Drag of Micro-Particles by an Extended Nematic-Isotropic Interface

Abstract

We studied the behaviour of polymer particles in a moving interface between the nematic (N) and isotropic (I) phases of a nematic liquid crystal (LC). We showed that the NI-interface is extended (E) and has a layered N-I-N structure in the vertical cross-section of the sample; the wedge of the isotropic phase is bounded by the nematic phase, which is limited by the cell substrates. The minimum of the cell free energy defines the position of particles in the interface region. We find that the preferable position of the particle is at the vertex of the wedge formed by the isotropic phase. The particles are captured by the vertex line and follow the interface when it moves.

Colloidal particles in liquid crystal films and at interfaces

“…When a colloidal particle is captured by a NI interface, it can be dragged by it. As a result, periodic, stripe-like structures can be obtained, with the period depending on particle mass, size, and interface velocity [115][116][117]. In combination with an externally applied electric field, a wide variety of particle structures is observed, ranging from a fine-grained cellular structure to stripes of varying periods, to a coarse-grained "root" structure [118].…”

Physico-Chemical Investigation of Composites Based on Nematic Liquid Crystals

“…С этой точки зрения наиболее приемлемыми оказались частицы полимеров. Описанные в работах [52][53][54][55][56][57][58][59][60] экспери-менты с системой PMMA -5СВ были повторены и дали аналогичные результаты.…”

“…Аналогичные работы проводились также в Институте жидких кристаллов при Кентском университете [59,60]. Исследователи изучали реологические и электрооптические свойства структурированных коллоидов.…”