Download or read book Solution Self assembly Behavior of A B C Triblock Polymers and the Implications for Nanoporous Membrane Fabrication written by 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 Behavior in Hydrophilic Block Copolymers written by Clara Valverde Serrano and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymers are receiving increasing attention in the literature. Reports on amphiphilic block copolymers have now established the basis of their self-assembly behavior: aggregate sizes, morphologies and stability can be explained from the absolute and relative block lengths, the nature of the blocks, the architecture and also solvent selectiveness. In water, self-assembly of amphiphilic block copolymers is assumed to be driven by the hydrophobic. The motivation of this thesis is to study the influence on the self-assembly in water of A b B type block copolymers (with A hydrophilic) of the variation of the hydrophilicity of B from non-soluble (hydrophobic) to totally soluble (hydrophilic). Glucose-modified polybutadiene-block-poly(N-isopropylacrylamide) copolymers were prepared and their self-assembly behavior in water studied. The copolymers formed vesicles with an asymmetric membrane with a glycosylated exterior and poly(N-isopropylacrylamide) on the inside. Above the low critical solution temperature (LCST) of poly(N-isopropylacrylamide), the structure collapsed into micelles with a hydrophobic PNIPAM core and glycosylated exterior. This collapse was found to be reversible. As a result, the structures showed a temperature-dependent interaction with L-lectin proteins and were shown to be able to encapsulate organic molecules. Several families of double hydrophilic block copolymers (DHBC) were prepared. The blocks of these copolymers were biopolymers or polymer chimeras used in aqueous two-phase partition systems. Copolymers based on dextran and poly(ethylene glycol) blocks were able to form aggregates in water. Dex6500-b-PEG5500 copolymer spontaneously formed vesicles with PEG as the "less hydrophilic" barrier and dextran as the solubilizing block. The aggregates were found to be insensitive to the polymer's architecture and concentration (in the dilute range) and only mildly sensitive to temperature. Variation of the block length, yielded different morphologies. A longer PEG chain seemed to promote more curved aggregates following the inverse trend usually observed in amphiphilic block copolymers. A shorter dextran promoted vesicular structures as usually observed for the amphiphilic counterparts. The linking function was shown to have an influence of the morphology but not on the self-assembly capability in itself. The vesicles formed by dex6500-b-PEG5500 showed slow kinetics of clustering in the presence of Con A lectin. In addition both dex6500-b-PEG5500 and its crosslinked derivative were able to encapsulate fluorescent dyes. Two additional dextran-based copolymers were synthesized, dextran-b-poly(vinyl alcohol) and dextran-b-poly(vinyl pyrrolidone). The study of their self-assembly allowed to conclude that aqueous two-phase systems (ATPS) is a valid source of inspiration to conceive DHBCs capable of self-assembling. In the second part the principle was extended to polypeptide systems with the synthesis of a poly(N-hydroxyethylglutamine)-block-poly(ethylene glycol) copolymer. The copolymer that had been previously reported to have emulsifying properties was able to form vesicles by direct dissolution of the solid in water. Last, a series of thermoresponsive copolymers were prepared, dextran-b-PNIPAMm. These polymers formed aggregates below the LCST. Their structure could not be unambiguously elucidated but seemed to correspond to vesicles. Above the LCST, the collapse of the PNIPAM chains induced the formation of stable objects of several hundreds of nanometers in radius that evolved with increasing temperature. The cooling of these solution below LCST restored the initial aggregates. This self-assembly of DHBC outside any stimuli of pH, ionic strength, or temperature has only rarely been described in the literature. This work constituted the first formal attempt to frame the phenomenon. Two reasons were accounted for the self-assembly of such systems: incompatibility of the polymer pairs forming the two blocks (enthalpic) and a considerable solubility difference (enthalpic and entropic). The entropic contribution to the positive Gibbs free energy of mixing is believed to arise from the same loss of conformational entropy that is responsible for "the hydrophobic effect" but driven by a competition for water of the two blocks. In that sense this phenomenon should be described as the "hydrophilic effect".
