3. Used as auxiliary dispersant
In the powder coating system, due to the small particle size and high surface energy of fumed silica, it can be adsorbed on the surface of the coating powder and form a surface layer on the surface of the powder to improve the dispersion and spraying performance of the coating, so it can be used as a A dispersant is used.

To improve the adhesion of co-dispersants to powder particles, hydrophobic silicas are more recommended because they maximize the adsorption of powder particles in the small micron size range. At the same time, because it is a hydrophobic product, it can reduce the adsorption of moisture when covering the powder particles, which can prevent the coating from caking.

4. Used as a matting agent
Due to the tiny particle size and the formed network structure, fumed silica has obvious light scattering ability. Therefore, fumed silica has good optical properties when used in varnishes, and has become the first choice for high-grade coating matting agents.

The main characteristic parameters affecting fumed silica matting agent are pore volume (porosity), average particle size and particle size distribution, surface treatment, etc. For a given fumed silica matting agent, its matting efficiency increases with increasing pore volume. The average particle size of fumed silica and its particle size distribution play an important role in the reduction of paint gloss. For a given coating and film thickness, the matting effect is best when the particle size of the matting agent corresponds to the dry film thickness of the coating. The narrower the frequency band of the particle size distribution, the higher the extinction efficiency.