CN103304814B - Intrinsic hydrophobic polyimide aerogel and preparation method thereof and application - Google Patents

Abstract

The invention discloses a polyimide airgel with intrinsic hydrophobic properties, a preparation method and application thereof. The structure of the airgel is shown in Formula I. The invention endows the polyimide airgel material with excellent hydrophobic properties by introducing special groups such as hydrophobic fluorine-containing groups and low-polarity alicyclic groups into the molecular structure of the polyimide. In addition, this type of polyimide airgel also has the characteristics of high porosity, low thermal conductivity, low density, large specific surface area, low dielectric constant and dielectric loss. Therefore, it is widely used in anti-heat insulation components of aircraft, satellites and other spacecraft, VLSI interlayer dielectric materials, anti-heat insulation layers of buildings, environmental protection, deep sea exploration, oil exploration, energy-saving buildings and home appliances, warm clothing, sports It has important application value in the field of equipment and so on. Formula I.

Description

Intrinsically hydrophobic polyimide airgel and its preparation method and application

technical field

The invention belongs to the field of high-performance polyimide materials, and relates to an intrinsic hydrophobic polyimide airgel and a preparation method and application thereof.

Background technique

Airgel is a kind of dry gel material whose dispersion medium is air, and its solid phase and pore structure are both on the nanometer scale. This structural feature makes airgel the solid material with the smallest density in the world (up to 0.0002g/cm ³ ), and the solid material with the smallest thermal conductivity in the world (up to 0.002W/m ^-1 K in air. ^-1 , up to 0.001W/m ^-1 K ^-1 at room temperature and vacuum, and the aerogel also has a very low dielectric constant (1.0-2.0) and dielectric loss. The above characteristics make aerogels have broad application prospects in the fields of integrated circuits, energy saving, aerospace and other fields (AegerterMA, LeventisN, KoebelM(eds).Aerogelshandbook.SpringerScience+BusinessMedia: NewYork, 2011)

Although aerogels have excellent thermal insulation properties, low density, and low dielectric constant, their highly microporous structure (~10nm) causes them to have a specific surface area of hundreds or even thousands of square meters per gram, such a high The specific surface area makes it extremely easy to absorb moisture and moisture in the air. The absorbed moisture can not only greatly increase the dielectric constant of the aerogel, but also cause a strong capillary force inside the aerogel. For brittle and fragile inorganic aerogels (such as silica aerogels, etc.), this surface tension will directly cause the breakage of the airgel material. Therefore, it is necessary to carry out surface hydrophobization treatment on aerogels in practical applications. Common hydrophobization treatment methods include treatment with chlorosilane or alkoxysilane compound vapor, and treatment with hexamethyldisilazane (HMDZ) vapor.

Polyimide (PI) is a class of organic polymer materials with excellent comprehensive properties. Airgel made of PI has the characteristics of high temperature resistance and excellent mechanical properties, so it has been developed rapidly in recent years (MeadorMAB, et al.ACS ApplMaterInterfaces, 2012, 4: 536-544). However, the molecular structure of ordinary PI has strong polarity, so the prepared airgel is also easy to absorb moisture. Due to the good mechanical flexibility of PI aerogels, although PI aerogels absorbing water will not break up like inorganic SiO ₂ aerogels, it will cause an increase in density and dielectric constant, which will affect its application. Effect. However, the traditional hydrophobization process will not effectively improve the hydrophilicity of PI airgel.

Contents of the invention

The object of the present invention is to provide a polyimide (PI) aerogel with intrinsic hydrophobic properties and its preparation method and application.

The compound or aerogel provided by the present invention has a general structural formula as shown in formula I,

Formula I

In the formula I, R is _a dianhydride monomer fragment, selected from any one of the following groups:

and

R ₂ is a diamine monomer fragment, selected from any one of the following groups:

and

T is an amino-terminated moiety, selected from any of the following groups:

and

n is an integer of 1-100, specifically an integer of 20-30, an integer of 30-40 or an integer of 20-40, more specifically 30.

