Cholesteryl nonanoate, also called cholesteryl pelargonate, 3β-cholest-5-en-3-ol nonaoate or cholest-5-ene-3-β-yl nonanoate, is an ester of cholesterol and nonanoic acid. It is a liquid crystal material forming cholesteric liquid crystals with helical structure. It forms spherulite crystals.[1]
It is used in some hair colors, make-ups, and some other cosmetic preparations; e.g. the ISP ColorFlow line is based on mixtures with e.g. cholesteryl chloride, cholesteryl oleyl carbonate and BHT. The mixture provides an opalescent, iridescent appearance.[2]
It is also used in some pleochroic dyes and together with e.g. cholesteryl oleyl carbonate and cholesteryl benzoate in some thermochromic applications.[3]
It can be also used as a component of the liquid crystals used for liquid crystal displays.