Interactions of polyelectrolytes and surfactants

The cationic polyelectrolyte PVp-S/anionic surfactant SDS and anionic polyelectrolyte P(SPMS-S) S/cationic surfactant CTAB, the viscosity of their aqueous solutions increases about 60 times for PVp - S/SDS system at molar ratio of SDS/cationic ion = 2.2-2.3 and 90 times for P(SPMS - S)/CTAB system at molar ratio of CTAB/anionic ion = 1.3-1.5. Beyond these molar ratios, the viscosity increased drops rapidly. It was found that the rise and drop of the viscosity are related closely with the aggregation and deaggregation of the polymer chains in surfactant aqueous solutions. In the case of SPS/CTAB system, the viscosity of the solution reaches two maximums at the molar ratio of CTAB/SPS (-SO3Na unit) = - 0.5 and - 1.5 at CAC and CMC of the CTAB. In the higher concentration of polyelectrolyte such as [SPS] = gt; 0.04mol/L, the solution will convert to a gel due to micelle crosslinking and it is reversible. The hydrophobic domains existed in polyelectrolyte/surfactant systems were detected using methyl orange as spectrum probe.EI0Suppl. pt 1162-1641