Structural, Optical and Hydrodynamic Properties of Liquid Crystals

A special issue of Symmetry (ISSN 2073-8994). This special issue belongs to the section "Chemistry: Symmetry/Asymmetry".

Deadline for manuscript submissions: closed (31 October 2023) | Viewed by 5235

Special Issue Editor


E-Mail Website
Guest Editor
Saint Petersburg Institute for Machine Sciences, The Russian Academy of Sciences, 199178 Saint Petersburg, Russia
Interests: liquid crystals; nanofluidics; optics of liquid crystals; hydrodynamics of liquid crystals; free-standing smectic films
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Liquid crystal (LC) materials are called curious, soft matter, but their influence on modern technologies is very impressive. The manipulation of tiny amounts of molecular liquids, such as LCs, has become a paradigm in various fields of applied chemistry, physics and biotechnology. The further development of LC applications requires the complex study of natural anisotropic soft materials through multicoupling interactions of internal fields initiated by external forces. Consisting of anisotropic molecules, LC materials interact with external fields and confined surfaces, which strongly influence their structure, optical and hydrodynamic properties. The problem of the externally driven manipulation of LC materials, especially by an externally applied electric field, has led to the development of an increasing number of integrated, small-scale microdevices used in displays, as well as LC sensors (LCSs) and LC actuators (LCAs). These LC materials have initiated a technological revolution in the display field. Widely used flat-panel twisted nematic (TN) displays consist of an LC film sandwiched between two plastic surfaces on a micrometer scale, through which voltage can be applied independently to each pixel of the liquid crystal display (LCD). This applied electric field can change the molecular configuration of the LC layer and thus change the optical characteristics of the LCD display. The advantages of TN include its low voltage requirements and ability to operate over a large wavelength range. With the development of the LC display market, a question concerning the further prospective applications of LC materials is raised. Perhaps there is no direction for LC materials more suitable than their application in LCSs and LCAs. They have various advantages compared other types of microsensors and microactuators, including their simple structure, high shape adaptability, easy downsizing and low driving voltages, due to their extreme sensitivity to external disturbances, and they can thus be used in the construction of stimuli-responsive devices.

We are inviting researchers to submit articles that discuss the structural, optical and hydrodynamic properties of liquid crystal compounds, as well as the applications of these compounds, from theoretical calculations to the study of materials and experimental viewing.

Prof. Dr. Alexandre Zakharov
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Symmetry is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • liquid crystals
  • viscoelastic properties of liquid crystals
  • optics of liquid crystals
  • microfluidics

Related Special Issues

Published Papers (3 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

36 pages, 6716 KiB  
Article
Fluctuating Flexoelectric Membranes in Asymmetric Viscoelastic Media: Power Spectrum through Mechanical Network and Transfer Function Models
by Edtson Emilio Herrera-Valencia and Alejandro D. Rey
Symmetry 2023, 15(5), 1004; https://doi.org/10.3390/sym15051004 - 29 Apr 2023
Cited by 3 | Viewed by 946
Abstract
Flexoelectric liquid crystalline membranes immersed in asymmetric viscoelastic media is a material system model with physiological applications such as outer hair cells (OHCs), where membrane oscillations generate bulk flow. Motivated by this physiological process, here we extend our previous work by characterizing the [...] Read more.
Flexoelectric liquid crystalline membranes immersed in asymmetric viscoelastic media is a material system model with physiological applications such as outer hair cells (OHCs), where membrane oscillations generate bulk flow. Motivated by this physiological process, here we extend our previous work by characterizing the force transmission output of our model in addition to viscoelastic fluid flow, since solid–fluid interactions are an essential feature of confined physiological flow and flow in immersed elastic structures. In this work, the rigidity of the confinement results in a passive force reception, while more complete solid–fluid interactions will be considered in the future. A significant contribution of this work is a new asymmetry linear viscoelastic electro-rheological model and the obtained implicit relation between force transmission and flow generation and how this relation is modulated by electric field frequency and the material properties of the device. Maximal force and flow are found at resonant frequencies of asymmetry viscoelastic bulk phases, flexoelectric and dispersion mechanisms through the elastic and Womersley numbers. Full article
(This article belongs to the Special Issue Structural, Optical and Hydrodynamic Properties of Liquid Crystals)
Show Figures

