Download or read book Non symmetric liquid crystal dimers written by Andrew Blatch and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Liquid Crystal Dimers written by Santanu Kumar Pal and published by Cambridge University Press. This book was released on 2017-03-06 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Discusses the design principles, synthesis and thermal behaviour of all types of LC dimers"--
Download or read book Liquid Crystals II written by D.M.P. Mingos and published by Springer. This book was released on 2003-09-04 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: The liquid crystalline state may be identified as a distinct and unique state of matter which is characterised by properties which resembles those of both solids and liquids. It was first recognised in the middle of the last century through the study of nerve myelin and derivatives of cholesterol. The research in the area really gathered momentum, however, when as a result of the pioneering work of Gray in the early 1970's organic compounds showing liquid crystalline properties were shown to be suitable to form the basis of display devices in the electronic products. The study of liquid crystals is truly multidisciplinary and has attached the attention of physicists, biologists, chemists, mathematicians and electronics engineers. It is therefore impossible to cover all these aspects fully in two small volumes and therefore it was decided in view of the overall title of the series to concentrate on the structural and bonding aspects of the subject. The Chapters presented in these two volumes have been organised to cover the following fundamental aspects of the subject. The calculation of the structures of liquid crystals, an account of their dynamical properties and a discussion of computer simulations of liquid crystalline phases formed by Gay Berne mesogens. The relationships between molecular conformation and packing are analysed in some detail. The crystal structures of liquid crystal mesogens and the importance of their X ray scattering properties for characterisational purposes are discussed.
Download or read book Unconventional Liquid Crystals and Their Applications written by Wei Lee and published by Walter de Gruyter GmbH & Co KG. This book was released on 2021-07-19 with total page 738 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work focuses on recent developments of the rapidly evolving field of Non-conventional Liquid Crystals. After a concise introduction it discusses the most promising research such as biosensing, elastomers, polymer films , photoresponsive properties and energy harvesting. Besides future applications it discusses as well potential frontiers in LC science and technology.
Download or read book Bent Shaped Liquid Crystals written by Hideo Takezoe and published by CRC Press. This book was released on 2017-07-20 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bent-Shaped Liquid Crystals: Structures and Physical Properties provides insight into the latest developments in the research on liquid crystals formed by bent-shaped mesogens. After a historical introduction, the expert authors discuss different kinds of mesophase structures formed by bent-shaped molecules. This book devotes the majority of its pages to physical properties such as polar switching, optics and non-linear optics, and behavior in restricted geometries. However, as chemistry is often highly relevant to the emergence of new phases, particularly with reflection symmetry breaking, it also involves a broad spectrum of interesting chemistry viewpoints.
Download or read book Liquid Crystals written by Carsten Tschierske and published by Springer Science & Business Media. This book was released on 2012-01-24 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluorinated Liquid Crystals: Design of Soft Nanostructures and Increased Complexity of Self-Assembly by Perfluorinated Segments, by Carsten Tschierske Liquid Crystalline Crown Ethers, by Martin Kaller and Sabine Laschat Star-Shaped Mesogens – Hekates: The Most Basic Star Structure with Three Branches, by Matthias Lehmann DNA-Based Soft Phases, by Tommaso Bellini, Roberto Cerbino and Giuliano Zanchetta Polar and Apolar Columnar Phases Made of Bent-Core Mesogens, by N. Vaupotič, D. Pociecha and E. Gorecka Spontaneous Achiral Symmetry Breaking in Liquid Crystalline Phases, by H. Takezoe Nanoparticles in Liquid Crystals and Liquid Crystalline Nanoparticles, by Oana Stamatoiu, Javad Mirzaei, Xiang Feng and Torsten Hegmann Stimuli-Responsive Photoluminescent Liquid Crystals, by Shogo Yamane, Kana Tanabe, Yoshimitsu Sagara and Takashi Kato
Download or read book Chemistry of Discotic Liquid Crystals written by Sandeep Kumar and published by CRC Press. This book was released on 2016-04-19 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: The self-contained properties of discotic liquid crystals (DLCs) render them powerful functional materials for many semiconducting device applications and models for energy and charge migration in self-organized dynamic functional soft materials. The past three decades have seen tremendous interest in this area, fueled primarily by the possibility
