The production of aerogel is divided into two types: supercritical drying and atmospheric drying.

supercritical drying

The performance of silica aerogel prepared by supercritical method is relatively good, but the equipment is complicated and expensive, the drying process is energy-intensive, dangerous, and the yield is low. The apparatus used for supercritical drying is an autoclave. In the supercritical state, there is no longer an interface between the gas and the liquid, but a homogeneous fluid between the gas and the liquid, which will gradually change from the gas to the liquid. excreted in the gel.

Atmospheric drying

The preparation of silica aerogel by atmospheric pressure drying does not require a large amount of equipment, and is highly operable, safe and environmentally friendly, which provides the possibility for large-scale industrial production of silica aerogel; however, the current preparation process at atmospheric pressure is cumbersome, and water glass is used as the Take the precursor as an example, which involves ion replacement, sol-gel process, surface hydrophobization modification, multi-gradient solvent replacement, drying and other processes in sequence. The production and preparation cycle takes a long time, and a large amount of solvent is consumed in production, and a variety of solvents are mixed. , the recovery and separation are difficult, and the cost of the product is increased, thus limiting the industrial large-scale preparation and wide application of aerogels.

Application space (structure + performance)

Structure - properties derived from porous nature

Excellent thermal insulation performance: A flower is heated by a flame through the aerogel, and the flower is hardly damaged.

Excellent adsorption performance: It is used to collect and adsorb interstellar dust in outer space on the spacecraft to analyze interstellar chemicals.

Super thermal insulation performance: made into thermal insulation felt, soft and easy to cut, low density, fireproof, green and environmental protection.

Performance - is composed of components that make up the aerogel backbone at the nanoscale

Certain properties inherent in nanoscale particles are often enhanced when they are in the form of aerogels. For example, electrode materials for lithium batteries.