Download or read book Probing the Phase Behavior of ABC Triblock Copolymers Near Network Phase Windows written by Maeva S. Tureau and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymers are one class of soft materials that consist of two or more covalently-bonded chains of chemically distinct monomers. Their ability to self-assemble into a variety of nanostructured materials with tailored chemical and physical properties has motivated extensive investigations for use in many emerging nanotechnologies such as nanotemplates, analytical separation membranes, and electrical and ionic conductors. Relative to cylindrical nanostructures that often require external alignment techniques to minimize structural defects, network structures possess co-continuous percolating domains in three-dimension and exhibit superior mechanical stability, short diffusion path lengths, and high internal interfacial areas, which can facilitate transport in applications such as water filtration and ion-conducting membranes. In this thesis project, the poly(ethylene- alt -propylene- b -styrene- b -methyl methacrylate) (EPSM) triblock copolymer system was produced from the selective poly(isoprene) hydrogenation of poly(isoprene- b -styrene- b -methyl methacrylate) (ISM) precursors. The EPSM system was selected due to the toughness given by the combined interactions of the glassy poly(styrene) (PS) and rubbery poly(ethylene- alt -propylene) (PEP) blocks, the mechanical strength provided by the PS block, and the ease of removal of the poly(methyl methacrylate) (PMMA) block. This dissertation first presents the phase behavioral exploration of anionically-synthesized ISM triblock copolymer precursors and associated ISM copolymer/homopolymer blends, which permitted the identification and refinement of network phase regions. The copolymer/homopolymer blending technique allowed for homopolymer-induced phase transformations to and from network structures where alternating gyroid (Q 214), core-shell gyroid (Q 230), and orthorhombic (O 70) network phases were identified. The ISM phase behavior was found to qualitatively match the predicted self-consistent mean field theory (SCFT) phase behavior of a model ABC triblock copolymer described by Tyler et al. Minor discrepancies in the size and location of the phase boundaries are rationalized on the basis of the block copolymer parameters. Second, this blending technique allowed for the precise targeting of multiple nanostructures from a single, low molecular weight disordered material. The latter finding is envisioned to be particularly useful for applications requiring materials of small feature sizes while retaining the ease of processability provided by the parent disordered copolymers. Finally, the PI hydrogenation of ISM precursors generated EPSM materials with enhanced resistance to oxidative, thermal, and UV degradation. Their initial morphological characterization permitted the identification of a relatively large Q 230 network phase region and highlighted the differences in phase behavior between the EPSM and ISM precursor systems. Altogether, this latter study established a foundation for generating environmentally-stable nanostructured materials, in view of creating functionalized nanoporous membranes able to capture and separate a wide range of biologically active molecules.
Download or read book Crystallization in Multiphase Polymer Systems written by Sabu Thomas and published by Elsevier. This book was released on 2017-09-15 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crystallization in Multiphase Polymer Systems is the first book that explains in depth the crystallization behavior of multiphase polymer systems. Polymeric structures are more complex in nature than other material structures due to their significant structural disorder. Most of the polymers used today are semicrystalline, and the subject of crystallization is still one of the major issues relating to the performance of semicrystalline polymers in the modern polymer industry. The study of the crystallization processes, crystalline morphologies and other phase transitions is of great significance for the understanding the structure-property relationships of these systems. Crystallization in block copolymers, miscible blends, immiscible blends, and polymer composites and nanocomposites is thoroughly discussed and represents the core coverage of this book. The book critically analyzes the kinetics of nucleation and growth process of the crystalline phases in multi-component polymer systems in different length scales, from macro to nanoscale. Various experimental techniques used for the characterization of polymer crystallization process are discussed. Written by experts in the field of polymer crystallization, this book is a unique source and enables professionals and students to understand crystallization behavior in multiphase polymer systems such as block copolymers, polymer blends, composites and nanocomposites. - Covers crystallization of multiphase polymer systems, including copolymers, blends and nanocomposites - Features comprehensive, detailed information about the basic research, practical applications and new developments for these polymeric materials - Analyzes the kinetics of nucleation and growth process of the crystalline phases in multi-component polymer systems in different length scales, from macro to nanoscale
Download or read book Biomimetic and Bioinspired Membranes for New Frontiers in Sustainable Water Treatment Technology written by Amira Abdelrasoul and published by BoD – Books on Demand. This book was released on 2017-12-06 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomimetic and bioinspired membranes are the most promising type of membrane for multiple usage scenarios, including commercial separation applications as well as water and wastewater treatment technologies. In recent years, aquaporin biomimetic membranes (ABMs) for water purification have raised considerable interest. These membranes display uniquely favorable properties and outstanding performances, such as diverse interactions, varied selective transport mechanisms, superior stability, high resistance to membrane fouling, and distinct adaptability. Biomimetic membranes would make a significant contribution to alleviate water stress, environmental threats, and energy consumption.
