Download or read book Poly ionic Liquid Thin Films Via Surface initiated Ring opening Metathesis Polymerization written by Ian Gitata Njoroge and published by . This book was released on 2017 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Conformal Polymer Thin Films on Structurally Complex Surfaces by Initiated Chemical Vapor Deposition written by Chia-Yun (Sharon) Hsieh and published by . This book was released on 2016 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Initiated chemical vapor deposition (iCVD) is a novel CVD technique for forming polymer thin films. Compared to traditional thermal and plasma CVD methods, iCVD operates at low substrate temperature and low power conditions. This has the benefit of enabling well-defined reaction pathways for polymerization that lead to stoichiometric polymers. The iCVD approach has been investigated for many polymer chemistries and the resulting iCVD polymers have been shown to possess analogous structures and properties as bulk polymers from liquid phase synthesis. Among iCVD reactions, free radical polymerization is the most common, where vinyl monomers can be polymerized with peroxide free radical initiators. Recently, cationic ring opening polymerization via iCVD was demonstrated by applying boron trifluoride diethyl etherate as a cationic initiator for the polymerization of ethylene oxide. This work will demonstrate for the first time the iCVD synthesis of polyglycidol (PGL) via cationic ring opening polymerization of glycidol. iCVD PGL shows similar structure and properties as liquid-synthesized PGL reported in literature based on spectroscopic analysis. Furthermore, the iCVD deposition behavior under different modes of iCVD polymerization environment - surface-driven, gas-driven, and supersaturation - will be discussed for forming polyglycidol (PGL), poly(2-hydroxyethyl methacrylate) (PHEMA), poly(tetrafluoroethylene) (PTFE) and polyvinylpyrrolidone (PVP) coatings on structurally complex substrates, including nanopores, nanorods, and microstructures. Two major parameters Pm/Psat that represents the ratio of the partial pressure of the monomer to its saturation pressure, and Knudsen number (Kn) will be evaluated and related with the observed deposition behavior. Surface-driven iCVD of PGL and PHEMA have been found to conformally deposit in nanoporous TiO2 and microcatheters by carefully controlling Pm/Psat over a wide range of Kn. However, with gas-driven iCVD of PTFE, although conformal coatings have been achieved on micropillars and nanorods, coating within nanoporous networks at very large Kn was difficult even with careful control of Pm/Psat. It is believed that the PTFE polymerization is significantly driven by gas phase reactions that are not well controlled with a surface Pm/Psat parameter and, by moving to smaller and more confined features, the gas phase chemistries dominate and interfere with surface polymerization. By controlling Pm/Psat > 1, i.e. in a supersaturated monomer state, a recent iCVD processing discovery was made. Under supersaturation conditions, PVP was found to selectively grow on certain material surfaces and not others. This is believed to be due to differences in wettability of the monomer that dictates where the polymer grows, and enables directed patterning through iCVD. With the ability to deposit polymer coatings on different substrates, this work will illustrate a number of applications that highlight iCVD as an enabling technology. iCVD of PHEMA on ventricular catheters is found to be an effective coating for reducing undesired cell attachment in vitro by 77% after 17 days in cultured media compared to bare catheters, and so has the potential for improving catheter viability and reliability. iCVD of PTFE on silicon micropillars and nickel nanorod arrays is able to produce effective non-wetting (superhydrophobic) surface structures for enhancing latent heat transfer. iCVD of PGL in mesoporous TiO2 nanoparticle networks produces polymer nanocomposites with ultrahigh nanofiller loading (>80 wt%), offering a valuable platform for studying polymer nanocomposites with uniform and ultrahigh loading that exceed conventional processing limits (10-15 wt%) due to filler particle aggregation. As a result, the PGL glass transition temperature is found to increase significantly by 50-60 ℗ʻC compared to bulk PGL films without TiO2 nanofiller. The enhanced glass transition is attributed to appreciable hydrogen bonding interactions between PGL and TiO2.

