Fumed silica wiki. Its unique properties, such as high surface area, thixotropy, and thermal stability, make it invaluable for enhancing the performance of products ranging from coatings and adhesives to cosmetics and pharmaceuticals. The three main classes of amorphous silica are pyrogenic silica, precipitated silica and silica gel. Fumed silica Fumed silica with surface area of 130 m 2 /g Fumed silica (CAS number 7631-86-9, also 112945-52-5), also known as pyrogenic silica because it is produced in a flame, consists of microscopic droplets of amorphous silica fused into branched, chainlike, three-dimensional secondary particles which then agglomerate into tertiary particles. The alkali–silica reaction (ASR), also commonly known as concrete cancer, [3] is a deleterious internal swelling reaction that occurs over time in concrete between the highly alkaline cement paste and the reactive amorphous (i. It appears as a light and fluffy white powder composed of microscopic droplets of amorphous silica. Fumed silica (CAS number 7631-86-9, also 112945-52-5), also known as pyrogenic silica because it is produced in a flame, consists of microscopic droplets of amorphous silica fused into branched, chainlike, three-dimensional secondary particles which then agglomerate into tertiary particles. The hydrophobic groups are normally alkyl or polydimethylsiloxane chains. It is characterized by lower moisture content and fewer surface hydroxyls due to its pyrogenic manufacture, making it suitable for premium applications, particularly in silicone rubbers. The production process for fumed silica Fumed silica is an ultrafine powder material obtained by high-temperature hydrolysis and condensation of halosilanes in a hydroxide flame. The resulting powder has an extremely low bulk density and high surface area. ryce prsfv qfvhktvs ghpzuhhy ovl enfbh mgkznow jpceu jwrpiu lggv