Download or read book Porous Polymers written by Michael S. Silverstein and published by John Wiley & Sons. This book was released on 2011-04-19 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers the various aspects of the porous polymer field into one volume. It not only presents a fundamental description of the field, but also describes the state of the art for such materials and provides a glimpse into the future. Emphasizing a different aspect of the ongoing research and development in porous polymers, the book is divided into three sections: Synthesis, Characterization, and Applications. The first part of each chapter presents the basic scientific and engineering principles underlying the topic, while the second part presents the state of the art results based on those principles. In this fashion, the book connects and integrates topics from seemingly disparate fields, each of which embodies different aspects inherent in the diverse field of porous polymeric materials.
Download or read book Miktoarm Star Polymers written by Ashok Kakkar and published by Royal Society of Chemistry. This book was released on 2017-04-13 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: The term ‘miktoarm polymers’ refers to asymmetric branched macromolecules, a relatively new entry to the macromolecular field. Recent advances in their synthesis and intriguing supramolecular chemistry in a desired medium has seen a fast expansion of their applications. The composition of miktoarm polymers can be tailored and even pre-defined to allow a desired combination of functions, meaning polymer chemists can have complete control of the overall architecture of these macromolecules. By carefully selecting the composition, they can create supramolecular structures with intriguing properties, particularly for applications in biology. Miktoarm Star Polymers features chapters from experts actively working in this field, and provides the reader with a unique introduction to the fundamental principles of this exciting macromolecular system. Topics covered include the design, synthesis, characterization, self-assembly and applications of miktoarm polymers. The book is an excellent overview and up to date guide to those working in research in polymer chemistry, materials science, and polymers for medical applications.
Download or read book Optical Metamaterials by Block Copolymer Self Assembly written by Stefano Salvatore and published by Springer. This book was released on 2014-07-11 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metamaterials are artificially designed materials engineered to acquire their properties by their specific structure rather than their composition. They are considered a major scientific breakthrough and have attracted enormous attention over the past decade. The major challenge in obtaining an optical metamaterial active at visible frequencies is the fabrication of complex continuous metallic structures with nano metric features. This thesis presents the fabrication and characterization of optical metamaterials made by block copolymer self assembly. This approach allows fabrication of an intriguing and complex continuous 3D architecture called a gyroid, which is replicated into active plasmonic materials such as gold. The optical properties endowed by this particular gyroid geometry include reduction of plasma frequency, extraordinarily enhanced optical transmission, and a predicted negative refractive index. To date, this is the 3D optical metamaterial with the smallest features ever made.
