Download or read book Synthesis Self assembly and Applications of Amorphous Polyferrocenylsilane Block Copolymers written by David Allen Rider and published by . This book was released on 2007 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of well-defined polystyrene-block-poly(ferrocenylethylmethylsilane) (PS-b-PFEMS) diblock copolymers was synthesized. Both PFEMS and PS- b-PFEMS were shown to be amorphous due to the atactic nature of the PFEMS. As a result, PS- b-PFEMS readily undergo solid-state self-assembly in the bulk producing a spectrum of ordered nanometer sized iron-rich morphologies. When cylinder-forming PS-b-PFEMSs were studied in thin films, well-ordered arrays of hexagonally packed iron-rich cylindrical microdomains oriented either parallel to or normal to the substrate were produced. The orientation was found to depend strongly on the film thickness and/or the conditions of annealing. The etching of these films using (i) reactive plasmas, and (ii) an oxidative chemical wet etch technique were investigated. Using (i), surface-patterned magnetic ceramics were produced as well as a nanotextured silver metal film. The latter was found to dramatically enhance the Raman spectroscopy of an adsorbed analyte molecule. Using (ii), nanoporous polystyrene films were generated by the quantitative elimination of PFEMS domains by exposure to a nucleophilic non-solvent under oxidizing conditions.Thin films of PS-b-PFEMS generated efficient iron nanoparticle catalysts for single-walled carbon nanotube (SWNT) growth via a chemical vapor deposition growth process. The kinetics of the formation of iron catalysts from PS- b-PFEMS and PFEMS were compared. Despite the lower iron content for PS-b -PFEMS films, more active iron sites were produced. Additionally, the tube diameter and density were tunable by adjusting the chain lengths of polyferrocenylsilane- block-polysiloxanes in thin films. Lastly, high-throughput field-effect SWNT transistors have been fabricated with more than 160 individually addressable devices on a chip.The influence of strong 3D confinement on the self-assembly of PS-b-PFEMS was studied. Both silica colloidal crystals and silica inverse colloidal crystals were used for directing the self-assembly. Unusual morphologies, such as concentric shells and branched lamellae, resulted from the interaction of the lamellar-forming PS-b-PFEMS with the high surface area templates. In addition, the control of the 3D confined morphology of cylinder-forming PS-b-PFEMS was demonstrated through mediation of the interfacial interactions within the colloidal crystal.For solution state self-assembly, PS-b -PFEMSs and polystyrene-block-poly(ferrocenylmethylphenylsilanes) (PS-b-PFEMSs) were stoichiometrically oxidized in solution. Due to a redox-induced polarity change for the PFEMS and PFMPS blocks, self-assembly into well-defined spherical micelles occurred. The micelles, composed of a core of partially oxidized PFS segments and a corona of PS, disassembled when treated with a reducing agent and regenerated unassociated free chains.Lastly, the photochemical treatment of metal-containing ferrocenophane monomers with low energy Pyrex-filtered light from a mercury lamp (lambda > 310 nm) or bright sunlight in the presence of an anionic initiator led to living polymerizations in which the conversion and molecular weight of the resulting polymer was controlled by irradiation time. The polymerization proceeded via attack of the initiator or propagating anion on the iron atom of the photoexcited monomer. The formation of functional block copolymer architectures was possible when the light is alternately switched on and off in between the sequential addition of different monomers.

Download or read book Block Copolymers with Crystallizable Blocks written by Holger Schmalz and published by . This book was released on 2022-03-14 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymers with crystallizable blocks have moved into the focus of current research, owing to their unique self-assembly behaviour and properties. New synthetic concepts give, for example, even access to tetrablock copolymers with four crystalline blocks, bio-based thermoplastic elastomers (e.g., based on ABA triblock copolymers with poly(L-lactide) (PLLA) hard segments), and allow new, exciting insights into the interplay of microphase separation and crystallization in controlling self-assembly in bulk (confined vs. break-out crystalliza-tion). Concerning self-assembly in solution, crystallization-driven self-assembly (CDSA) paved the way to a myriad of crystalline-core micellar structures and hierarchical super-structures that were not accessible before via self-assembly of fully amorphous block copolymers. This allows for the production of cylindrical micelles with defined lengths, length distribution, and corona chemistries (block type or patchy corona), as well as branched micelles and fascinating micellar superstructures (e.g., 2D lenticular platelets, scarf-shaped micelles, multidimensional micellar assemblies, and cross and "windmill"-like supermicelles). This Special Issue brings together new developments in the synthesis and self-assembly of block copolymers with crystallizable blocks and also addresses emerging applications for these exciting materials. It includes two reviews on CDSA and eight contributions spanning from membranes for gas separation to self-assembly in bulk and solution.

