Polymer modified silicon dioxide aerogel as well as preparation method and application thereof

Abstract

The invention provides polymer modified silicon dioxide aerogel as well as a preparation method and application thereof, relates to the technical field of composite materials, and aims to solve the problem that pure silicon dioxide aerogel is relatively poor in mechanical property. The polymer of the polymer modified silicon dioxide aerogel is formed by polymerization reaction of a double-bond-containing polymeric monomer and a double-bond-containing silane coupling agent.

Description

Technical Field

[0001] The present disclosure relates to the technical field of composite materials, and in particular to a polymer-modified silica aerogel and a preparation method and application thereof. Background Art

[0002] Silica aerogel, due to its lightweight and porous properties, has attracted considerable attention in the thermal insulation field. This material is composed of countless interconnected nanoscale silica particles, forming a complex, disordered three-dimensional network. This unique nanoporous structure simultaneously inhibits heat conduction, convection, and radiation, resulting in extremely low thermal conductivity, making it an ideal choice for high-efficiency thermal insulation. However, silica aerogel is brittle and has poor mechanical properties. Summary of the Invention

[0003] The purpose of the present disclosure is to provide a polymer-modified silica aerogel and its preparation method and application, in order to solve the problem of poor mechanical properties of silica aerogel.

[0004] To achieve the above objectives, the present disclosure adopts the following technical solutions:

[0005] In a first aspect, the present disclosure provides a polymer-modified silica aerogel, wherein the polymer is formed by a polymerization reaction between a double-bond-containing monomer and a double-bond-containing silane coupling agent.

[0006] The embodiments of the present disclosure provide a universal polymer-modified silica aerogel having a rich cross-linked network skeleton. In the silica aerogel, a double-bond-containing polymer monomer and a double-bond-containing silane coupling agent undergo a polymerization reaction to form a polymer-modified silica aerogel, which enhances the stability of the silica aerogel and provides additional support and toughness, thereby significantly improving the mechanical properties of the silica aerogel.

[0007] In some embodiments, the double bond-containing polymeric monomer is selected from: acrylic ester polymeric monomers, styrene, vinyl acetate, N-vinyl pyrrolidone, acrylamide, functionally modified forms thereof, or combinations thereof.

[0008] In some embodiments, the acrylic ester polymerizable monomer is selected from methyl methacrylate, trifluoroethyl acrylate, or a combination thereof.

[0009] In some embodiments, the form with functional modification is a form with magnetic functional modification.

[0010] In some embodiments, the functionally modified form is a form modified with magnetic particles or a form with a magnetic side group being a metal chelate.

[0011] In some embodiments, the double bond-containing silane coupling agent is selected from vinyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, styrylsilane, or a combination thereof.

[0012] In some embodiments, the polymerization reaction is a free radical copolymerization reaction.

[0013] In some embodiments, the polymer is chemically bonded to the silica aerogel.

[0014] In some embodiments, the polymer-modified silica aerogel is at least partially coated on the aerogel skeleton.

[0015] In some embodiments, the polymer is uniformly coated on the aerogel skeleton through chemical bonds.

[0016] The polymer-modified silica aerogel has a double network structure, which includes a network formed by the polymer and a silica network.

[0017] In some embodiments, the polymerization reaction is carried out in the presence of an initiator.

[0018] In some embodiments, the initiator is selected from azobisisobutyronitrile, dicumyl peroxide, dibenzoyl peroxide, or a combination thereof.

[0019] In some embodiments, the ratio of the mass of the double-bond-containing silane coupling agent to the mass of silica in the polymer-modified silica aerogel is in a range of 0.01 to 0.15.

[0020] In some embodiments, the ratio of the mass of the double bond-containing polymerized monomer to the mass of silica in the polymer-modified silica aerogel is in the range of 0.01 to 0.5.

[0021] In a second aspect, the present disclosure provides a method for preparing a polymer-modified silica aerogel. The method comprises preparing a wet silica gel. A polymerization reaction occurs in the wet gel, wherein a double-bond-containing monomer polymerizes with a double-bond-containing silane coupling agent. The wet gel after the polymerization reaction is dried to obtain the polymer-modified silica aerogel.

[0022] In some embodiments, preparing the silica wet gel comprises reacting a silicon source, water, and an organic solvent to obtain the silica wet gel.

[0023] In some embodiments, the method for preparing polymer-modified silica aerogel further comprises aging the wet gel before performing the polymerization reaction.

[0024] In some embodiments, the method for preparing polymer-modified silica aerogel further comprises aging the wet gel and performing solvent replacement before performing polymerization.

[0025] In some embodiments, a silane coupling agent containing a double bond is mixed with a silicon source, water, and an organic solvent, and then reacted to obtain a silicon dioxide wet gel.

[0026] In some embodiments, a silane coupling agent containing a double bond is mixed with a mixed solution containing a silicon source, water, and an organic solvent, and then reacted to obtain a silicon dioxide wet gel.

[0027] In some embodiments, after solvent replacement, a double bond-containing monomer is added to the obtained gel to carry out polymerization.

[0028] In some embodiments, after solvent replacement, a double bond-containing monomer and an initiator are added to the obtained gel to carry out polymerization.

[0029] In some embodiments, the ratio of the mass of the silane coupling agent containing double bonds to the mass of silica in the polymer-modified silica aerogel is in a range of 0.01 to 0.15.

[0030] In some embodiments, the ratio of the mass of the polymerized monomer containing double bonds to the mass of silica in the polymer-modified silica aerogel is in the range of 0.01 to 0.5.

[0031] In some embodiments, the aging temperature ranges from 45°C to 100°C.

[0032] In some embodiments, the aging time ranges from 24 hours to 48 hours.

[0033] In some embodiments, the organic solvent is ethanol.

[0034] In some embodiments, the solvent replacement is replacing the ethanol with DMF.

[0035] In some embodiments, the double bond-containing polymeric monomer is selected from: acrylic ester polymeric monomers, styrene, vinyl acetate, N-vinyl pyrrolidone, acrylamide, functionally modified forms thereof, or combinations thereof.

[0036] In some embodiments, the acrylic ester polymerizable monomer is selected from methyl methacrylate, trifluoroethyl acrylate, or a combination thereof.

[0037] In some embodiments, the form with functional modification is a form with magnetic functional modification.

