Charge-, salt- and flexoelectricity-driven anchoring effects in nematics

Everts, Jeffrey Christopher (author), Ravnik, Miha (author)

We investigate the effects of electric double layers and flexoelectricity on the surface anchoring in general nematic fluids. Within a simplified model, we demonstrate for a nematic electrolyte how the surface anchoring strength can be affected by the surface charge, bulk ion concentration and/or flexoelectricity, effectively changing not only the magnitude of the anchoring but also the anchoring type, such as from planar to tilted. In particular, we envisage possible tuning of the anchoring strength by the salt concentration in the regime where sufficiently strong electrostatic anchoring, as controlled by the (screened) surface charge, can compete with the non-electrostatic anchoring. This effect is driven by the competing energetic-torque couplings between nematic director and the emergent electrostatic potential, due to surface charge, ions and flexoelectricity. Our findings propose a way of influencing surface anchoring by using electrostatic effects, which could be used in various aspects, including in the self-assembly of colloidal particles in nematic fluids, optical and display patterns, and sensing.

• Language: English
• Keywords: nematic fluids, electrostatics, electric double layer, flexoelectricity, surface anchoring
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics
• Publication status: Published
• Publication version: Author Accepted Manuscript
• Year: 2021
• Number of pages: Str. 423-435
• Numbering: Vol. 48, iss. 3
• PID: 20.500.12556/RUL-117365
• UDC: 544.6/.7
• ISSN on article: 0267-8292
• DOI: 10.1080/02678292.2020.1786176
• COBISS.SI-ID: 21920003
• Publication date in RUL: 08.07.2020

Record is a part of a journal

• Title: Liquid crystals
• Shortened title: Liq. cryst.
• Publisher: Taylor & Francis
• ISSN: 0267-8292
• COBISS.SI-ID: 1690628

Secondary language

• Language: Slovenian
• Keywords: nematske tekočine, elektrostatika, električna dvojna plast, fleksoelektričnost, površinsko sidranje