The method for preparing compound shown in formula I or aerogel provided by the invention comprises the following steps:

1) Mixing the aromatic diamine monomer and the excess alicyclic dianhydride monomer in an organic solvent evenly for condensation polymerization, after the reaction is completed, an anhydride group-terminated polyamic acid solution is obtained;

2) adding an amino group-containing polyfunctional end-capping agent to the solution obtained in step 1) and mixing to carry out amidation reaction to obtain a cross-linked polyamic acid solution;

3) adding acetic anhydride and pyridine to the cross-linked polyamic acid solution obtained in step 2) and stirring, then injecting into the mold for dehydration reaction, and obtaining a gel containing the compound shown in formula I after the reaction is completed;

4) Soak the gel obtained in step 3) in a solvent, then dry it with supercritical carbon dioxide, and obtain the airgel after drying.

In step 1) of the above method, in said step 1), the alicyclic dianhydride is selected from 1,2,3,4-cyclobutanetetraacid dianhydride (CBDA), 1,2,4,5-cyclobutane Pentane tetra-acid dianhydride (CPDA), 1,2,4,5-cyclohexane tetra-acid dianhydride (CHDA), bicyclo[2.2.1]heptane-2,3,5,6-tetra-acid dianhydride and at least one of bicyclo[2.2.2]octane-2,3,5,6-tetraacid dianhydride;

The aromatic diamine is selected from 2,3,5,6-tetrafluoro-p-phenylenediamine (TFPDA), 3,3',5,5'-tetrafluoro-4,4'-diaminobiphenyl, octane At least one of fluorodiaminobiphenyl, 3,5-diaminotrifluorotoluene (TFMDA) and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFDB);

The organic solvent is selected from N-methylpyrrolidone (NMP), m-cresol, N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), specifically at least one selected from N-methylpyrrolidone (NMP) and N,N-dimethylacetamide (DMAc);

The molar ratio of the alicyclic dianhydride to the aromatic diamine is 1.00:(0.90-0.99), specifically 1.00:(0.95-0.98), more specifically 1.00:0.97;

In the step 1) in the condensation polymerization step, the time is 10 to 30 hours, specifically 20 to 25 hours, more specifically 24 hours;

The temperature is 0-35°C, specifically 15-25°C.

In the step 2), the amino group-containing polyfunctional end-capping agent is selected from 1,3,5-tri(amino)benzene, 1,3,5-tri(aminophenoxy)benzene (TAB), 2 , at least one of 6-bis(4'-aminophenyl)-4-(4'-aminophenyl)pyridine (TAPP), octa(aminophenyl)polysilsesquioxane (OAPS);

In the step 2) amidation reaction step, the time is 10-30 hours, specifically 20-25 hours, more specifically 24 hours;

The temperature is 0-35°C, specifically 15-25°C.

In the step 3), the molar ratio of the acetic anhydride to the alicyclic dianhydride is (2.00-10.00): 1.00, specifically (3.00-5.00): 1.00;

The molar ratio of the pyridine to the alicyclic dianhydride is (2.00-8.00): 1.00, specifically (3.00-5.00): 1.00;

In the dehydration reaction step, the stirring time is 10 minutes to 30 minutes, specifically 15 minutes to 20 minutes; in the dehydration reaction step, the stirring time is 1 hour to 10 hours, specifically 1 hour to 5 hours.

The temperature is 0-35°C, specifically 15-25°C.

In the step 4), the solvent is selected from at least one of methanol, ethanol, isopropanol and acetone;

In the supercritical carbon dioxide drying step, the pressure is 10-20MPa, specifically 15-18MPa;

The temperature is 30-80°C, specifically 40-60°C, more specifically 45°C.

The application of the compound represented by formula I or aerogel provided by the present invention as at least one of heat-resistant insulation material, interlayer dielectric material and thermal insulation material of VLSI also belongs to the protection scope of the present invention. Among them, the application can specifically be used in the preparation of heat-insulating components for aircraft, satellites and other spacecraft, VLSI interlayer dielectric materials, building heat-proof insulation layers, environmental protection, deep-sea exploration, oil exploration, energy-saving buildings and Applications in home appliances, thermal clothing, sports equipment and other fields.

