Investigation on the Interaction between Sodium Dodecyl Sulfate and Nonionic Polymer with Electrolytes by Viscosity and Surface Tension

Abstract

The interaction between sodium dodecyl sulfate (SDS) and the nonionic water-soluble polymer poly(ethylene glycol) (PEG) with electrolytes has been studied by viscosity and surface tension measurements at different temperatures, (298.15, 308.15, and 318.15) K. The experimental results showed that the critical aggregation concentration (CAC) value of SDS + (1, 3, and 5) g·kg−1 PEG with NaOH is lower than the critical micelle concentration (CMC) of SDS and that the PEG concentration has little effect on this value. When the SDS concentration is below the CAC, the viscosity of the SDS + PEG solutions with NaOH decreases with increasing SDS concentration, and the minimum viscosity of SDS + PEG complexes at the binding site confirmed the contraction of the polymer chain and the formation of a more compact structure. When the SDS concentration is above the CAC, the viscosity increases with increasing SDS concentration, indicating that the PEG chains are extended. The surface tension decreases remarkably with inc...