorption effect of DHC-240 aerogel on Orange G dye (a) and sodium fluorescein dye (b).
[0033] Fig. 9 This is the effect of DHC-240 aerogel artificially squeezed and adsorbed with OG dye. DETAILED DESCRIPTION
[0034] The present invention is described in detail below with reference to the embodiments, but the embodiments of the present invention are not limited thereto. Obviously, the embodiments described below are only partial embodiments of the present invention. For those skilled in the art, other similar embodiments obtained without creative labor all fall within the protection scope of the present invention.
[0035] Example 1
[0036] This embodiment provides a method for adjusting the pore size of aerogels, comprising the following steps:
[0037] (1) Preparation of hydrogel: Referring to the existing literature (DOI: 10.1016 / j.biortech.2023.129825, DOI: 10.1016 / j.jece.2021.106106), hemicellulose xylan and chitosan were used as the main raw materials to prepare hydrogel. Hemicellulose was oxidized to dialdehyde hemicellulose and then cross-linked with chitosan solution to generate a three-dimensional hydrogel. The specific process was as follows: 1 g of hemicellulose xylan was dissolved in deionized water, and then sodium periodate was added in a molar ratio of 1:1. The mixture was stirred with a magnetic stirrer for 24 h at 40 °C in complete darkness. 10 mL of ethylene glycol was added to the reaction mixture and dialyzed for one day to remove oligomers and impurities. Finally, the dialyzed solution was precipitated and filtered, poured into a culture dish and dried at below 40 °C for 24 h to obtain dialdehyde hemicellulose, named DS-DH.
[0038] After preparing DS-DH, 1.5 g of chitosan (CS) was dissolved in 30 mL of 2 wt% acetic acid aqueous solution, and stirred in a water bath at 40 °C for 20 min to obtain a transparent and uniform solution; 0.6 g of DS-DH was dissolved in 30 mL of deionized water, stirred evenly, and then poured into the CS solution, stirred quickly and evenly, poured into a mold, and kept at 20 °C for 12 h;
[0039] (2) Hydrogel pore expansion: The prepared hydrogel was immersed in a sodium chloride pore expansion solution with a solute concentration of 0.01 wt%, a solution pH of 6.8, an immersion temperature of 20°C, and a immersion time of 0 min, 5 min, 15 min, 30 min, 60 min, 120 min, 240 min, 480 min, and 1440 min to ensure that the solution enters the interior of the hydrogel; after the immersion, the hydrogel was taken out and placed at the same temperature, without direct sunlight, and without wind for 24 h to ensure the stability of the hydrogel structure and the uniform expansion of the pore size, and then washed with a deionized water solution to remove the residual pore expansion solution;
[0040] (3) Aerogel preparation: The hydrogel was immediately freeze-dried in a vacuum oven at -50 °C for 48 h to obtain aerogel. The aerogels obtained after immersion in the hydrogel solution for 0 min, 5 min, 15 min, 30 min, 60 min, 120 min, 240 min, 480 min, and 1440 min were named DHC-0, DHC-5, DHC-15, DHC-30, DHC-60, DHC-120, DHC-240, DHC-480, and DHC-1440, respectively.
[0041] Figure 1 Figure 2 shows the hydrogel before freeze-drying (a) and the aerogel after freeze-drying (b), where (a) is the hydrogel after being soaked in the solution for 0 min, 5 min, 15 min, 30 min, 60 min, 120 min, 240 min, 480 min, and 1440 min, and (b) is the upward straight line corresponding to the aerogel after freeze-drying in Figure (a). It can be seen that the volume of the hydrogel and aerogel increases with the immersion time.
[0042] Figure 2 The SEM images of the corresponding aerogels after freeze-drying of the hydrogels after being immersed in the solution for 0 min (a), 5 min (b), 15 min (c), 30 min (d), 60 min (e), 120 min (f), 240 min (g), 480 min (h), and 1440 min (i) respectively (scale bar 1 mm); It can be seen from the figure that the pore size changes at the microscopic level are compared. From a to i, the pore size gradually increases, and the pores are connected and merged.
[0043] Figure 3 Figure 2 shows the N2 adsorption-desorption isotherms (a) and the corresponding BJH pore size distribution diagram (b) of DHC-5, DHC-60, DHC-240 and DHC-1440 aerogels. DHC-5 has the least number of internal pores, while DHC-60 is mainly composed of mesopores, but the number is relatively small. The pore size of DHC-240 is mainly concentrated in the micropore and mesopore range (0-2nm), among which the number of micropores is the most abundant. The pore size of DHC-1440 is mainly concentrated in the mesopore range (2-50nm).
[0044] The mechanical properties of the aerogels obtained after immersion in the hydrogel state for 240 min were tested at 40%, 60%, and 80% compressive strains. Figure 4 As shown, the aerogel exhibits good flexibility and compressibility, can withstand compressive stress up to 25 kPa, and will not collapse at 80% strain, demonstrating its excellent elasticity; with the increase of compressive strain, a significant stress increase is observed in the low strain range.
