Silica aerogel heat insulation composite material containing nano semiconductor particle and preparation thereof

Abstract

The invention discloses an aerogel thermal insulation composite material containing an infrared opacifier of nanometer semiconductor antimony tin oxide (ATO) or aluminum zinc oxide (AZO) and a method for preparing the same. The aerogel thermal insulation composite material comprises the components of SiO2 aerogel, the infrared opacifier which is nanometer ATO or nanometer AZO particles, and reinforcing fiber. Silicasol and nanometer ATO or AZO ethanol slurry can be mixed together through mechanical agitation or ultrasonic action, and then the mixture is mixed with the reinforcing fiber and is poured into a mould directly to form a wet gel complex to further perform supercritical fluid drying. The aerogel thermal insulation composite material has good thermal conductivity and good barrier effect on solid heat conduction, air heat convection and infrared radiation heat transfer, and has good hydrophobicity, simple process and low cost simultaneously; the mechanical strength of the material can reach more than 1.2 MPa; besides, the aerogel thermal insulation composite material has wide application range and can meet the applications in occasions with higher thermal protection requirements for aviation, aerospace, military and civil use.

Description

technical field [0001] The invention belongs to the field of high-efficiency thermal insulation materials, and in particular relates to a silicon airgel thermal insulation composite material and a preparation method thereof. Background technique [0002] Silica airgel has the characteristics of high specific surface area, ultra-low density and nanoporous network structure. The porosity is as high as 98.9%. The pore size is generally in the mesopore range, and the specific surface area is as high as 1000m 2 / g, the density is 3~600kg / m 3 adjustable within the range. The structural specificity of airgel makes its refractive index, acoustic impedance and thermal conductivity low, and its adsorption performance is excellent. application prospects. [0003] Silica airgel is considered to be the solid material with the best thermal insulation performance at present, but the inherent low strength of airgel materials, high brittleness, difficulty in forming and high cost restrict...

AI Technical Summary

Problems solved by technology

When the binder is added, although the strength of the composite material can be improved to a certain extent, the high-efficiency thermal insulation properties of the airgel material are also lost at the same time; Adding agent (titanium dioxide) to form a gel and then drying the material by supercritical fluid (see Chinese patent 97106652.3 "Modified nano-insulation material and its production process"), the infrared opacifier is difficult to disperse evenly, and the mechanical strength is limited. Difficult to meet the use requirements of harsh environments; ③Using fiber as a reinforcing phase, adopting sol-gel process and supercritical fluid drying process to form airgel composite materials (see US Patent US6068882 and Chinese Patent 200510031952.0 "An Airgel Thermal Insulation Composite material and its preparation method"), the material has good thermal insulation effect and performance, but the US patent US6068882 reduces the infrared transmittance by depositing molecular carbon or metal on the surface of the fiber, and the process is more complicated, while China Patent 200510031952.0 is to prepare SiO by in-situ composite method 2 / TiO 2 Introduction of TiO after composite gel 2 The use of airgel to reduce the infrared transmittance, although the process is simpler than the former, but due to the formation of TiO 2 Amorphous, with limited IR blocking effect

In addition, the material made of US Patent US6068882 has poor hydrophobicity, and the heat insulation effect will be reduced due to water absorption during actual use