Fumed Silica powder Nano Grade
description1
Item |
Unit |
N-100 |
N-50 |
Test Method |
Specific Surface Area |
m²/g |
300±25 |
380±30 |
GB/T 10722 |
Suspension pH (4%) |
- |
3.6～4.5 |
3.6～4.5 |
ISO 787-9 |
Loss on Drying (105℃) |
m/m% |
≤1.5 |
≤1.5 |
ISO 3262-1 |
Loss on Ignition (1000℃) |
m/m% |
≤2.5 |
≤2.5 |
ISO 3262-1 |
Residue on Sieve |
m/m% |
≤0.05 |
≤0.05 |
ISO 787-18 |
Bulk Density |
g/L |
25～60 |
25～60 |
ISO 787-11 |
Silica Content |
m/m% |
≥99.8 |
≥99.8 |
ISO 3262-20 |
Carbon Content |
m/m% |
≤0.2 |
≤0.2 |
ISO 3262-20 |
Application: Additives, catalyst carriers, petrochemical industry, decolorizing agents, matting agents, rubber reinforcing agents, plastic fillers, ink thickeners, metal polishing agents, insulating and thermal filling materials, high-end daily cosmetic fillers, coating materials, pharmaceuticals, and environmental protection fields.
Performance
1. High Purity
Fumed silica is produced using highly refined raw materials and strict process management. As a result, it is a silica with minimal impurities.
2. High Dispersibility
Fumed silica is manufactured through high-temperature hydrolysis, resulting in fluffy agglomerates. With appropriate dispersion force, it can be dispersed into fine particles with diameters smaller than the wavelength of visible light (400-760 nm). The high specific surface area makes it ideal for resins and elastomers that require high transparency. Highly dispersed fumed silica does not affect the transparency of the resin.
3. High Specific Surface Area
The specific surface area of fumed silica typically ranges from 50 to 500 m²/g, with primary particle diameters of 5-50 nm. Since it is produced through high-temperature hydrolysis in the gas phase, it is an amorphous silica with no internal surface area.
4. Surface Chemistry
The surface of fumed silica contains silanol groups (Si-OH groups), typically around 1.5 per nm² shortly after production. While freshly manufactured fumed silica is moisture-free, it absorbs some atmospheric moisture after packaging. Hydrophobic treatment of the silanol groups reduces moisture absorption to less than one-tenth of that of untreated hydrophilic silica. By selecting either hydrophilic or hydrophobic grades, depending on the resin used, the desired viscosity and rheological properties can be achieved.