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Influence of polydispersity on the effective interaction in a quasi-two-dimensional pseudo-one-component colloid
1Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA.
Abstract:
We report the results of simulations of one-component and binary quasi-two-dimensional polydisperse hard sphere colloid fluids. When the polydisperse one-component system is regarded as an effective monodisperse one-component system, our results show that polydispersity gives rise to effective pair attraction and soft repulsion. These effective interactions depend on both the degree of polydispersity and the system density. At low density only the effective soft repulsion survives and the effective attraction becomes negligible. For the binary system, the depletion interaction develops extra features due to polydispersity, specifically a repulsive interaction with range twice the average particle diameter. At low density this extra feature vanishes. To carry out our study we have devised a method for continuous sampling of the polydisperse mixture according to a prescribed particle diameter distribution.
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