- ▸ Rheology control: thixotropy and anti-sag in coatings and adhesives
- ▸ Anti-settling: pigment and filler suspension in liquids
- ▸ Anti-caking: free-flow aid for powders
- ▸ Thickening: structure in non-aqueous and oil-phase systems
A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.
Request SDS →This material (CAS 68909-20-6) is fumed (amorphous) silicon dioxide whose surface has been treated with an organosilane (trimethoxycaprylyl silane) to render it hydrophobic. It is used as a rheology modifier, anti-settling and thickening agent, and free-flow/anti-caking additive in coatings, inks, adhesives, and personal-care and industrial systems.
Frequently Asked Questions
What is hydrophobic modified fumed silica (trimethoxycaprylyl silane)?
This material (CAS 68909-20-6) is fumed (amorphous) silicon dioxide whose surface has been treated with trimethoxycaprylyl silane to make it hydrophobic. The organosilane surface treatment lets it disperse and build structure in non-aqueous and oil-phase systems.
What is hydrophobic fumed silica used for?
It is used as a rheology modifier for thixotropy and anti-sag in coatings and adhesives, as an anti-settling agent for pigment and filler suspension, as an anti-caking free-flow aid for powders, and as a thickener in oil-phase systems.
How does hydrophobic fumed silica differ from hydrophilic grades like Aerosil 200?
Hydrophilic fumed silica has an untreated, silanol-rich surface, while this grade is surface-treated with trimethoxycaprylyl silane to be hydrophobic. The hydrophobic treatment improves performance in non-aqueous, solvent, and oil-phase systems where hydrophilic grades can struggle to wet out.
What is the CAS number for trimethoxycaprylyl-silane-treated fumed silica?
The treated material is CAS 68909-20-6 (organosilane-treated amorphous silica). A Certificate of Analysis and SDS ship with each lot; confirm BET surface area and carbon content against the grade specification.
How is hydrophobic fumed silica supplied in bulk?
RawSource supplies this fumed silica in bagged and bulk quantities for coatings, inks, adhesives, and industrial use. Because it is a low-bulk-density powder, packaging and freight drive cost; request a bulk quote for current pricing and lead time.