Aggregation behavior of a PEO–PPO–PEO block copolymer + ionic surfactants mixed systems in water and aqueous salt solutions

Cloud points, surface tension, viscosity and dynamic light scattering data on solutions of a poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (PEO–PPO–PEO); Pluronic P105, in water and NaBr solutions and for the similar systems in the presence of two ionic surfactants, sodium dodecyl sulphate (NaDS) and dodecyltrimethylammonium bromide (DTABr) are reported. The addition of NaBr to copolymer decreases cloud point, increases surface activity, shifts micellization to lower concentration. The DLS results reveal that presence of ionic surfactant (below CMC) leads demicellization of copolymer P105. Furthermore, in the presence of NaBr more surfactant is needed for demicellization of P105 micelles. The surface tension study of P105-ionic surfactant indicates stronger interaction in case of NaDS as compared to DTABr. Also, the interaction seems to diminish in the presence of NaBr.