Nematic Films at Chemically Structured Surfaces
Abstract
We investigate theoretically the morphology of a thin nematic film adsorbed at flat substrate patterned by stripes with alternating aligning properties, normal and tangential respectively. We construct a simple "exactly-solvable" effective interfacial model where the liquid crystal distortions are accounted for via an effective interface potential. We find that chemically patterned substrates can strongly deform the nematic-air interface. The amplitude of this substrate-induced undulations increases with decreasing average film thickness and with increasing surface pattern pitch. We find a regime where the interfacial deformation may be described in terms of a material-independent universal scaling function. Surprisingly, the predictions of the effective interfacial model agree semi-quantitatively with the results of the numerical solution of a full model based on the Landau-de Gennes theory coupled to a square-gradient phase field free energy functional for a two phase system.
Cite
@article{arxiv.1609.01637,
title = {Nematic Films at Chemically Structured Surfaces},
author = {Nuno M. Silvestre and Margarida M. Telo da Gama and Mykola Tasinkevych},
journal= {arXiv preprint arXiv:1609.01637},
year = {2017}
}