[0038] In some embodiments, the functionally modified form is a form modified with magnetic particles or a form with a magnetic side group being a metal chelate.

[0039] In some embodiments, the double bond-containing silane coupling agent is selected from vinyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, styrylsilane, or a combination thereof.

[0040] In some embodiments, the polymerization reaction is a free radical copolymerization reaction.

[0041] In some embodiments, the polymer is chemically bonded to the silica aerogel.

[0042] In some embodiments, the polymer-modified silica aerogel is at least partially coated on the aerogel skeleton.

[0043] In some embodiments, the polymer is uniformly coated on the aerogel skeleton through chemical bonds.

[0044] In some embodiments, the aerogel has a double network structure; the double network structure includes a network formed by a polymer and a silica network.

[0045] In some embodiments, the polymerization reaction is carried out in the presence of an initiator.

[0046] In some embodiments, the initiator is selected from azobisisobutyronitrile, dicumyl peroxide, dibenzoyl peroxide, or a combination thereof.

[0047] In some embodiments, the ratio of the molar amount of the initiator to the molar amount of double bonds in the double bond-containing polymerizable monomer is in a range of 0.01 to 0.02.

[0048] In a third aspect, the present disclosure provides a polymer-modified silica aerogel prepared according to the method for preparing a polymer-modified silica aerogel according to any one of the above embodiments.

[0049] In a fourth aspect, the present disclosure provides a thermal insulation material comprising: polymer-modified silica aerogel or aerogel prepared by the method for preparing the polymer-modified silica aerogel disclosed herein.

[0050] It can be understood that the beneficial effects of the preparation method and thermal insulation material of the polymer-modified silica aerogel provided by the above embodiments of the present disclosure can be referred to the beneficial effects of the polymer-modified silica aerogel above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0052] Figure 1 This is a flow chart of a method for preparing a polymer-modified silica aerogel provided in Example 3 of the present disclosure;

[0053] Figure 2 This is an SEM image of a polymer-modified silica aerogel provided in Example 3 of the present disclosure;

[0054] Figure 3 This is an infrared spectrum of a polymer-modified silica aerogel provided in Comparative Example 1 and Examples 1 to 2 of the present disclosure;

[0055] Figure 4 This is a graph of thermal conductivity of a polymer-modified silica aerogel provided in Comparative Example 1 and Examples 4 to 6 of the present disclosure;

[0056] Figure 5 A graph showing the mechanical properties of a polymer-modified silica aerogel provided in Comparative Example 1 and Examples 7 and 8 of the present disclosure;

[0057] Figure 6 A contact angle diagram of a polymer-modified silica aerogel provided in Example 7 of the present disclosure;

[0058] Figure 7 This is an infrared thermal image of a polymer-modified silica aerogel provided in Comparative Example 1 and Examples 7 to 8 of the present disclosure. DETAILED DESCRIPTION

[0059] The following will be combined with the accompanying drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the embodiments described are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present disclosure.

[0060] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this disclosure, unless otherwise specified, "plurality" means two or more.

[0061] In the embodiments of the present disclosure, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present disclosure should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0062] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0063] The embodiments of the present disclosure provide a polymer-modified silica aerogel, wherein the polymer is formed by a polymerization reaction between a double-bond-containing monomer and a double-bond-containing silane coupling agent.

[0064] Understandably, silica aerogel has a rich cross-linked network skeleton. In the silica aerogel, the double-bond-containing polymer monomer and the double-bond-containing silane coupling agent undergo polymerization reaction to form polymer-modified silica aerogel, which enhances the stability of the silica aerogel and provides additional support and toughness, thereby significantly improving the mechanical properties of the silica aerogel.

[0065] Furthermore, the polymerization reaction is a free radical copolymerization reaction.

[0066] Furthermore, the polymer is chemically bonded to the silica aerogel.

[0067] Furthermore, in the polymer-modified silica aerogel, the polymer is at least partially coated on the aerogel skeleton. Preferably, the polymer is uniformly coated on the aerogel skeleton through chemical bonds.

[0068] Furthermore, the aerogel has a double network structure, which includes a network formed by a polymer and a silica network.

[0069] It can be understood that the polymer is a free radical copolymerization reaction of a double-bond-containing polymer monomer and a double-bond-containing silane coupling agent, so that the polymer is bonded to the silica aerogel through a chemical bond, forming a polymer at least partially coated on the aerogel skeleton. Preferably, the polymer is uniformly coated on the aerogel skeleton, so that the polymer-modified silica has a double network structure, including a network formed by the polymer and a silica network. This can further improve the stability of the polymer-modified silica aerogel and increase the mechanical properties of the polymer-modified silica aerogel.

[0070] In some embodiments, the double bond-containing polymeric monomer is selected from: acrylic ester polymeric monomers, styrene, vinyl acetate, N-vinyl pyrrolidone, acrylamide, functionally modified forms thereof, or combinations thereof.

[0071] Preferably, the acrylic ester polymerizable monomer is selected from methyl methacrylate, trifluoroethyl acrylate or a combination thereof.

[0072] Preferably, the form with functional modification is a form with magnetic functional modification.

[0073] More preferably, the form with functional modification is a form modified with magnetic particles or a form with magnetic side groups as metal chelates.

[0074] In some embodiments, the functionally modified form is an acrylate monomer with magnetic ferrosoferric oxide particles and an acrylate monomer with a magnetic metal chelate as a side group.

[0075] The polymer-modified silica aerogel disclosed herein also has improved hydrophobicity, which can effectively prevent moisture from invading the thermal insulation material, thereby improving the stability and durability of the entire material.

[0076] Magnetic organic polymer materials can make polymer-modified silica aerogels magnetic and can be used for magnetic separation.

[0077] In some embodiments, the double bond-containing silane coupling agent is selected from vinyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, styrylsilane, or a combination thereof.

[0078] It can be understood that the above-mentioned double bond-containing polymer monomers can form hydrophobic organic polymers through polymerization reactions, which can effectively prevent moisture from invading the insulation material, thereby improving the stability and durability of the entire material; or form magnetic organic polymer materials, which can make the polymer-modified silica aerogel magnetic and can be used for magnetic separation.

[0079] In some embodiments, the polymerization reaction is carried out in the presence of an initiator.

[0080] Preferably, the initiator is selected from azobisisobutyronitrile (AIBN), dicumyl peroxide (DCP), dibenzoyl peroxide (BPO), or a combination thereof.

