A kind of preparation method of anti-powder falling silica airgel

Abstract

The invention belongs to the technical field of airgel preparation and discloses a preparation method of powder-falling-proof silica airgel. Mix silicon source, ethanol and water evenly, then add NH 4 Stir the F solution and ammonia water evenly, and let it stand still to obtain a wet gel; take hydroxyl silicone oil and orthosilicate and mix evenly to form a silicone mixed solution; soak the wet gel in the silicone mixed solution, and then add an alkaline catalyst, Static reaction at 30~60°C for 8~24 h, drying treatment, the anti-powder falling silica airgel can be obtained. Molecular silicone reacts with the hydroxyl group in the wet gel skeleton to form a wet gel skeleton wrapped by small molecule silicone, which fixes the silica airgel network skeleton, so after the drying is completed, the aerogel The bonding with the small molecule silicone fixes the silica airgel particles microscopically, so it can prevent the occurrence of powder falling.

Description

technical field [0001] The invention belongs to the technical field of airgel preparation, and in particular relates to a preparation method of powder-falling-proof silica airgel. Background technique [0002] At present, the development of new energy, the improvement of the utilization rate of existing energy and the conservation of energy have attracted great attention from all countries. my country is an energy-poor country, therefore, rational use of energy and energy conservation are of great significance to the sustainable development of our society. Adopting new technologies and processes to develop environmentally friendly heat insulation materials is one of the most effective and economical measures to save energy. [0003] SiO 2 As an emerging super heat insulation material, airgel has an extremely low thermal conductivity, which is far lower than the thermal conductivity of 0.25W / m K of static air at room temperature, and has an incomparable heat insulation effe...

AI Technical Summary

Problems solved by technology

At present, the usual anti-powder solution is to use glass fiber cloth, aluminum foil cloth, etc. to stick on the surface of airgel fiber mat. This method has high labor costs and is not conducive to large-scale production. Moreover, the flexibility of the material after the front and back sides are pasted is not good. Good curling, bending, storage, transportation, construction and installation are not convenient enough

The coating preparation technology on the surface of airgel felt is one of the methods developed recently to avoid powder shedding. Usually, solvent-based coatings are applied on the surface of airgel to prevent slag, and solvent-based coatings will bring environmental pollution. In addition, the solvent will penetrate into the interior of the airgel, destroying the pore structure and reducing its thermal insulation performance.