Special Issue "Liquid Crystalline Polymers"

Guest Editor
Dr. Patrick Keller
Institut Curie-Centre De Recherche, CNRS UMR 168, 26 rue d\'Ulm 75248 Paris Cedex 05, France
Website: http://umr168.curie.fr/en/research-groups/molecular-and-macromolecular-architecture-organized-fluids-and-interfaces/molecular-
E-Mail: patrick.keller@curie.fr
Interests: liquid crystalline polymers and elastomers; biomimetic responsive surfaces; self-assembly; amphiphilic block copolymers; actuators

Dear Colleagues,

Classically, liquid crystalline polymers (LCPs) have been divided in lyotropic LCPs and thermotropic LCPs. Over the years, we have noticed a marked shift in the development of new LCPs, based on new potential applications in domains like actuators, organic photovoltaic or renewable energy. Beside historical families of LCPs (main-chain, side-chain, side-on, combined), new macromolecular architectures have been explored like liquid crystalline elastomers, dendritic LCPs or block copolymers. This special issue aims to provide a channel to showcase the recent developments in liquid crystalline polymer domain: synthesis, characterization, physical properties and applications.

Dr. Patrick Keller
Guest Editor

Submission

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Polymers is an international peer-reviewed Open Access quarterly 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 500 CHF (Swiss Francs). English correction and/or formatting fees of 250 CHF (Swiss Francs) will be charged in certain cases for those articles accepted for publication that require extensive additional formatting and/or English corrections.

• main-chain LCP
• side-chain LCP
• jacketed LCP
• LC elastomer
• dendritic LCP
• actuator
• azo polymer
• smart materials

Type of Paper: Review
Title: Liquid Crystalline Cellulosic Films and Fibers
Authors: M.H. Godinho, J.P. Canejo and J.P. Borges
Affiliation: Departamento de Ciência dos Materiais, CENIMAT/I3N, Faculdade de Ciênciase Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal; E-Mail: mhg@fct.unl.pt
Abstract: This paper brings together recent advances in the field of liquid crystalline cellulosic systems with an emphasis on their chiral nematic helical organization which are responsible for the remarkable optical properties observed for solid-state films and fibers. By comparing different preparation and characterization techniques general structure-properties, for fibers and films prepared from Cellulose Liquid Crystal systems, are obtained. In the last part, how these cellulosic materials can be tuned into usable devices using diverse interdisciplinary subjects is described.

Type of Paper: Review
Title: Carbon-Based Liquid Crystalline Polymer Nanocomposites
Authors: Henry K.F. Cheng, Nanda G. Sahoo *, Lin Li, and Siew H. Chan
Affiliation: School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore; E-Mail: ngsahoo@ntu.edu.sg; Tel.: +65-6790 5336
Abstract: Liquid crystalline Polymers (LCPs) are of aromatic polyester polymers. Because of these extraordinary properties, such as high thermal stability, flame retardant, high chemical resistance and high mechanical strength, LCPs has recently gained more attention and they are useful for many applications which require chemical inertness and high strength. Due to the recent advances in the nanotechnology, LCPs are usually compounded with particle fillers to form particulate composites to enhance their properties such as barrier properties, electrical properties, mechanical properties and thermal properties. Therefore, the LCP nanocomposites are a new class of materials with high performance. Carbon-based nanofiller such as carbon black (CB), carbon nanotube (CNT), Graphene and Graphene oxide, ceramic-based nanoclay such as layered silicates, montmorillonite nanoclay (MMT) and organically modified hydrophobic nanoclay (OMT) and metal-based nanofiller such as Titanium oxide (TiO₂) and nanosilver particles are the most common nanofillers used for the LCP matrices. The biggest issues in the preparation of LCP nanocomposites are inherent in the dispersion of nanofillers into the LCP matrix, the alignment and control of the nanofillers in the LCP matrix and the load-transfer between the LCP matrix and the nanofillers. Therefore, this paper reviews recent advances in the modification of LCP by nanofillers and the fabrication methods of LCP nanocomposites. In addition, discussions on mechanical, thermal, electrical and applications of LCPs and their nanocomposites are included.

Type of Paper: Review
Title: Nanoparticle-Liquid Crystalline Elastomer Composite
Authors:Yan Ji, Jean E. Marshall and Eugene M. Terentjev
Affiliation: Cavendish Laboratory, University of Cambridge, UK; E-Mail: emt1000@cam.ac.uk
Abstract: Liquid crystalline elastomers (LCEs) exhibit a number of remarkable physical effects, including a uniquely high-stroke reversible mechanical actuation triggered by external stimuli. Fundamentally, all such stimuli affect the degree of liquid crystalline order in the polymer chains crosslinked into an elastic network. Heat and the resulting thermal actuation act by promoting entropic disorder, same as the addition of solvents. Photo-isomerization is another mechanism of actuation, reducing the orientational order by diminishing the fraction of active mesogenic units, mostly studied for azobenzene derivatives.  Incorporating nanoparticles provides a new promising strategy to add functionality to LCEs and ultimately enhance their performance as sensors and actuators. The motivation is to provide better-controlled actuation stimuli, such as electric and magnetic fields, and broad-spectrum light, by selecting and configuring the appropriate nanoparticles in the LCE matrix. Here we give an overview of recent advances in this area with a focus on preparation and physical properties of photo-actuating nanocomposites.