Download or read book Synthesis and Investigation of Chiral Polycarbodiimides with Reversible Dynamic Properties written by Justin Glenn Kennemur and published by . This book was released on 2010 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: polymer, helical, circular dichroism, polycarbodiimide, polyguanidine, polarimetry, conformational change.
Download or read book Unique Architectures Built on Chiral Polycarbodiimides written by Dumindika Aththanayake Siriwardane and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter one introduces the basic synthetic routes for ureas, carbodiimide monomers, polymers and strategies utilized for screw sense polymerization to achieve control chiral architectures. It also presents a comprehensive review of the most recent developments in post-polymerization modifications, properties of polycarbodiimides and their potential applications in the material sciences and bio-medical field. Chapter two illustrates the synthesis of novel Ni(II) initiators for screw sense polymerization of chiral monomers and it explained Ni(II) mediated “living” polymerization used in the synthesis of multi-arm star polymers. This star and its linear analogs have been used to conduct kinetic of polymerization and solvent tunable self-assembly behavior studies. Chapter three describes the unusual observation made years ago, that a particular chiral polymer (predominantly P or M helices) synthesized by using chiral BINOL-Ti(IV) catalysts which show specific racemization behavior when heated. This behavior was unique in more than 150 different carbodiimides we have polymerized to date. We postulated that it was due to stereocomplexation formed via racemization between two opposite helical sense. Different characterization techniques and molecular models were employed to investigate this particular observation. By enhancing helical, polycarbodiimide architectures, chapter four introduces the synthesis of hairy polymers which showed micellization in an aqueous medium. These types of amphiphilic graft co-polymers can be utilized in drug delivery applications. The synthesis and optical switching behavior of UV and thermo responsive polycarbodiimides have been illustrated in chapter five. Properties of the polymer were altered through the isomerization behavior, such as its topology and liquid crystallinity. The synthesis of various chiral designs build upon polycarbodiimide helical frameworks are also included to pursue possible future projects.
Download or read book Synthesis and Characterization of Helical Polycarbodiimide Copolymers Containing Long chain Branched kinked Alkyl Groups written by Michael W. Duff and published by . This book was released on 2015 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycarbodiimides are a class of helical rigid-rod polymers with a host of interesting properties and potential applications. One polycarbodiimides in particular, poly(N-naphthyl-N'-octadecylcarbodiimide) (PNOC), has been studied extensively and is notable for its reversible solvent-dependent chiroptical switching behavior as well as its potential application as part of an "electronic nose." It is not yet fully understood what role the octadecyl side chains play in interesting the properties of this polymer. In this work, branched and kinked alkyl groups were introduced in place of the octadecyl side chain via the synthesis of several copolymers and the effect of these changes on the properties of the polymers was evaluated. It was found that copolymers containing branched and kinked groups in place of octadecyl side chains exhibit different thermal characteristics as well as unique thin film morphologies in different solvents, however the switching behavior and chirality of the pure polymer is retained.
Download or read book Synthesis of Helical Polycarbodiimides and Their Properties written by Galappaththi De Silva and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycarbodiimides are a relatively new class of synthetic macromolecules. Their helical conformation and tunable pendant groups made them special class of polymer which displayed interesting properties. We evaluated the properties of carbodiimide polymers consisting of long chain branched aliphatic groups. Newly synthesized helical polycarbodiimides with branched aliphatic side chains were introduced to evaluate the effect of these branched alkyl chains on the properties of the polymers. These polymers displayed different thermal and lyotropic liquid crystalline properties depending on the amount of branched side chains attached to the polymer backbone. The synthesis of water-soluble polymers and their potential applications were extensively studied. The significant properties of the water-soluble polycarbodiimides were evaluated. The pH dependent behavior of self-assembled polycarbodiimides were studied. This could be a potential candidate for the nano carrier applications. In addition, we investigated biomimetic polycarbodiimides which exhibited antimicrobial and cytotoxic properties.
Download or read book Chemistry and Technology of Carbodiimides written by Henri Ulrich and published by John Wiley & Sons. This book was released on 2008-03-11 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbodiimides play an important role as condensation agents in the synthesis of polypeptides, polynucleotides, polysaccharides and numerous other chemical transformations. Chemistry and Technology of Carbodiimides is the first book to examine both the chemistry and technology of carbodiimides. This book provides a comprehensive and in-depth coverage of the synthesis and reactions of this industrially important class of chemicals while focusing on industrial applications, including the $M-sectors of biochemical synthesis, pharmaceuticals, polymers, ceramics, and herbicides. Written by a well-known authority in the field this book will prove a valuable reference tool for anyone working in this area of chemistry.
