Preparation method of cellulose toughened silica airgel

Abstract

A preparation method of cellulose-toughened silicon dioxide aerogel includes following steps: (1), according to a proportion of 1g:(15-30)mL, soaking cotton in concentrated sulfuric acid for 20-35min,stirring at 40-60 DEG C for 2-3h, using deionized water to flush, centrifuging for several times until a solution is close to neutral, and extracting the deionized water to obtain cellulose sol; (2),mixing methyl trimethoxy silane, dimethyl dimethoxy silane, cetyl trimethyl ammonium bromide, N, N-dimethylformamide, CH3COOH and CH3CH2OH according to a proportion of 1mL:(0.4-0.9)mL:(0.1-0.3)g:(0.4-0.8)mL:(8-20)mL:(5-10)mL, and stirring at 25-40 DEG C for 60-80min; (3), adding the cellulose sol into mixed liquid according to a proportion of 1mL:(0.5-4.0)g, using ammonia water to adjust pH to 8-9, and aging at 35-50 DEG C for 5-8h; (4), using isopropanol and n-hexane for washing, drying at 30-35 DEG C for 10-15h, and drying at 38-45 DEG C for 20-40h to obtain the cellulose-toughened silicondioxide aerogel. The aerogel is high in porosity, hydrophobicity, mechanical performance and oil absorption rate and reusable.

Description

technical field [0001] The invention belongs to the field of airgel, and in particular relates to a preparation method of cellulose toughened silica airgel. Background technique [0002] Silica airgel is a new type of amorphous solid porous material composed of nano-sized particles and air as the dispersion medium. Due to its low density, high porosity, high specific surface area, low thermal conductivity, low acoustic wave With a series of characteristics such as propagation rate and low dielectric constant, it is a kind of nanoporous lightweight material with high specific surface area and excellent adsorption performance, and has broad application prospects in the fields of environmental protection and energy utilization. [0003] Since the traditional SiO prepared from tetraethyl orthosilicate as precursor 2 The surface of airgel is connected with hydrophilic group -OH, and has a porous structure, which will lead to SiO 2 Airgel readily absorbs moisture. The re-evapor...

AI Technical Summary

Problems solved by technology

Although the airgel prepared by this method has good flexibility, the supercritical drying method used in the drying process requires high-pressure equipment, high energy consumption for the process, very expensive production equipment and production costs, and strict control of process conditions. It is dangerous, and the whole drying process takes a long time, and it is difficult to achieve continuous large-scale production, thus limiting its development to a large extent

[0005] Material composite method is an important method to improve the strength and toughness of silica aerogels. The most widely used methods include additive method, fiber reinforcement method, secondary composite method and polymer method. Among them, the fiber reinforcement method has the characteristics of simple operation, but Inorganic fibers can improve the mechanical properties of aerogels, but doping them into aerogels will destroy the skeleton structure of aerogels to a certain extent