Download or read book Bimetallic Nanostructures written by Ya-Wen Zhang and published by John Wiley & Sons. This book was released on 2018-05-16 with total page 738 pages. Available in PDF, EPUB and Kindle. Book excerpt: Systematically summarizes the current status and recent advances in bimetallic structures, their shape-controlled synthesis, properties, and applications Intensive researches are currently being carried out on bimetallic nanostructures, focusing on a number of fundamental, physical, and chemical questions regarding their synthesis and properties. This book presents a systematic and comprehensive summary of the current status and recent advances in this field, supporting readers in the synthesis of model bimetallic nanoparticles, and the exploration and interpretation of their properties. Bimetallic Nanostructures: Shape-Controlled Synthesis for Catalysis, Plasmonics and Sensing Applications is divided into three parts. Part 1 introduces basic chemical and physical knowledge of bimetallic structures, including fundamentals, computational models, and in situ characterization techniques. Part 2 summarizes recent developments in synthetic methods, characterization, and properties of bimetallic structures from the perspective of morphology effect, including zero-dimensional nanomaterials, one-dimensional nanomaterials, and two-dimensional nanomaterials. Part 3 discusses applications in electrocatalysis, heterogeneous catalysis, plasmonics and sensing. Comprehensive reference for an important multidisciplinary research field Thoroughly summarizes the present state and latest developments in bimetallic structures Helps researchers find optimal synthetic methods and explore new phenomena in surface science and synthetic chemistry of bimetallic nanostructures Bimetallic Nanostructures: Shape-Controlled Synthesis for Catalysis, Plasmonics and Sensing Applications is an excellent source or reference for researchers and advanced students. Academic researchers in nanoscience, nanocatalysis, and surface plasmonics, and those working in industry in areas involving nanotechnology, catalysis and optoelectronics, will find this book of interest.
Download or read book Points Lines and Walls written by Maurice Kléman and published by John Wiley & Sons. This book was released on 1983 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Block Copolymers II written by Volker Abetz and published by Springer Science & Business Media. This book was released on 2005-12-02 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: . A.J. M ller, V. Balsamo, M.L. Arnal: Nucleation and Crystallization in Diblock and Triblock Copolymers.- 2 J.-F. Gohy: Block Copolymer Micelles.- 3 M.A. Hillmyer: Nanoporous Materials from Block Copolymer Precursors.- 4 M. Li, C. Coenjarts, C.K. Ober: Patternable Block Copolymers.-
Download or read book Azo Polymers written by Xiaogong Wang and published by Springer. This book was released on 2016-10-19 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores functional polymers containing aromatic azo chromophores in side-chain, main-chain and other parts of their structures, known as azo polymers and which share common photoresponsive properties. It focuses on the molecular architecture of azo polymers, the synthetic methods and their most important functions, such as photoinduced birefringence and dichroism, surface-relief-grating (SRG) formation, and light-driven deformation of liquid crystal elastomers. It combines a general survey of the subject and in-depth discussions of each topic, including numerous illustrations, figures, and photographs. Offering a balance between an introduction to the core concepts and a snapshot of hot and emerging topics, it is of interest to graduate students and researchers working in this and related fields. Xiaogong Wang is a Professor at the Department of Chemical Engineering, Tsinghua University, China.
Download or read book Polyfluorenes written by Ullrich Scherf and published by Springer Science & Business Media. This book was released on 2008-07-29 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: With this collection of short review papers we would like to present a broad overview of research on poly?uorenes and related heteroanalogues over the last two decades. The collection begins with papers on the synthesis of po- ?uorenesandrelatedpolyheteroarenes, thenreportsphotophysicalproperties of this class of conjugated polymers both at the ensemble and the single chain level, continues with a discussion of the rich solid state structures of poly?uorenes, and ?nally switches to device applications (e.g. in OLEDs). In addition, two chapters are devoted to de?ned oligo?uorenesas lowmolecular weight model systems forpoly?uorenes and also to degradation studies. We feel that this up-to-date collection will be very helpful to all polymer chemists and physicists, and will also aid graduate students interested in this fascinating and still growing area of research, since such a compact overview is only now available. All articles are presented by leading scientists in their ?elds, insuring state-of-the-art coverage of all relevant aspects. Together with the body of references this volume is meant to assist researchers in the daily lab routine. Moreover, Advances in Polymer Science, as an established series of high quality review papers, represents a very appropriate platform for our project.Wehopethatthisshortcollectionwillbeofgreatvaluebothforbeg- ners and established researchscientists inthe?eldofpoly?uorene research.
