... purity 4.Surface chemical 5.hydrophobic Sealed fumed silica Sealed fumed silica has size small, super specific surface area, ... thickening sex, thixotropy, electrical insulation, etc. Sealed fumed silica is mainly used for Silicone Rubber ,Adhesives, Sealants,Coatings, ... ,colloidal silicon dioxide that is generallyregarded as unique in industry because of its unusual particle characteristics. white ...