One-pot preparation of sio 2 - Method for cellulose composite airgel material

Abstract

The invention relates to a method for preparing a SiO2-cellulose composite aerogel material with a one-pot method. The method comprises the following steps: taking cellulose as a raw material and dissolving the cellulose with a green alkaluria solvent; taking organic sodium silicate as a silicon source, and stirring and dispersing to obtain a uniformly mixed aqueous solution of the cellulose and the sodium silicate; combining a sol-gel method to obtain regenerated cellulose wet gel containing a silicon source; taking cellulose gel as a framework and taking inorganic acid as a reaction solvent, and inducing to generate SiO2; finally, drying through a CO2 supercritical drying process to obtain the SiO2-cellulose organic-inorganic composite aerogel. The method has the advantages that the process is simple and rapid, has high feasibility and is green and environment-friendly; the problems in an in-situ immersion method that the SiO2 has poor dispersity, low complex content, poor complex stability and the like in a cellulose porous network structure are effectively solved; the prepared inorganic-organic composite aerogel has relatively low coefficient of heat conductivity and good heat insulation performance and has good application prospect in the aspects of low-temperature cold insulation materials, middle-temperature and low-temperature heat insulation and heat preservation materials and adsorption materials.

Description

technical field [0001] The invention belongs to the field of preparation of polymer nano functional materials, and relates to a one-pot method for preparing SiO 2 - Method of cellulose composite airgel material. Background technique [0002] Cellulose airgel is a new type of new natural biomass material developed in recent years. Cellulose is the green renewable resource with the largest reserves on the earth. Cellulose airgel has both the characteristics of renewable natural polymers and many advantages of traditional high-porosity nano-inorganic porous materials. Cellulose airgel has the characteristics of good toughness and easy processing. Therefore, cellulose aerogel has become a new material with broad application prospects and high development value. Electrode materials for carbon batteries and fuel cells have great potential. [0003] Cellulose airgel has many excellent properties, but the limitations of polysaccharide airgel itself, such as poor stability and poo...

AI Technical Summary

Problems solved by technology

[0004] Conventional SiO 2 - Cellulose composite aerogels are usually impregnated with wet cellulose membranes into tetraethyl orthosilicate / methyl orthosilicate, silica airgel is formed in the micropores of the cellulose matrix, and then 2 Medium drying, etc., however, this method will quickly gel the silica on the outer surface of the cellulose, thereby blocking the pore openings and hindering the penetration of silica into the cellulose matrix, resulting in an urgent decrease in porosity

However, it is not advisable to directly mix the cellulose solution with tetraethyl orthosilicate, the alkali-soluble cellulose solution is a metastable system, and directly mixing with the silane hydrolyzate will cause the cellulose to coagulate immediately and the silica sol to phase separate

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