Download or read book Order in Side chain Liquid Crystalline Diblock Copolymers written by Mitchell Anthamatten and published by . This book was released on 2001 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: The architecture of side-chain liquid crystalline diblock copolymers (SCLCBC's) involves order on two different but interdependent length scales. Through molecular-scale interactions, liquid crystalline moieties self-assemble into a variety of mesophases, and on a larger length scale, chemical differences between the two blocks can result in phase-segregated block copolymer microstructures. This combination of organizational tendencies offers experimentally and theoretically challenging problems that precede a wide array of applications. Using sequential anionic polymerization we synthesized a large number of well-defined SCLCBC's. These materials consist of an amorphous, polystyrene (PS) block and a methacrylate-based, LC block with side-chain mesogens that exhibit the Sc* mesophase. The samples' block copolymer morphology was evaluated using a combination of small angle X-ray scattering (SAXS) and electron microscopy, and thermal transitions were identified using polarized microscopy, calorimetry, and elevated temperature-SAXS. We found the formation of micron-sized domains and focal-conic superstructures to depend on the length of the PS block and the overall molecular weight. A morphological phase diagram was constructed based on LC volume fraction for molecular weights up to 40,000 Daltons. A broad lamellar regime was identified that extends to unusually low LC compositions. At intermediate LC fractions, just over 50 %-wt. LC, where one would expect lamellar morphologies for analogous coil-b-coil diblocks, morphologies are predominately lamellar, but exhibit perforated defects that connect the lamellar LC microdomains.

Download or read book Order and Interplay in Side Chain Liquid Crystalline Block Copolymers written by Paula T. Hammond and published by . This book was released on 1998 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Side Chain Liquid Crystal Polymers written by C.B. McArdle and published by Springer Science & Business Media. This book was released on 1990-04-30 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis of Side Chain Liquid Crystal Polymers by Living Ring Opening Metathesis Polymerization 4 Synthesis of Amorphous and Side Chain Liquid Crystal AB Block Copolymers written by and published by . This book was released on 1992 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diblock copolymers with well defined block length yield ordered phase separation. Morphology of the microphase separation is controllable by varying the weight ratio of the two blocks and the length of each block. If one of the blocks is a side chain liquid crystalline polymer (SCLCP), microphase separated systems with liquid crystalline microphases may be realized. Such systems are of fundamental as well as practical interest. The effect of size and type of the liquid crystalline microphase transition is one of the fundamental questions. This effect is recently investigated by the polymer system in which low molecular weight liquid crystals are dispersed. Different from the low molecular weight liquid crystals dispersed systems, the block copolymer can give several types of microdomains (lamellae, cylinders, or spheres).

Download or read book Molecular Design Synthesis Characterization and Processing of Liquid Crystalline Diblock Copolymers written by Guoping Mao and published by . This book was released on 1997 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Liquid Crystalline Order in Polymers written by Alexandre Blumstein and published by . This book was released on 1978 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid Crystalline Order in Polymers ...

Download or read book Liquid Crystal Polymers written by D. Coates and published by iSmithers Rapra Publishing. This book was released on 2000 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid crystal polymers (LCPs) have a wide range of uses, from strong engineering plastics to delicate gels for use in liquid crystal (LC) displays. For this reason, it is essential reading for materials scientists, engineers or technologists in industry, as well as research laboratories or academia. An additional indexed section containing several hundred abstracts from the Rapra Polymer Library database gives useful references for further reading.

Download or read book Synthesis and Characterization of Polystyrene Polysiloxane Side Chain Liquid Crystalline Diblock Copolymers written by Aaron J. Moment and published by . This book was released on 1998 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydrogen bonded Side Chain Liquid Crystalline Block Copolymer written by Chi-Yang Chao and published by . This book was released on 2003 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Liquid Crystalline Polymer Systems written by Avraam I. Isayev and published by . This book was released on 1996 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a comprehensive report on the synthesis, structure, rheology, processing, performance, and applications of liquid-crystalline polymers (LCPs). Discusses self-reinforced composites prepared through the melt processing of thermoplastics and thermotropic LCPs. Addresses current research efforts in making polymer-dispersed liquid crystals. Reports recent studies on the structure and phase behavior of mesophases. Describes the synthesis and properties of new main-chain and side-chain liquid-crystalline block copolymers, mesogen-jacketed LCPs, and liquid-crystalline thermosets.

