Neutral colloidal silica is of three types, ZS-20, ZS-25 and ZS-30. Their standards are as follows:
Designation | Standards | ||
ZS-20 | ZS-25 | ZS-30 | |
Appearance | Slight milky transparent to translucent liquid | ||
SiO2 (wt%) | 20±1% | 25±1% | 30±1% |
Na2O (wt%) | ≤0.2% | ||
PH (20°C) | 6.5-8.0 | ||
Density (20°C, g/cm3) | 1.12-1.14 | 1.15-1.17 | 1.19-1.21 |
Viscosity(20°C, mPa•S) | ≤10 | ||
Particle size (nm) | 8-15 | ||
Stability | Six months |