Micellar Structure Changes in Aqueous Mixtures of Nonionic Surfactants

Abstract:
Rheology and small-angle neutron scattering (SANS) are used to probe the structure of nonionic surfactant mixtures of triblock copolymers (Pluronics) and a C_14 diol (Surfynol 104) in water. Small amounts of Surfynol 104 incorporate into the existing Pluronic micelles and cause enormous rheological changes when added to aqueous solutions of some Pluronics with certain molecular compositions. The hydrophobic C_14 diol is only soluble up to 0.1wt% in pure water, but can be added in large quantities to aqueous solutions of the Pluronics. Particularly, a structural transition from spherical to wormlike micelles in solution has been identified by SANS to be responsible for the rheological changes in the mixture of Pluronic P105 and the C_14 diol.

Last modified 19-February-2002