[0081] The present invention provides a method for preparing a polymer-modified silica aerogel. Figure 1 As shown, it includes: S1~S3.

[0082] S1: Preparation of silica wet gel.

[0083] S2: A polymerization reaction occurs in the wet gel, wherein the polymerization reaction is the polymerization of a double-bond-containing polymerization monomer and a double-bond-containing silane coupling agent.

[0084] S3: Drying the wet gel after the polymerization reaction to obtain polymer-modified silica aerogel.

[0085] In some embodiments, the method for preparing polymer-modified silica aerogel further comprises: aging the wet gel before performing a polymerization reaction.

[0086] Preferably, the aging temperature range of the aging is 45°C to 100°C.

[0087] For example, the aging temperature can be 45° C., 60° C., 75° C., or 100° C., etc., which is not limited here.

[0088] Preferably, the aging time ranges from 24 hours to 48 hours.

[0089] For example, the aging time can be 24 hours, 30 hours, 36 hours, 42 hours or 48 hours, etc., which is not limited here.

[0090] Preferably, a silane coupling agent containing a double bond is mixed with a silicon source, water and an organic solvent and reacted to obtain a silicon dioxide wet gel.

[0091] In some embodiments, S1 preparing the wet silica gel includes: reacting a silicon source, water, and an organic solvent to obtain the wet silica gel.

[0092] Preferably, the organic solvent is ethanol.

[0093] Illustratively, reacting the silicon source, water, and organic solvent can include mixing the silicon source, solvent, and a silane coupling agent containing double bonds, hydrolyzing the mixture under an acidic catalyst, and then reacting the mixture under an alkaline catalyst to form an initial gel. For example, the acidic catalyst includes at least one of hydrochloric acid, nitric acid, acetic acid, and oxalic acid. For example, the alkaline catalyst includes at least one of aqueous ammonia, tetraethylammonium hydroxide, triethanolamine, diethylamine, and triethylamine.

[0094] More preferably, a silane coupling agent containing a double bond is mixed with a mixed solution containing a silicon source, water and an organic solvent, and then reacted to obtain a silicon dioxide wet gel.

[0095] Preferably, the ratio of the mass of the silane coupling agent containing double bonds to the mass of silica in the polymer-modified silica aerogel is in the range of 0.01 to 0.15.

[0096] For example, the ratio of the mass of the silane coupling agent containing double bonds to the mass of silica in the polymer-modified silica aerogel can be 0.01, 0.05, 0.10, 0.11, 0.12, 0.13, 0.14 or 0.15, etc., which is not limited here.

[0097] As can be understood, by setting the ratio of the mass of the double-bond-containing silane coupling agent to the mass of the gel within the range of 0.01 to 0.15, the content of the double-bond-containing silane coupling agent is sufficient to introduce necessary organic functional groups or adjust the network structure, but not excessive enough to cause looseness or defects in the network. This reasonable ratio helps form a small or mesoporous network with a good pore structure and stability, thereby optimizing the mechanical properties and specific surface area of ​​the thermal insulation material.

[0098] In some embodiments, the method for preparing polymer-modified silica aerogel further comprises aging the wet gel and performing solvent replacement before performing polymerization.

[0099] Preferably, the solvent replacement is replacement of ethanol with N,N-dimethylformamide (DMF).

[0100] Preferably, after solvent replacement, a double bond-containing monomer is added to the obtained gel to carry out polymerization reaction.

[0101] Preferably, the ratio of the mass of the double bond-containing polymer monomer to the mass of silica in the polymer-modified silica aerogel is in the range of 0.01 to 0.5.

[0102] For example, the ratio of the mass of the double bond-containing polymer monomer to the mass of silica in the polymer-modified silica aerogel can be 0.01, 0.02, 0.03, 0.04 or 0.05, etc., which is not limited here.

[0103] It can be understood that by setting the ratio of the mass of the double bond-containing polymer monomer to the mass of the gel within the range of 0.01 to 0.5, within this ratio range, the content of the double bond-containing polymer monomer is sufficient to introduce functional organic groups, but not too much to cause the pore structure to become too loose or chaotic, and multiple scattering and air layers can be formed, which helps to maintain the stability of the polymer-modified silica aerogel.

[0104] Preferably, after solvent replacement, a double bond-containing polymerization monomer and an initiator are added to the obtained gel to carry out polymerization reaction.

[0105] For example, the ratio of the molar amount of the initiator to the molar amount of double bonds in the double-bond-containing polymerizable monomer is in the range of 0.01 to 0.02.

[0106] For example, the ratio of the molar amount of the initiator to the molar amount of double bonds in the double-bond-containing polymerizable monomer can be 0.01, 0.012, 0.014, 0.016, 0.018 or 0.02, etc., which is not limited here.

[0107] It can be understood that by setting the ratio of the molar amount of the above-mentioned initiator to the molar amount of double bonds in the polymerizing monomer within the range of 0.01 to 0.02, it is possible to avoid excessive reaction or initiation of excessive polymerization, thereby helping to obtain a uniform and well-controlled polymer network, avoiding excessive or insufficient polymerization of branches, promoting more sufficient cross-linking and network formation, and enhancing the overall performance of the polymer-modified silica aerogel.

[0108] In some embodiments, the double bond-containing polymeric monomer is selected from: acrylic ester polymeric monomers, styrene, vinyl acetate, N-vinyl pyrrolidone, acrylamide, functionally modified forms thereof, or combinations thereof.

[0109] Preferably, the acrylic ester polymerizable monomer is selected from methyl methacrylate, trifluoroethyl acrylate or a combination thereof.

[0110] Preferably, the form with functional modification is a form with magnetic functional modification.

[0111] More preferably, the functionally modified form is modified with magnetic particles or with magnetic side groups. For example, the magnetic particles or the side groups with magnetic metal chelates can be acrylate-modified magnetic ferrosoferric oxide particles, with the side groups being (meth)acrylate-based polymerized monomers of the magnetic metal chelate.

[0112] In some embodiments, the double bond-containing silane coupling agent is selected from vinyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, styrylsilane, or a combination thereof.

