The difference between hydrophilic and hydrophobic silica of fumed silica Hydrophilic fumed silica is produced by hydrolysis of volatile chlorosilanes in an oxyhydrogen flame. Chemically, these loose white powders consist of high-purity amorphous silica. Hydrophilic silica is wettable with water and dispersible in water. In addition to traditional industrial applications such as polyesters, silicones, paints and coatings, hydrophilic fumed silica products are increasingly used successfully in high-tech applications. The nanoparticle nature and high purity of fumed silica have led to its use in the electronics and optical fiber industries. The hydrophilic fumed silica product has an amorphous structure by X-ray analysis. According to different markets and application fields, we can provide primary particles with different particle sizes and products with different specific surface areas. Some fumed silica products are available compressed and some are pharmaceutical grade.
The functions of hydrophilic fumed silica: suitable for processing, adjusted to the best rheology; reinforcement of silicone elastomers; thickening of non-polar liquids; glidant for food and industrial powders; high chemical Purity; excellent insulating properties even at high temperatures; liquids turned into powders, such as medicine, cosmetics.

Hydrophobic fumed silica is produced by chemically reacting hydrophilic fumed silica with reactive silanes 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, hydrophobic fumed silica is produced by treating modified hydrophilic grade fumed silica with silane or siloxane. In the final product, the chemical treatment agent is chemically bonded to the original hydrophilic oxide. superior. In addition to the above-mentioned advantages of hydrophilic products, hydrophobic fumed silica products are characterized by: low hygroscopicity, good dispersibility, and rheological adjustment even for polar systems. Some products, on the basis of hydrophobic treatment, undergo structural modification, which can provide further help for customers to develop new products and improve product performance. For example, in liquid systems, hydrophobic fumed silica can be added in high amounts with little effect on the viscosity of the system.
The functions of hydrophobic fumed silica: the most suitable rheology in processing and use; thickening of polar liquids, such as epoxy resins; reinforcement of silicone elastomers; high addition levels, such as in molded products; good Hydrophobicity, improves corrosion resistance; improves dielectric properties, such as in cable composites; powder flow aids, such as in powder coatings and fire extinguishing agents; improves scratch resistance in coatings and plastics.