Download or read book Synthesis Morphology and Properties of Semicrystalline Block Copolymers written by and published by . This book was released on 1995 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three years of research on the synthesis, structure and properties of semicrystalline block copolymers are summarized. Novel aspects of this relatively unexplored category of microphase-separated materials include: strongly path-dependent morphologies, unusual gas transport characteristics, compositionally enriched surfaces and favorable mechanical properties. Two industrial and one academic collaboration are mentioned. (MM).

Download or read book Block Copolymers in Nanoscience written by Massimo Lazzari and published by John Wiley & Sons. This book was released on 2007-06-27 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first book to take a detailed look at one of the key focal points where nanotechnology and polymers meet provides both an introductory view for beginners as well as in-depth knowledge for specialists in the various research areas involved. It investigates all types of application for block copolymers: as tools for fabricating other nanomaterials, as structural components in hybrid materials and nanocomposites, and as functional materials. The multidisciplinary approach covers all stages from chemical synthesis and characterization, presenting applications from physics and chemistry to biology and medicine, such as micro- and nanolithography, membranes, optical labeling, drug delivery, as well as sensory and analytical uses.

Download or read book The Synthesis Mechanical Properties and Morphology of Star Block Copolymers written by Le-Khac Bi and published by . This book was released on 19?? with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Block Copolymers written by Francisco Balta Calleja and published by CRC Press. This book was released on 2000-06-09 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt: A summary of block copolymer chemical structures and synthesis. It discusses physical methods of characterization such as computer simulation, microhardness, dielectric spectroscopy, thermal mechanical relaxation, ultrasonic characterization, transmission electron microscopy, X-ray scattering, and NMR, among others. It also outlines rheological and processing parameters in the multiphase polymer systems with stable microstructures.

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 Block Copolymers written by Nikos Hadjichristidis and published by John Wiley & Sons. This book was released on 2003-04-28 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers may be classified as either homopolymers, consisting of one single repeating unit, or copolymers, consisting of two or more distinct repeating units. Block copolymers contain long contiguous blocks of two or more repeating units in the same polymer chain. Covering one of the hottest topics in polymer chemistry, Block Copolymers provides a coherent overview of the synthetic routes, physical properties, and applications of block copolymers. This pioneering text provides not only a guideline for developing synthetic strategies for creating block copolymers with defined characteristics, but also a key to the relationship between the physical properties of block copolymers and the structure and dynamics of materials. Covering features of the chemistry and physics of block copolymers that are not found in comparable texts, Block Copolymers illustrates the structure-activity relationship of block copolymers and offers suggestions for the design of specific applications. Divided into five sections-Block Copolymers includes chapters on: * Block Copolymers by Chemical Modification of Precursor Polymers * Nonlinear Block Copolymers * Adsorption of Block Copolymers at Solid-Liquid Interfaces * Theory of Block Copolymer Segregation * Phase Transformation Kinetics * Block Copolymer Morphology * Block Copolymer Dynamics Polymer chemists, physicists, chemical engineers, and materials scientists, as well as graduate students in polymer science, will find Block Copolymers to be an invaluable text.

Download or read book Nanostructured Polymer Blends written by Gity Mir Mohamad Sadeghi and published by Elsevier Inc. Chapters. This book was released on 2013-11-28 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymers (BCPs) consist of two or more chemically different polymers connected covalently, and are polymer alloys. Due to their thermodynamic incompatibility and chain connectivity, the phase separation between two (or more) blocks occurs only in a tens of nanometers range. Nanostructures are based on block copolymer self-assembly. They are functional nanomaterials less than 100nm in size and have received extensive scientific and technological attention due to their potential applications in electronic, biomedical, and optical materials. This chapter examines a variety of different synthetic strategies for preparation of linear diblock copolymers by anionic polymerization. Triblocks can be synthesized according to an appropriate synthetic pathway, depending on the monomers used and their sequence in the triblock chain. Nonlinear block copolymers including star block copolymers, graft copolymers, miktoarm star copolymers, cyclic block copolymers, and other complex architectures are explained. Microphase separation drives BCPs to self-assemble, resulting in ordered nanostructures, including spheres, cylinders, gyroids, and lamellae, depending on the composition of the BCP. In nanotechnology, self-assembly (SA) underlies various types of molecular structures built from nanoparticles, nanotubes, or nanorods. Supramolecular structures generated from amphiphilic block copolymers are characterized by a slow rate of intermicellar chain exchange which makes them interesting for a variety of applications. Basic principles of self-assembly and micellization of block copolymers in dilute solution, methods for stabilization of the macromolecular aggregates, are discussed. Stabilized nanoparticles, the so-called “smart materials,” which show responses to environmental changes (pH, temperature, ionic strength, etc.), are presented with a focus on their applications.

