Self-assembly of skyrmion-dressed chiral nematic colloids with tangential anchoring

Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Jun;89(6):060502. doi: 10.1103/PhysRevE.89.060502. Epub 2014 Jun 30.

Abstract

We describe dipolar nematic colloids comprising mutually bound solid microspheres, three-dimensional skyrmions, and point defects in a molecular alignment field of chiral nematic liquid crystals. Nonlinear optical imaging and numerical modeling based on minimization of Landau-de Gennes free energy reveal that the particle-induced skyrmions resemble torons and hopfions, while matching surface boundary conditions at the interfaces of liquid crystal and colloidal spheres. Laser tweezers and videomicroscopy reveal that the skyrmion-colloidal hybrids exhibit purely repulsive elastic pair interactions in the case of parallel dipoles and an unexpected reversal of interaction forces from repulsive to attractive as the center-to-center distance decreases for antiparallel dipoles. The ensuing elastic self-assembly gives rise to colloidal chains of antiparallel dipoles with particles entangled by skyrmions.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Anisotropy
  • Colloids / chemistry*
  • Computer Simulation
  • Elasticity
  • Imaging, Three-Dimensional
  • Microscopy, Video
  • Models, Chemical
  • Nonlinear Dynamics
  • Optical Imaging
  • Optical Tweezers

Substances

  • Colloids