Keywords: explanation, characteristics and application of silica gel materials.

Silica gel itself is not toxic, but some silica gel contains harmful additives to the human body:
Key words 1: silica gel.
Silica gel is a kind of high activity adsorption material, which belongs to amorphous substance, and its chemical molecular formula is mSiO2·nH2O. Insoluble in water and any solvent, non-toxic and tasteless, chemically stable, except strong alkali, hydrofluoric acid without any reaction with any matter. Various types of silica gel form different microporous structures due to different manufacturing methods. Chemical components and physical structure of the silica gel, determines it has many other similar materials difficult to replace features: high adsorption properties, thermal stability, chemical stability, has high mechanical strength, etc. According to the size of the pore diameter, the silica gel is divided into: macroporous silicon, coarse pore silicone, type B silicone, and fine pore silicone. Because of the different pore structure, their adsorption properties are characteristic. Coarse silica gel in the case of high relative humidity had higher adsorption capacity, pore silica gel, in the case of low relative humidity adsorption amount higher than the coarse silica gel, and b-type silica gel because the pore structure between coarse and fine silica and its adsorption quantity also between coarse and fine mesh. Macroporous silica gel is used as catalyst carrier, light - reducing agent, toothpaste abrasive, etc. Therefore, different varieties should be selected according to different USES. After silica gel absorbs moisture, it can be regenerated by exposure, baking, air drying and other methods.
[safety performance].
Silica gel is mainly composed of silica, chemically stable and non-toxic. Silica gel has a strong adsorption capacity, can produce drying effect on human skin. If the silica gel enters the eye, use a lot of water to rinse, and seek medical treatment as soon as possible. Blue silica gel, due to a small amount of cobalt chloride, is toxic and should avoid contact with food and inhalation. If poisoning occurs, seek medical attention immediately.
(main use)
The use of silica gel has strong adsorption ability to quickly and effectively adsorb the water in the sealed package, stable chemical property, non-toxic and harmless characteristics; Combined with continuous innovation and development in recent years, all kinds of silica gel has been used in drug purification, DNA separation, dry food, and high precision electronics, cosmetics, sewage purification, purification of beer, advanced coating and resin production or storage, etc. In our daily life and production and operation activities, silica gel is often used in the following aspects: precision optical instrument, electronic and electronic drying anti-mildew packaging; The drying aspect of leather: if it is placed in leather garment, leather bag and leather shoes, it can be used to dry and protect the skin. Food drying: it is found in biscuits and Fried foods to ensure the crispness of food. Drug drying: put in the bottle to ensure the extension of the drug; Dry container, transportation of container in different latitude will form a box "in the rain", if you use silica gel desiccant, it can moisture adsorption weight of its own, as long as 50 days for ocean transportation, can effectively reduce the dew point and make the container of condensate phenomenon under control. The hotel USES item class, if put in the wardrobe, the shoe and under the bed, absorb all sorts of peculiar smell, keep the air dry and fresh.