The preparation process of the polyimide airgel provided by the present invention comprises firstly preparing a polyimide gel by using an alicyclic dianhydride monomer, a fluorine-containing aromatic diamine monomer and a multifunctional amino compound crosslinking agent, It is then dried using supercritical carbon dioxide. The invention endows the polyimide airgel material with excellent hydrophobic properties by introducing special groups such as hydrophobic fluorine-containing groups and low-polarity alicyclic groups into the molecular structure of the polyimide. In addition, this type of polyimide airgel also has the characteristics of high porosity, low thermal conductivity, low density, large specific surface area, low dielectric constant and dielectric loss. Therefore, it is widely used in anti-heat insulation components of aircraft, satellites and other spacecraft, VLSI interlayer dielectric materials, anti-heat insulation layers of buildings, environmental protection, deep sea exploration, oil exploration, energy-saving buildings and home appliances, warm clothing, sports It has important application value in the field of equipment and so on.

Description of drawings

Fig. 1 is the infrared spectrum of the obtained polyimide airgel prepared in Example 1.

2 is a scanning electron micrograph of the polyimide airgel prepared in Example 1.

Figure ₃ is the N adsorption-desorption curve of the polyimide airgel prepared in Example 1.

FIG. 4 is an X-ray photoelectron spectroscopy (XPS) spectrum of the polyimide airgel prepared in Example 1.

Figure 5 is the water contact angle of the polyimide airgel prepared in Example 1.

FIG. 6 is the thermogravimetric (TGA) curve of the polyimide airgel prepared in Example 1.

FIG. 7 is a test curve of the dielectric constant and dielectric loss of the polyimide airgel prepared in Example 1.

Figure 8 is the water contact angle of the polyimide airgel prepared in Example 2.

Figure 9 is the water contact angle of the polyimide airgel prepared in Example 3.

Figure 10 is the water contact angle of the polyimide airgel prepared in Comparative Example 1.

Detailed ways

The present invention will be further described below in conjunction with specific examples, but the present invention is not limited to the following examples. The methods are conventional methods unless otherwise specified. The materials can be obtained from public commercial sources unless otherwise specified.

The N ₂ adsorption-desorption curve was measured by ASAP2000 surface area and pore size distribution analyzer, the adsorbed gas was N ₂ , and the samples were vacuum degassed at 80°C for 10 hours before the test.

Photoelectron spectroscopy (XPS) was carried out using a ^{VGScientificESCALab220i} -XL photoelectron spectrometer. The excitation source was MgKα X-rays with a power of about 300W. 284.8eV) correction.

The water contact angle is measured in a Dataphysics OCA-20 contact angle instrument at room temperature (25°C). A 2 μL water drop is dropped into the object to be measured, and the contact angle value is read out by the instrument.

The dielectric constant and dielectric loss are measured by Agilent vector analyzer, the size of the measurement sample is 50mm×30mm×2mm, and the test frequency is 2-12GHz

Thermogravimetric analysis (TGA) was measured with a Q-50 thermal analyzer from TA Company of the United States, the heating rate was 20°C/min, and the test environment was a nitrogen atmosphere.

Example 1

1) Add 1.9741g (6.16mmol) 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFDB) and 25 g of freshly distilled N-methylpyrrolidone (NMP) was bubbled with nitrogen. After TFDB was completely dissolved, 1.2479g (6.36mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) and 25g of NMP were added, and condensation polymerization was carried out at 25°C for 24h to obtain anhydride-terminated polycarbonate. Amic acid solution.

2) Add 0.0574g (0.0497mmol) of amino group-containing polyfunctional capping agent octa(aminophenyl) polysilsesquioxane (OAPS) to the system, and carry out amidation reaction at 25°C for 24h to obtain crosslinked Polyamic acid solution.

3) Add 2.52g (31.82mmol) of pyridine and 3.25g (31.82mmol) of acetic anhydride to the cross-linked polyamic acid solution obtained in step 2), stir for 20 minutes, and pour it into a mold for dehydration reaction. The system gels within 4 hours. A gel containing the compound of formula II is obtained.

4) The polyimide gel obtained in step 3) was taken out from the mold, and soaked repeatedly with ethanol for 3 times. Add the obtained polyimide wet gel into a supercritical CO ₂ reactor for drying, and dry it at 45° C. and 15 MPa for 6 h to obtain a polyimide airgel.

The structure of the airgel is shown in formula II:

Formula II

where T is: n is 30.

The infrared spectrum of the airgel is shown in FIG. 1 , and it can be seen from the above that the structure of the airgel is correct and belongs to the compound of formula II.

