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

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.

6 pages, 1 figure

References in corpus (2)

• The `Friction' of Vacuum, and other Fluctuation-Induced Forces
• Polymer Shape Anisotropy and the Depletion Interaction

Cited by in corpus (7)

• The Casimir effect: from quantum to critical fluctuations
• Critical Casimir Effect: Exact Results
• Thermal Casimir drag in fluctuating classical fields
• Pretransitional behavior in a water-DDAB-5CB microemulsion close to the demixing transition. Evidence for intermicellar attraction mediated by paranematic fluctuations
• Textures in Polygonal Arrangements of Square Nanoparticles in Nematic Liquid Crystals Matrices
• Casimir Torques between Anisotropic Boundaries in Nematic Liquid Crystals
• Manipulation and amplification of the Casimir force through surface fields using helicity