[0113] It can be understood that the above-mentioned silicon source, solvent and silane coupling agent gradually break down in water to generate active intermediates with silanol groups. After hydrolysis under acidic conditions, a condensation reaction is carried out under alkaline conditions. The condensation reaction is the formation of chemical bonds between silanol groups, so that the sol gradually transforms into a gel state. Gel aging makes the gel structure more stable, and then the solvent in the gel is removed by solvent replacement. The initial solvent is removed while retaining the pore structure by successive solvent replacement, which is not limited by the drying equipment and sample size, while retaining the pore structure of the gel.

[0114] In other words, the disclosed solution has universal applicability. A silane coupling agent containing double bonds can be used to co-hydrolyze with a silicon source, and then copolymerized with a double-bond-containing polymerization monomer. This can relatively uniformly introduce organic polymer chains into the network structure of the silica aerogel. These organic chains play a role in strengthening and toughening the silica aerogel, significantly improving the toughness and strength of the silica aerogel, enabling it to withstand greater external forces without breaking, thereby expanding its application in fields with high requirements for mechanical properties.

[0115] Example 1

[0116] Example 1 provides a polymer-modified silica aerogel. The preparation method of the polymer-modified silica aerogel comprises steps (1) to (5).

[0117] Step (1): 15.2 g of tetraethyl silicate, 22.6 g of ethanol, and 6.5 g of water are added, and vinyl trimethoxysilane is added dropwise. While stirring, hydrochloric acid is added dropwise to adjust the pH of the system to approximately 2, and then stirred at room temperature (20° C. to 25° C.) for 5 hours to ensure smooth hydrolysis. After the hydrolysis is completed, ammonia water is added to adjust the pH to 6.5 to promote a condensation reaction in the system to form a gel; the ratio of the mass of vinyl trimethoxysilane to the mass of silicon dioxide calculated after all the silicon source (i.e., 15.2 g of tetraethyl silicate) is converted into silicon dioxide is 0.05.

[0118] Step (2): A small amount of ethanol is added to the surface of the gel formed in step (1) as an aging solution, and then aged in an oven at 60°C for 24 hours. After the aging is completed, the ethanol is gradiently replaced with N,N-dimethylformamide (DMF) so that the system becomes a DMF solvent.

[0119] Step (3): After the replacement is completed, trifluoroethyl acrylate and azobisisobutyronitrile (AIBN) are added, and then the mixture is placed at room temperature (20°C to 25°C) under sealed conditions and allowed to stand for 12 hours to ensure that the polymerization monomer and initiator can be evenly dispersed in the pores of the gel to obtain an initial gel; the ratio of the mass of trifluoroethyl acrylate to the mass of silica calculated after all silicon sources (i.e., 15.2g of tetraethyl silicate) are converted into silica is 0.3; the ratio of the molar amount of azobisisobutyronitrile to the molar amount of double bonds in trifluoroethyl acrylate is 0.01.

[0120] Step (4): The initial gel obtained in step (3) was placed in an oven at 75° C. for reaction for 12 h to ensure that the groups reacted completely, thereby obtaining an initial polymer-modified silica aerogel.

[0121] Step (5): After the initial polymer-modified silica aerogel obtained in step (4) is cooled to room temperature (20°C to 25°C), DMF is replaced with a gradient of ethanol. After the gradient replacement is completed, fresh ethanol is used for solvent replacement, and finally, supercritical drying with ethanol is performed to obtain the polymer-modified silica aerogel.

[0122] Example 2

[0123] Example 2 provides a polymer-modified silica aerogel. The preparation method of the polymer-modified silica aerogel comprises steps (1) to (5).

[0124] Step (1): 10.4 g of tetraethyl silicate, 17.8 g of ethanol, and 4.3 g of water are added, followed by the addition of 3-methacryloyloxypropyltriethoxysilane. While stirring, nitric acid is added dropwise to adjust the pH of the system to approximately 2.5, and then stirred at room temperature (20° C. to 25° C.) for 6 hours to ensure smooth hydrolysis. After the hydrolysis is completed, tetraethoxyammonium hydroxide is added to adjust the pH to 6.7 to promote a condensation reaction in the system to form a gel; the ratio of the mass of vinyltrimethoxysilane to the mass of silicon dioxide calculated after all the silicon source (i.e., 10.4 g of tetraethyl silicate) is converted into silicon dioxide is 0.1.

[0125] Step (2): A small amount of ethanol was added to the surface of the gel formed in step (1) as an aging solution, and then aged in a 45°C oven for 48 hours. After the aging, the ethanol was replaced with DMF in a gradient manner, so that the system became a DMF solvent.

[0126] Step (3): After the replacement is completed, methyl methacrylate and azobisisobutyronitrile are added, and then the mixture is placed at room temperature (20°C to 25°C) under sealed conditions and allowed to stand for 12 hours to ensure that the polymerization monomer and initiator can be evenly dispersed in the pores of the gel; an initial gel is obtained; the ratio of the mass of methyl methacrylate to the mass of silicon dioxide calculated after all silicon sources (i.e., 10.4g of tetraethyl silicate) are converted into silicon dioxide is 0.1; and the ratio of the molar amount of azobisisobutyronitrile to the molar amount of double bonds in methyl methacrylate is 0.015.

[0127] Step (4): The initial gel system obtained in step (3) was placed in an oven at 80° C. for reaction for 12 h to ensure that the groups reacted completely, thereby obtaining an initial polymer-modified silica aerogel.

[0128] Step (5): After the initial polymer-modified silica aerogel obtained in step (4) is cooled to room temperature (20°C to 25°C), DMF is replaced with a gradient of ethanol. After the gradient replacement is completed, fresh ethanol is used for solvent replacement, and finally, supercritical drying with ethanol is performed to obtain the polymer-modified silica aerogel.

[0129] Example 3

[0130] Example 3 provides a polymer-modified silica aerogel. The preparation method of the polymer-modified silica aerogel comprises steps (1) to (5).

[0131] Step (1): 20.7 g of tetraethyl silicate, 33.4 g of ethanol, and 9.3 g of water are added, and styrene trimethoxysilane is added dropwise. While stirring, oxalic acid is added dropwise to adjust the pH of the system to approximately 2.3. The mixture is then stirred at room temperature (20° C. to 25° C.) for 5 hours to ensure smooth hydrolysis. After the hydrolysis is completed, triethylamine is added to adjust the pH to 6.8 to promote a condensation reaction in the system to form a gel. The ratio of the mass of styrene trimethoxysilane to the mass of silicon dioxide calculated after all the silicon source (i.e., 20.7 g of tetraethyl silicate) is converted into silicon dioxide is 0.08.

