A kind of ultra-low density silica airgel with adjustable transparency and its preparation method and application

Abstract

The invention relates to an ultra-low density silica airgel with adjustable transparency, a preparation method and application thereof. The method comprises the following steps: forming a thin layer of long-chain alkane on the inner surface of a mold; adding sol for preparing ultra-low-density silica airgel to the mold to obtain a transparent wet gel; raising the temperature to restrict the diffusion of long-chain alkane on the surface of the mold Enter the interior of the gel, and obtain an opaque wet gel after cooling; put the opaque wet gel into an ethanol solution containing long-chain alkanes for solvent replacement to obtain an alcohol gel; dry the alcohol gel with supercritical carbon dioxide to obtain a transparent tuned ultra-low density silica airgel. The light transmittance of the airgel prepared by the present invention has obvious temperature responsiveness. When the ambient temperature is lower than the long-chain alkane phase transition temperature, the aerogel is completely opaque under visible light. When the ambient temperature is higher than the long-chain alkane phase transition temperature At high temperature, airgel is completely transparent under visible light, and has great application value in smart home, high-end display, personal privacy and other fields.

Description

Ultra-low density silica aerogel with adjustable transparency and preparation method thereof application technical field The invention belongs to nanoporous material technical field, relate to a kind of preparation method of silica aerogel, especially The invention relates to an ultra-low density silica aerogel with adjustable transparency, a preparation method and application thereof. Background technique [0002] Ultra-low density transparent silica aerogel, due to its light weight (density 10 ~ 60mg / cm 3 ), optically transparent (visible Band light transmittance 70%~93%), high thermal insulation (thermal conductivity 0.017~0.024W / m·K), low refractive index (refractive index 1.01~1.03) and other notable features, in deep space exploration, high-energy physics, building lighting, transparent display, solar heat collection, medical evaporation Steam disinfection, climate transformation and many other fields have been widely used or have great application prospect...

AI Technical Summary

Problems solved by technology

However, the optical transparency of the transparent aerogels reported in these patent applications is heavily dependent on the formula used. Once the formula is determined, its light transmittance is fixed and cannot be adjusted automatically according to environmental changes.

So far, there have been no reports on ultra-low-density airgel materials whose transparency under visible light can be dynamically adjusted according to the ambient temperature.

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