Confinement-Induced Colloidal Attractions in Equilibrium

Yilong Han, David G. Grier

    Research output: Contribution to journalArticle

    Abstract

    The Poisson-Boltzmann theory for colloidal electrostatic interactions predicts that charged colloidal spheres dispersed in water should repel each other, even when confined by charged surfaces. Direct measurements on highly charged polystyrene spheres, however, reveal strong, long-ranged confinement-induced attractions that have yet to be explained. We demonstrate that anomalous attractions also characterize the equilibrium pair potential for more weakly charged colloidal silica spheres sedimented into a monolayer above a glass surface. This observation substantially expands the range of conditions for which mean-field theory incorrectly predicts the sign of macroions’ interactions, and provides new insights into how confinement induces long-ranged like-charge attractions.

    Original languageEnglish (US)
    JournalPhysical Review Letters
    Volume91
    Issue number3
    DOIs
    StatePublished - Jul 17 2003

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    ASJC Scopus subject areas

    • Physics and Astronomy(all)

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