Download or read book Double Gyroid Structured Functional Materials written by Maik Rudolf Johann Scherer and published by Springer Science & Business Media. This book was released on 2013-06-25 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of new high-tech applications and devices has created a seemingly insatiable demand for novel functional materials with enhanced and tailored properties. Such materials can be achieved by three-dimensional structuring on the nanoscale, giving rise to a significant enhancement of particular functional characteristics which stems from the ability to access both surface/interface and bulk properties. The highly ordered, bicontinuous double-gyroid morphology is a fascinating and particularly suitable 3D nanostructure for this purpose due to its highly accessible surface area, connectivity, narrow pore diameter distribution and superb structural stability. The presented study encompasses a wide range of modern nanotechnology techniques in a highly versatile bottom-up nanopatterning strategy that splits the fabrication process into two successive steps: the preparation of mesoporous double-gyroid templates utilizing diblock copolymer self-assembly, and their replication with a functional material employing electrochemical deposition and atomic layer deposition. The double-gyroid structured materials discussed include metals, metal oxides, and conjugated polymers, which are applied and characterized in high-performance devices, such as electrochromic displays, supercapacitors, chemical sensors and photovoltaics. This publication addresses a wide range of readers, from researchers and specialists who are professionally active in the field, to more general readers interested in chemistry, nanoscience and physics.
Download or read book Biomimetic Polymers written by C.G. Gebelein and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: The term biomimetic is comparatively new on the chemical scene, but the concept has been utilized by chemists for many years. Furthermore, the basic idea of making a synthetic material that can imitate the func tions of natural materials probably could be traced back into antiquity. From the dawn of creation, people have probably attempted to duplicate or modify the activities of the natural world. (One can even find allusions to these attempts in the Bible; e. g. , Genesis 30. ) The term "mimetic" means to imitate or mimic. The word "mimic" means to copy closely, or to imitate accurately. Biomimetic, which has not yet entered most dictionaries, means to imitate or mimic some specific bio logical function. Usually, the objective of biomimetics is to form some useful material without the need of utilizing living systems. In a simi lar manner, the term biomimetic polymers means creating synthetic poly mers which imitate the activity of natural bioactive polymers. This is a major advance in polymer chemistry because the natural bioactive polymers are the basis of life itself. Thus, biomimetic polymers imitate the life process in many ways. This present volume delineates some of the recent progress being made in this vast field of biomimetic polymers. Chemists have been making biomimetic polymers for more than fifty years, although this term wasn't used in the early investigations.
Download or read book Basic X ray Scattering for Soft Matter written by Wilhelmus Hendrikus Jeu and published by Oxford University Press. This book was released on 2016 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: X-ray scattering is a well-established technique in materials science. The aim of this text is to explain basic principles and applications of x-ray scattering in a simple way using many practical examples followed by more elaborate case studies. It contains a separate chapter on the different types of order/disorder in soft matter that play such an important role in modern self-assembling systems. Finally the last chapter treats soft matter surfaces and thin film that are increasingly used in coatings and in many technological applications, such as liquid crystal displays and nanostructured block copolymer films
Download or read book Introduction to Soft Matter written by Ian W. Hamley and published by John Wiley & Sons. This book was released on 2013-03-18 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an introduction to this exciting and relativelynew subject with chapters covering natural and synthetic polymers,colloids, surfactants and liquid crystals highlighting the many andvaried applications of these materials. Written by an expert in thefield, this book will be an essential reference for people workingin both industry and academia and will aid in understanding of thisincreasingly popular topic. Contains a new chapter on biological soft matter Newly edited and updated chapters including updated coverageof recent aspects of polymer science. Contain problems at the end of each chapter to facilitateunderstanding
