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Fumed silica is also known as pyrogenic silica because it is produced in flame pyrolysis of silicon tetrachloride or from quartz sand vaporized in a 3000 °C electric arc. Fumed Silica consists of microscopic droplets of amorphous silica fused into branched, chainlike, three-dimensional secondary particles, agglomerating into tertiary particles. The resulting powder has an extremely low bulk density of 2.5-11.8 lbs/ft3 (40–190 kg/m3), a primary particle size of 5–50 nm (smaller than the average p Fumed silica is a universal thickening agent and an anticaking agent (free-flow agent) in powders. Like silica gel, it serves as a desiccant. It is used in cosmetics for its light-diffusing properties. It is used as a light abrasive in products like toothpaste. Other uses include filler in silicone elastomer and viscosity adjustment in paints, coatings, printing inks, adhesives, and unsaturated polyester resins. It is also used in producing cat litter box fillers and as a core material in produc Fumed silica is an artificial substance, so it’s no surprise that it’s known by multiple names—Diatomaceous earth, Diatomaceous silica, Diatomite, Silicon dioxide (amorphous), and Vitreous silica, at least. In fact, before 1989, its official name was silica (amorphous). Today, however, industry and regulators tend to call the substance fumed silica—not to be confused with silica fume, which is an industrial byproduct quite different from fumed silica. Fumed silica is a beneficial industrial chem The benefits of fumed silica and silica fume in the manufacturing and construction industries are well known. While the two terms seem similar, the products have apparent differences. Unfortunately, most people use the terms interchangeably. Here is everything you need to know about fumed silica and silica fume. Fumed silica or pyrogenic silica is a multi-purpose silica-based additive commonly used to manipulate viscosity and rheology and enhance the functionality of existing polymer matrices. I What is Fumed Silica?Fumed Silica is a form of silicon dioxide, or silicon, with the molecular formula SiO2 and a molecular weight of 60.0843 g/mol. Fumed silica is also known as pyrogenic silica. It is an odorless white powder consisting of droplets of fused silica cooled by forming three-dimensional chains. These are organized into particles of amorphous matter of very low apparent density and very high specific surface area. Fumed silica is insoluble in water. Fumed silica (CAS number 112945- The Aerosil® 200 silica used by the invention, with a BET surface area, differs from the known Aerosil® 300, which has a surface area of 300 m2/g, not only in the surface size but also in the average primary particle size. The Aerosil® 300 has an average primary particle size of 7 nm. Based on these differences, these silicas have different performance properties. The fumed silica of the invention contains no hydrophobic fractions. Despite this, the silica of the invention shows no propensity to The prior art can only prevent deagglomeration if the hydrophilic silica is mixed with 3% by weight of hydrophobic silica and if this mixture is ground utilizing an air-jet mill or a pinned-disc mill (EP 0 076 377 B1). In this case, for a fumed silica having a BET surface area of 200 m2/g, even after compaction to 73 or 107 g/l, a goniometer value of 35 is achieved. For a fumed silica with a BET surface area of 300 m2/g, adding hydrophobic silica before grinding produces a goniometer value of 10 A known procedure is to render fumed silica hydrophobic, grind it in a pinned-disc mill, and then classify it (U.S. 2004/0110077 A1). This known silica is used as an external additive in toner mixtures. Reducing the agglomerate size by dispersing outside a liquid system, in other words, in practice, in the air, or by grinding in the conventional sense, is possible only to a limited extent since in the case of material with a given propensity to agglomerate the comminution is followed immediately The primary particles and aggregates of a fumed silica agglomerate form larger assemblies whose size is generally in inverse proportion to the primary particle size or proportion to the specific surface area. The agglomerate size also increases with the extent to which the fumed silica is compacted. The binding forces holding these agglomerates together are relatively weak. Nevertheless, a certain shearing energy is required when these agglomerates are incorporated into and broken down in a liqu Fumed silica having a BET surface area of 200±15 m2/g, a goniometer value of less than 30 μm, and a median value by PCS of 65 to 85 nm are prepared by grinding a fumed silica having a surface area of 200±25 m2/g, and silicone rubber containing this silica. This application is a continuation of Ser. No. 12/095,840 filed Jun. 2, 2008, a U.S. National Stage Filing of international No. PCT/EP2006/068889 filed Nov. 24, 2006, which claims priority from EP 051125334 filed Dec. 20, 2005, which all are b

What is fumed silica

Since the German Degussa Company successfully developed the production technology of gaseous phase SiO2 in 1941, the total annual production of gaseous phase SiO2 in the world has exceeded 150000 tons in 2007, and the production technology is highly concentrated. The global market is mainly controlled by a few companies such as German Degussa, Wacker, U.S. Cabot, and Japan Tokuyama, and the technology is also tightly controlled. A basic model for developing gaseous phase SiO2 globally is the clo

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