Small Angle Neutron Scattering and Viscosity Measurements on Silicone, Ionic, and Nonionic Surfactant Mixed Systems in Aqueous Solutions

The structural features of mixed micelles of a silicone surfactant (SS-1) with a comb-like structure, and three hydrocarbon surfactants (HS), sodium dodecyl sulfate, SDS, tetradecyl trimethylammonium bromide, DTAB, and t-octylphenoxy polyethoxyethanol, TX-100 in water were investigated using dilute solution phase characteristics, small angle neutron scattering (SANS) and solution viscosity measurements. The surfactants interact with the SS-1 micelles leading to the formation of highly hydrophilic complexes. The enhanced hydrophilicity shifts the unimer ↔ micelle in favor of former. The reduced viscosities of the mixed systems of SS-1—ionic surfactants in the very low SS-1 concentrations were high and show a curvature suggesting strong repulsive interactions among the complexes. The intrinsic viscosity of mixture solutions are more than the SS-1 micellar solutions indicating enhanced hydration. The hydrophilicity increased the cloud points of SS-1 in simple surfactants.