Silica Gel is a very porous form of silica gel with a great deal of internal surface area. It is a tasteless, odorless, non-toxic, non-corrosive, and chemically inert substance. It is a highly activated adsorbent that is available in numerous mesh sizes designed for many uses in industry. During adsorption, there is no chemical reaction in the silica gel, and no byproducts are created. Silica gel is non-deliquescent, and its shape and size never change. Its outer surfaces stay dry and it remains free-flowing, even when it is saturated with water.
Silica gel strongly prefers to adsorb water over most other substances. However, it also works well as an adsorbent for sulfur and nitrogen compounds, CO2, C12, HC1, gasoline-range hydrocarbons, aromatics, and many other compounds. Bulk Silica Gel can adsorb many of these substances in large quantities. It is used widely for a broad range of industrial applications requiring a selective adsorbent or a high-capacity desiccant.
Because it is chemically inert, non-reactive, retains its shape and size, and is tasteless and odorless, it is a nontoxic non-corrosive moisture control technology. By adsorbing moisture, it can stop mold from growing and prevent items from spoiling or being damaged in other ways.
Packets of silica gel are used to absorb moisture in all kinds of consumer products, from medicines to electronics to, of course, shoe-boxes. They are also widely used in compressed air systems. It's possible to prevent system breakdowns due to the build up of moisture by filtering the compressed air through a packet of silica gel. This technique is used in compressed air systems in railway locomotives and industrial settings. Compressed air systems with moisture absorbers are also needed to prevent the degradation of the signals transmitted by high-capacity radio and satellite transmitters.
Silica gel is also commonly used as a preservation tool in libraries and museums. Many of the items stored by these institutions are prone to moisture damage due to their great age. Silica gel packets preserve the items' integrity by removing moisture from the air around them. Silica gel desiccants can also be used in long-term storage and as an ingredient in cat litter.
Silica gel is the naturally occurring mineral silicon dioxide that has been purified and processed into a beaded or granular form, and is also non-corrosive and chemically inert. Silica gel’s interconnected pores form a vast surface area that will attract and hold water by adsorption and capillary condensation, enabling silica gel to adsorb about 40% of its weight in water vapor at 100% humidity. Silica gel will remove moisture at temperatures as high as 150ºF, but it is best used at room temperature (70°‐90°F) and high relative humidity (60‐90% RH).