Preparation method of hydrophobic lipophilic sponge aerogel composite material

Abstract

The invention discloses a hydrophobic lipophilic sponge aerogel composite material. The composite material is a porous hydrophobic lipophilic solid with compressive strength higher than 0.1MPa, density of 0.09-0.12g/cm<3>, porosity of 90-95%, pore size of 1-10mum, and organic liquid absorption capacity higher than 0.7ml/cm<3>. The preparation method comprises 4 steps: (1) a silicon source and a solvent are mixed; deionized water is added; and the mixture is stirred such that a silicon source solution is formed; (2) an acidic catalyst is added into the silicon source solution for regulating the pH value of the solution; a hydrolysis accelerator is added and the mixture is stirred; an alkaline catalyst is added and the mixture is stirred, such that silica sol is obtained; (3) the silica sol is added into a container containing sponge blocksn, and is allowed to stand, such that wet gel is formed; and (4) the wet gel is dried under normal pressure, such that the hydrophobic lipophilic sponge aerogel composite material is obtained. The preparation method provided by the invention is simple; a preparation period is short, and the entire preparation process can be completed within 12h; steps such as gel aging and solvent exchange are not needed; and a preparation success rate is higher than 98%.

Description

technical field [0001] The invention belongs to the technical field of porous materials, and in particular relates to a preparation method of a sponge airgel porous material. Background technique [0002] Silica airgel is a porous material with low density. After treatment, the material has excellent hydrophobic and lipophilic properties, and can absorb floating oil in water. However, the material has poor mechanical properties and is brittle, which limits its application. The "Preparation and Characterization of Flexible Block Hydrophobic Silica Airgel" reported in "Journal of Silicates" all use methyltrimethoxysilane as the precursor, and the wet gel is prepared by the sol-gel method. , solvent exchange and other steps, followed by normal pressure drying to prepare silica airgel with certain flexibility, but the preparation process is relatively complicated and the preparation cycle is long. "Microporous and Mesoporous Materials" (MICROPOROUS AND MESOPOROUS MATERIALS, 20...

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Problems solved by technology

However, the material has poor mechanical properties and is brittle, which limits its application

The "Preparation and Characterization of Flexible Block Hydrophobic Silica Airgel" reported in "Journal of Silicates" all use methyltrimethoxysilane as the precursor, and the wet gel is prepared by the sol-gel method. , solvent exchange and other steps, and dry under normal pressure to prepare silica airgel with certain flexibility, but the preparation process is relatively complicated and the preparation cycle is long

"Microporous and Mesoporous Materials" (MICROPOROUS AND MESOPOROUS MATERIALS, 2012, 148:152-158) reported the stress-strain curve of the flexible aerogel based on methyltrimethoxysilane, indicating that the material is resistant to The compressive strength is very low. When it is compressed by 60%, the required stress is only 22kPa, and it is fragile, so it is not suitable for transportation and carrying

[0003] About adopting sponge to strengthen the report, a kind of preparation method of low-density SiO2 airgel / sponge composite material, adopt two-step sol-gel method to combine CO2 supercritical drying to prepare low-density SiO2 airgel / sponge composite material, adopted The silicon source is methyl orthosilicate, ethyl orthosilicate, water glass or silica sol, and supercritical drying is used, which consumes a lot of energy and costs high, and the final airgel is hydrophilic, so its application is limited. The preparation process is complex (3-8 solvent replacements are required)

A reusable cheap silicon airgel oil-absorbing sponge and its preparation method, using alkoxysilane as a precursor, aging and physical extrusion washing treatment after gelation, the process is relatively complicated, and the extrusion washing scale is difficult to control, Easy to damage the gel structure

Although the final gel has a certain degree of elasticity, the adsorbed organic solvent or oil can be recovered by physical extrusion, but the efficiency of this extrusion recovery method is too low, and it is unlikely in the case of a large amount of fuel oil leakage Effectively stop the flow of oil pollution and pollution behavior

The prior art also discloses a method for hydrophobic and lipophilic treatment of sponges. The cost of the precursor solution and nano-hydrophobic silica particles used is high, and the treatment of the sponge is uneven, and some pores may be blocked.

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