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Updated: Aug 7, 2026

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
Destabilizing effect of a surface electric field generated by ionic adsorption on the molecular orientation of
H A Pereira1, F Batalioto, L R Evangelistaa
1Departamento de Física, Universidade Estadual de Maringá, Avenida Colombo 5790, 87020-900 Maringá, Paraná, Brazil.
Abstract:
The destabilizing effect of a surface electric field, produced by selective ionic adsorption, on the molecular orientation of a nematic-liquid-crystal sample is analyzed for a cell in the shape of a slab of thickness d. The electric-field distribution considered in the analysis is the one obtained in the limit in which essentially all the positive ions are adsorbed. Because of the coupling of this surface field with the nematic director, the surface anchoring energy depends on the thickness of the sample as well as on the adsorption energy characterizing the surfaces. A relation connecting the threshold field for the destabilization of the homeotropic pattern to the adsorption energy and to the thickness of the sample is established in closed form, after solving a set of two coupled non-linear equations determining the electric-field distribution across the sample. It is shown that the values of surface electric field generated by adsorbed ions that can lead to a destabilization of the homeotropic alignment can be attained by real samples.
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