Download or read book Design Synthesis Morphology and Properties of Semiconducting Block Copolymers for Photonic Applications written by Bert de Boer and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Processing Structure and Properties of Block Copolymers written by M.J. Folkes and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymers represent an important class of multi-phase material, which have received very widespread attention, particularly since their successful commercial development in the mid-1960s. Much of the interest in these polymers has arisen because of their rather remarkable micro phase morphology and, hence, they have been the subject of extensive microstructural examination. In many respects, the quest for a comprehensive interpretation of their structure, both theoretically and experimentally, has not been generally matched by a corresponding enthusiasm for developing structure/property relationships in the context of their commercial application. Indeed, it has been left largely to the industrial companies involved in the development and utilization of these materials to fulfil this latter role. While it is generally disappointing that a much greater synergism does not exist between science and technology, it is especially sad in the case of block copolymers. Thus these materials offer an almost unique opportunity for the application of fundamental structural and property data to the interpretation of the properties of generally processed artefacts. Accordingly, in this book, the editor has drawn together an eminent group of research workers, with the specific intention of highlighting some of those aspects of the science and technology of block copolymers that are potentially important if further advances are to be made either in material formulation or utilization. For example, special consideration is given to the relationship between the flow properties of block copo lymers and their microstructure.

Download or read book Shear Induced Morphology of Semicrystalline Block Copolymers written by Peter Kofinas and published by . This book was released on 1994 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of Poly 3 alkylthiophene containing Block Copolymers written by Victor Ho and published by . This book was released on 2014 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conjugated polymers have been widely studied for their use in lightweight, flexible, and solution-processable electronic devices. However, the optimization of such polymer-based devices has been largely Edisonian in nature due to both a poor understanding of and an inability to control the complex hierarchical structure observed in semicrystalline polymers. In this thesis, we show that simple chemical modifications to commonly-studied conjugated polymers can have a large effect on the observed structure ranging from the unit cell to that on the order of device features. In particular, the self-assembly of block copolymers in which one of the components is optoelectronically-active is presented as a facile method to obtain nanostructured materials. For the work in this thesis, we will focus on poly(3-alkylthiophenes), a widely studied class of conjugated polymers due to their favorable optoelectronic properties, high solubility in organic solvents, and susceptibility to simple chemical modification. Although the synthesis of conjugated block copolymers has been presented in the past, complexities arising from crystallization of the conjugated moiety have dominated the observed solid state morphologies. Specifically, the crystallization of the semicrystalline block dictates the block copolymer microphase separation, a well-known phenomenon in the literature for non-conjugated semicrystalline block copolymers, which has resulted in solid state morphologies that do not differ significantly from that of the semiconducting homopolymer. To address this, we first show that the side chain chemistry controls the thermal transitions and optoelectronic properties in poly(3-alkylthiophenes). Such control over the crystallization kinetics provides an experimentally convenient approach to investigate the importance of the crystalline structure over a wide range of length scales on the optoelectronic properties. Furthermore, the ability to control the thermal transition temperatures can be used to directly manipulate, and thereby balance, the competition between the driving forces for crystallization and self-assembly. As evidence, the nanoscale structure is shown to be directly controlled via synthesis of block copolymers in which one block is the low melting temperature semiconducting polymer, poly(3-(2-ethylhexyl)thiophene). A wide range of morphologies with curved interfaces are observed which, in the past, have been precluded by the crystallization of poly(3-alkylthiophenes) with unbranched aliphatic side chains such as poly(3-hexylthiophene). Importantly, confinement of the conjugated polymer to nanoscale domains is not detrimental to the crystallinity or to charge transport over device-scale dimensions. Additionally, this approach is shown to be effective for a number of different chemistries providing a flexible methodology for obtaining periodic, semiconducting domains on the nanoscale. Together, these simple synthetic strategies can be used to tune the morphology of various length scales of thin film active layers and provide synthetic rules for design of novel semiconducting polymer systems.

