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arXiv · 1407.7724

Effective interaction between a colloid and a soft interface near criticality

Adam D. Law·Ludger Harnau·Matthias Troendle·Siegfried Dietrich
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Abstract

Within mean-field theory we determine the universal scaling function for the effective force acting on a single colloid located near the interface between two coexisting liquid phases of a binary liquid mixture close to its critical consolute point. This is the first study of critical Casimir forces emerging from the confinement of a fluctuating medium by at least one soft interface, instead by rigid walls only as studied previously. For this specific system, our semi-analytical calculation illustrates that knowledge of the colloid-induced, deformed shape of the interface allows one to accurately describe the effective interaction potential between the colloid and the interface. Moreover, our analysis demonstrates that the critical Casimir force involving a deformable interface is accurately described by a universal scaling function, the shape of which differs from that one for rigid walls.

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Adam D. Law, Ludger Harnau, Matthias Troendle, Siegfried Dietrich. 2014-07-29. Effective interaction between a colloid and a soft interface near criticality. https://doi.org/10.1063/1.4896383

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