Next Article in Journal
Magnetron Sputtering for ZnO:Ga Scintillation Film Production and Its Application Research Status in Nuclear Detection
Previous Article in Journal
A Magnetic-Dependent Vibration Energy Harvester Based on the Tunable Point Defect in 2D Magneto-Elastic Phononic Crystals
Previous Article in Special Issue
Study of Liquid Crystals Showing Two Isotropic Phases by 1H NMR Diffusometry and 1H NMR Relaxometry
Article Menu
Issue 5 (May) cover image

Export Article

Open AccessReview

Peculiarities in the Director Reorientation and the NMR Spectra Evolution in a Nematic Liquid Crystals under the Effect of Crossed Electric and Magnetic Fields

1
Saint Petersburg Institute for Machine Sciences, The Russian Academy of Sciences, Saint Petersburg 199178, Russia
2
Poznan University of Economics and Business, Department of Mathematical Economics, Al. Niepodleglosci 10, 61-875 Poznan, Poland
*
Author to whom correspondence should be addressed.
Crystals 2019, 9(5), 262; https://doi.org/10.3390/cryst9050262
Received: 6 May 2019 / Revised: 14 May 2019 / Accepted: 15 May 2019 / Published: 20 May 2019
(This article belongs to the Special Issue Nuclear Magnetic Resonance of Liquid Crystals)
  |  
PDF [1389 KB, uploaded 28 May 2019]
  |  

Abstract

The illustrative description of the field-induced peculiarities of the director reorientation in the microsized nematic volumes under the effect of crossed magnetic B and electric E fields have been proposed. The most interesting feature of such configuration is that the nematic phase becomes unstable after applying the strong E . The theoretical analysis of the reorientational dynamics of the director field provides an evidence for the appearance of the spatially periodic patterns in response to applied large E directed at an angle α to B . The feature of this approach is that the periodic distortions arise spontaneously from a homogeneously aligned nematic sample that ultimately induces a faster response than in the uniform mode. The nonuniform rotational modes involve additional internal elastic distortions of the conservative nematic system and, as a result, these deformations decrease of the viscous contribution U vis to the total energy U of the nematic phase. In turn, that decreasing of U vis leads to decrease of the effective rotational viscosity coefficient γ eff ( α ) . That is, a lower value of γ eff ( α ) , which is less than one in the bulk nematic phase, gives the less relaxation time τ on ( α ) γ eff ( α ) , when α is bigger than the threshold value α th . The results obtained by Deuterium NMR spectroscopy confirm theoretically obtained dependencies of τ on ( α ) on α . View Full-Text
Keywords: liquid crystals; NMR; hydrodynamics of liquid crystals liquid crystals; NMR; hydrodynamics of liquid crystals
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Zakharov, A.V.; Sliwa, I. Peculiarities in the Director Reorientation and the NMR Spectra Evolution in a Nematic Liquid Crystals under the Effect of Crossed Electric and Magnetic Fields. Crystals 2019, 9, 262.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Crystals EISSN 2073-4352 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top