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Liquid crytals (LCs) are probably the most exciting state of matter. They attract scientists across disciplines such as chemistry, physics, materials science, and engineering—theorists and experimentalists alike. These days, you can buy quite affordable LCD TV sets around the corner, but that's just one of the many things liquid crystals can do. The selection of recent research articles presented below illustrates the broad interest in this area of soft condensed matter.
Find all articles on liquid crystals in Wiley Online Library...
See the International Liquid Crystal Society's website.
Delphine Coursault, Johan Grand, Bruno Zappone, Habib Ayeb, Georges Lévi, Nordin Félidj, Emmanuelle Lacaze
Linear Self-Assembly of Nanoparticles Within Liquid Crystal Defect Arrays [Communication]
In the presence of oriented smectic liquid crystal defects, hybrid systems of nanoparticles/liquid crystals form straight chains of nanoparticles of length longer than tens of micrometers and width equal to one single nanoparticle. The interparticle distance in a chain can be varied between a few micrometers and 1.5 nm, highlighting the control of optical absorption by light polarization monitored by gold nanoparticle concentration.
Mahima Goel, Manickam Jayakannan
C-H/π-Interaction-Guided Self-Assembly in π-Conjugated Oligomers [Full Paper]
Weak-force-driven self-assembly: CH/π hydrogen-bonding-driven diverse molecular self-assembly in π-conjugated molecules is reported (see figure). The self-organization of π-conjugated mesogens in three-dimensional crystal lattices is proved to be vital for tuning the thermotropic liquid-crystalline phases and their emission colour.
Chem. Eur. J., February 1, 2012, DOI: 10.1002/chem.201102670
Martin Butschies, Wolfgang Frey, Sabine Laschat
Designer Ionic Liquid Crystals Based on Congruently Shaped Guanidinium Sulfonates [Full Paper]
Tuning mesophase stability: Guanidinium sulfonate ion pairs with congruently shaped anions and cations with short alkyl chains R (see scheme) have favourable mesogenic properties with respect to mesophase stability in comparison with their guanidinium counterparts with spherical iodide anions.
Chem. Eur. J., February 1, 2012, DOI: 10.1002/chem.201101925
Abdelhak Belaissaoui, Isabel M. Saez, Stephen J. Cowling, Xiangbing Zeng, John W. Goodby
Supermolecular Chiral Mesogenic Tripedes [Full Paper]
The mesogenic behaviours of six tripedes based around two stereogenic cores were investigated. The major result concerns the transfer of the chiral information from the central core to the periphery and the effect on mesomorphic properties. These properties were fine-tuned by incorporating functional moieties within the chiral core without modifying its stereogenicity.
Verner K. Thorsmølle, Daniel Topgaard, Jan C. Brauer, Shaik M. Zakeeruddin, Björn Lindman, Michael Grätzel, Jacques-E. Moser
Conduction Through Viscoelastic Phase in a Redox-Active Ionic Liquid at Reduced Temperatures [Communication]
The phase diagram of the redox active ionic liquid 1-methyl-3-propylimidazolium iodide (PMII) is examined as a function of temperature and iodine concentration. Beyond a threshold concentration of 3.9 M, the formation of higher polyiodides gives rise to a viscoelastic phase upon cooling. Despite of the very high viscosity of such polyiodide-containing PMII melts a strikingly high conductivity is maintained through Grotthuss-type bond exchange and ionic conduction.
Dong Chen, Michael-Scott Heberling, Michi Nakata, Loren E. Hough, Joseph E. Maclennan, Matthew A. Glaser, Eva Korblova, David M. Walba, Junji Watanabe, Noel A. Clark
Structure of the B4 Liquid Crystal Phase near a Glass Surface [Article]
Nanofilaments: The B4 liquid crystal phase of bent-core molecules is one of the most complex hierarchical self-assemblies in soft materials. Near the glass substrate, the formation of twisted nanofilaments is suppressed and the chiral smectic layers self-assemble into parabolic focal conic arrays. Further from the substrate, homochiral helical nanofilaments nucleate smoothly on top of the underlying layers (see picture).