Download or read book Surface initiated Ring opening Metathesis Polymerization written by Carlos Andres Escobar and published by . This book was released on 2014 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthetic Applications written by Rajender S. Varma and published by Walter de Gruyter GmbH & Co KG. This book was released on 2022-05-09 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic nanocatalysts are an important tool for greener catalytic processes due to the ease of their removal from a reaction medium. This book explores different magnetic nanocatalysts, their use in synthesis, and their recyclability. Topics covered include magnetic nanocatalysts for S-S bond formation, N-hetercycle formation, C-heteroatom bond formation, silica-supported catalysts, multicomponent reactions, and their recyclability.

Download or read book Synthesis and Characterization of Functional Organic Thin Films by Surface Initiated Polymerizations written by Jianxin Feng and published by . This book was released on 2005 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes the synthesis of AIBN type initiators and their applications for surface initiated polymerization (SIP). It was found that the structure and quality of self-assembled monolayers (SAMs) of the initiators plays an important role in the formation of polymer brushes and affect their thickness and grafting density. To determine the effect of molecular weight on the growth of polymer brushes, tethered polymers were removed from the surfaces and analyzed by gel permeation chromatography (GPC). It was found that M n of polystyrene (PS) brushes is higher than that of PS formed in the bulk and the increase in thickness of the brushes is mainly attributed to the increase of grafting density rather than that of molecular weight. We also designed and synthesized dimethylamino-terminated monolayers for photoinduced surface polymerization on gold. Poly(methyl methacrylate) (PMMA) and PS brushes were successfully synthesized by using this type of novel initiator and the mechanism of the initiation was studied. We also synthesized binary brushes of PS and PMMA from an AIBN type free radical initiating SAM by using a two-step polymerization. We employed refection adsorption infrared spectroscopy (RAIRS) and x-ray photoelectron spectroscopy (XPS) to determine the composition of mixed polymer brushes. These brushes respond to various solvents, and this response is reversible. Treatment with THF brings both PS and PMMA to the air/liquid interface, whereas treatment in cyclohexane and isobutanol brings PS and PMMA to the air/liquid interface, respectively. The surface properties of the mixed brushes were further studied by atomic force microscopy (AFM). We successfully prepared amphiphilic mixed brushes of PS and polyacrylamide (PAAM) by using a "grafting-from" method on silicon. A novel azo-initiator was synthesized and used for formation of the mixed brushes through a two-step polymerization. Highly polar solvents like DMF and DMSO were used in the polymerization of PAAM. The mixed brushes show rapid switching in selective and nonselective solvents. The wettability of the surface can be changed from hydrophobic to hydrophilic states within one minute by just rinsing with neutral water.

Download or read book Functional Polymer Films 2 Volume Set written by Wolfgang Knoll and published by John Wiley & Sons. This book was released on 2013-02-12 with total page 1107 pages. Available in PDF, EPUB and Kindle. Book excerpt: Very thin film materials have emerged as a highly interesting and useful quasi 2D-state functionality. They have given rise to numerous applications ranging from protective and smart coatings to electronics, sensors and display technology as well as serving biological, analytical and medical purposes. The tailoring of polymer film properties and functions has become a major research field. As opposed to the traditional treatise on polymer and resin-based coatings, this one-stop reference is the first to give readers a comprehensive view of the latest macromolecular and supramolecular film-based nanotechnology. Bringing together all the important facets and state-of-the-art research, the two well-structured volumes cover film assembly and depostion, functionality and patterning, and analysis and characterization. The result is an in-depth understanding of the phenomena, ordering, scale effects, fabrication, and analysis of polymer ultrathin films. This book will be a valuable addition for Materials Scientists, Polymer Chemists, Surface Scientists, Bioengineers, Coatings Specialists, Chemical Engineers, and Scientists working in this important research field and industry.

Download or read book Polymerized Ionic Liquids written by Ali Eftekhari and published by Royal Society of Chemistry. This book was released on 2017-09-18 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series covers the fundamentals and applications of different smart material systems from renowned international experts.

