Preparation method of anti-powder-falling silicon dioxide aerogel

Abstract

The invention belongs to the technical field of aerogel preparation, and discloses a preparation method of anti-powder-falling silicon dioxide aerogel. The preparation method comprises the following steps: uniformly mixing a silicon source, ethanol and water, sequentially adding an NH4F solution and ammonia water, uniformly stirring, and standing to obtain wet gel; uniformly mixing hydroxyl silicone oil and orthosilicate to form an organic silicon mixed solution; dipping the wet gel into the organic silicon mixed solution, then adding a basic catalyst, carrying out static reaction for 8-24 hours at the temperature of 30-60 DEG C, and carrying out drying treatment, so as to obtain the anti-powder-falling silicon dioxide aerogel. By dipping the wet gel in the micromolecular organic silicon mixed solution, and carrying out bonding reaction on small molecular organic silicon and hydroxyl in a wet gel skeleton under alkaline catalysis, the wet gel skeleton coated with the small molecular organic silicon is formed to fix a silicon dioxide aerogel network framework, so that silicon dioxide aerogel particles are fixed microcosmically due to the bonding effect of the aerogel and the small molecular organic silicon after drying is finished, and the powder falling condition can be prevented.

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.