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.

Download or read book Synthesis Morphology and Properties of Rod coil Block Copolymers Poly fluorene block poly 4 vinylpyridine written by 孫翰笙 and published by . This book was released on 2009 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Developments in Block Copolymer Science and Technology written by Ian W. Hamley and published by John Wiley & Sons. This book was released on 2004-07-16 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focuses on recent advances in research on block copolymers, covering chemistry (synthesis), physics (phase behaviors, rheology, modeling), and applications (melts and solutions). Written by a team of internationally respected scientists from industry and academia, this text compiles and reviews the expanse of research that has taken place over the last five years into one accessible resource. Ian Hamley is the world-leading scientist in the field of block copolymer research Presents the recent advances in the area, covering chemistry, physics and applications. Provides a broad coverage from synthesis to fundamental physics through to applications Examines the potential of block copolymers in nanotechnology as self-assembling soft materials

Download or read book Synthesis and Characterization of Ionically Bonded Diblock Copolymers written by Lei Feng (Chemical engineer) and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymers consist of two or more incompatible polymer chains linked by covalent bonds. These block copolymer can separate into nanometer sized domains whose morphology depends upon the size of the block and interactions between them. The properties of block copolymers can be modified and potentially improved by introducing noncovalent interactions to replace covalent linkages between blocks to form supramolecular block copolymers. These kinds of materials combine the microphase separation inherent to block copolymers with the facile synthesis of supramolecular materials thereby affording new and unique materials. This dissertation focuses on synthesis and characterization of PS-b-PMA block copolymers with ion-pair junctions.Firstly, the chain-end sulfonated polystyrene ([omega]-sulfonated PS) was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization and postpolymerization modification. In the postpolymerization modification two methods were investigated: in the first one, the polymer was converted to a thiol-terminated polymer by aminolysis. Then a sulfonic acid end-group was produced then by oxidation of the thiol end-group with m-chloroperoxybenzoicacid (m-CPBA); in the second method, the RAFT-polymerized polymer was directly sulfonated by oxidation with m-CPBA. After purification by column chromatography, [omega]-sulfonated PS was obtained by both methods with greater than 95% end-group functionality as measured by titration. The sulfonic acid end-group could be neutralized with various ammonium or imidazolium counter ions through acid-base or ionic metathesis reactions. These polymers with ionic end-group can be used as model supramolecular building blocks.Secondly, ammonium end functionalized polymethylacrylate (PMA) was synthesized directly by RAFT polymerization using functional RAFT agent. Then chain-end sulfonated polystyrene and ammonium end functionalized polymethylacrylate (PMA) were used to synthesize A-B block copolymers by two different methods: the first method was by mixing two oppositely charged end group functionalized polymers; the second method was to ionically bond a RAFT agent to the chain end of an end sulfonated polymer to generate a supramolecular macro RAFT agent then an A-B block copolymer was prepared by RAFT polymerization using supramolecular macro-RAFT agent. The polymerization kinetics were investigated and the molecular weight and the chemical structure of the block copolymers were characterized by 1H-NMR and SEC. The results show that the ion-bonded supramolecular block copolymer, PS-PMA, have been successfully prepared with controlled molecular weight and narrow distribution.Thirdly, the morphology of the ion-bonded supramolecular PS-PMA diblock copolymers were investigated by small-angle X-ray scattering (SAXS) and rheological techniques. Several covalently bonded PS-PMA block copolymers were synthesized by RAFT polymerization and their micro domain structures and rheology behaviors were also investigated. The results showed that the electrostatic interactions between the end ion groups are able to overcome the thermodynamic repulsion of two blocks result in the formation of diblock copolymers with similar behaviors and morphology of traditional covalent bonded diblock copolymers and their micro domain structures remain to high temperatures.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Morphology and Properties of Segmented Copolymers and Blends written by Carl Baa-sun Wang and published by . This book was released on 1982 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: