Search results
Results from the WOW.Com Content Network
The first crystalline silicic acid was prepared from the phyllosilicate natrosilite (Na 2 Si 2 O 5) in 1924. More than 15 crystalline acids are known and comprise at least six modifications of H 2 Si 2 O 5. Some acids can adsorb and intercalate organic molecules, and therefore are interesting alternatives to silica. [10]
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.
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide).The atoms are linked in a continuous framework of SiO 4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO 2.
Synthetic amorphous / pyrogenic silica / amorphous silica: 68155-20-4: Tall oil fatty acid diethanolamine: Foamer, wellbore cleaner 8052-48-0: Tallow fatty acids sodium salt: Soap 72480-70-7: Tar bases, quinoline derivs., benzyl chloride-quaternized: 68647-72-3: Terpene and terpenoids: Solvent 68956-56-9: Terpene hydrocarbon byproducts: Solvent ...
Each individual organic group is covalently bonded to two or more silicon atoms in the framework. The pores in the material are periodically ordered with diameter in the range 2 -30 nm. [7] Depending on the synthetic conditions used to make mesoporous organosilicas, the mesoscale structure can either be amorphous or crystalline. [8]
Sodium silicates are colorless glassy or crystalline solids, or white powders. Except for the most silicon-rich ones, they are readily soluble in water, producing alkaline solutions. [citation needed] When dried up it still can be rehydrated in water. [16] Sodium silicates are stable in neutral and alkaline solutions.
Aluminium silicate is a type of fibrous material made of aluminium oxide and silicon dioxide, (such materials are also called aluminosilicate fibres). These are glassy solid solutions rather than chemical compounds. The compositions are often described in terms of % weight of alumina, Al 2 O 3 and silica, SiO 2. Temperature resistance increases ...
W-silica is an unstable low-density form involving SiO tetrahedra sharing opposite edges instead of corners, forming parallel chains similarly to silicon disulfide (SiS 2) and silicon diselenide (SiSe 2): it quickly returns to forming amorphous silica with heat or traces of water. [14] Condensed polysilicic acid. Silica is rather inert chemically.