Interaction Between Water Soluble Polymers and Charged Surfactants : Conductance and Surface Tension Studies

To investigate the effect of non-ionic polymers polyvinyl pyrrolidone (PVP), polyethylene oxide and polyvinyl alcohol on critical micelle concentration of an anionic surfactant, sodium dodecyl sulfate and a cationic surfactant, cetyltrimethyl ammonium bromide at different temperatures by conductivity and surface tension techniques. The CMC of SDS decreased in presence of the polymers. The degree of this decrease in CMC of SDS was greater for PVP than for PEO and PVA. Increase in the micellar ionization degree was observed for SDS-polymer mixtures. Gcomp values for SDS-polymer mixtures were higher, more negative for SDS-polymer mixtures than pure SDS. These results showed that as compared to PEO and PVA, PVP interacts more strongly with SDS. The critical aggregation concentration of SDS-PVP, SDS-PEO and SDS-PVA mixtures slightly decreased with rise in temperature. and Gcomp of SDS-polymer mixtures increased with increase in temperature reflecting that complexation is favored at high temperatures. The krafft temperature of CTAB did not show any dependence on the concentration of the polymers.