[0132] Step (2): Add a small amount of ethanol as an aging solution to the surface of the gel formed in step (1), and then age it in an oven at 100°C for 12 hours. After the aging is completed, use DMF to gradient replace the ethanol so that the system becomes a DMF solvent.

[0133] Step (3): After the replacement is completed, styrene and dibenzoyl peroxide (BPO) are added, and then the mixture is placed at room temperature (20°C to 25°C) under sealed conditions and allowed to stand for 12 hours to ensure that the polymerization monomers and initiator can be evenly dispersed in the pores of the gel to obtain an initial gel; the ratio of the mass of styrene to the mass of silica calculated after all the silicon source (i.e., 20.7g of tetraethyl silicate) is converted into silica is 0.5; the ratio of the molar amount of dibenzoyl peroxide to the molar amount of double bonds in trifluoroethyl acrylate is 0.01.

[0134] Step (4): The initial gel obtained in step (3) was placed in an oven at 120° C. for reaction for 24 h to ensure that the groups reacted completely, thereby obtaining an initial polymer-modified silica aerogel.

[0135] Step (5): After the initial polymer-modified silica aerogel obtained in step (4) is cooled to room temperature (20°C to 25°C), DMF is replaced with a gradient of ethanol. After the gradient replacement is completed, fresh ethanol is used for solvent replacement, and finally, supercritical drying with ethanol is performed to obtain the polymer-modified silica aerogel.

[0136] like Figure 2 As shown, Figure 2This is an SEM image of a polymer-modified silica aerogel provided in Example 3 of the present disclosure. It can be seen that the organic polymer material does not destroy the original porous structure of the polymer-modified silica aerogel, and can maintain the original low density and high porosity of the polymer-modified silica aerogel.

[0137] Example 4

[0138] Example 4 provides a polymer-modified silica aerogel. The preparation method of the polymer-modified silica aerogel comprises steps (1) to (5).

[0139] Step (1): 32.1 g of tetraethyl silicate, 54.7 g of ethanol, and 13.8 g of water are added, and vinyl trimethoxysilane is added dropwise. While stirring, oxalic acid is added dropwise to adjust the pH of the system to approximately 2.1, and then stirred at room temperature (20° C. to 25° C.) for 5 hours to ensure smooth hydrolysis. After the hydrolysis is completed, triethylamine is added to adjust the pH to 6.2 to promote a condensation reaction in the system to form a gel; the ratio of the mass of vinyl trimethoxysilane to the mass of silicon dioxide calculated after all the silicon source (i.e., 32.1 g of tetraethyl silicate) is converted into silicon dioxide is 0.01.

[0140] Step (2): A small amount of ethanol was added to the surface of the gel formed in step (1) as an aging solution, and then aged in a 55°C oven for 36 hours. After the aging, the ethanol was replaced by DMF in a gradient manner, so that the system became a DMF solvent.

[0141] Step (3): After the replacement is completed, vinyl acetate and BPO are added, and then the mixture is placed at room temperature (20°C to 25°C) under sealed conditions and allowed to stand for 12 hours to ensure that the polymerization monomers and initiator can be evenly dispersed in the pores of the gel; an initial gel is obtained; the ratio of the mass of vinyl acetate to the mass of silica calculated after all the silicon source (i.e., 32.1 g of tetraethyl silicate) is converted into silica is 0.35; the ratio of the molar amount of BPO to the molar amount of double bonds in vinyl acetate is 0.02.

[0142] Step (4): The initial gel system obtained in step (3) was placed in an oven at 85° C. for reaction for 10 h to ensure that the groups reacted completely, thereby obtaining an initial polymer-modified silica aerogel.

[0143] Step (5): After the initial polymer-modified silica aerogel obtained in step (4) is cooled to room temperature (20°C to 25°C), DMF is replaced with a gradient of ethanol. After the gradient replacement is completed, fresh ethanol is used for solvent replacement, and finally, supercritical drying with ethanol is performed to obtain the polymer-modified silica aerogel.

[0144] Example 5

[0145] Example 5 provides a polymer-modified silica aerogel. The method for preparing the polymer-modified silica aerogel comprises steps (1) to (5).

[0146] Step (1): Take 35.7 g of tetraethyl orthosilicate, 52.3 g of ethanol, and 15.5 g of water, then add styrene trimethoxysilane, drop by drop, while stirring, to adjust the pH of the system to about 2.7 with acetic acid, and then stir at room temperature (20-25°C) for 5 h to ensure the smooth progress of the hydrolysis process. After the hydrolysis is completed, add diethylamine to adjust the pH to 6.8 to promote the condensation reaction of the system to form a gel; the mass ratio of styrene trimethoxysilane to the mass of silica after all silicon sources (i.e., 35.7 g of tetraethyl orthosilicate) are converted into silica is 0.09.

[0147] Step (2): Add a small amount of ethanol as an aging liquid to the surface of the gel formed in step (1), then age in a 70°C oven for 24 h, and after aging is completed, use DMF to perform gradient replacement of the ethanol to make the system a DMF solvent.

[0148] Step (3): After the replacement is completed, add acrylamide and dicumyl peroxide (DCP), then place it in a sealed condition at room temperature (20-25°C) for 12 h to ensure that the polymer monomer and initiator are uniformly dispersed in the pores of the gel to obtain an initial gel; the mass ratio of acrylamide to the mass of silica after all silicon sources (i.e., 35.7 g of tetraethyl orthosilicate) are converted into silica is 0.2; the ratio of the molar amount of DCP to the molar amount of double bonds in acrylamide is 0.016.

[0149] Step (4): Place the initial gel system obtained in step (3) in a 120°C oven for 24 h to ensure that the group reaction is complete to obtain an initial polymer-modified silica aerogel.

[0150] Step (5): After the initial polymer-modified silica aerogel obtained in step (4) is cooled to room temperature (20-25°C), use ethanol to perform gradient replacement of the DMF. After the gradient replacement is completed, continue to use fresh ethanol for solvent replacement, and finally use ethanol supercritical drying to obtain a polymer-modified silica aerogel.

[0151] Example 6

[0152] Example 6 provides a polymer-modified silica aerogel. The method for preparing the polymer-modified silica aerogel comprises steps (1) to (5).

