... small; 2.High specific surface area 3.High purity 4.Surface chemical 5.hydrophobic Sealed fumed silica Sealed fumed silica has ... , thickening sex, thixotropy, electrical insulation, etc. Sealed fumed silica is mainly used for Silicone Rubber ,Adhesives, Sealants,Coatings, ... Paints and Inks,Rubber ,plastic,etc. Sealed fumed silica is a synthetic,amorphous,colloidal silicon dioxide that is ...