Download or read book Synthesis Self assembly and Applications of Polyferrocenylsilane Diblock Copolymers written by Jean-Charles Eloi and published by . This book was released on 2009 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Anionic Polymerization written by Nikos Hadjichristidis and published by Springer. This book was released on 2015-09-01 with total page 1075 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents these important facts: a) The mechanism of anionic polymerization, a more than 50-year challenge in polymer chemistry, has now become better understood; b) Precise synthesis of many polymers with novel architectures (triblock, multi-block, graft, exact graft, comb, cyclic, many armed stars with multi-components, dendrimer-like hyper-branched, and their structural mixed (co)polymers, etc.) have been advanced significantly; c) Based on such polymers, new morphological and self-organizing nano-objects and supra molecular assemblies have been created and widely studied and are considered nanodevices in the fields of nano science and technology; d) New high-tech and industrial applications for polymeric materials synthesized by anionic polymerization have been proposed. These remarkable developments have taken place in the last 15 years. Anionic polymerization continues to be the only truly living polymerization system (100 % termination free under appropriate conditions) and consequently the only one with unique capabilities in the synthesis of well-defined (i.e., precisely controlled molecular weight, nearly mono-disperse molecular weight distribution, structural and compositional homogeneity) complex macromolecular architectures. This book, with contributions from the world’s leading specialists, will be useful for all researchers, including students, working in universities, in research organizations, and in industry.

Download or read book Synthesis Self assembly and Application of All conjugated Block Copolymers and Their Applications in Nanohybrid System written by 魏凡凱 and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book SYNTHESIS OF POLYFERROCENYLSILANE BLOCK COPOLYMERS AND THEIR CRYSTALLIZATION DRIVEN SELF ASSEMBLY IN PROTIC SOLVENTS written by Hang Zhou and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Polyferrocenylsilane (PFS) di-block copolymers self-assemble in selective solvents to form rod-like micelles, driven be the crystallization of the PFS block in the core. One of the unique features of these rod-like micelles is that the length can be extended upon addition of an extra amount of PFS block copolymers in a good solvent for both blocks. This process, referred to as the living crystallization-driven self-assembly (CDSA), has been utilized to prepare near monodisperse rod-like micelles. To further investigate the potential bio-medication application of these rods, I set out to synthesize new PFS BCPs with water-soluble thermoresponsive corona to prepare uniform nano-rods in polar media, and study their solution behavior. The first part of my thesis describes the synthesis and living CDSA of poly(ferrocenyldimethylsilane-b-N-isopropyl acrylamide) (PFS-b-PNIPAM) by a Cu-catalyzed alkyne/azide coupling reaction to covalently combine the two homopolymers. In self-assembly studies, I found that the growth rate of the rod-like micelles in alcohol solvents decreased dramatically when the number of PNIPAM repeating units was increased. Varies attempts to transfer the micelles to water were accompanied by extensive fragmentation. I attributed the phenomenon to the cononsolvency of PNIPAM corona in alcohol/water mixture. The second part describes the preparation of a photocleavable PFS-hv-poly(2-vinylpyridine) (P2VP) block copolymer bearing an o-nitrobenzyl ester (ONB) group at the junction. I investigated in detail the UV light-induced cleavage of the P2VP corona chains from the rod-like micelles by GPC, TEM and multiangle light scattering. The third part in the thesis describes the formation of rod-like co-micelles with segregated coronas via living CDSA of two mixed unimers of PFS-b-PNIPAM and PFS-hv-P2VP. By controlling the epitaxial growth rate of the two competing species, the morphology of the co-micelles could be varied from patchy to block co-micelles. The fourth part describes the synthesis and living CDSA of PFS-b-poly(oligo(ethylene glycol) methyl ether methacrylate) (PFS-b-POEGMA). I explored the self-assembly condition of this polymer in different alcohol media and found a methanol/ethanol mixture as selective solvent to prepare uniform nano-rods by living CDSA. These nano-rods stayed intact after transfer to water. The thermoresponsiveness of these uniform cylindrical brushes was investigated by multiangle light scattering.

