Physico-chemical properties of mixed anionic/cationic surfactant solution: Mixtures of sodium laurate methyl ester o-sulphonate and tetradecyltrimethylammonium bromide

Interface activitv between liquid and air (liquid/air) of palm-based anionic surfactant sodium laurate met hl ester a-sulphonate (ci2mes),cationic surfactant tetradecyltrimethylammonium bromide (ttab) and their mixtures at various mixing ratio was investigated using surface tens iometei variation of surface tension with concentration zvas used to determine the critical micelle concentration (cmc) of the individual surfactants as well as their mixtures at different mixing ratios. it was observed that the cmc for the mixed surfactants were 10 times lower than its individual counterpart. this showed that the surfactant mixtures were more effective and had higher surface activity than their single components. the surface tension at cmc for surfactant mixtures were around 25 mn m,where as for single surfactants,the value zvas above 28 mn m . foaming properties (such as foaming power and foaming stability),wetting and emulsfi cation performance of the mixed surfactant systems zvas also evaluated at different water hardness in this zvork. mixed surfactants especially at equimolar mixing ratio were found to exhibit superior performance as compared to their individual parent surfactants.