01 Introduction of aerogel
[Basic concept of gel]
What could be the first reaction? What kind of sacred substance is this frozen smoke like substance in front of us? It is not smoke, but a solid. To be more precise, it is the lightest solid in the world - aerogel. Aerogel is actually a kind of gel, while gel is an elastic semi-solid with uniform appearance and certain shape formed by a certain concentration of polymer solution or sol and gradually losing its fluidity under specific conditions. Jelly is a kind of gel that we are familiar with. It is filled with water or other liquids. However, another kind of gel is filled with gas, and this gel is named "aero gel".

[History and development of aerogels]
In 1931, American scientist Samuel Stephens Kistler successfully prepared a new material and named it "aerogel", namely aerogel. The name is ingeniously combined with "aero" (meaning air) and "gel" (meaning gel), which appropriately describes this new material - a gel filled with gas.


02 Characteristics and preparation of aerogel
Unique Features
Compared with ordinary porous materials, aerogel is unique in its skeleton size at the nanometer level. Because of this characteristic and its extremely low density, aerogels are known as the lightest solids in the world. At present, the lightest known aerogel is "all carbon aerogel", its density is only 0.16mg/cm3 (air density has been removed), which is only one sixth of the air density. Gently place this material on top of the flower, and the soft stamen will hardly notice any deformation. The excellence of aerogel derives from its unique structure and porous characteristics, which endow it with many excellent physical properties. For example, it shows excellent heat insulation, making the flame pass through the flowers heated by the aerogel without damage. In addition, aerogels such as "carbon sponge" also show remarkable adsorption performance, with absorption capacity up to 250 or even 900 times of its own mass, and high elasticity, which can still be recovered after 80% compression. This characteristic makes it have great potential in dealing with offshore oil spills, as it can quickly absorb oil spills and recover oil fractions through elastic recovery for recycling, providing a new solution for offshore oil spill management.

[Preparation Process]
The preparation process of aerogel includes two key steps: first, wet gel is prepared by sol-gel method. This method disperses highly chemically active compounds in solvent, and generates active monomers through hydrolysis reaction. These monomers further polymerize to form sol, and finally generate gel with three-dimensional spatial structure. Secondly, the wet gel was treated by special drying technology. Due to the effect of surface tension, the volatilization of liquid in gel under normal conditions will lead to the collapse of its fragile skeleton. However, this problem has been effectively solved through freeze-drying technology. The wet gel was frozen at low temperature, and then dried in vacuum. Since the liquid in the gel has changed into solid in the freezing process, these solids are separated from the gel skeleton in the form of sublimation under the vacuum environment, thus avoiding the influence of liquid volatilization on the skeleton, and successfully preparing the desired aerogel.


03 Application value of aerogel
Multi purpose application
"What is the application value of aerogel?" This question may be raised by everyone. The answers are various: "It has excellent thermal insulation performance, which can be called super thermal insulation material", "It can also be used as electrode material", "Aerogel also plays an important role in the field of pollution control"... The excellence of aerogel comes from its unique structure and porous characteristics, giving it many excellent physical properties.

Research and Exploration
Although aerogel came out at the beginning of the 20th century, it is not a new material discovered in recent years, but its comprehensive excellent properties have aroused widespread interest. Further research and exploration are still needed for the application of this material. The size of the components constituting the framework of aerogel has reached the nanometer scale. When the particles of this nanometer scale are presented in the form of aerogel, some of their original properties will be significantly enhanced. For example, manganese dioxide (MnO2), the electrode material of lithium battery, has significantly improved the discharge performance of lithium battery in the form of aerogel.