Interactions of Polyacrylamide with Cationic Surfactants: Thermodynamic and Surface Parameters

The aggregation behaviour of two cationic surfactants, viz. cetyl trimethyl ammonium bromide (CTAB) and N-cetyl pyridinium chloride (CPC), in different concentrations of water-soluble polyacrylamide has been studied in alkaline medium by electrical conductivity and surface tension measurements. A decrease in the critical micelle concentration (CMC) of the surfactant with an increase in polymer content in the mixture was observed. The thermodynamic and surface parameters have been determined and discussed. The results indicate that micellisation becomes more favourable at higher polymer content.