[0153] Step (1): 20.7 g of tetraethyl silicate, 33.4 g of ethanol, and 9.3 g of water are added, and 3-methacryloxypropyltriethoxysilane is added in an amount of 15% of the amount of silica in the mixed solution. While stirring, hydrochloric acid is added dropwise to adjust the pH of the system to approximately 3, and then stirred at room temperature (20° C. to 25° C.) for 5 hours to ensure smooth hydrolysis. After the hydrolysis is completed, triethanolamine is added to adjust the pH to 7 to promote a condensation reaction in the system to form a gel; the ratio of the mass of vinyltrimethoxysilane to the mass of silica calculated after all the silicon source (i.e., 20.7 g of tetraethyl silicate) is converted into silica is 0.01.

[0154] Step (2): A small amount of ethanol was added to the surface of the gel formed in step (1) as an aging solution, and then aged in an oven at 60°C for 30 hours. After the aging was completed, DMF was used to gradiently replace the ethanol so that the system became a DMF solvent.

[0155] Step (3): After the replacement is completed, N-vinyl pyrrolidone and AIBN are added, and then the mixture is placed at room temperature (20°C to 25°C) under sealed conditions and allowed to stand for 12 hours to ensure that the polymerization monomers and initiators can be evenly dispersed in the pores of the gel; an initial gel is obtained; the ratio of the mass of N-vinyl pyrrolidone to the mass of silica calculated after all the silicon source (i.e., 20.7g of tetraethyl silicate) is converted into silica is 0.30; the ratio of the molar amount of AIBN to the molar amount of double bonds in N-vinyl pyrrolidone is 0.02.

[0156] Step (4): The initial gel system obtained in step (3) was placed in an oven at 90° C. for reaction for 20 h to ensure that the groups reacted completely, thereby obtaining an initial polymer-modified silica aerogel.

[0157] Step (5): After the initial polymer-modified silica aerogel obtained in step (4) is cooled to room temperature (20°C to 25°C), DMF is replaced with a gradient of ethanol. After the gradient replacement is completed, fresh ethanol is used for solvent replacement, and finally, supercritical drying with ethanol is performed to obtain the polymer-modified silica aerogel.

[0158] Example 7

[0159] Example 7 provides a polymer-modified silica aerogel. The preparation method of the polymer-modified silica aerogel comprises steps (1) to (5).

[0160] Step (1): 15.7 g of tetraethyl silicate, 24.2 g of ethanol, and 6.5 g of water are added, followed by 3-methacryloxypropyltriethoxysilane. Hydrochloric acid is added dropwise while stirring to adjust the pH of the system to approximately 2.6, and then stirred at room temperature (20° C. to 25° C.) for 5 hours to ensure smooth hydrolysis. After the hydrolysis is completed, triethanolamine is added to adjust the pH to 6.3 to promote a condensation reaction in the system to form a gel; the ratio of the mass of 3-methacryloxypropyltriethoxysilane to the mass of silicon dioxide calculated after all the silicon source (i.e., 15.7 g of tetraethyl silicate) is converted into silicon dioxide is 0.07.

[0161] Step (2): A small amount of ethanol was added to the surface of the gel formed in step (1) as an aging solution, and then aged in a 75°C oven for 24 hours. After the aging was completed, DMF was used to gradiently replace the ethanol so that the system became a DMF solvent.

[0162] Step (3): After the replacement is completed, trifluoroethyl acrylate and AIBN are added, and then the mixture is placed at room temperature (20°C to 25°C) under sealed conditions and allowed to stand for 12 hours to ensure that the polymerization monomers and initiator can be evenly dispersed in the pores of the gel to obtain an initial gel; the ratio of the mass of trifluoroethyl acrylate to the mass of silica calculated after all silicon sources (i.e., 15.7g of tetraethyl silicate) are converted into silica is 0.25; the ratio of the molar amount of AIBN to the molar amount of double bonds in trifluoroethyl acrylate is 0.02.

[0163] Step (4): The initial gel system obtained in step (3) was placed in an oven at 100° C. for reaction for 15 h to ensure that the groups reacted completely, thereby obtaining an initial polymer-modified silica aerogel.

[0164] Step (5): After the initial polymer-modified silica aerogel obtained in step (4) is cooled to room temperature (20°C to 25°C), DMF is replaced with a gradient of ethanol. After the gradient replacement is completed, fresh ethanol is used for solvent replacement, and finally, supercritical drying with ethanol is performed to obtain the polymer-modified silica aerogel.

[0165] Example 8

[0166] Example 8 provides a polymer-modified silica aerogel. The preparation method of the polymer-modified silica aerogel comprises steps (1) to (5).

[0167] Step (1): 21.6 g of tetraethyl silicate, 31.8 g of ethanol, and 8.6 g of water are added, followed by 3-methacryloxypropyltriethoxysilane. Hydrochloric acid is added dropwise while stirring to adjust the pH of the system to approximately 3, and then stirred at room temperature (20° C. to 25° C.) for 5 hours to ensure smooth hydrolysis. After the hydrolysis is completed, ammonia water is added to adjust the pH to 6.8 to promote a condensation reaction in the system to form a gel; the ratio of the mass of 3-methacryloxypropyltriethoxysilane to the mass of silicon dioxide calculated after all the silicon source (i.e., 21.6 g of tetraethyl silicate) is converted into silicon dioxide is 0.06.

[0168] Step (2): A small amount of ethanol was added to the surface of the gel formed in step (1) as an aging solution, and then aged in a 50°C oven for 45 hours. After the aging was completed, DMF was used to gradiently replace the ethanol so that the system became a DMF solvent.

[0169] Step (3): After the replacement is completed, methyl methacrylate and AIBN are added, and then the mixture is placed at room temperature (20°C to 25°C) under sealed conditions and allowed to stand for 12 hours to ensure that the polymerization monomers and initiator can be evenly dispersed in the pores of the gel; an initial gel is obtained; the ratio of the mass of methyl methacrylate to the mass of silica calculated after all the silicon source (i.e., 21.6 g of tetraethyl silicate) is converted into silica is 0.05; and the ratio of the molar amount of AIBN to the molar amount of double bonds in methyl methacrylate is 0.017.

[0170] Step (4): The initial gel system obtained in step (3) was placed in an oven at 80° C. for reaction for 20 h to ensure that the groups reacted completely, thereby obtaining an initial polymer-modified silica aerogel.

