First, what are the preparation methods of aerogel
     The preparation process of aerogel is mainly divided into two steps: the first step is gel prepared by sol-gel process; The second step is to replace the liquid substance in the gel with gas through a certain drying method to produce aerogel.
In the sol-gel process, by controlling the hydrolysis and condensation reaction conditions of the solution, nano-clusters with different structures are formed in the solution, and the mutual adhesion between the clusters forms a gel, while the solid skeleton of the gel is filled with liquid reagents remaining after chemical reaction.
In the drying stage, the structure of aerogel network is easily destroyed due to the existence of liquid surface tension. At present, the commonly used drying methods of aerogel are mainly divided into four categories: supercritical drying, subcritical drying, freeze-drying and atmospheric drying.




     Supercritical drying method means that the temperature and pressure of the drying solvent are raised above its supercritical point, so as to eliminate the gas-liquid interface in the gel hole, which is a method for drying the sample.
Subcritical drying is to dry the sample by raising the temperature and pressure of the drying reagent below its supercritical point. Compared with supercritical drying, the risk of sub-critical drying is relatively low.
     Freeze-drying is also commonly used to prepare aerogels, which are made by freezing the liquid inside the gel pores and sublimating it under vacuum conditions.
     Atmospheric drying is the simplest and most economical of the four common drying methods. It does not require the autoclave used in supercritical drying and costly supercritical drying reagents, but requires a long solvent replacement process, so as to avoid the gel water absorption and gas-liquid interfacial tension during the drying process to cause deformation or even damage to the gel skeleton.


     Second, the simple method of aerogel
1, the first production of aerogel requires material gel balls and alumina crystals, gel balls can actually be found in many places, you can turn around the Aurora.
2, close to the gel ball is a small ball with many small purple points of light on the surface, with a knife.
3, put the ground base and outdoor planting box in the water, and plant the gel ball seeds on it, and soon there will be enough gel ball materials to use.
4, alumina crystals are relatively easy to find, generally can find several in a row.
5, open the workbench, and finally you can use gel balls and alumina crystals to complete the synthesis of aerogel.