Combining molecular dynamics and Monte Carlo simulation we study defect structures around an elongated colloidal particle embedded in a nematic liquid crystal host. By studying nematic ordering near the particle and the disclination core region we are able to examine the defect core structure and the difference between two simulation techniques. In addition, we also study the torque on a particle tilted with respect to the director, and modification of this torque when the particle is close to the cell wall.

We perform large-scale Monte Carlo simulations of orientational ordering in nematic shells and study the type and position of topological defects when an external electric field (homogeneous or quadrupolar) is applied. The field-induced variation of the defect number (and strength) can be used to change the valence of colloidal particles coated with a nematic layer.

We present a systematic lattice Monte Carlo simulation study of nematic ordering in thin nematic shells on uniaxial and biaxial colloidal particles. Typically, four mutually repulsive half-strength defect lines penetrating the shell are observed, as found for spherical particles. For shells of constant thickness, the defect lines tend to accumulate in the high curvature regions. If the thickness of the nematic coating varies across the surface, the defect lines tend to be located in the thinnest regions. On increasing the shell thickness, the defect lines transform into escaped structures with surface point defects.

Liquid crystal elastomers (LCE)polymer networks constructed with liquid crystal unitsare functional materials characterized by a pronounced coupling between elastic strain and liquid crystalline orientational ordering. When prepared by polymerization and cross-linking in the isotropic phase, and then cooled (“isotropic genesis”), a polydomain LCE presents an extraordinary “supersoft” elastic behavior under unidirectional pulling, with a plateau-like low elastic modulus region in the stress–strain curve, before turning into a monodomain LCE where a standard elastic resistance is recovered. The physical mechanism of this behavior is of great interest, but still mysterious. This work investigates its origin, reproducing the experiment and succeeding to observe the plateau-like stress–strain behavior by means of large-scale molecular iso-stress Monte Carlo simulations. The results not only show that the basic molecular mechanism behind supersoft elasticity hinges on local domain rotation and growth but also suggest that this is assisted by a newly proposed dissipation of the elastic energy stored in the defects created by the isotropic genesis process, explaining also the irreversibility observed in main-chain LCE.