Evonik produces a large number of silica products, each of which is optimized for the particular area of application. Highly porous silica, for example, is used to absorb liquids, while silicas with more compact structure serve as abrasives in toothpastes. Other silicas are produced in such a way that they are easily incorporated into liquids, which they thicken. Further information on various applications is available on our web page:
Evonik has an extensive product portfolio of various silica grades, which are basically produced by two different processes. AEROSIL® fumed silicas are produced by flame hydrolysis from chlorosilanes, hydrogen, and oxygen at temperatures exceeding 1000°C. The second production method is the precipitation process, in which sodium silicate (water glass) and sulfuric acid are reacted in aqueous solution when silica precipitates out as a solid. SIPERNAT®, ULTRASIL®, and ZEOFREE® products, for example, are produced by this process. In addition, the various silicas can be ground, granulated, or hydrophobized (chemically modified so that they cannot be wetted by water). By varying all these parameters the silicas can be optimally adapted for their intended use.