Aerogel heat insulation coating as well as preparation method and application thereof

Abstract

The invention relates to the technical field of aerogel heat insulation coatings, in particular to an aerogel heat insulation coating as well as a preparation method and application thereof. The coating is prepared from the following raw materials in parts by weight: 100 parts of organic silicon resin emulsion, 60-100 parts of heat-insulating filler dispersion liquid, 1-10 parts of a dispersing agent and 1-10 parts of a thickening agent, wherein the heat insulation filler dispersion liquid contains 50 to 95 weight percent of graphene oxide silicon carbide nanowire composite aerogel. The aerogel heat insulation coating provided by the invention has the advantages of low heat conductivity coefficient, good heat insulation performance, excellent mechanical property, difficulty in falling, convenience in transportation and storage and environmental friendliness.

Description

Technical Field

[0001] The present invention relates to the technical field of aerogel thermal insulation coatings, and particularly relates to an aerogel thermal insulation coating, a preparation method thereof, and an application thereof. Background Art

[0002] An aerogel is a solid material with a nano-porous network structure and a gaseous dispersion medium filling the pores, and it is the lightest solid in the world. The aerogel thermal insulation coating prepared by using aerogel is an innovative thermal insulation material, which combines the airtight microporous structure and reticular fiber structure of aerogel, has a low thermal conductivity, excellent thermal insulation performance, and a wide applicable temperature range. In addition, it also has properties such as light weight, cold insulation, shock resistance, and sound absorption, and is widely used in industries such as metallurgy, chemical industry, petroleum, shipbuilding, textile, medicine, transportation, thermoelectricity, and construction. Moreover, this aerogel thermal insulation coating is convenient for construction, does not cause pollution to the environment, does not irritate the skin, and there is no waste during construction.

[0003] However, this aerogel thermal insulation coating also has its own limitations, and generally mainly has the following defects: 1) The thermal conductivity of the coating is still relatively large and needs to be further reduced; 2) The adhesion ability of the coating on the substrate is poor and it is easy to fall off; 3) The mechanical properties of the coating are poor and the service life is short.

[0004] Therefore, there is an urgent need to provide an aerogel thermal insulation coating with advantages such as a small thermal conductivity, good mechanical properties, a long service life, and not being easy to fall off. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems existing in the aerogel thermal insulation coating, such as a large thermal conductivity, poor mechanical properties, and easy falling off, and to provide an aerogel thermal insulation coating, a preparation method thereof, and an application thereof.

[0006] To achieve the above purpose, the first aspect of the present invention provides an aerogel thermal insulation coating, wherein the preparation raw materials of the coating include: 100 parts by weight of an organosilicon resin emulsion, 60 - 100 parts by weight of a thermal insulation filler dispersion liquid, 1 - 10 parts by weight of a dispersant, and 1 - 10 parts by weight of a thickener; wherein, the thermal insulation filler dispersion liquid contains 50 - 95 wt% of a graphene oxide silicon carbide nanowire composite aerogel.

[0007] The second aspect of the present invention provides a preparation method of an aerogel thermal insulation coating, wherein the method includes the following steps:

[0008] (1) Dispersing the graphene oxide silicon carbide nanowire composite aerogel in water to obtain a thermal insulation filler dispersion liquid;

[0009] (2) Mixing the thermal insulation filler dispersion liquid and the organosilicon resin emulsion to obtain a mixed emulsion;

[0010] (3) Add a dispersant and a thickener to the mixed emulsion to obtain an aerogel thermal insulation coating;

[0011] Among them, the mass ratio of the silicone resin emulsion, the heat insulation filler dispersion, the dispersant and the thickener is 100:60 - 100:1 - 10:1 - 10.

[0012] The third aspect of the present invention provides an application of the aerogel thermal insulation coating described in the first aspect of the present invention or the aerogel thermal insulation coating prepared by the method described in the second aspect of the present invention in the fields of aerospace and oil wells.

[0013] Through the above technical solutions, the beneficial technical effects of the present invention are as follows:

[0014] 1) The aerogel thermal insulation coating provided in the present invention has the advantages of low thermal conductivity, good heat insulation performance, excellent mechanical properties, not easy to fall off, convenient for transportation and storage, and environmentally friendly, and can withstand high temperatures above 300 °C;

[0015] 2) The preparation method of the aerogel thermal insulation coating provided in the present invention is simple and suitable for industrial promotion. Specific Embodiments

[0016] The endpoints and any values disclosed in this article are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoints of each range, between the endpoints of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in this article.

