Foamed ceramic reinforcing fiber aerogel insulating material and preparation method thereof

Abstract

The invention discloses a foamed ceramic reinforcing fiber aerogel insulating material and a preparation method thereof. The method comprises the following steps of: preparing a fiber silicasol-containing foamed ceramic composite material; continuously stirring the composite material by a sol-gel process so as to uniformly disperse chopped fiber in SiO2 sol; filling the composite material consisting of the fiber and the sol in the pores of porous ceramics through vacuum impregnation technology; and preparing the insulating material by processes such as aging, modifying and drying and the likefor preparing aerogel. The insulating material has high intensity and low heat conduction coefficient, wherein foamed ceramics are taken as the framework of the composite material to have reinforcingand supporting effects, so that the main intensity of the composite material is borne by the foamed ceramics; the chopped fiber has certain reinforcing effect and can prevent the SiO2 aerogel from great contraction after being dried and falling from the foamed ceramics; and the SiO2 aerogel mainly has heat insulation effect by means of the superior heat-insulating property of the aerogel on the composite material.

Description

technical field [0001] The invention relates to a thermal insulation material and a preparation method thereof, in particular to a foam ceramic reinforced fiber airgel thermal insulation material and a preparation method thereof. Background technique [0002] Porous foam ceramics have excellent properties such as low density, high hardness, low thermal conductivity, large porosity, high temperature resistance, corrosion resistance, and wear resistance, and are widely used in environmental protection, construction, kiln furniture, energy, chemical industry, smelting, etc. field. [0003] SiO 2 Airgel has a nanoporous structure with a porosity of over 90% and a density as low as 0.001g / cm 3 , is currently the lightest solid material known in the world, and is also recognized as the material with the lowest thermal conductivity. Its thermal conductivity is lower than that of air, so it has a very wide application prospect. [0004] Although porous ceramic foam has excellent ...

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Problems solved by technology

[0004] Although porous ceramic foam has excellent properties such as low density, high hardness, low thermal conductivity, large porosity, high temperature resistance, corrosion resistance, and wear resistance, its relative thermal conductivity is relatively high, mostly above 0.25, and to a certain extent Restricts its promotion in practical applications; SiO 2 Due to its good thermal insulation performance, airgel is considered to be the best thermal insulation material in the world and the most promising thermal insulation material. However, as an aerogel itself, it has many inherent disadvantages of aerogel. Such as low strength, high brittleness and high cost restrict its promotion in engineering applications

[0005] Existing solution has following several: 1) short inorganic fiber and ceramic foam are compounded under certain conditions (referring to 101475400A " a kind of ceramic foam strengthens fiber porous ceramic "), greatly improved the intensity of ceramic foam, but its insulation Poor thermal performance; 2) Compositing airgel with short fibers, that is, adding dispersed inorganic short fibers during the sol process, allowing the fibers to accompany the entire sol-gel process, and finally forming a material through supercritical fluid drying (see 97106652.3 No. "Modified Nano Insulation Material and Its Production Technology"), although its mechanical strength has been improved, it is still difficult to meet the requirements of harsh environments. Furthermore, it uses supercritical fluid for drying, which has high cost, poor safety, and complicated equipment. And the intensity is also low; 3) the composite of fiber prefabricated body and airgel material, sol is impregnated as in the fiber prefabricated body by impregnation process, then by supercritical fluid drying (referring to 200510031952.0 "A kind of airgel composite material and its preparation method"), although the mechanical strength and thermal conductivity have been greatly improved, the strength of the fiber prefabricated body as a skeleton is still much smaller than that of foamed ceramics. In addition, it is dried by supercritical fluid, and the equipment is complicated and dangerous. ,high cost

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