... 1.Size small; 2.High specific surface area 3.High purity 4.Surface chemical 5.hydrophobic Sealed fumed silica Sealed fumed silica ... sex, thixotropy, electrical insulation, etc. Sealed fumed silica is mainly used for Silicone Rubber ,Adhesives, Sealants, ... and Inks,Rubber ,plastic,etc. Sealed fumed silica is a synthetic,amorphous,colloidal silicon dioxide that ... . white carbon black SiO2 silica sand