"At the moment only about 300 ionic liquids are commercialized" This information I have get from one Chemistry thesis of 2017. In the case of Ionic liquid based surfactant what should be number? How to get this information?
All liquid detergents worldwide are based more or less on sodium lauryl sulphate, which is an anionic surfactant. Shampoos, hand washes etc also contain anionic surfactants. Check out the link below.
Cationic surfactants are widely used in disinfectants and antiseptics again worldwide. Cetyl trimethyl ammonium bromide is one of the most commonly used ones. IF you broadly search for quaternary ammonium compounds you will find so many commercialized.
I would say the number is probably around 400 to 500, depending on how you define ionic liquids. There are quite a few surfactant compounds, which have been commercialised even before the term ionic liquids became popular, and quite a few of those would fit in the modern definition of ILs, but are of course not counted within those cited numbers.