[0171] Step (5): After the initial polymer-modified silica aerogel obtained in step (4) is cooled to room temperature (20°C to 25°C), DMF is replaced with a gradient of ethanol. After the gradient replacement is completed, fresh ethanol is used for solvent replacement, and finally, supercritical drying with ethanol is performed to obtain the polymer-modified silica aerogel.

[0172] Here, the mass of silica in the polymer-modified silica aerogels involved in the above embodiments is based on the amount of silica generated by the complete reaction of the silicon source.

[0173] Comparative Example 1

[0174] Comparative Example 1 provides a polymer-modified silica aerogel. The preparation method of the polymer-modified silica aerogel comprises steps (1) to (4).

[0175] Step (1): 15.2 g of tetraethyl silicate, 22.6 g of ethanol, and 6.5 g of water are added, and vinyl trimethoxysilane is added dropwise. While stirring, hydrochloric acid is added dropwise to adjust the pH of the system to approximately 2, and then stirred at room temperature (20° C. to 25° C.) for 5 hours to ensure smooth hydrolysis. After the hydrolysis is completed, ammonia water is added to adjust the pH to 6.5 to promote a condensation reaction in the system to form a gel; the ratio of the mass of vinyl trimethoxysilane to the mass of silicon dioxide calculated after all the silicon source (i.e., 15.2 g of tetraethyl silicate) is converted into silicon dioxide is 0.05.

[0176] Step (2): A small amount of ethanol is added to the surface of the gel formed in step (1) as an aging solution, and then aged in an oven at 60°C for 24 hours. After the aging is completed, the ethanol is gradiently replaced with N,N-dimethylformamide (DMF) so that the system becomes a DMF solvent.

[0177] Step (3): The initial gel system obtained in step (2) was placed in an oven at 75° C. for reaction for 12 h to ensure that the groups reacted completely, thereby obtaining an initial polymer-modified silica aerogel.

[0178] Step (4): After the initial polymer-modified silica aerogel obtained in step (3) is cooled to room temperature (20°C to 25°C), DMF is replaced with a gradient of ethanol. After the gradient replacement is completed, fresh ethanol is used for solvent replacement, and finally, the silica aerogel is dried with ethanol supercritical fluid to obtain the silica aerogel.

[0179] Performance testing

[0180] Test 1: The polymer-modified silica aerogels obtained in the above examples and comparative examples were subjected to infrared spectroscopy testing, and the stretching vibration peak of the carbonyl group appeared in the infrared spectrum of the polymer-modified silica aerogel obtained in the example, indicating that the polymer-modified silica aerogel obtained in the example was successfully synthesized.

[0181] like Figure 3 As shown, Figure 3 The infrared spectra of a silica aerogel provided in Comparative Example 1 and a polymer-modified silica aerogel provided in Examples 1 and 2 of the present disclosure show that compared with the pure silica aerogel in Comparative Example 1 as a polymer-modified silica aerogel, the polymer-modified silica aerogel provided in Examples 1 and 2 has an infrared spectrum of 1735 cm -1 The stretching vibration peak of the carbonyl group appeared at , indicating that the polymer-modified silica aerogel provided by Examples 1 and 2 was successfully synthesized.

[0182] Test 2: The thermal conductivity of the polymer-modified silica aerogels obtained in the above examples and comparative examples was determined. The thermal conductivity of the polymer-modified silica aerogels obtained in the examples was not significantly different from that of the silica aerogels obtained in the comparative examples, indicating that the polymer-modified silica aerogels obtained in the examples had good thermal insulation performance.

[0183] As shown in Figure 4 , Figure 4 the thermal conductivity graph of the silica aerogel provided by Comparative Example 1 of the present disclosure and the polymer-modified silica aerogels provided by Examples 4-6 can be known. The thermal conductivity of the polymer-modified silica aerogels provided by Examples 4-6 was not significantly different from that of the silica aerogel provided by Comparative Example 1, indicating that the polymer-modified silica aerogels provided by Examples 4-6 had good thermal insulation performance.

[0184] Test 3: The mechanical properties of the polymer-modified silica aerogels obtained in the above examples and comparative examples were determined. The results showed that the mechanical properties of the polymer-modified silica aerogels obtained in the examples were significantly higher than those of the silica aerogels obtained in the comparative examples, with a maximum compressive strength of 2.3 MPa and a maximum compressive deformation of 40%, indicating that the polymer-modified silica aerogels obtained in the examples had good mechanical properties.

[0185] As shown in Figure 5 , Figure 5 the mechanical property graph of the silica aerogel provided by Comparative Example 1 of the present disclosure and the polymer-modified silica aerogels provided by Examples 7-8 can be known. The peak stress of Examples 7 and 8 was higher than that of Comparative Example 1, indicating that the strength of the polymer-modified silica aerogels provided by Examples 7-8 was improved, and the polymer-modified silica aerogels provided by Examples 7-8 could withstand greater deformation before breaking (better toughness).

[0186] Test 4: The hydrophobic properties of the polymer-modified silica aerogels obtained in the above examples and comparative examples were determined. The results showed that the hydrophobic properties of the polymer-modified silica aerogels obtained in the examples were significantly higher than those of the silica aerogels obtained in the comparative examples, indicating that the polymer-modified silica aerogels obtained in the examples had good hydrophobic properties.

[0187] As shown in Figure 6 , Figure 6The contact angle diagram of a polymer-modified silica aerogel provided in Example 7 of the present disclosure shows that the left contact angle is 145.868°; the right contact angle is 145.891°, indicating that the polymer-modified silica aerogel provided in Example 7 has strong hydrophobicity.

[0188] Test 5: Infrared thermal imaging tests were performed on the polymer-modified silica aerogels obtained in the above examples and comparative examples. The temperature rise of the polymer-modified silica aerogel obtained in the examples was smaller than that of the silica aerogel in the comparative example. The results showed that the polymer-modified silica aerogel in the examples had better thermal insulation performance.