Download or read book Patterning and Characterization Approaches of Polymer Thin Films written by Marvin Young Paik and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers have been used in thin film coatings as a way to produce tailor made surfaces. These thin films have been explored for use in a variety of applications to produce antifouling coatings, corrosion resistant coatings, biocompatible surfaces, and biomedical devices. Polymer brushes, polymer chains tethered to a substrate or surface, synthesized by surface-initiated polymerization have gained significant attention in recent years. As brushes offer a new pathway towards the preparation of functional surfaces and offer long term stability, even in adverse environments, they are attractive for use as high-tech coatings. Patterned polymer thin films have also seen growing interest for various applications. This dissertation will focus on the top-down direct patterning of polymer brushes and the bottom-up self-assembly of block copolymer thin films. A new approach to creating patterned polymer brushes is highlighted, which is a simpler approach than what is conventionally done. Various polymer brushes were patterned directly using electron beam lithography to create high resolution patterned polymer brushes in a single step. This method was then used to demonstrate the unique ability to create sub-surface patterns within the brush. Additionally, direct patterning was used to create high resolution patterned binary polymer brushes of PMMA and PEGMA. With this binary patterned surface, a surface that responds to its local environment was created. This thesis also details characterization techniques used in probing polymer thin films to better understand how to improve block copolymer self-assembly. By using a powerful technique called grazing incidence small angle X-ray scattering (GISAXS) on solvent vapor annealed block copolymer thin films while monitoring the solvent vapor swollen film thickness and controlling the film swelling with a nitrogen counterflow, the work presented demonstrates how to accurately determine the processing conditions necessary for the annealing process to take place. This process also provides information as to what changes are occurring during the annealing process. Another characterization technique known as near edge X-ray absorption fine structure (NEXAFS) is also highlighted. A more exact calculation of the electron escape depth (EED) for NEXAFS is done using polymer brushes as the calibration sample. With this information, we can do composition depth profiling on our polymer thin films to identify what is at the surface.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Polymer Surfaces Interfaces and Thin Films written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Self Healing Polymers written by Wolfgang H. Binder and published by John Wiley & Sons. This book was released on 2013-03-29 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-healing is a well-known phenomenon in nature: a broken bone merges after some time and if skin is damaged, the wound will stop bleeding and heals again. This concept can be mimicked in order to create polymeric materials with the ability to regenerate after they have suffered degradation or wear. Already realized applications are used in aerospace engineering, and current research in this fascinating field shows how different self-healing mechanisms proven successful by nature can be adapted to produce even more versatile materials. The book combines the knowledge of an international panel of experts in the field and provides the reader with chemical and physical concepts for self-healing polymers, including aspects of biomimetic processes of healing in nature. It shows how to design self-healing polymers and explains the dynamics in these systems. Different self-healing concepts such as encapsulated systems and supramolecular systems are detailed. Chapters on analysis and friction detection in self-healing polymers and on applications round off the book.

Download or read book CVD Polymers written by Karen K. Gleason and published by John Wiley & Sons. This book was released on 2015-04-01 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: The method of CVD (chemical vapor deposition) is a versatile technique to fabricate high-quality thin films and structured surfaces in the nanometer regime from the vapor phase. Already widely used for the deposition of inorganic materials in the semiconductor industry, CVD has become the method of choice in many applications to process polymers as well. This highly scalable technique allows for synthesizing high-purity, defect-free films and for systematically tuning their chemical, mechanical and physical properties. In addition, vapor phase processing is critical for the deposition of insoluble materials including fluoropolymers, electrically conductive polymers, and highly crosslinked organic networks. Furthermore, CVD enables the coating of substrates which would otherwise dissolve or swell upon exposure to solvents. The scope of the book encompasses CVD polymerization processes which directly translate the chemical mechanisms of traditional polymer synthesis and organic synthesis in homogeneous liquids into heterogeneous processes for the modification of solid surfaces. The book is structured into four parts, complemented by an introductory overview of the diverse process strategies for CVD of polymeric materials. The first part on the fundamentals of CVD polymers is followed by a detailed coverage of the materials chemistry of CVD polymers, including the main synthesis mechanisms and the resultant classes of materials. The third part focuses on the applications of these materials such as membrane modification and device fabrication. The final part discusses the potential for scale-up and commercialization of CVD polymers.

