Silica gel is a kind of highly active adsorbent material, is an amorphous material, its chemical molecular formula is mSiO2-nH2O, insoluble in water and any solvents, non-toxic, tasteless, chemically stable, in addition to strong alkali, hydrofluoric acid, does not react with any substances. Various models of silica gel due to its different manufacturing methods and the formation of different microporous structure.
Silica gel's chemical composition and physical structure, it has many other similar materials difficult to replace the characteristics: high adsorption performance, good thermal stability, chemical stability, high mechanical strength. Silica gel adsorption of water, can be exposed to sunlight, baking, air-drying and other methods of regeneration.
Functional use:
Mainly used for moisture adsorption and rust prevention of instruments, meters and equipments under airtight condition;
Cooperated with common silica gel desiccant, it can indicate the moisture adsorption degree of the desiccant and judge the relative humidity of the environment. As a packaging silica gel desiccant, it is widely used in precision instruments, leather, clothing, food, medicine and household appliances, etc.;
Silica gel can be used to make baby pacifiers and other supplies that are in direct contact with human body because of its food-grade use, in addition, silica gel can also be used to produce condoms.
Silicone performance:
Temperature characteristics of silicone products are silicone-oxygen (Si-O) bond as the main chain structure, C-C bond energy of 82.6 kcal/g molecule, Si-O bond energy in the silicone for the 121 kcal/g molecule, so the thermal stability of silicone products is high, high temperature (or radiation exposure) molecular bonds do not break, do not decompose. Silicone can not only high temperature resistance, but also low temperature resistance, can be used in a wide temperature range. Whether it is chemical properties or physical and mechanical properties, with the temperature change is very small;
Electrical insulation properties. Silicone products have good electrical insulation properties, its dielectric loss, voltage resistance, arc resistance, corona resistance, volume resistance coefficient and surface resistance coefficient, etc. are among the best in insulating materials, and their electrical properties by the temperature and frequency is very small. It is a stable electrical insulating material, which is widely used in electronic and electrical industries. Silicone in addition to excellent heat resistance, but also has excellent water repellency, which is the use of electrical equipment in wet conditions with a high degree of reliability of the guarantee;
Physiological inertia, polysiloxanes are known to be one of the most inactive compounds. They are very resistant to biological aging, and the animal body without rejection, and has a better anti-coagulation properties;
Low surface tension and low surface energy, silicone's main chain is very smooth, its intermolecular forces are much weaker than hydrocarbons, so than the same molecular weight of hydrocarbons with a low viscosity, surface tension is weak, the surface energy of the small, film-forming ability. This low surface tension and low surface energy is the main reason why it has gained many applications: hydrophobicity, defoaming, foam stabilization, anti-stickiness, lubrication, varnish and other excellent properties.
Reference:
Baidu Encyclopedia of Silica Gel