The English name of aerogel is "aerogel". "Aero" means flying, and "gel" means gel, which together is a flying gel. The name alone shows how light aerogel is. Over the years, scientists have continuously prepared more advanced aerogels, breaking the record of "the lightest solid in the world" again and again. Among the currently reported aerogels, the lowest density can reach 0.00016g/cm3, which is far lower than the density of air. After vacuuming, it can even float in the air.


The super high proportion of air in the structure of aerogel makes it have high specific surface area and high porosity. It is understood that the specific surface area of aerogels can be as high as 1000 ㎡/g. That is to say, the surface area of one piece of aerogel the size of a table tennis ball is equivalent to that of a football field. At the same time, the porosity of 80%~99.8% also means that in the aerogel with a volume of 1m3, the volume of nano pores is more than 0.8m3. This makes aerogels have excellent adsorption properties. Its adsorption capacity is much greater than that of ordinary sponges, making it the "ultimate sponge".


Materialists have adjusted the chemical state of the aerogel framework to make it selective in adsorption. For example, the adsorption capacity of silica aerogel for common harmful gases such as toluene is more than twice that of activated carbon and silica gel, which can be used to remove indoor harmful gases; The oil absorption capacity of carbon aerogel can reach 40~160 times of its own weight, and it is an ideal material for treating oil pollution at sea.


Aerogel has excellent thermal insulation performance due to its structural characteristics. The nano skeleton structure disperses the pathways of solid heat transfer, while the smaller nano pores hinder the heat transfer of gas molecules. Therefore, when the heat passes through the aerogel, it is like walking on a winding and rugged path, and the heat transfer speed is extremely slow. Thermal insulation performance has always been one of the focuses of attention in various industries. Taking the commonly used aerogel thermal insulation blanket in industry as an example, compared with traditional thermal insulation materials, the thermal insulation performance of silica aerogel thermal insulation blanket is 2~8 times that of traditional materials.


In addition, aerogels also have unparalleled catalytic properties. Its specific surface structure allows the active components to be evenly dispersed in the carrier. At the same time, the aerogel has good thermal stability, which can effectively reduce the occurrence of side reactions. Therefore, aerogels are often used as catalysts or catalyst carriers. At the beginning, aerogel catalyst was mainly used for some organic reactions with industrial application background, such as acetic acid conversion to acetone, propionic acid conversion to diethyl acetone, etc. In recent years, aerogel catalysts have been widely used. For example, graphene based aerogels have broad application prospects in fuel cells, dye-sensitized solar cells, microbial electrolytic cells and electrochemical sensors due to their excellent electrochemical activity and catalytic properties.