Neutron scattering study of micelle structure in isotropic aqueous solutions of poly(oxyethylene) amphiphiles

Connectivity of the Hexagonal, Cubic, and Isotropic Phases of the C12EO6/H2O Lyotropic Mixture Investigated by Tracer Diffusion and X-ray Scattering

“…We can thus consider that D def ∼ n def , which supports our hypothesis that the defects have very short lifetimes. It is then justified to use (8) for evaluating the mean distance between connections at the transition temperature L 0 : L 0 ≃ 4a ≃ 25 nm, in fairly good agreement with results of reference [15], which gives L 0 ≃ 17 nm. An important consequence is that the density of defects in the hexagonal phase is large at the transition; the picture of the hexagonal phase as being formed of infinitely long parallel columns is no longer accurate in these conditions.…”

“…The isotropic phase in C 12 EO 6 /H 2 O and other related systems has also been studied by elastic and quasi-elastic neutron scattering [8]. It is suggested from the observed fast relaxation times that the isotropic phase is formed of small, globular micelles, even in the vicinity of the hexagonal phase.…”

“…Interpretations in terms of small, attractively interacting (clustering) micelles have been put forward [8,9,10,11]. Other authors, however, claim that micelles grow in size and become anisotropic with increasing temperature or concentration [4,12,13].…”

Aggregates in Ionic Liquids and Applications Thereof

“…(Zulauf et al, 1985) [e] From (Herrington and Sahi, 1988); (Zulauf et al, 1985), the data corresponding to the C 12 E 4 surfactant was obtained near 0 °C.…”

“…This value was comparable with the one obtained from DLS measurements. Using an approximation of the surfactant volumes occupied in the micelle (Zulauf et al, 1985;van Os et al, 1993), we estimated the aggregation number in the micelles. Either increasing the alkyl chain length or decreasing the poly(oxylene) chain length contributes to both an enhanced hydrophobicity and an increase in aggregation number.…”