title: A reverse micellar mesophase of face-centered cubic Fm3m symmetry in phosphatidylcholine/water/organic solvent ternary systems.
abstract: We report the formation of a reverse micellar cubic mesophase of symmetry Fm3m (Q(225)) in ternary mixtures of soy bean phosphatidylcholine (PC), water, and an organic solvent, including cyclohexane, (R)-(+)-limonene, and isooctane, studied by small-angle X-ray scattering (SAXS) and oscillatory shear rheology at room temperature. The mesophase structure consists of a compact packing of remarkably large reverse micelles in a face-centered cubic (fcc) lattice, a type of micellar packing not yet reported for reverse micellar mesophases. Form factor fitting in the pure L2 phase and in the Fm3m-L2 coexistence region yields quantitative estimations of the PC interface rigidity. The compact Fm3m structure results mainly from release of lipid tail frustration and hard-sphere interactions between monodisperse micelles, as suggested by a comparison with the Fd3m structure found in the PC/water/α-tocopherol system.
authors.affiliation: Food and Soft Materials Science, Institute of Food, Nutrition & Health, ETH Zurich , Schmelzbergstrasse 9, CH-8092 Zurich, Switzerland.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Martiel
authors.forename: Laurent
authors.initials: L
authors.lastname: Sagalowicz
authors.forename: Raffaele
authors.initials: R
authors.lastname: Mezzenga
mesh_terms: D008823:Micelles; D009930:Organic Chemicals / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
chemical_list: D008823:Micelles; D009930:Organic Chemicals; D010713:Phosphatidylcholines; D012997:Solvents; D014867:Water