Download or read book Design of Liquid Crystal Dimers and Trimers written by Maria Gabriela Tamba and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermotropic liquid crystals; bent-core mesogens; calamitic mesogens; oligomers; chirality; anti(ferroelectricity); polar mesophases; dark-conglomerate-phases; electro-optic switching; X-ray scattering
Download or read book Physical Properties of Liquid Crystal Dimers written by and published by . This book was released on 2012 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Anisotropic Properties of Liquid Crystal Dimers Consisting of Ester and Disulphide Bridging Groups written by Faridah Osman and published by . This book was released on 2013 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Liquid Crystals from Linked Discs written by Oliver Calderon and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the burgeoning field of organic semiconducting devices, molecules able to self-assemble into columnar liquid crystal phases are being investigated due to the unique directional conductivity of their structures. Knowledge of how molecule-level structural features impact the formation of the larger columnar assemblies is of considerable interest. Studies of liquid crystal phases are already informally divided into shape categories, arising from molecules that are either rod-shaped or disc-shaped. Our interest lay in the middle ground where the basic disc-shape is elongated to a more elliptical one. In pursuit of this goal, a series of rigid dimers were prepared by condensation of 3,3'-diaminobenzidine with various 2,3,6,7-tetralkyloxyphenanthrene-9,10-diones. Investigation revealed that these dimers assemble into a number of unusual phases, including nematic and columnar oblique mesophases. In addition, a series of monomeric amide derivatives were synthesized by amidation of 2,3,6,7-Tetrakis(heptyloxy)dibenzo[a, c]phenazine-11-carboxylic acid. These molecules were found to spontaneously align in a homeotropic manner. They also supercooled into persistent glassy phases that preserved their alignment.
Download or read book Conformational Dynamics and Self assembly of Discotic Dimers written by Carson Zellman and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Disc-shaped (discotic) liquid crystals (DLCs) predominantly form columnar phases, which have been utilized as organic semiconductors in opto-electronic devices; yet these materials have been hampered by their thermal stability, often exhibiting liquid crystallinity at high and narrow temperature ranges. Discotic dimers, where two discotic moieties are tethered, overcome this hinderance through their unique ability to supercool and retain liquid crystallinity at device operating temperatures; however, the flexible linker that helps promote supercooling also makes dimers difficult to study - the dimer can adopt multiple conformations in equilibrium, including folded and extended structures. The effect these conformational dynamics have on the liquid crystal (LC) properties is still poorly understood. A series of dibenzo[a,c]phenazine diesters with subtle changes to the linking group were prepared and their conformational dynamics and self-assembly were probed. We observed a strong sensitivity between linker stereochemistry and supramolecular self-assembly. For a pair of 2,3-butyl dimers, the meso isomer, which extends more than its diastereomer, formed a substantially more thermally stable and ordered columnar phase. The different properties arose from differences in their conformational equilibria, as self-assembly from extended shapes was shown to stabilize and increase the order of the columnar hexagonal phase. In addition to the conformational equilibrium, the geometries had a significant impact on the supramolecular self-assembly. For a pair of 1,2-cyclohexyl diastereomers, one isomer was liquid crystalline, and the other was amorphous. The disparate phase behaviour stemmed from their unfolded shapes, as the mesogenic isomer formed an extended and fairly planar structure while the amorphous isomer could only adopt non-planar unfolded geometries. We also investigated the effect adjacent groups have on the conformational dynamics and self-assembly, as the majority of discotic dimers contain an ether group ortho to the linker. In discotic monomers, adjacent ether groups broadened and lowered the columnar thermal range through depression of the melting temperature and elevation of the clearing temperature. In dimers, the additional ether group deterred folding. While we anticipated this would enhance the columnar thermal stability, the opposite was observed. We discovered the adjacent ether group destabilizes the columnar phase from extended geometries. The ether group likely perturbs planarity in the columnar hexagonal array to some extent, highlighting again the importance of planarity for columnar self-assembly from extended shapes. Finally, the lessons learned from discotic dimer self-assembly was utilized to design discotic nematic materials. To promote the rarely observed phase, discotic dimers with a short direct ester bridge and an adjacent ether group were synthesized. The key was the non-planar, extended geometry, which allowed promotion of nematic ordering over columnar hexagonal assembly.
