Modern silica gel technology enables the production of highly pure, porous products.Silica gels belong to a class of synthetic silica materials known as hydrated silicas, which have an average water content of 6% to 8% by weight. Silica gels are produced from the acid treatment of an aqueous sodium silicate solution.
Mixing sulphuric acid and sodium silicate under controlled conditions produces the base gel from which all types of silica gels are made. This glass-like, solid gel material is broken down into granules, then washed and dried to produce the highly porous material needed for matting agents. By control of the washing and drying conditions, the important physical parameters such as porosity, pore size and surface area can be manipulated to produce a range of different silica gel types .
The physical properties of silica gel differ from other specialty silicas. The internal structure of silica gel is composed of a large network of interconnected microscopic pores that attract and hold water, hydrocarbons and other chemicals by the mechanism of physical adsorption and capillary condensation.