Why fumed silica is an extremely important high-tech ultra-fine inorganic new material?
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Author : Lzh
Update time : 2023-02-02 12:30:53
What is fumed silica? Vapor phasesilica (fumed white carbon black) is one of the most important high-tech ultra-fine inorganic new materials. Because of its small particle size, it has a large specific surface area, strong surface adsorption, large surface energy, high chemical purity, good dispersion performance, thermal resistance, and other aspects of special performance. With its superior stability, reinforcement, thickening, and thixotropy, it has unique characteristics in many disciplines and fields; It plays an irreplaceable role. Nano silica, commonly known as "ultra-fine white carbon black," is widely used in various industries as an additive, catalyst carrier, petrochemical industry, decolorizer, matting agent, rubber reinforcing agent, plastic filler, ink thickener, metal soft polishing agent, insulation and thermal insulation filler, advanced daily cosmetics filler and spraying materials, medicine, Environmental protection, and other fields, and provide the new material basis and technical guarantee for the development of related industrial fields. The molecular formula of fumed silica: SiO2, white fluffy powder foam, porous, non-toxic, tasteless, pollution-free, high temperature resistant. At the same time, its chemical inertia and special thixotropic properties significantly improve rubber products' tensile strength, tear resistance, and abrasion resistance, and the strength of rubber products after improvement is increased by tens of times. The rheological and thixotropic control of liquid systems, adhesives, polymers, etc., is used as an auxiliary for anti-sinking, thickening, and anti-sagging, as well as the reinforcement of HCR and RTV-2K silicone rubber; it can be used to adjust free flow and improve powder properties as an anti-caking agent.
How to produce fumed silica? The air and hydrogen are pressurized, separated, cooled, and dehydrated, and silica gel is dried, dedusted, and filtered before being sent to the synthetic hydrolysis furnace. The silicon tetrachloride raw material is sent to the distilling tower for rectification, then heated and evaporated in the evaporator, and sent to the synthetic hydrolysis furnace with the dried and filtered air as the carrier. After the silicon tetrachloride is gasified at high temperature (flame temperature 1000~1800 ℃), it is gasified with a certain amount of hydrogen and oxygen (or air) at a high temperature of about 1800 ℃; At this time, the gas phase silicon dioxide particles generated are very fine, forming aerosol with the gas, which is not easy to capture. Therefore, they are first gathered into larger particles in the aggregator, then collected by the cyclone separator, and then sent to the deacidification furnace. The gas phase silicon dioxide is purged with nitrogen air until the PH value is 4~6, which is the finished product.
Hydrophobicity of fumed silica Hydrophobic fumed silica is generally a post-treatment product. Different types of fumed silica or precipitated silica can be selected as raw materials to react with appropriate compounds through silyl hydrocarbon groups; For example, obtained by the reaction of siloxane with dimethyldichlorosilane. This product is hydrophobic because it is connected with nonhydrolytic methyl groups on the surface. Unlike the original hydrophilic silica, hydrophobic fumed silica cannot be wetted by water. Although the density of hydrophobic fumed silica is greater than that of water, it can float on the water surface; the amount of water absorbed will be greatly reduced compared with the original hydrophilic fumed silica. For example, in the air with 80% relative humidity, Hn-215 only absorbs 0.5% water. At the same time, the hydrophilic fumed silica Hn-150 with the same specific surface area can increase its water absorption by more than ten times.
Price of fumed silica Fumed silica particle size and purity will affect the product's Price, and the purchase volume can also affect the cost of fumed silica. A large amount of large amount will be lower. The Price of fumed silica can be found on our company's official website.
Fumed silica supplier Luoyang Tongrun Nano Technology Co. Ltd. (TRUNNANO) Luoyang City, Henan Province, China, is a reliable and high-quality global chemical material supplier and manufacturer. It has more than 12 years of experience providing ultra-high quality chemicals and nanotechnology materials, including fumed silica, nitride powder, graphite powder, sulfide powder, and 3D printing powder. If you are looking for high-quality and cost-effective fumed silica, you are welcome to contact us or inquire at any time.
