title: Aggregation behavior of aqueous solutions of ionic liquids.
abstract: The aggregation behavior in aqueous solutions of three ionic liquids based on the 1-alkyl-3-methylimidazolium cation has been investigated by means of surface tension, conductivity, and small-angle neutron scattering (SANS) measurements. From analysis of the SANS data, models for the shapes and sizes of aggregates have been proposed: the short-chain 1-butyl-3-methylimidazolium tetrafluoroborate [C4mim] [BF4] system can be best modeled by treating it as a dispersion of polydisperse spherical aggregates that form above a critical aggregation concentration, whereas the 1-octyl-3-methylimidazolium iodide, [C8mim] [I], solutions can be modeled as a system of regularly sized near-spherical charged micelles that form above a critical micelle concentration. Solutions of 1-octyl-3-methylimidazolium chloride, [C8mim]-[Cl], display weak long-range ordering of possibly disklike particles culminating in the formation of structures with distinct long-range order at higher concentrations.
authors.affiliation: Department of Chemistry, University of Exeter, Exeter EX4 4QD, United Kingdom.
authors.forename: James
authors.initials: J
authors.lastname: Bowers
authors.forename: Craig P
authors.initials: CP
authors.lastname: Butts
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Martin
authors.forename: Marcos C
authors.initials: MC
authors.lastname: Vergara-Gutierrez
authors.forename: Richard K
authors.initials: RK
authors.lastname: Heenan