Preparation method of silicon dioxide aerogel composite material

Abstract

The invention discloses a preparation method of a silicon dioxide aerogel composite material. The preparation method comprises the following steps: S10, providing a gel composite material; s20, putting the gel composite material into a reaction kettle for standing and aging; s30, introducing an acid solution and a silsesquioxane solution into a reaction kettle,pumping the solution at the bottom of the reaction kettle out, and injecting the solution from the top of the reaction kettle to form circulation so as to obtain a modified wet gel composite material ; and s40, performing drying treatment on the wet gel composite material to obtain the hydrophobic hybrid silicon dioxide aerogel composite material. Due to the fact that the circulation process is conducted continuously, an active modifier is generated continuously, the active modifier makes full contact with the gel composite material from top to bottom, and the modification process is conducted fully, so that the gel compositematerial can be fully and efficiently modified. In addition, a large number of active modifiers generated in the modification process can be subjected to self condensation reaction when meeting water to generate silsesquioxane, and the generated silsesquioxane can participate in the next circular reaction process.

Description

technical field [0001] The invention relates to the technical field of preparation of thermal insulation materials, in particular to a preparation method of a silica airgel composite material. Background technique [0002] In the process of preparing silica airgel by atmospheric drying method, the most critical is to realize low-cost and high-efficiency hydrophobic modification of hydrogel composite materials, and then dry under normal pressure conditions to modify the surface hydrophobicity. The quality directly determines the quality of the obtained silica airgel. [0003] In the prior art, the sol-gel method is usually used to prepare silica gel, and the surface of the silica gel is modified by using trimethylchlorosilane with strong activity as a surface modifier, and finally dried under normal pressure to obtain silica gas. Gel powder. Then, the prepared airgel powder is mixed with the fiber mat by vacuum infiltration method to obtain the silica airgel composite felt ...

AI Technical Summary

Problems solved by technology

[0004] The main purpose of the present invention is to propose a preparation method of silica airgel composite material, aiming at solving the complicated solvent exchange of silica gel in the prior art when carrying out surface modification to silica gel, which requires consumption A large amount of organic solvents, the problem of high airgel content on the surface of the composite material and low airgel content inside the composite material

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