Download or read book Self Healing Polymer Based Systems written by Sabu Thomas and published by Elsevier. This book was released on 2020-07-11 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-Healing Polymer-Based Systems presents all aspects of self-healing polymeric materials, offering detailed information on fundamentals, preparation methods, technology, and applications, and drawing on the latest state-of-the-art research. The book begins by introducing self-healing polymeric systems, with a thorough explanation of underlying concepts, challenges, mechanisms, kinetic and thermodynamics, and types of chemistry involved. The second part of the book studies the main categories of self-healing polymeric material, examining elastomer-based, thermoplastic-based, and thermoset-based materials in turn. This is followed by a series of chapters that examine the very latest advances, including nanoparticles, coatings, shape memory, self-healing biomaterials, ionomers, supramolecular polymers, photoinduced and thermally induced self-healing, healing efficiency, life cycle analysis, and characterization. Finally, novel applications are presented and explained. This book serves as an essential resource for academic researchers, scientists, and graduate students in the areas of polymer properties, self-healing materials, polymer science, polymer chemistry, and materials science. In industry, this book contains highly valuable information for R&D professionals, designers, and engineers, who are looking to incorporate self-healing properties in their materials, products, or components. Provides comprehensive coverage of self-healing polymeric materials, covering principles, techniques, and applications Includes the very latest developments in the field, such as the role of nanofillers in healing, life cycle analysis of materials, and shape memory assisted healing Enables the reader to unlock the potential of self-healing polymeric materials for a range of advanced applications
Download or read book Poly lactic acid Science and Technology written by Alfonso Jiménez and published by Royal Society of Chemistry. This book was released on 2015 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive overview of the synthesis, characterisation, properties and applications of poly(lactic acid) science and technology covering scientific, ecological, social and economic issues.
Download or read book Chiroptical Molecular Switches written by Anne Marie Schoevaars and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1998 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Green Solvents for Chemistry written by William M. Nelson and published by Oxford University Press. This book was released on 2003-03-27 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to introduce the use of green solvents throughout chemistry and to provide a comprehensive reference for solvents currently applicable in green chemistry. The first section covers solvents in chemical perspective, and the second section is a guide to green solvents. Overall, this volume defines characteristics of green solvents and their current usage, and explores their importance ecologically and economically. It includes a full range of commercial, industrial, and academic green solvents, and discusses solvents in specific commercial and non-commercial practices. Green Solvents for Chemistry differs from other works on solvents in that only solvents for green chemistry are included along with their chemical properties and toxicological issues.
Download or read book Optically Active Polymers written by E. Sélégny and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first four volumes of the series on 'Charged and Reactive Polymers' have been devoted to polymers in solution (Voh. I and II) or in gel and membrane forms (Vols. III and IV). In correlation with charges, other physical or chemical properties of macro molecules have been considered. Understanding of charge and hydrophobic effects is equally important for synthetic and biopolymers or their systems. Optically Active Polymers are related to problems of the same class, since optical activity is an inherent property of both natural macromolecules as well as a great variety of polymers synthesized in the Jast twenty years. Optical activity is a physical spectral property of chiral matter caused by asymmetrical configurations, conformations and structures which have no plane and no center of symmetry and consequently have two mirror image enantiomeric forms of inverse optical rotation. The racemic mixture of chiral enantiomers is optically inactive. The most common form of optical activity was first measured at a constant wavelength by the angle of rotation of linearly polarized light. More recently the measurements have been extended to the entire range of visible and attainable ultraviolet regions where electronic transitions are observed, giving rise to the ORD technique (Optical Rotatory Dispersion). The Cotton effects appear in the region of optically active absorption bands; outside of these bands the plain curve spectrum is also dependent on all the electronic transitions of the chromophores.
Download or read book Biobased Products from Food Sector Waste written by Teresa Cecchi and published by Springer Nature. This book was released on 2021-10-18 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past, food waste has been used to produce biogas and biofuels, fertilizers, and animal feed. Using it as a feedstock for innovative biorefineries is not only an ethical issue but also a smart application of the circular economy. This book explores the zero-waste concept in the thriving biobased sector, proposing technologies and procedures to meet the sustainable development goals. The volume categorizes food waste sources and proposes an impressive number of high value-added compounds (e.g., platform chemicals, enzymes, nutraceuticals, antioxidants, organic acids, phosphate, bioadsorbents, pectin, solvents, and pigments) that can be obtained in a sequential biocascade, via chemical, biochemical, thermal, and physical technologies. The synthesis of bioplastics from food waste, their copolymerization and blending, as well as the production of biocomposites and bionanocomposite with biofillers from food scraps, are presented: eluding the cost of waste disposal, reducing biobased materials price, and avoiding using edible resources as a starting material for biobased items are the main beneficial peculiarities of the process. The Authors illustrate challenging characteristics of new biobased materials, such as their mechanical and physico-chemical features, their biodegradability, compostability, recyclability, chemical compatibility, and barrier properties. The volume also delves into socioeconomic considerations and environmental concerns related to the upcycling of food waste, as well as the safety and life cycle assessment of biobased products. Finally, the authors address how advances in digital technology can make food waste upcycling a negative-cost process and discuss best practices to practically implement the biorefinery concept. Research gaps and needs are suggested, and recommendations for food waste handling and management during this COVID-19 pandemic are provided.