Download or read book Block Copolymers in Nanoscience written by Massimo Lazzari and published by John Wiley & Sons. This book was released on 2006-11-10 with total page 450 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 Synthesis and Self Assembly of Structurally Well Defined Polyferrocenylsilanes and Their Block Copolymers written by Kyoung Taek Kim and published by . This book was released on 2007 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymers of poly ferrocenylsilanes (PFSs) and polypeptide were synthesized by the ring-opening polymerization of strained [1]-silaferrocenophanes and alpha-amino acid-N-carboxyanhydrides (alpha-NCA). PFS-b-poly(gamma-benzyl-L-glutamate) (PFS- b-PBLG) block copolymers showed thermotropic liquid crystalline phases. The benzyl ester groups of poly(gamma-benzyl-L-glutamate) were deprotected under standard hydrogenation conditions, and the resulting amphiphilic block copolymer, PFS-b-poly(L-glutamic acid), formed micelles in water. Dendronized polyferrocenylsilanes were synthesized by a substitution reaction of reactive poly(chloromethylferrocenylsilane) with monodendrons with a focal hydroxy group. AFM studies of the fractionated high molecular weight PFS samples revealed a spherical cocoon structure for the single chains of the dendronized polymer as well as elongated single chain structures. Thermoreversible gelation of PFS-b-PBLG in toluene was observed. Organogels of PFS-b-PBLG were studied by transmission electron microscopy (TEM), atomic force microscopy (AFM), and small-angle X-ray scattering (SAXS). Based on the experimental results, a new mechanism for the self-assembly was proposed to explain the gelation of these PBLG block copolymers. This mechanism is likely to be general for numerous block copolymers based on helical polypeptides. Diblock copolymers, poly isoprene-b-polyferrocenylsilane (PI-b-PFS), were synthesized by living anionic polymerization. The PI block formed in cyclohexane showed a high content of 1,4-cis -microstructure rather than 1,2- or 3,4-microstructure. The micellization behavior of these block copolymers in hexane and decane (selective solvents for the PI block) was studied by TEM, and comparisons were made between polymers with high and low 1,4-cis-microstructure contents. New macromolecular self-assembling building blocks, dendron-helical polypeptide copolymers and dendritic-helical copolypeptides, have been synthesized. These materials possess a well-defined 3-D shape and self-assemble in solution to form nanoribbons via a mechanism proposed in this thesis. The well-defined 3-D structures of these macromolecular building blocks also affect their self-assembly behavior such as a lyotropic liquid crystal formation in organic solvents and micellization in water. Redox-active ferrocene groups were incorporated in conjugated polymer backbones. The resulting polymers with bissilylferrocenyl moieties showed photoluminescence triggered by the oxidation of ferrocene groups in the main chain. The intensity of the luminescence increased with increasing extent of oxidation of ferrocene groups in the polymer backbone. The polymer containing ferrocenyl groups in the backbone showed photovoltaic properties upon illumination.

Download or read book Complex Macromolecular Architectures written by Nikos Hadjichristidis and published by John Wiley & Sons. This book was released on 2011-04-20 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of CMA (complex macromolecular architecture) stands at the cutting edge of materials science, and has been a locus of intense research activity in recent years. This book gives an extensive description of the synthesis, characterization, and self-assembly of recently-developed advanced architectural materials with a number of potential applications. The architectural polymers, including bio-conjugated hybrid polymers with poly(amino acid)s and gluco-polymers, star-branched and dendrimer-like hyperbranched polymers, cyclic polymers, dendrigraft polymers, rod-coil and helix-coil block copolymers, are introduced chapter by chapter in the book. In particular, the book also emphasizes the topic of synthetic breakthroughs by living/controlled polymerization since 2000. Furthermore, renowned authors contribute on special topics such as helical polyisocyanates, metallopolymers, stereospecific polymers, hydrogen-bonded supramolecular polymers, conjugated polymers, and polyrotaxanes, which have attracted considerable interest as novel polymer materials with potential future applications. In addition, recent advances in reactive blending achieved with well-defined end-functionalized polymers are discussed from an industrial point of view. Topics on polymer-based nanotechnologies, including self-assembled architectures and suprastructures, nano-structured materials and devices, nanofabrication, surface nanostructures, and their AFM imaging analysis of hetero-phased polymers are also included. Provides comprehensive coverage of recently developed advanced architectural materials Covers hot new areas such as: click chemistry; chain walking; polyhomologation; ADMET Edited by highly regarded scientists in the field Contains contributions from 26 leading experts from Europe, North America, and Asia Researchers in academia and industry specializing in polymer chemistry will find this book to be an ideal survey of the most recent advances in the area. The book is also suitable as supplementary reading for students enrolled in Polymer Synthetic Chemistry, Polymer Synthesis, Polymer Design, Advanced Polymer Chemistry, Soft Matter Science, and Materials Science courses. Color versions of selected figures can be found at www.wiley.com/go/hadjichristidis

