Effect of short chain length alcohols on micellization behavior of cationic gemini and monomeric surfactants

Micellization of a cationic gemini, decanediyl-1,10-bis (dimethylhexadecylammonium bromide) and monomeric surfactants viz. cetyltriphenylphosphonium bromide (CTPB), tetradecyltripheylphosphonium bromide (TTPB) and cetylpyridinium bromide (CPB) in the presence of short chain length alcohols has been investigated at 300 K. The effect of short chain length of alcohols (methanol, ethanol and 1-propanol) on critical micelle concentration (cmc), and degree of micellar ionization (alpha) were investigated by using conductivity measurements. The experimental data show that the cmc values of cationic surfactants increase with addition of methanol to ethanol and decreases with 1-propanol. The thermodynamics parameters i.e. standard Gibbs free energy (Delta G*(m),), enthalpy (Delta H degrees(m)) and entropy (Delta S degrees(m),) of micellization of cetylpyridinium bromide (CPB) are also calculated. Crown Copyright (C) 2012 Published by Else vier B.V. All rights reserved.