Download or read book Special Issue Structure and Dynamics of Polymer Gels written by Isao Ando and published by . This book was released on 2000 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure and Dynamics of Associative Polymer Gels written by Ameya Rao and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Associative polymers have attracted wide attention for applications spanning biomedicine, soft robotics, and rheological modification due to their unique viscoelastic and stimuli-responsive properties imparted by their dynamic bonds. However, predicting the response of associative polymer networks remains a challenge due to the interplay between chain and bond dynamics on various timescales, which governs their properties such as self-diffusion, relaxation, and creep. In this thesis, a combined experimental and computation approach was used to provide new insight into the structure and dynamics of associative networks on various length and time scales, with the goal of understanding effects of key molecular parameters on their macroscopic behavior. The first part of this thesis studied molecular relaxation and self-diffusion of a model associative network formed by artificial coiled-coil proteins with a well-defined architecture. The combination of forced Rayleigh scattering (FRS) and neutron spin-echo (NSE) spectroscopy provided evidence for several regimes of gel relaxation behavior across a wide length scale range, including subdiffusive caging and two distinct regimes of apparent superdiffusion before terminal Fickian diffusion. The submolecular relaxation dynamics were further probed by varying the strand length and chain concentration, illustrating changes in segmental motion that reflected the underlying network design. Importantly, segmental relaxation rates were found to collapse onto a master curve when rescaled by the static inter-junction spacing measured by neutron scattering, indicating self-similar dynamics even in networks with different chain architecture and concentration. Furthermore, the presence of two distinct superdiffusive regimes on intermediate length scales suggested the existence of multiple origins for anomalous diffusion in associative systems, reflecting a complex interplay between distinct molecular states not captured by current theories. To obtain further insight into the molecular mechanisms underlying associative network dynamics, a coarse-grained bead-spring model was developed and implemented via Brownian dynamics simulations. Associative polymers were conceptualized as linear chains containing regularly spaced stickers interacting with a mean-field background, obviating the need to explicitly model multi-chain interactions and reducing computational cost. The simulations demonstrated the coexistence of multiple diffusive modes, termed walking and hopping, that give rise to the superdiffusive behavior seen experimentally. Importantly, the two superdiffusive regimes were found to occur by distinct mechanisms, with the lower regime occurring due to a transition between multiple walking modes (irrespective of the hopping mode) and the upper regime occurring due the onset of molecular hopping. Molecular hopping was shown to be important only in kinetics-limited systems, where the sticker association/dissociation dynamics are slower than the intrinsic Rouse relaxation of the network strands. The simulations were also used to probe the effects of molecular parameters such as the sticker density, chain concentration, and association/dissociation kinetics on self-diffusion. Notably, the results demonstrated the importance of loops in enabling chains with high sticker density to hop, whereas the mean-field prediction of purely Fickian diffusion of all length scales was recovered at high chain concentration where the hopping mode was effectively suppressed. Analytical theories were formulated to predict the characteristic walking and hopping diffusivities from the chain topological statistics and dissociation/association timescales, finding qualitative agreement with simulation. Finally, the last part of the thesis explored the possible contribution of multi-chain correlations toward network dynamics on different length scales, effects that are not captured by single-chain conceptualizations commonly used. Structural characterization of a model associative protein gel using small-angle and ultra-small-angle neutron scattering provided evidence for a previously unobserved static correlation length larger than the inter-junction spacing, indicating inhomogeneity in the chain density distribution in the gel. Self-diffusion measurements suggested a caging effect induced by this large-scale correlation length in governing a transition between distinct slow and fast diffusive modes. Finally, a comparison to the single-sticker dissociation time inferred from tracer diffusion measurements supported the single-chain mechanisms of walking and hopping as previously conceptualized, with the step size of the slow mode commensurate with the length of the bridging strands and the transition timescale to the fast mode consistent with the onset of hopping via dissociation of all stickers on a chain.
Download or read book Advancements in Gel Science A Special Issue in Memory of Toyoichi Tanaka written by Masayuki Tokita and published by MDPI. This book was released on 2019-08-19 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: A gel is a state of matter that consists of a three-dimensional cross-linked polymer network and a large amount of solvent. Because of their structural characteristics, gels play important roles in science and technology. The science of gels has attracted much attention since the discovery of the volume phase transition by Professor Toyoichi Tanala at MIT in 1978. MDPI planned to publish a Special Issue in Gels to celebrate the 40th anniversary of this discovery, which received submissions of 13 original papers and one review from various areas of science. We believe that readers will find this Special Issue informative as to the recent advancements of gel research and the broad background of gel science.
Download or read book NIST Special Publication written by and published by . This book was released on 1988 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Reports on NMR Spectroscopy written by and published by Academic Press. This book was released on 1997-06-24 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: NMR is used in all areas of modern science, and its applications continue to grow. In 1995 we celebrated the 50th anniversary of the discovery of NMR Spectroscopy and almost 30 years since the appearance of the firstvolume of Annual Reports on NMR Spectroscopy. During these years, a large and diverse collection of topics have been covered, and the contents of Volume 34 are no exception. This volume consists of six chapters covering a wide range of polymer science topics. Each chapter demonstrates the unique ability of NMR to provide information of both general and special interests.
Download or read book Molecular Gels written by Richard G Weiss and published by Royal Society of Chemistry. This book was released on 2018-08-06 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: An authoritative resource covering the latest developments in different types of gels.
