Sio with polymer modification and carbon nanofiber doping 2 Airgel and its preparation method

Abstract

The invention provides a polymer modified and nano-carbon fiber doped SiO2 aerogel and a preparation method thereof. The preparation method comprises: subjecting a water glass solution to ion exchange to obtain a silicic acid solution; dissolving a surfactant and nano-carbon fiber in the silicic acid solution, and carrying out ultrasonic dispersion to obtain nano-carbon fiber / SiO2 composite sol; adjusting the pH value of the composite sol, conducting standing at room temperature to obtain nano-carbon fiber / SiO2 gel; aging the gel at room temperature, and then transferring the gel into an aqueous solution of an organic solvent to conduct soaking; dissolving the soaked gel in an organic solvent of a silane coupling agent to carry out reaction under a heating condition; immersing the gel into a polymer monomer solution, conducting pumping filtering by a vacuum pump, and then carrying out polymerization reaction; and then performing washing and drying, thus obtaining the polymer modified and nano-carbon fiber doped SiO2 aerogel. The technical scheme provided by the invention has the advantages of safe operation and simple process, and the prepared SiO2 aerogel has excellent mechanical and thermal performance.

Description

technical field [0001] The present invention relates to a SiO 2 Airgel and its preparation method, especially related to a kind of SiO modified by polymer and doped with carbon nanofiber 2 The airgel and its preparation method belong to the field of preparation of nanoporous materials, functional materials and thermal insulation materials. Background technique [0002] SiO 2 As a lightweight porous nanomaterial, airgel has excellent properties such as low density, high porosity, high specific surface area, extremely low thermal conductivity and unique nanoporous structure in thermal insulation, heat insulation, adsorption, Catalysis, aerospace, high-energy physics, medicine, oil pollution treatment and other fields have great application prospects and application value. However, SiO 2 Airgel is brittle and brittle, has poor mechanical properties, and requires a complex process of supercritical drying, which seriously narrows the scope of its practical application. [00...

AI Technical Summary

Problems solved by technology

In the prior art, the airgel secondary particles prepared by the sol-gel method form a bead-like fractal network structure, and there are large pore spaces between the particle chain segments, which makes the airgel have an extremely low volume density. The brittleness of airgel comes from the connection between particles, the small connection area of ​​secondary particles, the density gradient caused by dense particle accumulation, and the chaotic material organization, which makes SiO 2 Airgel is easy to break under the action of external force; in addition, the surface hydrophobic modification is used in the prior art to graft hydrophobic groups such as methyl groups on the surface of the airgel, and the airgel can be prepared under normal pressure drying conditions, avoiding drying During the process, the dehydration polycondensation between the hydroxyl groups on the surface of the particles, although this method can retain the properties of low density, high specific surface area and large porosity of the airgel, but the mechanical properties of the obtained airgel are poor

[0004] The prior art adopts supercritical fluid drying technology in the preparation process, which can maintain the structural integrity and excellent pore characteristics of the airgel material, but the operation process is complicated, dangerous and costly, which further limits the SiO 2 Large-scale industrial production and application of airgel materials

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