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Silicates and Silicones:

Silicates:- Metal silicates having wide range of structures ranging from simple monomer to complex polymer is the general term given to metal ion attached to basic unit of tetrahedral nature of silicate ion. A silicate in general has Si-O bond and possesses a complex network solid having silicate ion groups, in cyclic groups, in infinite chains or infinite sheets given different structure to silicates such as chain silicates, ring silicates, cyclic silicates, sheet silicates, three dimensional silicates etc.

A large percentage of the earth’s crust consists of silicate minerals. As SiO₂ in earth crust it exists as silica, sand, quartz and flints. Some of the other important silicate minerals are asbestos (calcium magnesium silicate i.e., CaMgSi₂O₆), feldspar (potassium aluminum silicate, KAlSi₃O₈), zeolite (sodium aluminium silicate, Na₂Al²Si₂O₈xH₂O) and diopside (magnesium calcium silicate, MgCaSi₂O₆).

Silicones:- Silicones having R₂SiO units are organo-silicon synthetic polymers containing Si-O-Si linkages. The name silicone has been given for these polymeric compounds because their empirical formula resembles to ketone R₂CO. These are formed by the hydrolysis of alkyl or aryl substituted chlorosilanes and their subsequent polymerization. The alkyl or aryl substituted chlorosilanes are prepared by the reaction of Grignard reagent and silicon tetrachloride.

Silicates: A silicate (SiO44-) is a compound containing a silicon bearing anion. The silicates are the largest, the most interesting and the most complicated class of minerals than any other minerals. Approximately 30% of all minerals are silicates and some geologists estimate that 90% of the Earth`s crust is made up of silicates, (SiO44-) based material. Thus, oxygen and silicon are the two most abundant elements in the earth`s crust.Silicones: Silicones are polymers that include silicon together with carbon, hydrogen, oxygen, and sometimes other elements. Some common forms include silicone oil, silicone grease, silicone rubber, silicone resin. Silicones are inert, synthetic compounds with a variety of forms and uses. Typically heat-resistant and rubber-like, they are used in sealants, adhesives, lubricants, medical applications, cookware, and insulation. These are group of organosilicon polymers. The repeating units is . These are prepared by polymerization of alkyl or aryl substituted silicon chlorides, RnSiCl(4 − n),