Hydrophobic silica: hydrophobic fumed silica is generally the product after treatment. Different types of fumed silica or precipitated silica can be used as raw materials to react with appropriate compounds by silalkyl groups; this product is hydrophobic due to the surface connection of non hydrolyzed methyl groups.

Different from the original hydrophilic silica, hydrophobic fumed silica cannot be wetted by water. Although the density of hydrophobic fumed silica is higher than that of water, they can float on the water surface. After hydrophobicization, the amount of water absorbed will be greatly reduced compared with the original hydrophilic vapor silicon.

Hydrophobic silica characteristics: hydrophobic fumed silica is prepared by the chemical reaction between hydrophilic fumed silica and active silane (such as chlorosilane or hexamethyldisilazane). It is hydrophobic (hydrophobic) and cannot be dispersed in water. In order to solve some special technical problems in the industry, various types of hydrophobic fumed silica have been developed. For example, the hydrophobic fumed silica is produced by treating the modified hydrophilic fumed silica with silane or siloxane. In the final product, the chemical treatment agent is combined on the original hydrophilic oxide by chemical bond. In addition to the above advantages of hydrophilic products, hydrophobic fumed silica products are characterized by low moisture absorption, good dispersion, and rheological adjustment ability even for polar systems. Some products, after structural modification on the basis of hydrophobic treatment, can provide further help for customers to develop new products and improve product performance. For example, in the liquid system, hydrophobic fumed silica can reach a high content, but has little effect on the viscosity of the system.

Hydrophobic silica function: hydrophobic fumed silica is the most suitable rheological agent in processing and use. Thickening of polar liquids, such as epoxies. Silicone elastomer reinforcement, high addition, as in molded products. Good hydrophobicity, improved corrosion resistance, improved dielectric properties, such as in cable compounds. Powder flow aids, such as in fire extinguishing agents, improve scratch resistance in coatings and plastics.