Download or read book Organic Coatings written by Frank N. Jones and published by John Wiley & Sons. This book was released on 2017-10-02 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: The definitive guide to organic coatings, thoroughly revised and updated—now with coverage of a range of topics not covered in previous editions Organic Coatings: Science and Technology, Fourth Edition offers unparalleled coverageof organic coatings technology and its many applications. Written by three leading industry experts (including a new, internationally-recognized coatings scientist) it presents a systematic survey of the field, revises and updates the material from the previous edition, and features new or additional treatment of such topics as superhydrophobic, ice-phobic, antimicrobial, and self-healing coatings; sustainability, artist paints, and exterior architectural primers. making it even more relevant and useful for scientists and engineers in the field, as well as for students in coatings courses. The book incorporates up-to-date coverage of recent developments in the field with detailed discussions of the principles underlying the technology and their applications in the development, production, and uses of organic coatings. All chapters in this new edition have been updated to assure consistency and to enable extensive cross-referencing. The material presented is also applicable to the related areas of printing inks and adhesives, as well as areas within the plastics industry. This new edition Completely revises outdated chapters to ensure consistency and to enable extensive cross-referencing Correlates the empirical technology of coatings with the underlying science throughout Provides expert troubleshooting guidance for coatings scientists and technologists Features hundreds of illustrative figures and extensive references to the literature A new, internationally-recognized coatings scientist brings fresh perspective to the content. Providing a broad overview for beginners in the field of organic coatings and a handy reference for seasoned professionals, Organic Coatings: Science and Technology, Fourth Edition, gives you the information and answers you need, when you need them.
Download or read book Click Polymerization written by Anjun Qin and published by Royal Society of Chemistry. This book was released on 2018-08-28 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Click Polymerization has been edited by world renowned experts and provides an authoritative guide to this reaction type.
Download or read book Possible Scenarios for Homochirality on Earth written by Michiya Fujiki and published by . This book was released on 2019 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1978, Fred Hoyle proposed that interstellar comets carrying several viruses landed on Earth as part of the panspermia hypotheses. With respect to life, the origin of homochirality on Earth has been the greatest mystery because life cannot exist without molecular asymmetry. Many scientists have proposed several possible hypotheses to answer this long-standing L-D question. Previously, Martin Gardner raised the question about mirror symmetry and broken mirror symmetry in terms of the homochirality question in his monographs (1964 and 1990). Possible scenarios for the L-D issue can be categorized into (i) Earth and exoterrestrial origins, (ii) by-chance and necessity mechanisms, and (iii) mirror-symmetrical and non-mirror-symmetrical forces as physical and chemical origins. These scenarios should involve further great amplification mechanisms, enabling a pure L- or D-world.
Download or read book Building and Probing Small for Mechanics written by Christian Joachim and published by Springer Nature. This book was released on 2020-09-11 with total page 235 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents mechanics miniaturization trends explored step by step, starting with the example of the miniaturization of a mechanical calculator. The ultra-miniaturization of mechanical machinery is now approaching the atomic scale. In this book, molecule-gears, trains of molecule-gears, and molecule motors are studied -one molecule at a time- on a solid surface, using scanning probe manipulation protocols and in solution as demonstrated in the European project "MEMO". All scales of mechanical machinery are presented using the various lithography techniques currently available, from the submillimeter to the nanoscale. Researchers and nanomechanical engineers will find new inspirations for the construction of minute mechanical devices which can be used in diverse hostile environments, for example under radiation constraints, on the surface membrane of a living cell or immersed in liquid. The book is presented in a format accessible for university students, in particular for those at the Master and PhD levels.
Download or read book VCD Spectroscopy for Organic Chemists written by Philip J. Stephens and published by CRC Press. This book was released on 2012-06-25 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stimulated by the increasing importance of chiral molecules as pharmaceuticals and the need for enantiomerically pure drugs, techniques in chiral chemistry have been expanded and refined, especially in the areas of chromatography, asymmetric synthesis, and spectroscopic methods for chiral molecule structural characterization. In addition to synthet
