Method for rapid preparation of SiO2 aerogel microsphere

Abstract

A method for rapidly preparing SiO2 airgel microspheres belongs to the field of inorganic non-metallic materials, in particular to a method for rapidly preparing SiO2 airgel microspheres. The invention uses water glass as a raw material to obtain silicic acid with a pH of 2-3 through ion exchange, adds an alkaline catalyst, and then adds it into hydrophobic oil and stirs it at the same time. The silicic acid is stirred and sheared into tiny droplets, which are suspended in the oil in a spherical shape due to the surface tension until the gel forms gel microspheres, then the stirring is stopped, and then the oil is separated from the microspheres and washed with water to obtain Hydrogel microspheres. Alcohol gel microspheres are obtained by immersing the hydrogel microspheres in ethanol solution and absolute ethanol successively for solvent exchange, and airgel microspheres with a particle diameter of millimeter or micron can be obtained after drying. The invention has the advantages of low cost, simple and easy-to-control process, easy realization of large-scale production, good product quality and wide application prospects in the fields of heat insulation, catalysis and the like.

Description

technical field [0001] The invention belongs to the field of inorganic non-metallic materials, relates to a nanoporous material, in particular to a method for rapidly preparing SiO 2 Airgel microspheres approach. Background technique [0002] SiO 2 Airgel is a new type of solid material with nanoporous structure formed by the mutual aggregation of nanoparticles. It has the characteristics of low density, high porosity, large specific surface area, uniform distribution and good light transmission performance. It is very useful in many fields. The wide application prospect has been highly valued by material researchers and other researchers. [0003] Currently, on the preparation of SiO 2 There are many reports on aerogels, but the final products prepared are mostly blocks or powders of different sizes. SiO 2 Airgel bulk materials have the defects of being brittle and brittle and difficult for practical application, while powdered SiO 2 In practical applications, aerogel...

AI Technical Summary

Problems solved by technology

However, based on the necessary drop time as a reason for the reaction time of the gel, the overall height of the hydrogel to be injected would be very large

In order to reduce the height of the equipment, the patent No. 98805632.1 "Preparation method of near-spherical lyogel and aerogel" has further improved it. Adding lyosol to the steam not only accelerates the gel reaction, but also The glue time is shortened, and the falling direction of the liquid droplets is opposite to the direction of the steam flow, so the falling speed of the liquid droplets is reduced, and finally the height of the equipment is reduced, but the equipment and method used in this invention are still relatively complicated

Another SiO 2 Airgel pellets and TiO 2 / SiO 2 The preparation method of airgel microspheres also has some disadvantages. On the one hand, silica sol is used as the silicon source, which is more expensive. On the other hand, the first three patents use n-heptane or n-hexane, Span 80, Tuwen 85, n-butanol or n-hexanol are used as raw materials to prepare the oil phase, and the last patent uses ammonia water, cetyl ammonium bromide saturated solution and kerosene to prepare the oil phase, which not only makes the oil phase components complicated and the preparation process More cumbersome, and some chemical reagents may also cause environmental pollution problems