Download or read book Amphiphilic Block Copolymers written by and published by . This book was released on 2015 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis Self Assembly and Modification of Poly vinylpyridine Based Block Copolymers for the Creation of Well Ordered Charged Nanostructures written by Brandon Aubrey Fultz and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation investigates the use of block copolymer self-assembly to create nanostructures with unique domain properties. Precise control over nanoscale feature size and properties of materials has become increasingly more important to keep up the ever-decreasing size of technology. Bottom-up approaches using block copolymers has been progressively more attractive due to their ability to autonomously self-assembly into an array of complex morphologies with features sizes as small as 2-3 nanometers. Modifications of these systems has generally been limited to only one domain as the processes under which modifications are carried out generally result in the disruption or destruction of the underlying morphology. We originally set out to create a block polymer system containing poly(vinylpyridine) (PVP) segments which can undergo several transformations such as protonation, metal coordination, or quaternization. By coupling PVP segments with poly(tert-butyl methacrylate), we believed that a well-ordered charged mosaic containing segregated opposite charges could be created without disruption of the underlying morphology. Thin films of hexagonally packed P4VP cylinders were self-assembled perpendicular to the surface and subsequently treated with bromoethane vapor at various durations to quaternize pyridinyl nitrogens. The PtBMA matrix was then partially hydrolyzed to poly(methacrylic acid), PMAA, through HCl vapor treatment followed by neutralization by brief submersion in KOH solution. Using techniques such as AFM, contact angle testing, and ToF-SIMS, we were able to determine the success of these transformations as well as methodologies in which structural morphology was maintained. An additional exploration into the use of tris(trimethylsilyl)silane (TTMSS) as non-toxic alternative to tin hydrides using only light was investigated as a method to remove reversible addition-fragmentation transfer (RAFT) chain transfer agents. As the end group removal from PVP polymers derived from RAFT has to our knowledge never been reported, we felt that these results would be invaluable to the scientific community due to the ubiquitous use of PVP in many systems. Not only was TTMSS found to be an effective reagent for RAFT removal of PVP polymers, it was also found to be effective for the removal of RAFT end groups from polystyrene which has been generally reported in literature to be difficult due to the stability of the benzyl radical. Reactions were found to be complete for most polymers in less than 2 hours whereas, other reported reagents typically took 24 hours or as much as 1 week.

Download or read book Part I Morphology Transformation of Block Copolymer Micelles Containing Quantum Dots in the Corona written by Meng Zhang and published by . This book was released on 2013 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Block Copolymer Self assembly and Application for Polymer Electrodes written by Sirikorn Chasvised and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is part of the global effort to find alternative energies to those generating CO2, a greenhouse gas. Indeed, electrodes are herein developed to produce hydrogen from the electrolysis of water. Specifically, block copolymers were developed for use as a binder in ink formulations for electrode screen printing. After presenting a state of the art in the first chapter, we decided to study the effect of microwaves on the self-assembly and the hierarchical structuration of our first polymer binder, a block copolymer (MBM) based on methyl methacrylate (MMA) and butyl acrylate (BuA). The polymer films were annealed under microwave irradiation of 60 seconds at 10 watts. Atomic force microscopy (AFM) was used to study the orientation of the nano-segregation without destruction of the microstructure. Then this MBM copolymer was used as a binder to produce polymer electrodes by screen printing. The MBM is mixed with conductive graphite particles and then printed on the NAFION substrate to produce an electrode. These electrodes were functionalized with a ruthenium catalyst supplied by the group of Prof. Antoni Llobet and were used in the water oxidation process. We then worked on the synthesis and film structuration of a second block copolymer based on poly (3-hexylthiophene) (P3HT). The conjugated copolymer P3HT-b-PMMA was synthesized by coupling reaction via "click" chemistry. We demonstrate changes in the self-assembly morphology of the copolymer, by introducing an ionic group at the binding unit between the two blocks. Second, we use microwave annealing to destroy the P3HT fibrils. We observe that after annealing at 30W for 1 minute the fibrils disappear and highly ordered morphologies are successfully created. Finally, we present the synthesis of a new macromolecular catalyst based on P3HT to be integrated into the electrode for the production of hydrogen (reduction of protons). A simple, copper-free cycloaddition process is presented to couple a complex cobalt catalyst (provided by Vincent Artero's group) and the polymer. The electrochemical properties of the P3HT-Co catalyst were characterized by cyclic voltammetry.

