Flexible silicon dioxide aerogel and preparation method thereof

Abstract

The invention discloses flexible silicon dioxide aerogel and a preparation method thereof.The preparation method comprises the following steps that S1, water, acid and a surfactant are mixed, then organosilane with hydrophobic groups is added for mixing and stirring, and a mixed solution is obtained; s2, silica sol and alkali are added into the mixed solution, gelation and aging are carried out at the temperature of 60-90 DEG C, and wet gel is obtained; s3, the wet gel is cleaned and dried, and flexible silicon dioxide aerogel is obtained; acid is added into every 15 mL of water, so that the pH value of the solution is 5-6.5, 0.6-1.2 g of a surfactant, 0.018-0.033 mol of organosilane with hydrophobic groups, 0.013-0.025 mol of alkali and 50-250 [mu] L of silica sol are added. The prepared flexible silicon dioxide aerogel has excellent flexibility, hydrophobicity, thermal stability, compression resilience and organic pollutant adsorption capacity, and can be repeatedly used for multiple times in wastewater purification and adsorption and separation of organic pollutants.

Description

A kind of flexible silica aerogel and preparation method thereof technical field [0001] The present invention relates to the technical field of aerogels, in particular to flexible silica aerogels and a preparation method thereof. Background technique Aerogel is a kind of three-dimensional network skeleton composed of ultrafine particles or polymer molecules that aggregate with each other. It is a nanoporous solid material with a structure, and the pores are filled with a gas dispersion medium, which is known as the lightest solid material. Aerogel in Sound insulation, heat insulation, fire and flame retardant, filter materials, drug release materials, catalysts and catalyst carriers, fuel cells, etc. Domains have great advantages. Silica aerogel is the earliest developed aerogel with the most mature technology and the first industrial application. However, due to the shortcomings of low strength and high brittleness of silica aerogel, it is easy to open in the actu...

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Problems solved by technology

Silica aerogel is one of the earliest developed aerogels, the most mature technology, and the first to be put into industrial application. However, due to the disadvantages of low strength and high brittleness of silica aerogel, it is easy to appear The condition of cracking, breaking and failing

Although the flexibility of the aerogel is indeed improved by introducing hydrophobic groups, the maximum compressive strain can reach 80%, but due to the introduction of a large number of hydrophobic groups, it is prone to phase separation during the gelation process, resulting in a circular shape. The size of the secondary particles is large, and the neck connection formed between them is weak, resulting in weakened skeleton strength, poor mechanical properties, and low cyclic compression capacity

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