[0189] like Figure 7 As shown, Figure 7 The infrared thermal imaging images of the silica aerogel obtained in Comparative Example 1 of the present disclosure and the polymer-modified silica aerogel provided in Examples 7 and 8 show that the temperatures of the silica aerogel in Comparative Example 1 are 48.4°C and 50.3°C at 5 minutes and 10 minutes, respectively, indicating that it heats up quickly and has high thermal stability or thermal response performance. The temperatures of the polymer-modified silica aerogel in Example 7 are 54.3°C and 55.6°C at 5 minutes and 10 minutes, respectively, and the temperatures of the polymer-modified silica aerogel in Example 8 reach 55.3°C and 56.9°C at 5 minutes and 10 minutes, respectively. The temperature rise is significantly smaller than that of the silica aerogel in Comparative Example 1, indicating that the polymer-modified silica aerogels in Examples 7 and 8 have better thermal insulation performance.

[0190] The above are only specific embodiments of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this disclosure should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A polymer-modified silica aerogel; characterized in that, The polymer is formed by a polymerization reaction between a double-bond-containing polymer monomer and a double-bond-containing silane coupling agent.

2. The polymer-modified silica aerogel according to claim 1, characterized in that The double bond-containing polymer monomer is selected from: acrylate polymer monomers, styrene, vinyl acetate, N-vinyl pyrrolidone, acrylamide, functionally modified forms thereof, or combinations thereof; preferably, the acrylate polymer monomer is selected from methyl methacrylate, trifluoroethyl acrylate, or combinations thereof; preferably, the functionally modified form is a form modified with a magnetic function; more preferably, the functionally modified form is a form modified with magnetic particles or a side group with a magnetic metal chelate; and / or The double bond-containing silane coupling agent is selected from vinyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, styrylsilane or a combination thereof; and / or The polymerization reaction is a free radical copolymerization reaction; and / or The polymer is chemically bonded to the silica aerogel; and / or In the polymer-modified silica aerogel, the polymer is at least partially coated on the skeleton of the aerogel; and / or The polymer is uniformly coated on the skeleton of the aerogel through chemical bonds; and / or The polymer-modified silica aerogel has a double network structure; the double network structure includes a network formed by a polymer and a silica network; and / or The ratio of the mass of the double-bond-containing silane coupling agent to the mass of the silica in the polymer-modified silica aerogel is in the range of 0.01 to 0.15; and / or The ratio of the mass of the double bond-containing polymer monomer to the mass of silica in the polymer-modified silica aerogel is in the range of 0.01 to 0.5; and / or The polymerization reaction is carried out in the presence of an initiator; preferably, the initiator is selected from azobisisobutyronitrile, dicumyl peroxide, dibenzoyl peroxide or a combination thereof.

3. A method for preparing a polymer-modified silica aerogel, characterized in that: The method comprises: preparing a silica wet gel; A polymerization reaction occurs in the wet gel, wherein the polymerization reaction is polymerization of a double-bond-containing polymerization monomer and a double-bond-containing silane coupling agent; and The wet gel after the polymerization reaction is dried to obtain the polymer-modified silica aerogel.

4. The method for preparing polymer-modified silica aerogel according to claim 3, wherein: The preparation of the wet silica gel comprises reacting a silicon source, water and an organic solvent to obtain the wet silica gel; and / or The method for preparing the polymer-modified silica aerogel further comprises aging the wet gel before performing the polymerization reaction; and / or The method for preparing the polymer-modified silica aerogel further comprises aging the wet gel and performing solvent replacement before performing the polymerization reaction.

5. The method for preparing the polymer-modified silica aerogel according to claim 3 or 4, characterized in that: The organic solvent is ethanol; and / or The solvent replacement is replacing the ethanol with DMF; and / or The silane coupling agent containing a double bond is mixed with the silicon source, water and the organic solvent, and then reacted to obtain the silicon dioxide wet gel; further preferably, the silane coupling agent containing a double bond is mixed with a mixed solution containing the silicon source, water and the organic solvent, and then reacted to obtain the silicon dioxide wet gel; and / or After the solvent replacement, adding the double bond-containing polymerizable monomer to the obtained gel to carry out the polymerization reaction; and / or After the solvent replacement, the double bond-containing polymerization monomer and the initiator are added to the obtained gel to carry out the polymerization reaction.

6. The method for preparing the polymer-modified silica aerogel according to claim 3 or 4, characterized in that: The ratio of the mass of the double-bond-containing silane coupling agent to the mass of the silica in the polymer-modified silica aerogel is in the range of 0.01 to 0.15; and / or The ratio of the mass of the double bond-containing polymer monomer to the mass of silica in the polymer-modified silica aerogel is in the range of 0.01 to 0.5; and / or The aging temperature range of the aging is 45°C to 100°C; and / or The aging time range is 24h to 48h.

7. The method for preparing the polymer-modified silica aerogel according to claim 3 or 4, characterized in that: The double bond-containing polymer monomer is selected from: acrylate polymer monomers, styrene, vinyl acetate, N-vinyl pyrrolidone, acrylamide, functionally modified forms thereof, or combinations thereof; preferably, the acrylate polymer monomer is selected from methyl methacrylate, trifluoroethyl acrylate, or combinations thereof; preferably, the functionally modified form is a form modified with a magnetic function; more preferably, the functionally modified form is a form modified with magnetic particles or a side group with a magnetic metal chelate; and / or The double bond-containing silane coupling agent is selected from vinyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, styrylsilane or a combination thereof; and / or The polymerization reaction is a free radical copolymerization reaction; and / or The polymer is chemically bonded to the silica aerogel; and / or In the polymer-modified silica aerogel, the polymer is at least partially coated on the skeleton of the aerogel; and / or The polymer is uniformly coated on the skeleton of the aerogel through chemical bonds; and / or The aerogel has a double network structure; the double network structure includes a network formed by a polymer and a silicon dioxide network.

8. The method for preparing polymer-modified silica aerogel according to claim 7, wherein: The polymerization reaction is carried out in the presence of an initiator; preferably, the initiator is selected from azobisisobutyronitrile, dicumyl peroxide, dibenzoyl peroxide or a combination thereof; Preferably, the ratio of the molar amount of the initiator to the molar amount of double bonds in the double-bond-containing polymerizable monomer is in the range of 0.01 to 0.

02.

9. A polymer-modified silica aerogel prepared by the method for preparing a polymer-modified silica aerogel according to any one of claims 3 to 8.

10. A thermal insulation material, characterized in that: include: The polymer-modified silica aerogel according to claim 1 or 2, or an aerogel prepared by the method for preparing the polymer-modified silica aerogel according to any one of claims 3 to 8.

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