Download or read book Synthesis and Self assembly of Poly 3 hexylthiophene Based Block Copolymers written by 林國輝 and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis Characterization and Self assembly of Amphiphilic Block Copolymers written by Xiaojun Wang and published by . This book was released on 2012 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents a review on state-of-the-art research of well-defined charged block copolymers, including synthesis, characterization, bulk morphology and self-assembly in aqueous solution of amphiphilic block polyelectrolytes. In Chapter 1, as a general introduction, experimental observations and theoretical calculations devoted towards understanding morphological behavior in charged block copolymer systems are reviewed along with some of the new emerging research directions. Further investigation of charged systems is urged in order to fully understand their morphological behavior and to directly target structures for the tremendous potential in technological applications. Following this background, in Chapters 2, 3, 4 and 5 are presented the design and synthesis of a series of well-defined block copolymers composed of charged and neutral block copolymers with full characterization: sulfonated polystyrene-b-fluorinated polyisoprene (sPS-b-fPI) and polystyrene-b-sulfonated poly(1,3-cyclohexadiene) (PS-b-sPCHD). Their bulk morphological behaviors in melts and self-assembly of sPS-b-fPI, PS-b-sPCHD in water were investigated. Some unique behaviors of sPS-b-fPI were discovered. The mechanisms for formation of novel nanostructures in aqueous solution are discussed in details in Chapter 4. Spherical and vesicular structures were formed from strong electrolyte block copolymers, e.g. PS-bsPCHD. Detailed light scattering and transmission electron microscopy were applied to characterize these structures. The abnormal formation of vesicles as well as microstructure effects on self-assembly is discussed in Chapter 5. In Chapter 6, we describe the successful synthesis of a well-defined acid-based block copolymers containing polyisoprene while maintaining the integrity of the functionality (double bonds) of polyisoprene. A general purification method is also presented in order to remove homo polyisoprene, polystyrene, and PS-b-PI in the di-, and tri-block copolymers. The self-assembly of PS-b-PI-b-PAA triblock terpolymers was studied in order to form multicompartmental structures in aqueous environments. In the last Chapter 7, detailed synthesis and characterization of a novel conjugate: poly(L-leucine) grafted hyaluronan (HA) (HA-g-PLeu) are presented. This work describes a new method to synthesize HA-g-PLeu via a "grafting onto" strategy. Due to the amphiphilic nature of this graft copolymers, a "local network" formed by self-assembly which was characterized by atomic force microscopy and light scattering. The secondary structure of the polypeptide was revealed by circular dichroism.

Download or read book Mambo mortale written by Landesstelle Jugendschutz and published by . This book was released on 1990 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Solution State Self assembly of Linear dendritic Block Copolymers written by Kristoffer Keith Stokes and published by . This book was released on 2007 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Linear-dendritic block copolymers consisting of a poly(styrene) linear block and poly(amidoamine) dendrimer block were synthesized and examined for their ability to self-assemble in both aqueous environments and organic/aqueous mixtures. These polymers were shown to assemble into vesicle structures under a variety of conditions. Furthermore, size measurements of the dendritic portion were taken by means of Langmuir-Blodgett isotherms, demonstrating both the steric area, as well as the electrostatic area occupied by the dendrimer in a monolayer. Further studies into the rapid synthesis of such systems were also undertaken, with a particular interest in use of the so-called "click" reaction to be used as a facile means toward block copolymer synthesis.