The scanning electron micrograph, _N2 adsorption-desorption curve, X-ray photoelectron spectroscopy (XPS), water contact angle, thermal weight loss (TGA), dielectric constant and dielectric loss test results of the airgel material are as follows Figure 2, Figure 3, Figure 4, Figure 5, Figure 6 and Figure 7.

From the above test results, it can be seen that the PI airgel with the expected structure was successfully prepared in this example. The volume occupied by air (porosity) was 86%.

The airgel has a surface area of 407m ² /g, a bulk density (ρ _b ) of 0.22g/cm ³ , a water surface contact angle of 135°, a 5% thermal weight loss temperature of 442°C, and a dielectric constant of 2.75GHz. 1.19, the dielectric loss is 0.0011.

Moreover, the dielectric constant and dielectric loss of the PI airgel do not change significantly with the increase of ambient humidity.

Therefore, a PI airgel with intrinsic hydrophobic properties was prepared in this example. The material's good hydrophobic properties, relatively low polar molecular structure and high porosity structure endow the PI airgel with low dielectric constant and low loss.

Example 2

1) Add 1.1102g (6.16mmol) 3,5-diaminotrifluorotoluene (TFMDA) and 25g freshly distilled N-methylpyrrolidone (NMP) in a there-necked flask equipped with mechanical stirring, temperature and nitrogen inlet, Nitrogen was introduced. After TFMDA is completely dissolved, add 1.2479g (6.36mmol) 1,2,3,4-cyclobutanetetraacid dianhydride (CBDA) and 25g of NMP, and carry out condensation polymerization at room temperature (25°C) for 24h to obtain anhydride group Capped polyamic acid solution.

2) Add 0.0574g (0.0497mmol) of octa(aminophenyl)polysilsesquioxane (OAPS) to the system in step 1), and carry out amidation reaction at room temperature (25°C) for 24h to obtain a cross-linked polyamide acid solution.

3) Add 2.52g (31.82mmol) of pyridine and 3.25g (31.82mmol) of acetic anhydride to the crosslinked polyamic acid solution obtained in step 2). Stir for 20 minutes, pour into a mold for dehydration reaction, and the system gels within 1 hour to obtain a gel containing the compound of formula III.

4) Take the polyimide gel obtained in step 3) out of the mold and soak it in ethanol for 3 times. Add the obtained polyimide wet gel into a supercritical CO ₂ reactor for drying, and dry it at 45° C. and 15 MPa for 6 h to obtain a polyimide airgel.

The structure of the airgel is shown in formula III,

Formula III

where T is: n is 30.

The water contact angle of the airgel material is shown in FIG. 8 . The microscopic structure of the airgel is in the shape of intertwined nanofiber strings, the diameter of the fiber is between 10-50nm, and the volume (porosity) occupied by air in the airgel is 88%. The airgel has a surface area of 386m ² /g, a bulk density (ρ _b ) of 0.25g/cm ³ , a water surface contact angle of 99°, a 5% thermal weight loss temperature of 466°C, and a dielectric constant at 2.75GHz of 1.21, the dielectric loss is 0.0016, the dielectric constant and dielectric loss of the PI airgel will not change significantly with the increase of ambient humidity.

Example 3

1) Add 1.0858g (6.16mmol) 2,3,5,6-tetrafluoro-p-phenylenediamine (TFPDA) and 25g of freshly distilled N-methyl to a three-neck flask equipped with mechanical stirring, temperature and nitrogen inlet Pyrrolidone (NMP) with nitrogen gas. After TFPDA was completely dissolved, 1.2479g (6.36mmol) of 1,2,3,4-cyclobutane tetra-acid dianhydride (CBDA) and 25g of NMP were added. The polycondensation reaction was carried out at room temperature (25° C.) for 24 hours to obtain an anhydride group-terminated polyamic acid solution.

2) Add 0.0574g (0.0497mmol) of octa(aminophenyl)polysilsesquioxane (OAPS) to the system in step 1), and carry out amidation reaction at room temperature (25°C) for 24h to obtain a cross-linked polyamide acid solution.

3) Add 2.52g (31.82mmol) of pyridine and 3.25g (31.82mmol) of acetic anhydride to the crosslinked polyamic acid solution obtained in step 2). Stir for 20 minutes, pour into a mold for dehydration reaction, and the system gels within 1 hour to obtain a gel containing the compound of formula IV.

