²H NMR and DSC Study on Lyotropic Liquid Crystal in the Dioctadecyldimethylammonium Chloride/n-butanol/H₂O System

The equilibrium phase diagrams for the dioctadecyldimethylammonium chlioride （DODMAC）/alcohos （ⁿ-propanol, ⁿ-butanol, ⁿ-pentanol）/H₂O were determined at 50℃.The ²H NMR spectroscopy and DSC scan methods have been used in determining the structures for various samples in the DODMAC/ⁿ-butanol/H₂O liquid crystalline regions. The results showed; The areas of liquid crystalline regions increased with increase of the carbon chain length of alcohols used as cosurfactants. The liquid crystal phase constructures not only changed with varing of the content of water at a certain temperature, but also changed with varing of temperature at a certain composition.