[0017] The first aspect of the present invention provides an aerogel thermal insulation coating. Among them, the raw materials for preparing the coating include: 100 parts by weight of a silicone resin emulsion, 60 - 100 parts by weight of a heat insulation filler dispersion, 1 - 10 parts by weight of a dispersant, and 1 - 10 parts by weight of a thickener; among them, the heat insulation filler dispersion contains 50 - 95 wt% of a graphene oxide silicon carbide nanowire composite aerogel.

[0018] In a preferred embodiment of the present invention, the raw materials for preparing the coating include: 100 parts by weight of a silicone resin emulsion, 70 - 90 parts by weight of a heat insulation filler dispersion, 2 - 8 parts by weight of a dispersant, and 2 - 8 parts by weight of a thickener; among them, the heat insulation filler dispersion contains 70 - 90 wt% of a graphene oxide silicon carbide nanowire composite aerogel.

[0019] In a further preferred embodiment of the present invention, the raw materials for preparing the coating include: 100 parts by weight of silicone resin emulsion, 75 - 85 parts by weight of heat-insulating filler dispersion, 4 - 6 parts by weight of dispersant, and 4 - 6 parts by weight of thickener; wherein, the heat-insulating filler dispersion contains 75 - 85 wt% of graphene oxide silicon carbide nanowire composite aerogel.

[0020] In a preferred embodiment of the present invention, the solid content of the silicone resin emulsion is 50 - 90 wt%, preferably 70 - 80 wt%.

[0021] Among them, in the present invention, the silicone resin emulsion can be a commercially available product or can be prepared according to a known method. By changing the amount of solvent in the silicone resin emulsion, the solid content of the silicone resin emulsion can be adjusted.

[0022] In a preferred embodiment of the present invention, the silicone resin emulsion is selected from silicone resin emulsions containing phenyl and / or epoxy groups.

[0023] Among them, in the present invention, the inventors have found through research that the silicone resin emulsion containing phenyl and / or epoxy groups not only has good heat resistance and can withstand high temperatures above 300 °C, but also has an electron cloud enrichment, which can enhance the interaction between the coating and the substrate, increase the adhesion of the coating, and prevent the coating from peeling off.

[0024] In a preferred embodiment of the present invention, the silicone resin emulsion is selected from one or more of epoxy-modified silicone resin emulsion, methylphenyl silicone resin emulsion, and methylphenyl-modified silicone resin emulsion, preferably methylphenyl-modified silicone resin emulsion.

[0025] Among them, the present invention does not make special limitations on the epoxy-modified silicone resin emulsion, methylphenyl silicone resin emulsion, and methylphenyl-modified silicone resin emulsion, and conventional commercially available products in the art can be used in the present invention.

[0026] In a preferred embodiment of the present invention, the solvent in the heat-insulating filler dispersion is water. Among them, in the present invention, dispersing the heat-insulating filler in water can improve the dispersibility between the heat-insulating filler and the silicone resin emulsion, contribute to further improving the uniformity of the coating, and thereby improve the mechanical properties of the coating.

[0027] In a preferred embodiment of the present invention, the mass ratio of graphene oxide to silicon carbide nanowires in the graphene oxide silicon carbide nanowire composite aerogel is 1:1 - 4, preferably 1:1.5 - 2.5.

[0028] Among them, in the present invention, the graphene oxide silicon carbide nanowire composite aerogel can significantly reduce the thermal conductivity of the coating, thereby improving the heat preservation and heat insulation performance of the coating. Under the action of a dispersant and a thickener, the graphene oxide silicon carbide nanowire composite aerogel interacts with the silicone resin emulsion, which can further enhance the mechanical properties of the coating, thereby helping to extend the service life of the coating.

[0029] In a preferred embodiment of the present invention, the preparation method of the graphene oxide silicon carbide nanowire composite aerogel comprises the following steps:

[0030] (S1) Disperse graphene oxide into deionized water to prepare an aqueous graphene oxide solution;

[0031] (S2) Add silicon carbide nanowires treated with NaOH to the aqueous graphene oxide solution in step (S1), and stir well to obtain a graphene oxide silicon carbide nanowire mixed solution;

[0032] (S3) Add citric acid to the graphene oxide silicon carbide nanowire mixed solution in step (S2), and stir well to obtain a graphene oxide silicon carbide nanowire mixed reaction solution;

[0033] (S4) Hydrothermally react the graphene oxide silicon carbide nanowire mixed reaction solution in step (S3) to obtain a GO / SiC nanowire hydrogel;

[0034] (S5) Lyophilize the GO / SiC nanowire hydrogel in step (S4) to obtain a GO / SiC nanowire aerogel, that is, a graphene oxide silicon carbide nanowire composite aerogel.

