Airgel Composite Membranes Produced by Halogen-Free and Ammonia-Free Supercritical Process

Abstract

The invention discloses an airgel composite coil produced by a halogen-free and ammonia-free supercritical process. The airgel composite coil has a density of 160-180kg / m3, a thermal conductivity of ≤0.018W / (m·K), and a hydrophobic Rate ≥ 99.5%, vibration mass loss rate < 0.1%. Its preparation process includes the following steps: S1 uses tetraethyl orthosilicate as raw material, adds ethanol and water, and heats it at 50°C for 24 hours to obtain the first mixed solution; adds alkali without ammonia to modified organic silicon ester, ethanol and water to obtain the second mixed solution; S2, mix the first mixed solution and the second mixed solution in proportion to obtain the third mixed solution, and immerse the fiber coil in the third mixed solution to form a gel composite coil ; S3, subjecting the gel composite coil to supercritical drying to obtain the halogen-free and ammonia-free airgel composite coil of the present invention. This product does not contain halogen elements, and at the same time does not volatilize the irritating gas containing ammonia at high temperature. It can be used for heat insulation in indoor high temperature environment and fire protection and heat insulation under the condition of thermal instability.

Description

technical field [0001] The invention relates to the field of nanoporous airgel composite thermal insulation products. More specifically, the present invention relates to an airgel composite coil produced by a halogen-free and ammonia-free supercritical process. Background technique [0002] Airgel is a nanoporous, low-density, amorphous solid material with a continuous three-dimensional network structure. The common silica airgel has a porosity of over 90% and an average pore size of 20-40nm. It has the advantages of low thermal conductivity, low density, and small specific heat capacity. It plays an important role in the fields of heat insulation, flame retardant and fire prevention. At present, silica airgel has been put into production and use at home and abroad, and the domestic industrialization scale is growing rapidly. It has been put into use in many fields such as industrial equipment and pipelines, new energy vehicles, fire safety, building fire protection and ene...

AI Technical Summary

Problems solved by technology

[0005] Patent CN201810005328 reports a method for preparing silica airgel composite materials using a chlorine-free and alcohol-free process. The fire resistance and strength of airgel products will destroy the continuous three-dimensional network structure of airgel nanoporous, and at the same time, it is easy to produce toxic and harmful gases when used at high temperature, which will affect the performance and service life of airgel products, and limit the The service temperature and fire performance of airgel products

In addition, the report adopts an atmospheric pressure drying process, which is difficult to avoid the destruction of the microstructure of the gel caused by capillary force during the drying process, which will seriously pulverize the final product and reduce the thermal insulation performance and user experience of the airgel product.