Capillary Flows of Nematic Liquid Crystal

Abstract

In this paper we report the new experimental results on the rise of a liquid crystal in flat capillaries with inner photosensitive surfaces. The capillaries with different surface orientations were prepared by the use of the photo-alignment technique. Such a surface treatment makes it possible to eliminate the noncontrollable influence of a nanorelief on the wetting process, which takes place in the rubbing treatment technique previously used in similar experiments. The dynamics of the capillary rise of a nematic liquid crystal 5CB (4-cyano-4′-pentylbiphenyl) in vertical plane capillaries with photo-aligned substrates were studied for the first time. It was found that the stationary value of a contact angle weakly depends on the direction of a planar surface orientation relative to the direction of a capillary rise. It has been shown that the application of strong electric fields resulted in a decreasing of the contact angle. The results, obtained for the nematic liquid crystal, are compared with the results of an investigation of the capillary flow in a shock-free ferroelectric smectic phase.

Dynamic and Equilibrium Contribution of Nematic Order in Wetting and Contact Angles

“…Reasonable estimates for a number of parameters were used to calculate the two quantities above, which provided reasonable values for λ and h o . It should be mentioned that although Rey and Tusuji have reported a variety of flow behavior with changes in anchoring in their computations, Shmeliova et al do not see much change in their experimental work. It is possible that the flow in the liquid film has to be thin for the anchoring to have an effect, as seen near the contact line.…”

Geometry-structure models for liquid crystal interfaces, drops and membranes: wrinkling, shape selection and dissipative shape evolution

“…Biological liquid crystals [34][35][36][37][38][39][40][41][42] include biological solid analogues such as Bouligand plywoods, 43,44 in vitro solutions such as acidic collagen solutions 45,46 and colloidal dispersions, 47 and in vivo secretions such as silk. 48 Theoretical studies about liquid crystalline self-assembly, [49][50][51][52] rheology, 53,54 flows, [55][56][57][58][59] topological defects, [60][61][62] continuum mechanics framework [63][64][65][66][67] and applications [68][69][70] have been intensively studied. 71,72 Rich functionalities are associated with surface patterns, such as wrinkling and corrugations as well as with the shapes of drops, tactoids, and closed membranes.…”

Cluster-associated model of the viscosity of the lead-tin alloy in comparison with the Frenkel-Andrade model

“…Анализ литературных источников [1][2][3][4][5][6][7][8][9][10][11] показал, что природа вязкого состояния недостаточно изучена, имеется разрозненность температурных зависимостей вязкости, фрагментарность и узость экспериментального определения этой характеристики и невозможность ее отображения в полном температурном диапазоне жидкого состояния, особенно для расплавов. Этим и определяется актуальность данных исследований, в частности сложных соединений.…”