title: Changes in two-phase emulsion morphology in temperature-amphiphile concentration or fish diagram for ternary amphiphile/oil/water systems.
abstract: We examined the morphologies of two-phase emulsions in the ternary 2-butoxyethanol/n-decane/water system at various temperatures and water-to-oil ratios (WORs). The two-phase emulsion morphologies depended on temperature, WOR, and amphiphile concentration, and the results are presented in a temperature-amphiphile concentration coordinate system or a "fish" diagram. The observations made in this work contradict the predictions by the phase-inversion-temperature (PIT) concept. At WOR<1, a vertical inversion line was observed at T<T(lc) (lower critical endpoint temperature), dividing the two-phase region into the subregions of B/T (W/O) and T/B (O/W) emulsions. At T>T(uc) (upper critical endpoint temperature) and at low amphiphile concentrations, only B/T emulsions appeared, irrespective of temperature. At WOR>1, the situation was reversed; T/B emulsions at T<T(lc), T/B and B/T emulsions at T>T(uc), and T/B emulsions at low amphiphile concentrations, irrespective of temperature. At WOR=1, two horizontal inversion lines, one each at T<T(lc) and T>T(uc), were observed. The morphologies of the two-phase emulsions were B/T or T/B emulsions at low amphiphile concentrations, and at higher amphiphile concentrations T/B at T<T(lc) and B/T at T>T(uc). All these findings along with three-phase emulsion data result in complete emulsion morphology diagrams in the temperature-amphiphile concentration space or fish diagram.
authors.affiliation: Department of Chemical Engineering, Chung-Ang University, Seoul 156-756, Republic of Korea.
authors.forename: Jong-Moon
authors.initials: JM
authors.lastname: Lee
authors.forename: Kyung-Hee
authors.initials: KH
authors.lastname: Lim
mesh_terms: D000473:Alkanes / Q000737:chemistry*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004655:Emulsions; D005026:Ethylene Glycols / Q000737:chemistry*; D044367:Phase Transition; D013499:Surface Properties; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D000473:Alkanes; D004655:Emulsions; D005026:Ethylene Glycols; D014867:Water; C017096:n-butoxyethanol; C012867:decane