White carbon black (silica dioxide) is categorized into fumed (vapor-phase) and precipitated (liquid-phase) silica, each with distinct properties and use cases.
Fumed Silica
Fumed silica, produced via high-temperature hydrolysis of chlorosilanes in a hydrogen-oxygen flame, boasts purity ≥99.8%, nanoscale primary particles (7–40 nm), and an extremely high specific surface area (100–400 m²/g). It forms robust thixotropic networks, offering exceptional reinforcement, thermal stability, and electrical insulation. Ideal for high-end applications, it serves as a critical reinforcing agent in silicone rubbers, a rheology modifier in coatings/adhesives to prevent sagging, and a key additive in cosmetics, electronic encapsulants, and battery materials.
Precipitated Silica
Precipitated silica, manufactured by neutralizing sodium silicate with acid (e.g., H₂SO₄) followed by precipitation and drying, features purity around 93%, larger agglomerated particles (micron scale), and a moderate specific surface area (100–200 m²/g). Cost-effective and easy to process, it excels in cost-sensitive scenarios. It is widely used as a reinforcing filler in tires (reducing rolling resistance) and rubber products, a matting agent in paints, a friction agent in toothpaste, and a carrier/anti-caking agent in food and feed additives.
Fumed Silica (Vapor-Phase)
- Production: High-temperature hydrolysis of chlorosilanes in H–O flame
- Purity: ≥99.8%
- Particle Size: 7–40 nm (nanoscale primary particles)
- Specific Surface Area: 100–400 m²/g
- Key Properties: Thixotropic networks, exceptional reinforcement, thermal stability, electrical insulation
- Applications: Silicone rubbers, coatings/adhesives (anti-sagging), cosmetics, electronic encapsulants, battery materials
Precipitated Silica (Liquid-Phase)
- Production: Neutralizing sodium silicate with acid (e.g., H₂SO₄), precipitation & drying
- Purity: ~93%
- Particle Size: Micron scale (agglomerated)
- Specific Surface Area: 100–200 m²/g
- Key Properties: Cost-effective, easy to process, reliable performance
- Applications: Tires (rolling resistance reduction), rubber products, paint matting agent, toothpaste friction agent, food & feed additive carrier/anti-caking agent
Core Difference: Performance vs. Cost
The core difference lies in performance and cost: fumed silica delivers superior strength and stability for high-performance applications at a higher price, while precipitated silica offers reliable performance at a lower cost for general-purpose needs. Choosing the right type optimizes material performance, balances costs, and aligns with specific application requirements.
This article provides a clear overview to help you select the most suitable silica for your projects.
Post time: Apr-13-2026