4) The gel obtained in step 3) is taken out from the mold, and soaked in ethanol repeatedly for 3 times. Add the obtained polyimide wet gel into a supercritical CO ₂ reactor for drying, and dry it at 45° C. and 15 MPa for 6 h to obtain a polyimide airgel.

The structure of the airgel is shown in formula IV,

Formula IV

where T is: n is 30.

The water contact angle of the airgel material is shown in FIG. 9 . The water surface contact angle of the airgel is 100°, the dielectric constant at 2.75GHz is 1.20, and the dielectric loss is 0.0014. The dielectric constant and dielectric loss of the PI airgel will not occur with the increase of environmental humidity Significant changes.

Comparative example 1

Add 1.3268g (6.25mmol) 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl (DMBZ) and 25g of freshly distilled nitrogen form into a three-necked flask equipped with mechanical stirring Nylpyrrolidone (NMP), blown with nitrogen. After the DMBZ was completely dissolved, 1.8987g (6.45mmol) of 3,3',4,4'-diphenyl ether tetra-acid dianhydride (BPDA) and 25g of NMP were added. React for 24 hours to get a viscous solution, add 0.0581g (0.05mmol) octa(aminophenyl) polysilsesquioxane (OAPS) to the system, react for 24 hours, add 2.55g pyridine and 3.29g Acetic anhydride. Stir for 20min, pour into the mold, the system will gel within 2h, exchange the gel with ethanol, dry the exchanged wet gel at 45°C, 15MPa supercritical _CO2 reactor for 6h, and obtain polyimide gas gel.

The structure of the airgel is shown in formula V,

Formula V

where T is: n is 30.

The water contact angle of the airgel material is shown in FIG. 10 . It can be seen that the water contact angle of the PI airgel is 73°, which is a kind of hydrophilic PI airgel. Its dielectric constant at 2.75 GHz is 1.33, and its dielectric loss is 0.0032. This is mainly due to the fact that the hydrophilic properties of this type of PI airgel cause it to absorb moisture in the environment, thereby causing an increase in the dielectric constant.

Table 1 summarizes the main properties of the PI airgel obtained in the present invention and comparative examples.

Table 1. Properties of polyimide airgel

performance Example 1 Example 2 Example 3 Comparative example 1 Water contact angle (°) 135 99 100 73 Dielectric constant (2.75GHz) 1.11 1.21 1.20 1.33 Dielectric Loss (2.75GHz) 0.0011 0.0016 0.0014 0.0032

As can be seen from the table, the PI airgel prepared by the present invention has a higher contact angle, indicating that this type of airgel has intrinsic hydrophobicity, and the dielectric constant range of the PI airgel prepared by the present invention is 1.11 at 2.75 GHz. -1.33, dielectric loss has ultra-low dielectric constant and dielectric loss.

In summary, the prepared PI airgel performance of the present invention satisfies the requirements in the preparation of aircraft, satellites and other spacecraft anti-heat insulation parts, VLSI interlayer dielectric materials, building anti-heat insulation layer, environmental protection, Application requirements in deep sea exploration, oil exploration, energy-saving buildings and home appliances, thermal clothing, sports equipment and other fields.

Claims (13)

1. aerogel shown in formula I,

In described formula I, R ₁for dianhydride monomer fragment, be selected from following radicals any one:

R ₂for diamine monomer fragment, be selected from following radicals any one:

T is amino-terminated substrate section, is selected from any one in following radicals:

N is the integer of 1-100.

2. aerogel according to claim 1, is characterized in that: described n is the integer of 20-40.

3. aerogel according to claim 2, is characterized in that: described n is the integer of 20-30 or the integer of 30-40.

4. prepare a method for aerogel shown in arbitrary described formula I in claim 1-3, comprise the steps:

1) aromatic diamine monomer is mixed with excessive alicyclic dianhydride monomer in organic solvent carry out condensation polymerization reaction, react the complete polyamic acid solution obtaining acid anhydride base end-blocking;

2) to described step 1) add in gained solution and carry out amidate action containing the mixing of amino polyfunctional group end-capping reagent, obtain the polyamic acid solution be cross-linked;

3) to described step 2) add in the crosslinked polyamic acid solution of gained after diacetyl oxide and pyridine stir, carry out dehydration reaction in the mould that reinjects, react the complete gel obtained containing compound shown in formula I;

4) by step 3) in gained gel be placed in solvent and soak, then carry out supercritical co drying, after drying, obtain described aerogel.

