Whats this ?

Like frozen smoke.It's not smoke, but a solid, to be exact, the world's lightest solid ----Aerogel,.

What is Aerogel ?

At first, let's talk about gel . A certain concentration of polymer solution or sol, under appropriate conditions, the viscosity gradually increases, and finally loses fluidity, the whole system into a uniform appearance, and maintain a certain form of elastic semi-solid, this elastic semi-solid is called gel.

Jell-O is a type of gel first recognized by scientists, which is formed when water or other liquid is filled with it.Other gels are made by filling them with gas. These are called aerogels.In 1931, American scientist Samuel Stephenskistler prepared the new material and named it "Aerogel"."Aero" + "Gel" describe the new material's characteristics as a gel filled with gas.

Aerogels have one important characteristic compared to ordinary porous materials: their skeleton is at the nanoscale.so the Scattering is smaller When visible light passes through,Looks like "frozen smoke"

Aerogel has an extremely low density and is the lightest solid in the world.At present, the lightest aerogel is an "all-carbon aerogel" with a density of only 0.16mg/cm3 (without air density), which is only a sixth of the density of air.When this material is placed on flowers, the soft stamens almost no distortion.

The preparation process of aerogel is divided into two steps: the wet gel is prepared and the wet gel is dried by special technique.The most traditional preparation method of wet gel is sol-gel method.The compounds containing high chemical active components are dispersed in the solvent, and the active monomer is generated through hydrolysis reaction. The active monomer is polymerized to form the sol, and then the gel with a certain spatial structure is generated.The resulting gel is somewhat Jell-like, and then the Jell-like gel is further dried to produce aerogel.Under normal conditions, due to surface tension, the fluid inside the gel evaporates, causing the gel's fragile skeleton to collapse.The freeze-drying technology can solve this problem.The wet gel was frozen at a low temperature and then dried under vacuum conditions.Since the freezing process has turned the liquid inside the gel into a solid, it then sublimates out of the gel skeleton in a vacuum. This avoids the collapse of the skeleton caused by the volatilization of the liquid and gives us the desired aerogel.

What is Aerogel application ?

I believe everyone will have such a question, The answers will be varied,"It has very low thermal conductivity, it can be used as a super insulation material." "It can be used as an electrode." "It can be used for pollution control."In general, the properties of aerogels are mainly contributed by two parts: one is the structure, Simply put, properties derived from porous properties, such as excellent insulation.When a flower is heated by a flame through aerogel, it does little damage to the flower.In addition, some aerogels also show excellent adsorption properties, such as "carbon sponge"Aerogel can be made into thermal insulation felt, which is soft, easy to cut, low density, inorganic fire prevention, overall hydrophobic, green and environmental protection, etc., and is expected to replace glass fiber products, asbestos thermal insulation felt, silicate fiber products and other traditional flexible thermal insulation materials with poor environmental protection and thermal insulation performance.Existing oil absorbent products typically absorb only about 10 times their own mass of liquid, while "carbon sponge" absorbs about 250 times, up to 900 times.At the same time, the "carbon sponge" is highly elastic and can be compressed by 80% and still recover.This makes it tempting to think of using it to deal with oil spills at sea. Sprinkling them on the surface of the sea would absorb the oil quickly, because it is elastic and the absorbed oil can be pressed out and recycled.It is expected to play an important role in the treatment of offshore oil spills.Another part of the performance from the fact that the components that make up the aerogel skeleton are on the nanoscale.Some of the properties of nanoscale particles themselves tend to be enhanced when they are present in the form of aerogels.For example, the electrode material of lithium batteries, manganese dioxide (MnO2), is greatly improved when it is present in the form of aerogel.

As a material born in the early 20th century, aerogel is not one of the "new materials" discovered recently. However, its excellent properties in various aspects have attracted extensive attention. The application of this material still needs to be studied and explored continuously.