Fumed Silica, Cab-o-Sil® (Hydrophobic Silica)

Fumed Silica / Pyrogenic Silica (Aerosil® / Cab-O-Sil®) – 50g & 100g

Fumed Silica also known as pyrogenic silica, Aerosil®, or Cab-O-Sil® is a super-fine white powder used to thicken liquids, improve flow, and stop ingredients from separating. Just a small amount can make a big difference in many products like epoxy resin, paints, adhesives, and more.

This powder increases viscosity in adhesives and resins, helps control how a product flows (rheology), and makes it easier to apply. It also prevents sagging during drying and improves extrusion, making it ideal for vertical surfaces or thicker applications.

• Warning: Avoid inhaling dust. Use with ventilation or a suitable mask. Keep away from children.
• Storage: Keep dry, sealed, and away from moisture

Benefits & Advantages

• Thickens without affecting color or finish
• Helps resins and glues stay in place (no sagging)
• Makes extrusion smoother and more controlled
• Improves texture and work-ability in pastes and coatings
• Prevents settling of pigments or fillers
• Moisture control in powders (anti settling agent/anti-caking agent)

Common Uses:

• Epoxy resin art & casting – to thicken and create paste-like textures
• Paints and coatings – prevents drips on vertical surfaces
• Adhesives and sealants – improves viscosity and application control
• Industrial powders – stops clumping by absorbing moisture

Technical Details:

• Product Name: Fumed Silica / Pyrogenic Silica
• Also known as: Aerosil®, Cab-O-Sil®, Synthetic Amorphous Silica
• Appearance: Fine white fluffy powder
• Particle Size: 7–40 nanometers (primary particles)
• Surface Area: ~200 m²/g
• Solubility: Insoluble in water
• Available Pack Sizes: 50g/100G sealed in LDPE bag

Fumed silica, also known as pyrogenic silica, is now widely available in Sri Lanka for industrial and craft applications. Commonly referred to by brand names like Aerosil® and Cab-O-Sil®, this lightweight, fine powder is a form of synthetic amorphous silica with excellent thickening and anti-caking properties. Although colloidal silica typically refers to a suspension, the dry form is sometimes used interchangeably with fumed silica. It’s also known by other names such as silicon dioxide (amorphous) or hydrophilic silica (untreated) and hydrophobic silica (surface-treated). Whether you're working with resins, adhesives, or coatings, fumed silica offers consistent performance and is now easier to source locally in Sri Lanka.