Download or read book Liquid Crystalline Polymers written by Vijay Kumar Thakur and published by Springer. This book was released on 2015-11-16 with total page 627 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces anisotropic innovations in liquid crystalline polymers as well as new nanocomposite materials and testing techniques. The authors detail the newest discoveries of material properties, material types and phases, and material characterization. This interdisciplinary work creates valuable links that strengthen the approach to the evolving field of liquid crystalline polymers/ materials.

Download or read book Surface Morphology and Ordering in Side chain Liquid Crystal Diblock and Homopolymer Ultrathin Films written by Jung-Sheng Wu and published by . This book was released on 2002 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) Due to the wetting properties of the LC diblock copolymer, novel LC terraces were observed on the top surfaces corresponding to single smectic layer spacing. For diblock thin films, both blocks coexist at the air surfaces to form a mixed surface. Hybrid morphologies, consisting of both symmetrical and anti-symmetrical wettings, were noted for the lamellar morphology with film thicknesses between 0.5 and 1.5Lo. The surface properties are determined by LC orientation, which depends on the film thickness. Homeotropic anchoring of the smectic LC mesogens at the air interface was observed in both the homopolymer and the block copolymers, resulting in smectic terraces on the top surfaces of the films. In thicker films, when the influence of the substrate was decreased, the lamellar orientation was found to undergo a transition from parallel stacking near the substrate to perpendicular arrangement at the air surface. Effects of annealing and solvent exposure on the resulting thin-film behavior were also addressed.

Download or read book Molecular Engineering of Side chain Liquid Crystalline Brush Copolymers for Photonic and Nanoporous Membrane Applications written by and published by . This book was released on 2013 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Liquid Crystals Volume 3 written by Dietrich Demus and published by John Wiley & Sons. This book was released on 2008-08-29 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Handbook of Liquid Crystals is a unique compendium of knowledge on all aspects of liquid crystals. In over 2000 pages the Handbook provides detailed information on the basic principles of both low- and high-molecular weight materials, as well as the synthesis, characterization, modification, and applications (such as in computer displays or as structural materials) of all types of liquid crystals. The five editors of the Handbook are internationally renowned experts from both industry and academia and have drawn together over 70 leading figures in the field as authors. The three volumes of the Handbook are designed both to be used together or as stand-alone reference sources. Some users will require the whole set, others will be best served with one or two of the volumes. Volume 1 deals with the basic physical and chemical principles of liquid crystals, including structure-property relationships, nomenclature, phase behavior, characterization methods, and general synthesis and application strategies. As such this volume provides an excellent introduction to the field and a powerful learning and teaching tool for graduate students and above. Volume 2 concentrates on low-molecular weight materials, for example those typically used in display technology. A high quality survey of the literature is provided along with full details of molecular design strategies, phase characterization and control, and applications development. This volume is therefore by far the most detailed reference source on these industrially very important materials, ideally suited for professionals in the field. Volume 3 concentrates on high-molecular weight, or polymeric, liquid crystals, some of which are found in structural applications and others occur as natural products of living systems. A high-quality literature survey is complemented by full detail of the synthesis, processing, analysis, and applications of all important materials classes. This volume is the most comprehensive reference source on these materials, and is therefore ideally suited for professionals in the field.

