Stability of Water/Poly(ethylene oxide)43-b-poly(ε-caprolactone)14/Cyclohexanone Emulsions Involves Water Exchange between the Core and the Bulk

Mario E. Flores, Francisco Martínez, Andrés F. Olea, Toshimichi Shibue, Natsuhiko Sugimura, Hiroyuki Nishide, Ignacio Moreno-Villoslada

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    4 Citations (Scopus)

    Abstract

    The formation of emulsions upon reverse self-association of the monodisperse amphiphilic block copolymer poly(ethylene oxide)43-b-poly(ε-caprolactone)14 in cyclohexanone is reported. Such emulsions are not formed in toluene, chloroform, or dichloromethane. We demonstrate by magnetic resonance spectroscopy the active role of the solvent on the stabilization of the emulsions. Cyclohexanone shows high affinity for both blocks, as predicted by the Hansen solubility parameters, so that the copolymer chains are fully dissolved as monomeric chains. In addition, the solvent is able to produce hydrogen bonding with water molecules. Water undergoes molecular exchange between water molecules associated with the polymer and water molecules associated with the solvent, dynamics of major importance for the stabilization of the emulsions. Association of polymeric chains forming reverse aggregates is induced by water over a concentration threshold of 5 wt %. Reverse copolymer aggregates show submicron average hydrodynamic diameters, as seen by dynamic light scattering, depending on the polymer and water concentration.

    Original languageEnglish
    Pages (from-to)15929-15937
    Number of pages9
    JournalJournal of Physical Chemistry B
    Volume119
    Issue number52
    DOIs
    Publication statusPublished - 2015 Dec 31

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    ASJC Scopus subject areas

    • Physical and Theoretical Chemistry
    • Materials Chemistry
    • Surfaces, Coatings and Films

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