[0045] Figure 5 The state and transparency of the hydrogel after immersion in the solution for 1440 minutes. It can be seen that the hydrogel after immersion in the solution for 1440 minutes has the highest water content, transparency and hardness, and the performance is stable. The volume and properties of the hydrogel remain unchanged and can still be salvaged intact, indicating that the material has good resistance to water immersion and is suitable for long-term application. There is no need to worry about excessive immersion affecting the material performance.
[0046] Adsorption experiment: The intermittent adsorption method was used to study the adsorption performance of DHC on OG and FS. The operating steps are as follows: At 293K, 50mg DHC-240 was placed in 50mL of 500mg / L dye solution (original pH = 6.8), and the total adsorption time was 1440min. The adsorption process was carried out under a water bath oscillator (100rpm, 12h), and 2.0mL of the solution was sampled at certain time intervals. The filtrate was diluted to a certain concentration, and its concentration was detected using a full-wavelength ultraviolet spectrophotometer. All tests were repeated three times. Adsorption amount q e (mg / g) is calculated according to formula 1-1:
[0047] qe=(C0-Ce)×V / m (1-1)
[0048] Among them C e and C0 are the equilibrium concentration and initial concentration (mg / L), respectively. V is the volume of the solution (L), and m is the weight of the added aerogel (g).
[0049] The dye removal rate η (%) is calculated according to formula 1-2:
[0050] η=(C0-C t ) / C0×100% (1-2)
[0051] Where C0 is the initial concentration (mg / L), C t is the final concentration (mg / L).
[0052] The adsorption curves of DHC-0, DHC-5, DHC-15, DHC-30, DHC-60, DHC-120, DHC-240, DHC-480, and DHC-1440 aerogels are shown in the figure. Figure 6 As shown, it can be seen that the immersion time has a significant effect on the adsorption rate of the aerogel, but has almost no effect on the adsorption amount. In addition, DHC-240, DHC-480 and DHC-1440 immersed for a long time showed a higher adsorption rate, and the adsorption efficiency of the target was higher than that of the unexpanded aerogel (DHC-0 material), which greatly shortened the adsorption equilibrium time. This may be because the specific surface area and pore size of the sample are moderate, with sufficient macropores, mesopores and micropores.
[0053] Figure 7 The swelling and deswelling of the hydrogel after immersion in the solution for 30 minutes. It can be seen that the hydrogel swells as a whole after being immersed in the solution for 210 minutes. After being taken out and placed under the same conditions, that is, not immersed in the solution, the hydrogel deswells after 60 minutes. This means that the same hydrogel can be dynamically adjusted to control the internal pore size, and then the corresponding aerogel can be obtained.
[0054] Figure 8 This is the adsorption effect diagram of DHC-240 aerogel on Orange G dye (a) and sodium fluorescein dye (b), OG is the target Orange G dye, FS is the target sodium fluorescein, the solid line is the UV-visible absorption intensity of the target under full wavelength scanning, and the dotted line is the UV-visible absorption intensity of the target after adsorption by DHC-240 aerogel. It can be concluded from the figure that the removal effect of OG and FS is obvious after 240 minutes of adsorption by DHC-240 aerogel.
[0055] Fig. 9 This is a picture of the effect of DHC-240 aerogel artificially squeezed to adsorb OG dye. The DHC-240 aerogel was subjected to repeated extrusion tests, and it was observed that the extruded liquid was clear and transparent. The liquids extruded multiple times were all clear and transparent. Under the action of multiple external forces, the DHC-240 structure was stable and it was still able to firmly adsorb pollutants, avoiding the risk of secondary pollution.
[0056] Example 2
[0057] This embodiment provides a method for adjusting the pore size of aerogels, comprising the following steps:
[0058] (1) Preparation of hydrogel: Referring to the existing literature (DOI: 10.1016 / j.biortech.2023.129825, DOI: 10.1016 / j.jece.2021.106106), hemicellulose xylan and chitosan were used as the main raw materials to prepare hydrogel. Hemicellulose was oxidized to dialdehyde hemicellulose and then cross-linked with chitosan solution to generate a three-dimensional hydrogel. The specific process was as follows: hemicellulose xylan was dissolved in deionized water, and then sodium periodate was added in a molar ratio of 1:1. The mixture was stirred with a magnetic stirrer for 24 h at 40 °C in complete darkness. 10 mL of ethylene glycol was added to the reaction mixture and dialyzed for one day to remove oligomers and impurities. Finally, the dialyzed solution was precipitated and filtered, poured into a culture dish and dried at below 40 °C for 24 h to obtain dialdehyde hemicellulose, named DS-DH.
