Silicones are a large group of compounds that include large polymers containing silicon. Depending on the formula and the degree of polymerization and cross-linking of the polymers, they may be slippery liquids, waxes, or rubbers.
Silicones are used as emollients (skin softeners), as lubricants, as thickeners, and as volatile liquids that make coatings feel smooth, but evaporate without leaving a greasy residue.
Highly cross-linked silicone films are used in cosmetics to form films that absorb sebum (skin oils) and prevent shine.
Cyclopentasiloxane is a low viscosity, volatile liquid used as a carrier. It lubricates, and prevents hair sprays from being sticky to the touch. It evaporates completely, leaving no residue.
Dimethicone is another name for polydimethylsiloxane and is used to impart a soft velvety feel to hair or skin products. It is also used as an emulsifier for "water-in-oil" emulsions.
Trimethylsiloxysilicate is a film forming resin, used to keep hand lotions and sunscreens from washing off.
Cetearyl methicone is a polysiloxane wax. It replaces petrolatum in products such as hand lotions to give them a non-greasy feel.
Silicone A-1100]: InChI=1/C9H23NO3Si/c1-4-11-14(12-5-2,13-6-3)9-7-8-10/h4-10H2,1-3H3