Download or read book Advanced Applications of Ionic Liquids written by Jamal Akhter Siddique and published by Elsevier. This book was released on 2022-11-02 with total page 569 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Applications of Ionic Liquids discusses the intersection of nanotechnology with ionic liquids (ILs) and materials, along with opportunities for advanced engineering applications in various research fields. Novel materials at nano scales with ILs creates an upsurge in the thermal and electrochemical constancy of the nano scale particles, making them ideal for industrial applications. The implementation of ILs at nano scale includes an interaction of constituents, which is beneficial for electron transfer reactions. These new composites can be implemented as sensors, electronics, catalysts and photonics. Including ILs in polymer composites enhance electrochemical consistency, govern particle size, upsurge conductivity, reduce toxicity, and more. This book is a comprehensive reference for researchers working with IL based technologies for environmental and energy applications. - Covers all industrial aspects and advanced applications of ionic liquids (ILs) - Discusses the advanced applications of ILs across multiple fields, including industrial chemistry and chemical engineering - Includes a discussion of the use of ionic liquids in functional polymers, with applications for catalysis, energy conservation, sensors, and more

Download or read book Applications of Ionic Liquids in Polymer Science and Technology written by David Mecerreyes and published by Springer. This book was released on 2015-04-08 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes the latest knowledge in the science and technology of ionic liquids and polymers in different areas. Ionic liquids (IL) are actively being investigated in polymer science and technology for a number of different applications. In the first part of the book the authors present the particular properties of ionic liquids as speciality solvents. The state-of-the art in the use of ionic liquids in polymer synthesis and modification reactions including polymer recycling is outlined. The second part focuses on the use of ionic liquids as speciality additives such as plasticizers or antistatic agents. The third part examines the use of ionic liquids in the design of functional polymers (usually called polymeric ionic liquids (PIL) or poly(ionic liquids)). Many important applications in diverse scientific and industrial areas rely on these polymers, like polymer electrolytes in electrochemical devices, building blocks in materials science, nanocomposites, gas membranes, innovative anion sensitive materials, smart surfaces, and a countless set range of emerging applications in different fields such as energy, optoelectronics, analytical chemistry, biotechnology, nanomedicine or catalysis.

Download or read book Bio Nanoparticles written by Om V. Singh and published by John Wiley & Sons. This book was released on 2015-06-22 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanoparticles are the building blocks for nanotechnology; they are better built, long lasting, cleaner, safer, and smarter products for use across industries, including communications, medicine, transportation, agriculture and other industries. Controlled size, shape, composition, crystallinity, and structure-dependent properties govern the unique properties of nanotechnology. Bio-Nanoparticles: Biosynthesis and Sustainable Biotechnological Implications explores both the basics of and advancements in nanoparticle biosynthesis. The text introduces the reader to a variety of microorganisms able to synthesize nanoparticles, provides an overview of the methodologies applied to biosynthesize nanoparticles for medical and commercial use, and gives an overview of regulations governing their use. Authored by leaders in the field, Bio-Nanoparticles: Biosynthesis and Sustainable Biotechnological Implications bridges the gap between biology and technology, and is an invaluable resource for students and researchers alike.

Download or read book Abstracts of Papers American Chemical Society written by American Chemical Society. Meeting and published by . This book was released on 1985 with total page 1174 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Controlled living Radical Polymerization written by Krzysztof Matyjaszewski and published by . This book was released on 2000 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines recent progress in controlled/living radical polymerization. The volume focuses on three synthetic methods: atom transfer radical polymerization, nitroxide mediated polymerization and degenerative transfer via addition fragmentation. In addition, the volume covers the preparation and characterization of many never before seen materials using ATRP, NMP and RAFT.