[0059] After preparing DS-DH, 1.5 g of chitosan (CS) was dissolved in 30 mL of 2 wt% acetic acid aqueous solution, and stirred in a water bath at 40 °C for 20 min to obtain a transparent and uniform solution; 0.6 g of DS-DH was dissolved in 30 mL of deionized water, stirred evenly, and then poured into the CS solution, stirred quickly and evenly, poured into a mold, and kept at 20 °C for 12 h;
[0060] (2) Hydrogel pore expansion: The prepared hydrogel was immersed in a calcium carbonate pore expansion solution with a solute concentration of 0.01 wt %, a solution pH of 6.8, an immersion temperature of 20° C., and a immersion time of 0 min, 5 min, 15 min, 30 min, 60 min, 120 min, 240 min, 480 min, and 1440 min to ensure that the solution enters the interior of the hydrogel; after the immersion, the hydrogel was taken out and placed at the same temperature, without direct sunlight, and without wind for 24 h to ensure the stability of the hydrogel structure and the uniform expansion of the pore size, and then washed with a deionized water solution to remove the residual pore expansion solution;
[0061] (3) Aerogel preparation: The hydrogel was immediately freeze-dried in a vacuum oven at -50 °C for 48 h to obtain aerogel. The aerogels obtained after immersion in the hydrogel solution for 0 min, 5 min, 15 min, 30 min, 60 min, 120 min, 240 min, 480 min, and 1440 min were named DHC / 0, DHC / 5, DHC / 15, DHC / 30, DHC / 60, DHC / 120, DHC / 240, DHC / 480, and DHC / 1440, respectively.
[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for adjusting the pore size of aerogels, characterized in that: The steps include: (1) Preparation of hydrogel: preparing a three-dimensional hydrogel using one or a combination of two or more of cellulose and its derivatives, hemicellulose and its derivatives, gelatin and its modifications, chitosan and its derivatives, collagen, alginate, hyaluronic acid, polyethylene glycol, polyurethane, polylactic acid, polyvinyl pyrrolidone, polyvinyl alcohol, polyacrylic acid, polyacrylamide, (poly)acrylic acid and its derivatives, carbomer, silicon dioxide, agar, starch and its derivatives, and pectin as main components; (2) Hydrogel pore expansion: The prepared hydrogel is immersed in a pore expansion solution with a concentration of 0 wt% to 100 wt%, a solution pH controlled at 1 to 14, an immersion temperature of 10°C to 100°C, and a time of 10 to 1440 min to ensure that the solution enters the interior of the hydrogel; after the immersion, the hydrogel is taken out and placed at the same temperature, without direct sunlight and wind for 0 to 24 h to ensure the stability of the hydrogel structure and the uniform expansion of the pore size, and then washed with a washing solution to remove the residual pore expansion solution; (3) Aerogel preparation: The obtained hydrogel is immediately freeze-dried in a vacuum oven at a freezing temperature of -10°C to -80°C and a drying time of 12h to 48h to obtain an aerogel.
2. The method according to claim 1, characterized in that The specific process of step (1) is as follows: 1-2 g of hemicellulose xylan is dissolved in deionized water, and then sodium periodate is added in a molar ratio of 1:1-1:2, and the reaction is stirred for 20-30 hours at 35-45° C. in complete darkness; 5-20 mL of ethylene glycol is added to the reaction mixture, dialyzed to remove oligomers and impurities, the dialyzed solution is precipitated and filtered, and dried at a temperature below 40° C. for 20-48 hours to obtain dialdehyde hemicellulose powder; chitosan is dissolved in a 1.0-3.0 wt % acetic acid aqueous solution to prepare a chitosan acetic acid aqueous solution with a concentration of 0.01-0.05 g / mL; the dialdehyde hemicellulose powder is dissolved in deionized water to prepare a dialdehyde hemicellulose powder aqueous solution with a concentration of 0.01-0.05 g / mL, the dialdehyde hemicellulose powder aqueous solution and the chitosan acetic acid aqueous solution are mixed evenly in a volume ratio of 1:1, poured into a mold, and kept at 15-25° C. for 10-20 hours to obtain a hydrogel.
3. The method according to claim 1, characterized in that: The pore expansion solution described in step (2) includes but is not limited to water, methanol, ethanol, propanol, acetone, ethyl acetate, dimethyl sulfoxide, N,N-dimethylformamide, tetrahydrofuran, acetonitrile, dichloromethane, chloroform, and carbon tetrachloride; the anions in the solution are one of tartrate, acetate, phosphate, citrate, sulfate, sulfate oxide, carbonate, carbonate cyanide, dioxyphosphate, thiosulfate, and chloride ions, and the cations in the solution are one of ammonium ions, lithium ions, potassium ions, sodium ions, manganese ions, calcium ions, and barium ions.
4. The method according to claim 1, characterized in that: The washing solution described in step (2) includes but is not limited to water.
5. An aerogel with adjustable pore size obtained by the method according to any one of claims 1 to 4.
6. The aerogel with adjustable pore size according to claim 5, characterized in that: The pore size of the aerogel is 1nm-10mm.
7. Use of the aerogel with adjustable pore size according to claim 5 or 6 in medical devices, environmental pollutant adsorption, sanitary products, cosmetics, fertilizers, food and medicine.