Hydrated silica

Hydrated silica

Hydrated silica is a form of silicon dioxide, which has a variable amount of water in the formula. It is also known as silicic acid, a term usually used for its form dissolved in water. It is found in nature, as opal, which has been mined as a gemstone for centuries and in the cell walls of diatoms. It is also manufactured for use in toothpaste. Once dehydrated the gel is used as a desiccant known as Silica gel. It is also used in various paints and varnishes and in the production of beer.


In its pure form, as manufactured for toothpaste, it is an odourless, tasteless, white, gelatinous substance, which is chemically inert.

Chemical formula

Chemical Formula: SiO2 · nH2O SiO2 = 1, H2O = 1: H2SiO3 SiO2 = 2, H2O = 1: H2Si2O5 SiO2 = 2, H2O = 3: H6Si2O7 SiO2 = 3, H2O = 2: H4Si3O8 SiO2 = 3, H2O = 4: H8Si3O10 SiO2 = 4, H2O = 1: H2Si4O9 SiO2 = 4, H2O = 2: H4SiO4 [also known as Si(OH)4 ]

Use in toothpaste

Hydrated silica is a mild gel abrasive, which, when combined with calcium carbonate (from chalk) helps to remove plaque. Milled to a slightly larger size, the grains are more abrasive and will help to whiten teeth.


Hydrated silica is listed by the US Food and Drug Administration as "Generally Recognised as Safe".


Toothpaste: [http://www.tomsofmaine.com/toms/ifs/hydrated_silica.asp] Chemistry: [http://sci-toys.com/ingredients/hydrated_silica.html] Opal: [http://www.galleries.com/minerals/mineralo/opal/opal.htm] Paint/Varnish: [http://householdproducts.nlm.nih.gov/cgi-bin/household/brands?tbl=chem&id=1683] Beer: [http://www.freepatentsonline.com/4975405.html]

Wikimedia Foundation. 2010.

См. также в других словарях:

  • hydrated silica — silicio rūgštis statusas T sritis chemija apibrėžtis Gelio pavidalo medžiaga. formulė SiO₂·nH₂O atitikmenys: angl. hydrated silica; silic acid rus. кремневая кислота …   Chemijos terminų aiškinamasis žodynas

  • silica — n. silicon dioxide, occurring as quartz etc. and as a principal constituent of sandstone and other rocks. Phrases and idioms: silica gel hydrated silica in a hard granular form used as a desiccant. Derivatives: siliceous adj. (also silicious).… …   Useful english dictionary

  • silica gel — noun hydrated silica in a hard granular hygroscopic form used as a desiccant …   English new terms dictionary

  • Silica gel — Identifiers CAS number 63231 67 4  …   Wikipedia

  • Biogenic silica — (BSi) is the equivalent to the terms opal, biogenic opal, and amorphous opaline silica. BSi is essential to many plants and animals. Chemically, BSi is hydrated silica (SiO2• n H2O).Diatoms in both fresh and salt water extract silica from the… …   Wikipedia

  • DNA separation by silica adsorption — is an important method of DNA separation that is used in novel technologies that use micro channels. The principle behind this type of separation relies on DNA molecules binding to silica surfaces in the presence of certain salts and under… …   Wikipedia

  • Opal — For other uses, see Opal (disambiguation). Opal An opal bracelet. The stone size is 18 by 15 mm (0.7 by 0.6 in) General Category …   Wikipedia

  • Mars Reconnaissance Orbiter — Conceptual image depicting the Mars Reconnaissance Orbiter in an elliptical low planet orbit around Mars Operator NASA / JPL Major contractors Lockheed Ma …   Wikipedia

  • papermaking — [pā′pər māk΄iŋ] n. the making of paper papermaker n. * * * pa·per·mak·ing (pāʹpər mā kĭng) n. The process or craft of making paper.   paʹper·mak er n. * * * Introduction       formation of a matted or felted sheet, usually of cellulose fibres,… …   Universalium

  • Physical Sciences — ▪ 2009 Introduction Scientists discovered a new family of superconducting materials and obtained unique images of individual hydrogen atoms and of a multiple exoplanet system. Europe completed the Large Hadron Collider, and China and India took… …   Universalium

Поделиться ссылкой на выделенное

Прямая ссылка:
Нажмите правой клавишей мыши и выберите «Копировать ссылку»