[0035] Furthermore, the concentration of the aqueous graphene oxide solution in step (S1) is 0.5 - 3.5 mg / mL, preferably 1.5 - 2.5 mg / mL, and more preferably 2 mg / mL.

[0036] Furthermore, the operation of treating silicon carbide nanowires with NaOH includes: placing the silicon carbide nanowires in an NaOH solution, soaking at room temperature for 2 - 4 h, and then washing and drying.

[0037] Furthermore, the concentration of the NaOH solution is 1 - 3 mol / L, preferably 1.5 - 2.5 mol / L, and more preferably 2 mol / L.

[0038] Furthermore, the stirring time in step (S2) is 2 - 4 h.

[0039] Further, in step (S2), the mass ratio of graphene oxide in the graphene oxide aqueous solution to the silicon carbide nanowires treated with NaOH is 1:1 - 3, preferably 1:1.5 - 2.5, and more preferably 1:2.

[0040] Further, in step (S3), the molar ratio of citric acid added to the silicon carbide nanowires treated with NaOH is 1:0.5 - 2.5, preferably 1:0.8 - 1.5, and more preferably 1:1.

[0041] Further, the hydrothermal reaction conditions in step (S4) are 100 - 140 °C, preferably 110 - 130 °C, and even more preferably 120 °C.

[0042] Further, the hydrothermal reaction time in step (S4) is 3 - 15 h, preferably 9 - 12 h.

[0043] Further, the freezing temperature in step (S5) is -60 °C to -20 °C, preferably -50 °C to -35 °C, and more preferably -42 °C.

[0044] Further, the freeze-drying time in step (S5) is 6 - 48 h, preferably 18 - 36 h, and more preferably 24 h.

[0045] In a preferred embodiment of the present invention, the dispersant is selected from one or more of BYK-163 dispersant, BYK-9076 dispersant, and BYK-AT204 dispersant, and preferably BYK-9076 dispersant.

[0046] In a preferred embodiment of the present invention, the thickener is selected from magnesium aluminum silicate suspension thixotropic thickener and / or alkali-swellable thickener, and preferably magnesium aluminum silicate suspension thixotropic thickener.

[0047] Among them, in the present invention, the magnesium aluminum silicate thickener can be commercially available magnesium aluminum silicate PT-XZ18 suspension thixotropic thickener or commercially available magnesium aluminum silicate PT-XL58F suspension thixotropic thickener, and the alkali-swellable thickener can be commercially available ASE-60 alkali-swellable thickener.

[0048] Among them, the aerogel thermal insulation coating provided in the present invention may also contain other commonly known modification additives in the art such as lubricants, bactericides, antioxidants, color fillers, etc. according to actual needs.

[0049] The second aspect of the present invention provides a method for preparing an aerogel thermal insulation coating, wherein the method comprises the following steps:

[0050] (1) Dispersing the graphene oxide silicon carbide nanowire composite aerogel in water to obtain a heat insulation filler dispersion liquid;

[0051] (2) Mix the heat-insulating filler dispersion liquid and the silicone resin emulsion to obtain a mixed emulsion;

[0052] (3) Add a dispersant and a thickener to the mixed emulsion to obtain an aerogel thermal insulation coating;

[0053] Among them, the mass ratio of the silicone resin emulsion, the heat-insulating filler dispersion liquid, the dispersant and the thickener is 100:60 - 100:1 - 10:1 - 10.

[0054] In step (1):

[0055] In a preferred embodiment of the present invention, the mass ratio of graphene oxide to silicon carbide nanowires in the graphene oxide silicon carbide nanowire composite aerogel is 1:1 - 4, preferably 1:1.5 - 2.5.

[0056] In a preferred embodiment of the present invention, the preparation method of the graphene oxide silicon carbide nanowire composite aerogel is the same as the preparation method of the graphene oxide silicon carbide nanowire composite aerogel described in the first aspect of the present invention.

[0057] In a preferred embodiment of the present invention, the dispersion in step (1) is carried out at room temperature and stirred at a speed of 1500 - 3500 rpm / min for 2 - 5 h.

