Fumed silica is a nanometer white powder produced by the hydrolysis of silicon halide at high temperature in an oxyhydrogen flame. It is a kind of amorphous silicon dioxide product, the primary particle size is between 7~40nm, the aggregate particle size is about 200-500 nm, the specific surface area is 100~400m2/g, high purity, and SiO2 content is not less than 99.8%. The vapor phase silica aggregates with untreated surfaces contain a variety of silica hydroxyl groups. One is an isolated, undisturbed free hydroxyl group; The other is bonded silyl groups that are linked and form hydrogen bonds to each other. The vapor phase silica aggregates with the untreated surface are aggregates containing multiple -Oh compounds, which can easily form a uniform three-dimensional network structure (hydrogen bond) in the liquid system. This three-dimensional network structure (hydrogen bond) with external force (shear force, electric force, etc.) will be destroyed, the medium becomes thin, the viscosity drops, and once the external force disappears, the three-dimensional structure (hydrogen bond) will restore itself, the viscosity rises, that is, this thixotropy is reversible.
Fumed silica is one of the most important new inorganic materials. It has a small particle size, large specific surface area, strong surface adsorption, large surface energy, high chemical purity, good dispersion performance, thermal resistance, resistance, and other aspects of specific performance. In addition, its high stability, its reinforcing effect, thickening, and thixotropy, in many fields of unique characteristics make it irreplaceable. It is widely used in various industries as additives, catalyst carriers, petrochemical, decolorizing agent, matting agent, rubber reinforcing agent, plastic filling agents, ink thickening agents, metal soft polishing agents, insulation and adiabatic filler, advanced daily cosmetic filler, and spraying materials, medicine, environmental protection, and other fields.
Fumed silica mainly has two "sex”: hydrophilic and hydrophobic. People can use physical, chemical, and mechanical methods to deal with the fumed silica surface or interface, in order to change its chemical and physical properties of the fumed silica surface, such as surface energy, surface wettability, electrical, adsorption, and reaction characteristics, surface structure and functional groups, etc. Therefore, it can meet the modern new material, new technology, and the needs of the development of new technology.
Hydrophobic fumed silica applications Thickening of polar liquids, such as epoxy resins; Silicone elastomer reinforcement; High addition, as in molded products; Good hydrophobicity, improving anticorrosion; Improved dielectric properties, as in cable composites; Powder flow AIDS, such as powder coatings and fire extinguishing agents; Improve scratch resistance in coatings and plastics.
Luoyang Tongrun Nano Technology Co. Ltd. (TRUNNANO) is a trusted global chemical material supplier & manufacturer with over 12-year-experience in providing super high-quality chemicals and Nanomaterials, including silicon powder, nitride powder, graphite powder, zinc sulfide, calcium nitride, 3D printing powder, etc. If you are looking for high-quality fumed silica at a very good price, please feel free to contact us and send an inquiry. ([email protected])