Graphical abstract

27 pages, 5839 KiB  
Article
Liquid Crystal-Based Geometric Phase-Enhanced Platform for Polarization and Wavefront Analysis Techniques with the Short-TeraHertz FEL Oscillator TerRa@BriXSinO
by Bruno Piccirillo, Domenico Paparo, Andrea Rubano, Antonello Andreone, Marcello Rossetti Conti, Dario Giove, Verónica Vicuña-Hernández, Can Koral, Maria Rosaria Masullo, Giovanni Mettivier, Michele Opromolla, Gianpaolo Papari, Andrea Passarelli, Giuseppe Pesce, Vittoria Petrillo, Ester Piedipalumbo, Marcel Ruijter, Paolo Russo and Luca Serafini
Symmetry 2023, 15(1), 103; https://doi.org/10.3390/sym15010103 - 30 Dec 2022
Cited by 4 | Viewed by 1980
Abstract
In this work, we propose to design a liquid crystal–based modular and extendable platform of cutting-edge optical technologies for studying materials based on the analysis of polarization and wavefront of light in the wavelength range of 10–50 μm, which is considered to work [...] Read more.
In this work, we propose to design a liquid crystal–based modular and extendable platform of cutting-edge optical technologies for studying materials based on the analysis of polarization and wavefront of light in the wavelength range of 10–50 μm, which is considered to work even in the longer wavelengths range. This platform will be driven by the future THz-FEL source TerRa@BriXSinO that produces high power radiation in THz-range from 6 THz up to 30 THz (Mid-/Far-IR). The lack of optical infrastructures in this range has been tackled by fabricating liquid crystal–based geometric phase components that have been specifically designed for this purpose. This is in order to optimally exploit all the source’s potential for maximum accuracy and efficiency in determining polarization- and wavefront-sensitive properties of materials. We present an overview of a few experiments for characterizing bulk inhomogeneities, dielectric anisotropy, surface roughness, cracks, impact damages, and stress and strain effects with special emphasis on non-destructive tests on composite structures. The tools for wavefront shaping developed within our platform will be exploited to add a further degree of freedom, i.e., orbital angular momentum, to nonlinear optics techniques, such as Terahertz Hyper-Raman spectroscopy, for investigating chiral agents’ properties. Full article
(This article belongs to the Special Issue Structural, Optical and Hydrodynamic Properties of Liquid Crystals)
Show Figures

Figure 1

14 pages, 13055 KiB  
Article
Optical Imaging and Analytical Design of Localized Topological Structures in Chiral Liquid Crystals
by Igor Lobanov, Elena Aksenova, Tetiana Orlova, Darina Darmoroz, Valery Uzdin and Alexei D. Kiselev
Symmetry 2022, 14(12), 2476; https://doi.org/10.3390/sym14122476 - 22 Nov 2022
Viewed by 1587
Abstract
We combine numerical modeling and analytical design techniques to study several of the most common localized topological structures in frustrated chiral nematic liquid crystal cells. An energy minimization procedure is applied to the lattice model to simulate the director field distributions. These distributions [...] Read more.
We combine numerical modeling and analytical design techniques to study several of the most common localized topological structures in frustrated chiral nematic liquid crystal cells. An energy minimization procedure is applied to the lattice model to simulate the director field distributions. These distributions are also approximated using the suitably designed analytical ansatz. We present both simulated and approximated results for optical polarizing microscopy textures and different visualizations of director field structure such as distributions of the azimuthal director angle and isolines for the normal component of the director in coordinate planes. The ansatz correctly mimicked the geometry and optical properties of the solitonic structures under consideration. Full article
(This article belongs to the Special Issue Structural, Optical and Hydrodynamic Properties of Liquid Crystals)
Show Figures

Figure 1

Back to TopTop