Download or read book New Platform of Functional Liquid Crystalline Copolymers Synthesis Morphology Properties and Applications written by Dennis Ndaya and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The design of novel, complex and tailored macromolecules that present and combine unique features such as stimuli responsive, self-assembly and hierarchical architectures for applications in fields ranging from healthcare, energy to engineering, is one of the major challenges that need to be addressed by a polymer chemist. One way to address this, is through the combination of monomers with desirable roles such as stimuli responsive (liquid crystalline), solubility (polar or non-polar), targeting and payload release functional monomers. Polymerization techniques such as controlled and living polymerization enables the regulation of the connectivity and composition of these diverse monomers in the synthesis of block, random or gradient copolymers. Ring-opening metathesis polymerization (ROMP) majorly employed in most of the work in this thesis, is a robust living polymerization technique which delivers highly functionalized block or random copolymers that serves as nanotemplates (chapter 2), nanoporous membranes for separation (chapter 3), photonic crystals (chapter 4), shape memory devices (chapter 5), stimuli responsive optical materials (chapter 6), drug delivery vehicles and imaging agents (chapter 7). This dissertation focuses on a new platform for the synthesis of novel liquid crystalline polymers, their architectures, morphologies, properties and applications. The control of composition and polymer architecture is key in tuning the properties of copolymers for desired applications. Side-chain Liquid Crystalline Copolymers (SCLPs) which combines the basic properties of conventional polymers and liquid crystals, exhibit low viscosity, unique self-assembly as compared to linear copolymer counterparts due to reduced entanglements. Liquid crystalline block copolymers (LCBCPs) that comprises of brush-like semicrystalline or amorphous units and comblike side chain liquid crystalline moieties will be the center of focus in this dissertation in chapter 2, chapter 4 and part of chapter 7 due to formation of hierarchical structures as a result of two competing processes: (a) microphase separation by the copolymer superstructure and (b) orientational ordering by liquid crystalline mesogens. This supramolecular cooperative assembly leads into a well-defined interface with liquid crystalline ordering in the range of 3 -10nm nanostructures and block microphase segregation of 10- 100nm microstructures. The first part of this dissertation focuses on the understanding of liquid crystalline brush-like block copolymers self-assembly, phase behavior and morphology as a function of copolymer composition and molecular weight. Here, I describe the synthesis and characterization of norbornene functionalized side chain liquid crystalline brush-like block copolymers, where one of the blocks comprises of cyanobiphenyl liquid crystalline mesogens with twelve methylene spacer and the other semi-crystalline polylactide (PLA) side chains. The self-assembly of these LC block copolymers into liquid crystalline mesophase provides the handle for magnetic alignment of the formed LCBBCs superstructures (chapter 7). The displayed morphologies such as hexagonally packed PLA cylinders in the LC matrix is put into use in the creation of functional nanoporous membranes for water purification and heavy metal sequestering (chapter 3). The high molecular weight of this LCBBCs assemble into photonic crystals of large domain sizes with different optical properties (chapter 4). In the second part of the dissertation we explore harnessing of stimuli responsive functional cholesteric random copolymers for multifunctional elastomeric platform and optical materials that cover a wide range from visible to near infrared (NIR) of electromagnetic spectrum. Overall, understanding the structure-properties of these liquid crystalline polymers leads to various applications such as membranes for separation, optics, sensors and drug delivery.

Download or read book Liquid Crystalline Rod coil Block Copolymers by Stable Free Radical Polymerization written by Padma Gopalan and published by . This book was released on 2002 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling Self assembly and Structure property Relationships in Block Copolymers written by Manas Ravindra Shah and published by . This book was released on 2009 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymers have been subject of tremendous research interest owing to their capability of undergoing self-assembly which allows them to tailor their electrical, optical, and mechanical properties. Statistical mechanics of flexible block copolymers is well understood. However, there are many unresolved issues with confinement of block copolymers as well as structure formation in block copolymers having non-flexible polymer blocks. We develop mean field theory models to address the issues arising in thermodynamics of such complex block copolymers. Also, we develop theoretical formalisms to understand the link between morphology and macroscopic properties in these block copolymers. We study the stability and ordering in thin films of flexible diblock copolymer in the presence of compressible solvent using a combined polymer mean field theory and lattice gas model for binary fluid mixtures. We utilize mean field theory model to understand the self-assembly behavior in side-chain liquid crystalline block copolymers which involve interplay between microphase separation and liquid crystalline ordering of side chain mesogenic units. We extend the field theoretic models for block copolymer to account for self-assembly in semicrystalline block copolymers. The semicrystalline chain is modeled as a semiflexible chain having non-bonded attractions between parallel bonds. We characterize the structure formation in such block copolymers as a function of the rigidity of the semicrystalline chain. Then we extend the formalism to study semicrystalline triblock and pentablock copolymers and evaluate bridging fractions in different sequences of semicrystalline multiblock copolymers. Rod-coil block copolymers have a flexible polymer covalently linked to rigid polymer. Such polymers have potential applications as organic LEDs and photovoltaic devices. We study the self-assembly of such block copolymer under confinement. To make these block copolymers viable as photovoltaic devices, we performed the photovoltaic modeling of devices based on self-assembly of block copolymers. We characterize the interplay between self-assembly and anisotropy of charge transport (arising due to rigid polymer chains) in determining the eventual photovoltaic properties.