Impact of poly (ethylene glycol) on the structure and interaction parameters of aqueous micellar solutions of anionic surfactants

The changes in the structure and interaction of micelles of anionic surfactant, dodecylbenzene sulphonic acid (DBSA), in aqueous solutions upon addition of neutral polymer poly (ethylene glycol) (PEG) were analyzed using the data of small-angle neutron scattering (SANS) and surface tension measurements. The surface tension data showed the formation of surfactant-polymer complexes, which resulted in a shift of critical micelle concentration as compared to non-modified surfactant solutions and also in the appearance of a critical aggregation concentration. The variations in the dependences of the structure and interaction parameters of micelles (aggregation number, fractional charge, charge per micelle, surface potential, etc.) derived from the SANS data analysis were interpreted as an influence of micelle binding on polymer chains and surfactant-polymer association. The obtained results are compared with the previous data on aqueous solutions of another anionic surfactant, sodium oleate. (C) 2018 Elsevier B.V. All rights reserved.