Ionically charged topological defects in nematic fluids

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

Abstract

Charge profiles in liquid electrolytes are of crucial importance for applications such as supercapacitors, fuel cells, batteries, or the self-assembly of particles in colloidal or biological settings. However, creating localized (screened) charge profiles in the bulk of such electrolytes generally requires the presence of surfaces—for example, provided by colloidal particles or outer surfaces of the material—which poses a fundamental constraint on the material design. Here, we show that topological defects in nematic electrolytes can perform as regions for local charge separation, forming charged defect cores and, in some geometries, even electric multilayers, as opposed to the electric double layers found in isotropic electrolytes. Using a Landau-de Gennes-Poisson-Boltzmann theoretical framework, we show that ions highly effectively couple with the topological defect cores via ion solvability and with the local director-field distortions of the defects via flexoelectricity. The defect charging is shown for different defect types—lines, points, and walls—using geometries of ionically screened flat isotropic-nematic interfaces, radial hedgehog point defects, and half-integer wedge disclinations in the bulk and as stabilized by (charged) colloidal particles. More generally, our findings are relevant for possible applications where topological defects act as diffuse ionic capacitors or as ionic charge carriers.

Keywords

fizika kondenzirane snovi;nematski tekoči kristali;topološki defekti;elektrostatska dvojna plast;condensed matter physics;nematic liquid crystals;topological defects;electrostatic double layer;

Data

Language:	English
Year of publishing:	2021
Typology:	1.01 - Original Scientific Article
Organization:	UL FMF - Faculty of Mathematics and Physics
UDC:	538.9
COBISS:	55545603
ISSN:	2160-3308
Views:	514
Downloads:	230
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	Slovenian
Secondary keywords:	fizika kondenzirane snovi;nematski tekoči kristali;topološki defekti;elektrostatska dvojna plast;
Type (COBISS):	Article
Pages:	str. 011054-1-011054-17
Volume:	ǂVol. ǂ11
Issue:	ǂiss. ǂ1
Chronology:	2021
DOI:	10.1103/PhysRevX.11.011054
ID:	12657602