5. method according to claim 4, is characterized in that: described step 1) in, alicyclic dianhydride is selected from 1,2,3,4-tetramethylene tetracarboxylic dianhydride, 1,2,4,5-pentamethylene tetracarboxylic dianhydride, 1,2,4,5-hexanaphthene tetracarboxylic dianhydride, dicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic dianhydride and dicyclo [2.2.2] octane-2, at least one in 3,5,6-tetracarboxylic dianhydride; Or,

Described aromatic diamine is selected from 2,3,5,6-tetrafluoro Ursol D, 3, fluoro-4, the 4'-benzidines of 3', 5,5'-tetra-, octafluoro benzidine, 3, the at least one of 5-diamino trifluoromethylbenzene and 2,2'-two (trifluoromethyl)-4,4'-in benzidine; Or,

Described organic solvent is selected from least one in N-Methyl pyrrolidone, meta-cresol, DMF, N,N-dimethylacetamide, dimethyl sulfoxide (DMSO); Or,

The molar ratio of described alicyclic dianhydride and aromatic diamine is 1.00:(0.90 ~ 0.99); Or,

Described step 1) in condensation polymerization reactions steps, the reaction times is 10 ~ 30 hours; Or,

Temperature is 0 ~ 35 DEG C.

6. method according to claim 5, is characterized in that: the molar ratio of described alicyclic dianhydride and aromatic diamine is 1.00:(0.95 ~ 0.98); Or,

Described step 1) in condensation polymerization reactions steps, the reaction times is 20 ~ 25 hours; Or,

Temperature is 15 ~ 25 DEG C.

7. method according to claim 4, it is characterized in that: described step 2) in, the described polyfunctional group end-capping reagent containing amino is selected from 1,3,5-tri-(amino) benzene, 1, at least one in 3,5-tri-(amino-benzene oxygen) benzene, 2,6-two (4'-aminophenyl)-4-(4'-aminophenyl) pyridines, eight (aminophenyl) polysilsesquioxane; Or,

Described step 2) in amidation reaction steps, the time is 10 ~ 30 hours; Or,

Temperature is 0 ~ 35 DEG C.

8. method according to claim 7, is characterized in that: described step 2) in amidation reaction steps, the time is 20 ~ 25 hours; Or,

Temperature is 15 ~ 25 DEG C.

9. method according to claim 4, is characterized in that: described step 3) in, the molar ratio of described diacetyl oxide and alicyclic dianhydride is (2.00 ~ 10.00): 1.00; Or,

The molar ratio of described pyridine and alicyclic dianhydride is (2.00 ~ 8.00): 1.00; Or,

Described step 3) in dehydration reaction step, the time of stirring is 10 minutes ~ 30 minutes; Or,

In described dehydration reaction step, the time is 1 hour ~ 10 hours; Or,

Temperature is 0-35 DEG C.

10. method according to claim 9, is characterized in that: described step 3) in, the molar ratio of described diacetyl oxide and alicyclic dianhydride is (3.00 ~ 5.00): 1.00; Or,

The molar ratio of described pyridine and alicyclic dianhydride is (3.00 ~ 5.00): 1.00; Or,

Described step 3) in dehydration reaction step, the time of stirring is 15 minutes ~ 20 minutes; Or,

In described dehydration reaction step, the time is 1 hour ~ 5 hours; Or,

Temperature is 15-25 DEG C.

11., according to described method arbitrary in claim 4-10, is characterized in that: described step 4) in, at least one in described solvent selected from methanol, ethanol, Virahol and acetone; Or,

In described supercritical co drying step, pressure is 10 ~ 20MPa; Or,

Temperature is 30 ~ 80 DEG C.

12. methods according to claim 11, is characterized in that: in described supercritical co drying step, and pressure is 15 ~ 18MPa; Or,

Temperature is 40 ~ 60 DEG C.

Aerogel shown in the arbitrary described formula I of 13. claim 1-3 is as the interlevel dielectric material of anti-lagging material, super large-scale integration and the application of heat insulating material formed middle at least one; Or,

The application of aerogel at least one in deep-sea detecting, environment protection and petroleum prospecting shown in the arbitrary described formula I of claim 1-3.