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Hydrated silica is a form of silicon dioxide, which has a variable amount of water in the formula. When dissolved in water, it is usually known as silicic acid . It is found in nature as opal [ 2 ] (which has been mined as a gemstone for centuries), and in the cell walls of diatoms .
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula SiO 2, commonly found in nature as quartz. [5] [6] In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and abundant families of materials, existing as a compound of several minerals and as a
Silica gel is non-toxic, and non-reactive and stable with ordinary usage. It will react with hydrogen fluoride, fluorine, oxygen difluoride, chlorine trifluoride, strong acids, strong bases, and oxidizers. [22] Silica gel is irritating to the respiratory tract and may cause irritation of the digestive tract.
Silicic acids can be seen as hydrated forms of silica, namely 2 H 2x SiO x+2 = SiO 2 ·(H 2 O) x. Indeed, in concentrated solutions, silicic acids generally polymerize and condense, and ultimately degrade to silicon dioxide and water. The intermediate stages may be very thick liquids or gel-like solids.
In acidic solutions, the silicate ions react with hydrogen ions to form silicic acids, which tend to decompose into hydrated silicon dioxide gel. [citation needed] Heated to drive off the water, the result is a hard translucent substance called silica gel, widely used as a desiccant. It can withstand temperatures up to 1100 °C. [citation needed]
Plus, it also has antioxidants to reduce the effects of free radicals, as well as jojoba esters to hydrate, according to the brand. ... It has silica powders that give skin a velvety, but not ...
In alkaline-to-neutral aqueous solutions, hexafluorosilicic acid readily hydrolyzes to fluoride anions and amorphous, hydrated silica ("SiO 2 "). Strong bases give fluorosilicate salts at first, but any stoichiometric excess begins hydrolysis. [7] At the concentrations usually used for water fluoridation, 99% hydrolysis occurs: [6] [8] SiF 2−
There's no foolproof way to know the future for U.S. Silica Holdings (NYS: SLCA) or any other company. However, certain clues may help you see potential stumbles before they happen -- and before ...