title: The lyotropic phase behaviour of ester quaternary surfactants.
abstract: The lyotropic phase behaviour of two analogues of dioctadecyl dimethylammonium chloride was investigated. Both the inclusion of ester groups and subsequent minor structural rearrangement of the interfacial region of the surfactant were found to increase the chain melting temperature, although the overall phase behaviour remained similar for both compounds. Both of the two analogues were found to underswell, due to the formation of multi-lamellar vesicles. We also found that the inclusion of these ester linkages substantially reduced the metastability of the 'gel phase' in which the surfactants usually reside, accelerating the rate of collapse to a coagel state. This occurred via a nucleation-growth mechanism, where the growth was found to be one-dimensional, i.e. needle-like.
authors.affiliation: Department of Chemistry, Imperial College London, Exhibition Road, South Kensington, London SW7 2AZ, UK.
authors.forename: Gemma C
authors.initials: GC
authors.lastname: Shearman
authors.forename: Stephane
authors.initials: S
authors.lastname: Ugazio
authors.forename: Laurent
authors.initials: L
authors.lastname: Soubiran
authors.forename: John
authors.initials: J
authors.lastname: Hubbard
authors.forename: Oscar
authors.initials: O
authors.lastname: Ces
authors.forename: John M
authors.initials: JM
authors.lastname: Seddon
authors.forename: Richard H
authors.initials: RH
authors.lastname: Templer