title: Coexisting lamellar phases in water-oil-surfactant systems induced by the addition of an amphiphilic block copolymer.
abstract: We report here a pioneering study using quadrupolar splitting NMR to detect new phases and phase compositions in the quasi-ternary microemulsion system water-decane-C(10)E(4)/PEP5-PEO5. The striking observation is that at certain compositions the polymer is apparently no longer incorporated into the membranes of the lamellar phase due to space restrictions. The polymer therefore induces a phase separation into two different lamellar phases L(alpha)(1) and L(alpha)(2) such that it fits into L(alpha)(1) while the excess surfactant forms a polymer-free L(alpha)(2) phase.
authors.affiliation: Institut für Physikalische Chemie, Universität zu Köln, Luxemburger Str. 116, D-50939 Köln, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Frank
authors.forename: Reinhard
authors.initials: R
authors.lastname: Strey
authors.forename: Claudia
authors.initials: C
authors.lastname: Schmidt
authors.forename: Cosima
authors.initials: C
authors.lastname: Stubenrauch