Ultra low density aerogel material, and preparation method and applications thereof

Abstract

The invention provides a preparation method of an ultra low density aerogel material. The preparation method comprises following steps: a silicon source, methanol, and hydrochloric acid are added formixed reaction, distillation is carried out to remove methanol, and acetonitrile is added so as to obtain a sol precursor; the sol precursor is mixed with ammoniacal liquor, and acetonitrile is addedto prepare silica sol; the silica sol is subjected to gelling and aging successively so as to obtain a wet gel material; a hydrophobic agent is adopted for hydrophobization treatment of the wet gel material so as to obtain a hydrophobized gel material; the hydrophobized gel material is subjected to solvent displacement so as to obtain a solvent displaced gel; the solvent displaced gel is introduced into a drying kettle for supercritical drying so as to obtain the ultra low density aerogel material. The largest complete size of the ultra low density aerogel material is 300mm*300mm, the thickness ranges from 10 to 30mm; the density is lower than 20kg / m3, the size shrinkage rate is lower than 1%, the agglutinable volatile matter content is 0.06% or lower. The invention also provides applications of the ultra low density aerogel material in the field of deep space detection.

Description

technical field [0001] The invention belongs to the field of thermal protection, in particular to the technical field of thermal protection materials for thermal control systems used in deep space exploration, and specifically relates to an ultra-low-density airgel material and its preparation method and application. Background technique [0002] Airgel material is a new type of low-density nanoporous material. It is the solid material with the best thermal insulation performance. Airgel is formed by the mutual accumulation of nanoparticles and has a three-dimensional network nanoporous structure. The Lawrence Livermore National Laboratory of the United States was the first to achieve a breakthrough in the preparation of ultra-low-density silica airgel, and the density of the prepared airgel material can be as low as 3kg / m 3 . The U.S. Jet Propulsion Laboratory used the laboratory technology to realize the application of ultra-low-density aerogels in the aerospace field; in...

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Problems solved by technology

[0003] However, domestic research on ultra-low-density aerogels focuses on small samples and performance research in the laboratory, and there are no reports on the application of large-scale materials.

This preparation technology also has the following disadvantages: 1) the product size shrinkage rate is 15%, and the size shrinkage will bring greater difficulty to the size control in material application; 2) the product yield is low, and the literature reports only about 25%, resulting in Product production efficiency is low, cost is high; 3) this preparation method can only use supercritical ethanol drying technology, in supercritical CO 2 Under these conditions, ultra-low density aerogels are prone to cracks and become powder materials.

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