Organo functional silicone compounds differ in not only the type of solvents in which they are soluble, but also in the ionic charge present on the silicone. Silicone polymers can be anionic, cationic, nonionic or amphoteric. The presence of ionic groups affects the silicone in an analogous way to how ionic groups affect fatty surfactants. For example, cationic silicones are more substantive to hair than nonionic silicones, just like cationic surfactants are more substantive to hair than nonionic surfactants. This is due to the anionic groups on hair made through the oxidation of the sulfur-containing amino acids in hair.
Just as anionic surfactants such as sodium lauryl sulfate have minimal compatibility with fatty cationic compounds such as stearalkonium chloride, cationic silicones have minimal solubility in anionic systems. This incompatibility limits the ability to formulate using these ingredients.
Molecular modifications to anionic and cationic silicones to make them compatible with one another have been developed. In these modifications, the two opposing charged silicones are attracted and form a salt. After modification, these silicones form an ionic complex that remains soluble in water, referred to as a soft complex.
The complexation of silicone anionics and silicone cationics results in raw materials that can be added to shampoos and other anionic containing systems to obtain conditioning and compatibility. Such complexes are highly efficient conditioners that can be easily added to formulations.