HMFSIL-B170 Hydrophobic Fumed Silica HMFSIL-B170 HMFSIL-B170 Fumed Silica is a Fumed Silica after treated with HMDS (hexamethyldisilazane) based on Specific Surface Area 200m /g. Application: ¦Coating, Paint ¦RTV Silicone Sealant, ¦Silicone Rubber, ¦Adhesive, Ink ect. Properties: ¦As a thickening, thixotropic agent and anti-settling agent in coating, paint, adhesive, sealant and silicone etc.