SHORT-RANGE STRUCTURE OF SIMULATED FLOCS OF PARTICLES WITH BRIDGING POLYMER

E DICKINSON, S R EUSTON

    Research output: Contribution to journalArticle

    Abstract

    Bridging flocculation of colloidal particles by adsorbing polymer is simulated in three dimensions by an off-lattice Monte Carlo model. Polymer chains are modelled as freely jointed, freely rotating, excluded volume random walks of 50 segments in length. Two types of particle-particle interaction are modelled: (i) hard-sphere repulsions, and (ii) soft-sphere repulsions. Particles and polymer interact via a square-well potential. Numerical results are presented for the effects of square-well depth and particle-particle interaction on the conformation of adsorbed polymer and the structure of particle flocs that are formed. The floc structures obtained from modelling particles with soft-sphere repulsions are compared to experimental data from small-angle neutron scattering studies, obtained from the literature. Soft-sphere repulsive interactions results in less compact floc structures, which have a more short-range, fluid-like character than those formed from hard spheres. The structure of flocs obtained from modelling soft spheres is more reminiscent of the floc structure found in experimental systems.

    Original languageEnglish
    Pages (from-to)231-242
    Number of pages12
    JournalColloids and Surfaces
    Volume62
    Issue number3
    Publication statusPublished - 5 Feb 1992

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