Method for preparing fiber-loaded rutile type TiO2 composite SiO2 aerogel

Abstract

The invention discloses a method for preparing fiber-loaded rutile type TiO2 composite SiO2 aerogel. The method comprises the following steps: performing hydroxylation treatment on fiber by using a piranha solution; soaking the fiber after hydroxylation treatment into a TiO2 solution, loading the surface of fiber after hydroxylation treatment with TiO2 sol by using a soaking-lifting method, and performing high-temperature so as to obtain fiber of which the surface is loaded with rutile TiO2; soaking the fiber of which the surface is loaded with rutile TiO2 into SiO2 sol so as to obtain SiO2 composite sol; performing aging, decontamination, solvent replacement, surface modification and normal-pressure drying on the SiO2 composite sol, so as to obtain the fiber-loaded rutile type TiO2 composite SiO2 aerogel. By adopting the method, not only is the problem that TiO2 is not uniformly dispersed in the SiO2 aerogel solved, but also the mechanical properties and the thermal-insulating heat-preservation properties of the SiO2 aerogel can be improved; by adopting the SiO2 aerogel composite material prepared by using the method, infrared radiation heat conduction can be effectively inhibited, and a relatively low heat conduction coefficient can be achieved.

Description

technical field [0001] The invention relates to the technical field of thermal insulation materials, in particular to a fiber-loaded rutile TiO 2 Composite SiO 2 Airgel preparation method. Background technique [0002] SiO 2 Airgel is a novel low-density, transparent, and structurally controllable nanoporous material with a continuous three-dimensional network structure. Its density is 3~500mg / cm 3 It is a solid material with the lowest density that has been found to be prepared. The porosity can reach 80%-99.8%, and the pore spacing is small (1-100nm), and it has a high specific surface area (about 1000m 2 / g), so it can effectively inhibit gas convective heat transfer and reduce solid-state heat conduction, and has low thermal conductivity (0.01-0.03W / m·K), which is the solid material with the lowest thermal conductivity known so far. [0003] But SiO 2 There are still two problems in airgel to replace traditional thermal insulation materials: (1) due to SiO 2 The h...

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Problems solved by technology

[0003] But SiO 2 There are still two problems in airgel to replace traditional thermal insulation materials: (1) due to SiO 2 The high porosity and porous network structure of airgel itself lead to its poor mechanical properties, and the properties of the material bring certain difficulties to the actual thermal insulation engineering; (2) the thermal insulation properties of the material depend on heat conduction, heat convection and thermal insulation. Three basic ways of radiation

[0005] Although the current SiO 2 The research on airgel composites is relatively extensive, but there are still some problems that need to be further solved: (1) Fibers are used as reinforcement and toughening phases, although it can improve the SiO 2 The mechanical properties of airgel, but its thermal conductivity increases rapidly with the increase of temperature; (2) although adding infrared opacifier can reduce the SiO 2 Infrared radiation heat transfer of airgel, but most of the opacifiers are directly added to SiO by mechanical means such as stirring and ultrasonic 2 In aerogels, the nanoparticles have high specific surface area and high specific surface energy, and are prone to agglomeration. Traditional mechanical methods cannot be dispersed, which may easily cause uneven dispersion of opacifiers, and sometimes reduce SiO 2 Thermal insulation properties of airgel composites

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