A kind of preparation method of sponge-silicon airgel composite material

Abstract

The invention provides a preparation method of a sponge-silicon aerogel composite material, which comprises the following steps: mixing a silicon source and a solvent, adding deionized water, and stirring to form a silicon source solution; sequentially adding an acidic catalyst, an alkaline catalyst and a drying control chemical additive into the silicon source solution, and stirring to obtain a silica sol with the pH value of 5-7; pouring the silica sol into a sponge-containing container, and standing to form a gel; adding a polar solvent to perform aging and exchange, and adding a non-polar solvent to exchange out the polar solvent in the gel; and finally, immersing in a silane coupling agent-non-polar solvent mixed solution to perform surface modification on the gel, and carrying out graded drying under normal pressure to obtain the high-hydrophobicity high-adsorptivity sponge-silicon aerogel composite material. The sponge-silicon aerogel composite material is hydrophobic and oleophylic, and has high adsorption rate for n-hexane, gasoline, kerosene, benzene and other organic solvents; the adsorption capacity can reach more than 95% of the self volume; and the sponge-silicon aerogel composite material has very high application value in the aspect of municipal sewage treatment, ocean oil pollution or the like.

Description

technical field [0001] The invention belongs to the technical field of macromolecules, and in particular relates to a preparation method of a super-hydrophobic and highly absorbent sponge-silicon airgel composite material. Background technique [0002] Sponge is a porous material with good water absorption, but its pores are large, its water storage capacity is weak, and its water absorption is not large; airgel is a nanoporous material with a large specific surface area and a low density. (about 0.1g / cm 3 ); and the surface-hydrophobic-treated, atmospheric-dried silica-aerogel can absorb a large amount of organic matter, but it does not absorb water at all. [0003] In view of the very harsh conditions for the preparation of silica aerogels by supercritical drying and the high requirements for equipment, the preparation method of normal pressure drying has become the focus of research. For example, Ni Xingyuan et al. (Chinese patent, application number 200810042222.4) dis...

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Problems solved by technology

[0004] The above-mentioned pure silica airgel particles prepared by the atmospheric pressure drying method are small and irregular in shape, and are prone to cracking during use, thereby limiting its application. In fact, pure silica airgel is also rarely used directly

[0005] In addition, the Chinese patent (application number CN103073008A) uses tetraethyl orthosilicate as the silicon source, and through the steps of sol-gel, aging, solvent exchange, surface modification, etc., the silicon dioxide aerosol is prepared under normal pressure drying conditions. Glue, its preparation process is more complicated, the adsorption performance is not good

Cui Sheng, Zhou Dan, etc. (Chinese patent, application number 201310675505.3) used tetraethyl orthosilicate as a silicon source to prepare a hydrophilic airgel / sponge composite material through a sol-gel method under carbon dioxide supercritical drying conditions , the use of supercritical drying process greatly increases the risk and cost of operation, and secondly, the prepared compound is hydrophilic, and the absorption effect on oil pollution in water is not good

Bian Zhaoyong, Wang Hui, etc. (Chinese Patent, Application No. 201310271648.8) used functional group-substituted alkoxysilane mixtures as precursors to prepare silicon airgel oil-absorbing sponges under normal pressure drying conditions. Although the preparation process is simple, but The alkoxysilanes substituted with functional groups are expensive and not suitable for mass production

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