[0058] In a preferred embodiment of the present invention, in the heat-insulating filler dispersion liquid, the content of the graphene oxide silicon carbide nanowire composite aerogel is 50 - 95 wt%, preferably 70 - 90 wt%, and further preferably 75 - 85 wt%.

[0059] In step (2):

[0060] In a preferred embodiment of the present invention, the solid content of the silicone resin emulsion is 50 - 90 wt%, preferably 70 - 80 wt%.

[0061] In a preferred embodiment of the present invention, the silicone resin emulsion is selected from one or more of an epoxy-modified silicone resin emulsion, a methylphenyl silicone resin emulsion, and a methylphenyl-modified silicone resin emulsion, and preferably a methylphenyl-modified silicone resin emulsion.

[0062] In step (3):

[0063] In a preferred embodiment of the present invention, the dispersant is selected from one or more of BYK-163 dispersant, BYK-9076 dispersant, and BYK-AT204 dispersant, and preferably BYK-9076 dispersant.

[0064] In a preferred embodiment of the present invention, the thickener is selected from magnesium aluminum silicate suspension thixotropic thickener and / or alkali-swellable thickener, preferably magnesium aluminum silicate suspension thixotropic thickener.

[0065] In a preferred embodiment of the present invention, the mass ratio of the organosilicon resin emulsion, the heat-insulating filler dispersion, the dispersant and the thickener is 100:70 - 90:2 - 8:2 - 8, preferably 100:75 - 85:4 - 6:4 - 6.

[0066] The third aspect of the present invention provides an application of the aerogel thermal insulation coating described in the first aspect of the present invention or the aerogel thermal insulation coating prepared by the preparation method described in the second aspect of the present invention in the fields of aerospace and oil well.

[0067] The present invention will be described in detail below through examples.

[0068] Among them, the methylphenyl modified organosilicon resin emulsion is purchased from Silicone Home, with the brand number 9604A and a solid content of 75 wt%; the epoxy modified organosilicon resin emulsion is purchased from Jiangyin Zhongxin Silicon Materials Co., Ltd., with the brand number SH-023 and a solid content of 70 wt%; the methylphenyl silicone resin emulsion is purchased from Jiangyin Zhongxin Silicon Materials Co., Ltd., with the brand number SH-96 and a solid content of 80 wt%. The dispersant is BYK-9076, purchased from BYK, with the brand number BYK-9076; the thickener is magnesium aluminum silicate, purchased from Shuohui Industrial Products, with the brand number PT-XZ18.

[0069] Preparation of graphene oxide silicon carbide nanowire composite aerogel:

[0070] (S1) Disperse 40 mg of graphene oxide into deionized water to prepare a graphene oxide aqueous solution with a concentration of 2 mg / mL;

[0071] (S2) Place the silicon carbide nanowires in a 2 mol / L NaOH solution, soak them at room temperature for 2 h, then wash and dry them to obtain NaOH-treated silicon carbide nanowires; add 80 mg of NaOH-treated silicon carbide nanowires to the graphene oxide aqueous solution in step (S1), and stir well for 2 h to obtain a graphene oxide silicon carbide nanowire mixed solution;

[0072] (S3) Add citric acid to the graphene oxide silicon carbide nanowire mixed solution in step (S2), with the molar ratio of silicon carbide nanowires:citric acid = 1:1, stir well to obtain a graphene oxide silicon carbide nanowire mixed reaction solution;

[0073] (S4) Hydrothermally react the graphene oxide silicon carbide nanowire mixed reaction solution in step (S3) under hydrothermal conditions of 120 °C for 15 h to obtain a GO / SiC nanowire hydrogel;

[0074] (S5) Lyophilize the GO / SiC nanowire hydrogel in step (S4) at -42 °C for 24 h to obtain a graphene oxide silicon carbide nanowire composite aerogel.

[0075] Example 1

[0076] (1) Disperse the graphene oxide silicon carbide nanowire composite aerogel in water and stir at a speed of 2500 rpm / min for 3 h to obtain a heat-insulating filler dispersion liquid with a graphene oxide silicon carbide nanowire composite aerogel content of 80 wt%;

[0077] (2) Mix 80 g of the above heat-insulating filler dispersion liquid and 100 g of a methylphenyl-modified silicone resin emulsion at room temperature to obtain a mixed emulsion;

[0078] (3) Add 5 g of a dispersant and 5 g of a thickener to the above mixed emulsion and mix evenly to obtain an aerogel thermal insulation coating.

