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Long-range Casimir interactions between impurities in nematic liquid crystals and the collapse of polymer chains in such solvents

D. Bartolo·D. Long·J. -B. Fournier
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Abstract

The elastic interactions between objects embedded in a nematic liquid crystal are usually caused by the average distorsion-rather than by the fluctuations-of the nematic orientational field. We argue that for sufficiently small particles, the nematic-mediated interaction originates purely from the fluctuations of the nematic director. This Casimir interaction decays as d^(-6), d being the distance between the particles, and it dominates van der Waals interactions close to the isotropic-to-nematic transition. Considering the nematic as a polymer solvent, we show that the onset of this Casimir interaction at the isotropic-to-nematic transition can discontinuously induce the collapse of a flexible polymer chain from the swollen state to the globular state, without crossing the Theta-point.

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D. Bartolo, D. Long, J. -B. Fournier. 1999-11-19. Long-range Casimir interactions between impurities in nematic liquid crystals and the collapse of polymer chains in such solvents. https://doi.org/10.1209/epl%2Fi2000-00211-3

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