Hydrophilic Fumed Silica

Product Overview

Hydrophilic Fumed Silica 200 is an ultra-fine, amorphous fumed silica powder with an exceptionally high surface area (~200 m²/g), used to precisely control rheology and improve performance in composites, coatings, adhesives, and putties. It enhances structural consistency, prevents sagging, and ensures uniform dispersion in a variety of resin systems.

Key Features & Benefits

• Thixotropic & Anti-Sag Control
  Forms a reversible, three-dimensional network that provides superior anti-sag properties in vertical or overhead applications.

• Excellent Anti-Settling & Rheology Tuning
  Improves storage stability and consistency in formulations containing fillers, pigments, or reactive agents.

• High Purity & Chemical Stability
  Composed of >99.8% SiO₂, offering low moisture content and excellent compatibility with most resin systems.

Technical Specifications

• BET Surface Area: 200 ±25 m²/g

• SiO₂ Content: >99.8%

• Loss on Drying: <1.5%

• pH (4% dispersion in water): 3.7–4.5

• Tamped Density: ~50 g/L

• Addition Rate: 1–2% by total weight, depending on viscosity target

• Shelf Life: 24 months (sealed packaging, dry storage)

Applications

• Epoxy adhesives and putties

• Marine fairing compounds and gelcoats

• Structural pastes and gap fillers

• Non-sag coatings and FRP laminates

Handling & Safety

• Dust Hazard: Fine particles; use local exhaust ventilation and appropriate PPE (TWA limit: 2.4 mg/m³)

• Storage: Store in cool, dry conditions to prevent moisture absorption and clumping

• Non-Hazardous: Inert silica with minimal environmental or health risk when handled per guidelines

Mechanism of Action

Hydrophilic Fumed Silica 200 generates a "house of cards" network in resin matrices. This structure provides high viscosity at rest and thins under shear—ideal for controlled flow and self-levelling formulations. The network rebuilds rapidly upon standing, restoring sag resistance.