[0079] Example 2

[0080] (1) Disperse the graphene oxide silicon carbide nanowire composite aerogel in water and stir at a speed of 2500 rpm / min for 3 h to obtain a heat-insulating filler dispersion liquid with a graphene oxide silicon carbide nanowire composite aerogel content of 75 wt%;

[0081] (2) Mix 85 g of the above heat-insulating filler dispersion liquid and 100 g of a methylphenyl-modified silicone resin emulsion at room temperature to obtain a mixed emulsion;

[0082] (3) Add 4 g of a dispersant and 6 g of a thickener to the above mixed emulsion and mix evenly to obtain an aerogel thermal insulation coating.

[0083] Example 3

[0084] (1) Disperse the graphene oxide silicon carbide nanowire composite aerogel in water and stir at a speed of 2500 rpm / min for 3 h to obtain a heat-insulating filler dispersion liquid with a graphene oxide silicon carbide nanowire composite aerogel content of 85 wt%;

[0085] (2) Mix 75 g of the above heat-insulating filler dispersion liquid and 100 g of a methylphenyl-modified silicone resin emulsion at room temperature to obtain a mixed emulsion;

[0086] (3) Add 6 g of a dispersant and 4 g of a thickener to the above mixed emulsion and mix evenly to obtain an aerogel thermal insulation coating.

[0087] Example 4

[0088] (1) Disperse the graphene oxide silicon carbide nanowire composite aerogel in water and stir at a speed of 2500 rpm / min for 3 h to obtain a heat-insulating filler dispersion liquid with a graphene oxide silicon carbide nanowire composite aerogel content of 70 wt%.

[0089] (2) Mix 70 g of the above heat-insulating filler dispersion liquid and 100 g of the epoxy-modified silicone resin emulsion at room temperature to obtain a mixed emulsion.

[0090] (3) Add 2 g of a dispersant and 2 g of a thickener to the above mixed emulsion and mix evenly to obtain an aerogel thermal insulation coating.

[0091] Example 5

[0092] (1) Disperse the graphene oxide silicon carbide nanowire composite aerogel in water and stir at a speed of 2500 rpm / min for 3 h to obtain a heat-insulating filler dispersion liquid with a graphene oxide silicon carbide nanowire composite aerogel content of 90 wt%.

[0093] (2) Mix 90 g of the above heat-insulating filler dispersion liquid and 100 g of the methylphenyl silicone resin emulsion at room temperature to obtain a mixed emulsion.

[0094] (3) Add 8 g of a dispersant and 8 g of a thickener to the above mixed emulsion and mix evenly to obtain an aerogel thermal insulation coating.

[0095] Comparative Example 1

[0096] Same as Example 1, except that the heat-insulating filler dispersion liquid is omitted.

[0097] Comparative Example 2

[0098] Same as Example 1, except that the graphene oxide silicon carbide nanowire composite aerogel is replaced with an equal amount of SiO 2 aerogel.

[0099] Comparative Example 3

[0100] Same as Example 1, except that the addition amount of the heat-insulating filler dispersion liquid is 40 g.

[0101] Test Example 1

[0102] The properties of the coatings prepared in Examples 1-5 and Comparative Examples 1-3 were tested, and the results are shown in Table 1. Among them, the thermal conductivity was tested by the transient plane source method (TPS) according to GB / T 32064-2015. The adhesion was tested by the pull-off adhesion test for paints and varnishes according to GB / T 5210-2006. The pencil hardness was tested by the pencil method for film hardness according to GB / T 6739-2006. The tensile strength of the film was tested using an electronic universal testing machine according to the standard test method of GB / T1040.3-2006.

[0103] Table 1

[0104]

[0105] Among them, as can be seen from Table 1, the thermal conductivity of the aerogel thermal insulation coating prepared in the present invention is below 0.2 W / m·K, having excellent heat preservation and insulation properties. The adhesion of the aerogel thermal insulation coating is between 20-25 MPa, indicating that the coating is firmly bonded to the substrate and is not easily peeled off. The aerogel thermal insulation coating has a high pencil hardness and a large tensile strength, indicating that the coating has good mechanical properties, is scratch-resistant and wear-resistant, and can be used for a long time.

[0106] By comparing Example 1 and Comparative Example 2, it can be seen that compared with SiO 2 aerogel, the graphene oxide silicon carbide nanowire composite aerogel can greatly improve the adhesion of the coating on the substrate, as well as the hardness and tensile strength of the coating. By comparing Example 1 with Comparative Example 1 and Comparative Example 3, it can be seen that without adding the heat insulation filler dispersion liquid, or with too little addition amount of the heat insulation filler dispersion liquid, the heat insulation effect, adhesion and modification effect of the mechanical properties of the coating are all poor.

