Preparation method of aerogel material and application thereof

Abstract

The invention provides a preparation method of an aerogel material and an application thereof, the method utilizes the strong water absorption performance of strong acid, and the aqueous solution is insoluble in hexamethyldisiloxane, so that the migration of water in gel to the acid direction and the migration and replacement of hexamethyldisiloxane to pores can be accelerated. The strong acid is recycled through cyclic concentration, so that the cost and the environmental influence can be reduced while waste liquid is reduced. According to the method, the silicon dioxide hydrogel is directly subjected to in-situ modification by adopting the mixed solution of concentrated sulfuric acid and hexamethyldisiloxane, so that the process of surface modification after multi-solvent replacement is omitted, and the surface modification period is shortened. In addition, except that the drying and heat treatment processes are carried out at high temperature, other technological processes can be carried out at normal temperature, the conditions are mild, and the technological cost is greatly reduced.

Description

technical field [0001] The invention belongs to the field of preparation of nanoporous materials, in particular to a preparation method and application of an airgel material. Background technique [0002] The super thermal insulation performance of silica airgel materials has been widely recognized, and it has been put into use in many fields such as petrochemical industry, heat pipe network, and new energy vehicles, and has shown excellent performance, but there are only a handful of enterprises that have achieved large-scale production Countable, the reason is that the process involved in the construction of special structures is limited, resulting in high costs. [0003] Airgel is obtained when the liquid in the pores of the wet gel is replaced by gas without the structure collapsing. The supercritical method utilizes the characteristics of supercritical fluids such as no surface tension, high diffusivity, and high solubility to effectively avoid the collapse of the gel ...

AI Technical Summary

Problems solved by technology

[0002] The super thermal insulation performance of silica airgel materials has been widely recognized, and it has been put into use in many fields such as petrochemical industry, heat pipe network, and new energy vehicles, and has shown excellent performance, but there are only a handful of enterprises that have achieved large-scale production Countable, the reason is that the process involved in the construction of special structures is limited, resulting in high costs

First, the desalination efficiency of the resin is low and the regeneration of the resin will generate a large amount of saline wastewater

Secondly, solvent replacement is to replace the water in the nanopores with alcohol solvents, and then replace the alcohol solvents with aprotic solvents such as hydrocarbons or ethers, and perform multiple mass transfer processes in the gel nanopores, with a long period of time. , The efficiency is extremely low and it is difficult to replace completely, and at the same time, a large amount of waste solvents with different concentrations and components are produced, and the recycling cost and environmental protection cost are high

Finally, trimethylchlorosilane and hexamethyldisilazane are often used for surface methyl silylation modification. These silylating reagents are expensive and can react with water or alcohol reagents. Thoroughly, a large amount of silylating reagents will be lost, which will greatly increase the production cost

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