A 1H nuclear magnetic resonance chemical-shift study of inverted microemulsions of aerosol OT in benzene and cyclohexane. Partitioning of water between hydrocarbon and aqueous phases

Abstract

Chemical shifts in inverted microemulsions of sodium bis(2-ethyl-hexyl)sulphosuccinate (AOT) in perdeuterobenzene and perdeuterocyclo-hexane have been measured as a function of AOT concentration, H₂O/AOT ratio (R) and temperature. Free water in the hydrocarbon phase has been detected and quantified. The concentration of free water depends on R, and approaches the solubility of water in pure hydrocarbon when R 1. There is evidence of a specific interaction between the AOT polar headgroup and C₆D₆, leading to deshielding of the protons. The AOT headgroup conformation shows little dependence on composition.