[0107] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A silica aerogel thermal insulation coating, characterized in that, the raw materials for preparing the coating include: 100 parts by weight of an organosilicon resin emulsion, 60 - 100 parts by weight of a heat insulation filler dispersion, 1 - 10 parts by weight of a dispersant, and 1 - 10 parts by weight of a thickener; wherein, the heat insulation filler dispersion contains 50 - 95 wt% of graphene oxide silicon carbide nanowire composite aerogel.

2. The coating according to claim 1, wherein, the raw materials for preparing the coating include: 100 parts by weight of an organosilicon resin emulsion, 70 - 90 parts by weight of a heat insulation filler dispersion, 2 - 8 parts by weight of a dispersant, and 2 - 8 parts by weight of a thickener; wherein, the heat insulation filler dispersion contains 70 - 90 wt% of graphene oxide silicon carbide nanowire composite aerogel.

3. The coating according to claim 2, wherein, the raw materials for preparing the coating include: 100 parts by weight of an organosilicon resin emulsion, 75 - 85 parts by weight of a heat insulation filler dispersion, 4 - 6 parts by weight of a dispersant, and 4 - 6 parts by weight of a thickener; wherein, the heat insulation filler dispersion contains 75 - 85 wt% of graphene oxide silicon carbide nanowire composite aerogel.

4. The coating according to claim 1, wherein, the solid content of the organosilicon resin emulsion is 50 - 90 wt%; and / or, the organosilicon resin emulsion is selected from organosilicon resin emulsions containing phenyl and / or epoxy groups.

5. The coating according to claim 4, wherein, the organosilicon resin emulsion is selected from one or more of epoxy modified organosilicon resin emulsions, methyl phenyl silicone resin emulsions, and methyl phenyl modified silicone resin emulsions.

6. The coating according to claim 1, wherein, the mass ratio of graphene oxide to silicon carbide nanowires in the graphene oxide silicon carbide nanowire composite aerogel is 1:1 - 4; and / or, the preparation method of the graphene oxide silicon carbide nanowire composite aerogel includes the following steps: (S1) Disperse graphene oxide into deionized water to prepare a graphene oxide aqueous solution; (S2) Add silicon carbide nanowires treated with NaOH to the graphene oxide aqueous solution in step (S1), and stir well to obtain a graphene oxide silicon carbide nanowire mixed solution; (S3) Add citric acid to the graphene oxide silicon carbide nanowire mixed solution in step (S2), and stir well to obtain a graphene oxide silicon carbide nanowire mixed reaction solution; (S4) Hydrothermally react the graphene oxide silicon carbide nanowire mixed reaction solution in step (S3) to obtain a GO / SiC nanowire hydrogel; (S5) Lyophilize the GO / SiC nanowire hydrogel in step (S4) to obtain the graphene oxide silicon carbide nanowire composite aerogel.

7. The coating according to claim 1, wherein, the dispersant is selected from one or more of BYK - 163 dispersant, BYK - 9076 dispersant, and BYK - AT204 dispersant; and / or, the thickener is selected from magnesium aluminum silicate suspension thixotropic thickener and / or alkali - swellable thickener.

8. A preparation method of a silica aerogel thermal insulation coating, characterized in that, The method comprises the following steps: (1) Dispersing the graphene oxide silicon carbide nanowire composite aerogel in water to obtain a heat insulation filler dispersion liquid; (2) Mixing the heat insulation filler dispersion liquid and the silicone resin emulsion to obtain a mixed emulsion; (3) Adding a dispersant and a thickener into the mixed emulsion to obtain an aerogel thermal insulation coating; wherein, the mass ratio of the silicone resin emulsion, the heat insulation filler dispersion liquid, the dispersant and the thickener is 100:60 - 100:1 - 10:1 - 10.

9. According to the preparation method described in claim 8, wherein, the mass ratio of the silicone resin emulsion, the heat insulation filler dispersion liquid, the dispersant and the thickener is 100:70 - 90:2 - 8:2 - 8, preferably 100:75 - 85:4 - 6:4 - 6.

10. Application of the aerogel thermal insulation coating described in any one of claims 1 - 7 or the aerogel thermal insulation coating prepared by the method described in claim 8 or 9 in the fields of aerospace and oil well downhole.

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