Zeinab Serhan, Andrea Borgogno, Isabelle Billault, Alberta Ferrarini, Philippe Lesot
Analysis of NAD 2D-NMR Spectra of Saturated Fatty Acids in Polypeptide Aligning Media by Experimental and Modeling Approaches [Full Paper]
Fatty acids—oriented but not slimmed: The analysis C14 to C18 fatty acids by using natural abundance deuterium 2D-NMR in polypeptide liquid crystals has been achieved. Almost all 2H sites of solutes could be resolved. Assignment of quadrupolar doublets was achieved by an experimental strategy combining various sources of information, and was confirmed by a theoretical model predicting the anisotropic distribution of fatty acids in the polypeptide solution (see figure).
Sebastian Reimann, Muhammad Sharif, Martin Hein, Alexander Villinger, Kai Wittler, Ralf Ludwig, Peter Langer
Site-Selective Sonogashira Reactions of 1,4-Dibromo-2-fluorobenzene – Synthesis and Properties of Fluorinated Alkynylbenzenes [Full Paper]
Several alkynyl-substituted fluorinated benzene derivatives have been prepared by cross-coupling reactions of 1,4-dibromo-2-fluorobenzene. The reactions proceed with very good site-selectivity in favor of the 4-position. The regioselectivity is explained by the results of DFT calculations. Thefluorescence properties of the products have been studied. In addition, the mesomorphic properties have been investigated.
Yasuhiro Ishida, Hiroaki Sakata, Ammathnadu S. Achalkumar, Kuniyo Yamada, Yuki Matsuoka, Nobutaka Iwahashi, Sayaka Amano, Kazuhiko Saigo
Guest-Responsive Covalent Frameworks by the Cross-Linking of Liquid-Crystalline Salts: Tuning of Lattice Flexibility by the Design of Polymerizable Units [Full Paper]
Solid-state hosts with covalent frameworks were obtained by the in situ cross-linking of liquid-crystalline salts composed of a polymerizable carboxylic acid and an enantiopure amino alcohol (see scheme). In response to the desorption and adsorption of the amino alcohol unit, the cross-linked polymers reversibly changed their structures. The dynamic properties of the cross-linked polymers could be tuned by the choice of cross-linking units.
Haifeng Yu, Takaomi Kobayashi, Huai Yang
Liquid-Crystalline Ordering Helps Block Copolymer Self-Assembly [Research News]
Haifeng Yu, Tomiki Ikeda
Photocontrollable Liquid-Crystalline Actuators [Review]
Coupling photochromic molecules with liquid crystalline (LC) materials enables one to reversibly photocontrol unique LC features such as phase transition, photoalignment, and molecular cooperative motion. LC elastomers show photomechanical and photomobile properties, directly converting light energy into mechanical energy. In well-defined LC block copolymers, regular patternings of nanostructures in macroscopic scales are fabricated by photo-manipulation of LC actuators.
Michael Draper, Isabel M. Saez, Stephen J. Cowling, Pratibha Gai, Benoït Heinrich, Bertrand Donnio, Daniel Guillon, John W. Goodby
Self-Assembly and Shape Morphology of Liquid Crystalline Gold Metamaterials [Feature Article]
Gold nanoparticles offer the possibility of creating novel metamaterials, and additionally, liquid crystals offer the possibility of creating self-organizing and self-assembling materials. These two concepts are combined in an attempt to create self-assembling materials that possess unique optical properties.
Mary O’Neill, Stephen M. Kelly
Ordered Materials for Organic Electronics and Photonics [Progress Report]
Materials with ordered liquid crystalline phases are increasingly found in a wide range of electronic and photonic devices including transistors, photovoltaics, OLEDs and lasers. We present a critical report of semiconducting/light emitting, liquid crystalline materials with emphasis on discussing the various trade-offs involved in ensuring that the inherent order of the phase is exploited to improve device performance.
© Wiley-VCH 2011.
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