title: Multilamellar structures induced by hydrophilic and hydrophobic ions added to a binary mixture of D2O and 3-methylpyridine.
abstract: A phase transition is observed between a one-phase disordered phase and an ordered phase with multilamellar (onion) structures in an off-critical mixture of D2O and 3-methylpyridine (3MP) containing 85 mM of a salt in the absence of a surfactant. The salt consists of hydrophilic cations and hydrophobic anions that interact asymmetrically with the solvent composition fluctuations inducing mesophases. The structure factor of the composition distribution obtained from small-angle neutron scattering has a peak at an intermediate wave number in the disordered phase and multiple peaks in the ordered phase. Lamellar layers forming onions are composed of solvation-induced charged membranes swollen by D2O. The onion phase is realized only for small volume fractions of 3MP (in D2O-rich solvent).
authors.affiliation: Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Sadakane
authors.forename: Akira
authors.initials: A
authors.lastname: Onuki
authors.forename: Koji
authors.initials: K
authors.lastname: Nishida
authors.forename: Satoshi
authors.initials: S
authors.lastname: Koizumi
authors.forename: Hideki
authors.initials: H
authors.lastname: Seto