High-strength ultralow-density transparent silicon dioxide aerogel as well as preparation method and application thereof

[0031]In the first aspect, the present invention provides a method for preparing a high-strength ultra-low-density transparent silica aerogel. The method includes the following steps:

[0032](1) Mix the silicone ester, alcohol solvent, water, acid catalyst and structure enhancer monomers uniformly to obtain a mixed solution, and then subject the mixed solution to a pre-hydrolysis reaction to obtain a pre-hydrolyzed compound, and then use an alcohol solvent to The pre-hydrolyzed compound is diluted to obtain a silicon source precursor (also referred to as silicon source precursor solution); in the present invention, the pre-hydrolyzed compound is a semi-hydrolyzed and semi-condensed compound with higher reactivity, and the silicon source precursor The reaction activity of the silicon source is relatively high, and the silicon source precursor is a semi-hydrolyzed and semi-condensed silicon source precursor with relatively high reactivity; in the present invention, the alcohol solvent cont

[0058]Example 1

[0059]①Add 15.2g of methyl orthosilicate, 32g of methanol, 3.6g of water, 10μL of 0.1mol / L dilute hydrochloric acid and 2.7g of 10-alkenylundecyltrimethoxysilane (structural strengthening Mix it with magnetic stirring, heat up to 70℃, reflux reaction (pre-hydrolysis reaction) at this temperature for 36h, cool to room temperature after the reaction, add 640g methanol for dilution, and obtain a semi-hydrolysis with relatively high reaction activity Semi-condensed silicon source precursor solution, the raw materials of each component in the silicon source precursor solution are in molar ratio Methyl orthosilicate: 10-alkenyl undecyl trimethoxysilane: methanol: water: contained in dilute hydrochloric acid The HCl is 1:0.1:210:2:10-6, Where the amount of methanol includes methanol for reaction (32g) and methanol for dilution (640g).

[0060]②Add 5 mL of 1mol / L lysine aqueous solution to the aforementioned silicon source precursor solution, stir and mix with magnetic force, p

[0064]Example 2

[0065]Embodiment 2 is basically the same as embodiment 1, except that:

[0066]In step ①, add 15.2g of methyl orthosilicate, 32g of methanol, 1.8g of water, 10μL of 0.1mol / L dilute hydrochloric acid and 1.35g of 10-alkenylundecyltrimethoxy into a single-necked flask. Silane (structural enhancer monomer), stir and mix with magnetic force, heat up to 70℃, reflux reaction (pre-hydrolysis reaction) at this temperature for 36h, cool to room temperature after the reaction, add 640g methanol for dilution, and get relatively reactive reaction Highly semi-hydrolyzed and semi-condensed silicon source precursor solution. The raw materials of each component in the silicon source precursor solution are in molar ratio. Methyl orthosilicate: 10-alkenyl undecyl trimethoxysilane: methanol: water: The HCl contained in dilute hydrochloric acid is 1:0.05:210:1:10-6, Where the amount of methanol includes methanol for reaction (32g) and methanol for dilution (640g).

[0067]In step ②, add 1 mL of