Download or read book Asymmetric Fluorinated Dimers for Dual Frequency Liquid Crystal Mixtures written by David Allan and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Self Assembly of Homomeric Dipeptides Bisamides and Dimers written by Govindaswamy Shanker and published by LAP Lambert Academic Publishing. This book was released on 2015-08-03 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The spontaneous interaction of molecules/molecular entities featuring distinct properties through non-covalent interactions lead to the formation of molecular assemblies called 'superstructures'. The microscopic and macroscopic properties of such superstructures generally depend on the nature of the constituent molecules. For example, shape anisometric molecules usually composed of rigid and flexible moieties tend to self-assemble and form liquid crystal (LC) phases (mesophases).In this book, Chapter I describes about LCs and applications. Chapter II comprises with the synthesis and characterization of self-assembly homomeric dipeptides and bisamides derived from naturally occurring amino acids. They are formed by covalently linking phenyl rings substituted with alkoxy tail/s through a self-complementing spacer derived from amino acid residue/s (L/D-alanine, L/D-leucine, L/D-valine). The nature of the constituent amino acid residue/s, influence their LC behavior, in particular polar columnar phase involving hydrogen (H) bonding. Chapter III describes the synthesis and thermal behavior of non-symmetric dimers and Chapter IV about bidentate ligands and their Cu/Pd(II) metal complexes
Download or read book Syntheses Characterisation and Mesophase Investigation of a New Class of Hydrazine Based Liquid Crystal Dimers written by Umairah Abd Rani and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure property Relationships in Discotic and Elliptical Mesogens written by Christine Lavigueur and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid crystals are a promising class of materials used in or proposed for a wide variety of applications, ranging from liquid crystal displays and light emitting diodes to photovoltaic devices and field effect transistors. Many molecular level structural features are known to influence the properties of liquid crystalline materials, but the outcome of this influence is often poorly understood. A strategy was developed for the formation of elliptical mesogens having a shape intermediate between the well-known rods and discs by rigidly linking two disc-shaped molecules. These studies have led to investigations of structure-property relationships in discotic and elliptical mesogens, including not only the effect of shape and overall symmetry, but also the influence of the presence and position of a nitrogen atom in the core, the location of functional groups, and the length of alkoxy chains. Disc-shaped molecules were assembled through the condensation of 2,3,6,7-tetrakis(alkoxy)phenanthrene-9,10-diones with diamines, allowing the preparation of mesogens bearing a wide variety of functional groups. A simple and inexpensive capillary furnace was developed to improve and facilitate the study of liquid crystalline materials using variable temperature X-ray diffraction. Two of the systems studied appear to form elliptical mesogens through hydrogen bonding, and it was found that elongation of the mesogen shape from a disc to an ellipse promotes the formation of nematic and rectangular columnar phases, as well as supercooling of the columnar phases resulting in columnar ordering at room temperature. The formation of non-elliptical dimers of discs was attempted in two different ways, but in both cases, no rigidly-linked dimers were observed in the mesophases. However, one of these systems was found to result in solution self-assembly and in hexagonal columnar phases stable over remarkably broad temperature ranges, which appears to be the result of hydrogen bonding within the columns.
Download or read book Linear and H shaped Chiral Dimers for Applications in Photonic Liquid Crystals written by and published by . This book was released on 2010 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
