J. Phys. IV France 10 (2000) Pr5-27-Pr5-38
Effective interactions between charged colloidal particles : Repulsion, attraction and phase separationJ. P. Hansen1, D. Goulding1 and R. van Roij2
1 Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
2 H.H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1 TL, U.K.
The paper summarizes recent theoretical work on the effective interactions between charge-stabilized, spherical colloidal particles. Despite the purely repulsive nature of the effective pair potential, fluid-fluid phase separation is shown to occur at very low salt concentrations, due to a frequently forgotten "volume" term. A long-range attractive component to the pair interaction is predicted when the colloidal particles are confined by charged surfaces (e.g. in slit or pore geometries), in agreement with recent experimental findings. The importance of excluded volume and solvent effects is briefly discussed.
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