Download or read book NBS Special Publication written by and published by . This book was released on 1968 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure and Dynamics of Polymer and Colloidal Systems written by Redouane Borsali and published by . This book was released on 2014-01-15 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physical Gels from Biological and Synthetic Polymers written by Madeleine Djabourov and published by Cambridge University Press. This book was released on 2013-05-16 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting a unique perspective on state-of-the-art physical gels, this interdisciplinary guide provides a complete, critical analysis of the field and highlights recent developments. It shows the interconnections between the key aspects of gels, from molecules and structure through to rheological and functional properties, with each chapter focusing on a different class of gel. There is also a final chapter covering innovative systems and applications, providing the information needed to understand current and future practical applications of gels in the pharmaceutical, agricultural, cosmetic, chemical and food industries. Many research teams are involved in the field of gels, including theoreticians, experimentalists and chemical engineers, but this interdisciplinary book collates and rationalises the many different points of view to provide a clear understanding of these complex systems for researchers and graduate students.
Download or read book Structure and Dynamics of Confined Polymers written by John J. Kasianowicz and published by Springer Science & Business Media. This book was released on 2002-07-31 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers are essential to biology because they can have enough stable degrees of freedom to store the molecular code of heredity and to express the sequences needed to manufacture new molecules. Through these they perform or control virtually every function in life. Although some biopolymers are created and spend their entire career in the relatively large free space inside cells or organelles, many biopolymers must migrate through a narrow passageway to get to their targeted destination. This suggests the questions: How does confining a polymer affect its behavior and function? What does that tell us about the interactions between the monomers that comprise the polymer and the molecules that confine it? Can we design and build devices that mimic the functions of these nanoscale systems? The NATO Advanced Research Workshop brought together for four days in Bikal, Hungary over forty experts in experimental and theoretical biophysics, molecular biology, biophysical chemistry, and biochemistry interested in these questions. Their papers collected in this book provide insight on biological processes involving confinement and form a basis for new biotechnological applications using polymers. In his paper Edmund DiMarzio asks: What is so special about polymers? Why are polymers so prevalent in living things? The chemist says the reason is that a protein made of N amino acids can have any of 20 different kinds at each position along the chain, resulting in 20 N different polymers, and that the complexity of life lies in this variety.
Download or read book Polymer Gels written by D. DeRossi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains a series of papers originally presented at the Symposium on Polymer Gels organized and sponsored by the Research Group on Polymer Gels,The Society of Polymer Science of Japan and co-sponsored by the Science and Technology Agency (ST A) and MIT!, Japan. The Symposium took place at Tsukuba Science City on 18th and 19th September, 1989. Recognized experts in their fields were invited to speak and there was a strong attendance from government, academic and industrial research centers. The purpose of the Symposium was to review the state of the art and to present and discuss recent progress in the understanding of the behavioral properties of polymer gels and their application to biomedical, environmental and robotic fields. Most of the papers and related discussions concentrated on the swelling behavior of hydrogels and chemomechanical systems, both artificial and naturally occurring, in which external stimuli of a physical or chemical nature control energy transformation or signal transduction. The recent great interest in chemomechanical systems based on polymer gels has stimulated considerable effort towards the development of new sensors and actuators, controllable membrane separation processes, and delivery systems in which the functions of sensing, processing and actuation are all built into the polymeric network device. Artificial chemomechanical systems, through the use of environmentally sensitive polymer gels, are emerging as interesting materials for mimicking basic processes previously only confined to the biological world, and commercially viable applications are also foreseen in the not-too-distant future.
Download or read book Special Issue on Structure Vs Mechanical Behavior of Polymers written by and published by . This book was released on 1974 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymeric Drug Delivery Systems written by Glen S. Kwon and published by CRC Press. This book was released on 2005-04-12 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emphasizing four major classes of polymers for drug delivery-water-soluble polymers, hydrogels, biodegradable polymers, and polymer assemblies-this reference surveys efforts to adapt, modify, and tailor polymers for challenging molecules such as poorly water-soluble compounds, peptides/proteins, and plasmid DNA.
Download or read book Hydrogels Based on Natural Polymers written by Yu Chen and published by Elsevier. This book was released on 2019-10-23 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogels Based on Natural Polymers presents the latest research on natural polymer-based hydrogels, covering fundamentals, preparation methods, synthetic pathways, advanced properties, major application areas, and novel characterization techniques. The advantages and disadvantages of each natural polymer-based hydrogel are also discussed, enabling preparation tactics for specific properties and applications. Sections cover fundamentals, development, characteristics, structures and properties. Additional chapters cover presentation methods and properties based on natural polymers, including physical and chemical properties, stimuli-responsive properties, self-healing properties, and biological properties. The final section presents major applications areas, including the biomedical field, agriculture, water treatments, and the food industry. This is a highly valuable resource for academic researchers, scientists and advanced students working with hydrogels and natural polymers, as well as across the fields of polymer science, polymer chemistry, plastics engineering, biopolymers and biomaterials. The detailed information will also be of great interest to scientists and R&D professionals, product designers, technicians and engineers across industries. Provides systematic coverage of all aspects of hydrogels based on natural polymers, including fundamentals, preparation methods, properties and characterization Offers a balanced assessment of the specific properties and possibilities offered by different natural polymer-based hydrogels, drawing on innovative research Examines cutting-edge applications across biomedicine, agriculture, water treatments, and the food industry
Download or read book Computer Simulations of Polymer Gels written by Natasha Kamerlin and published by . This book was released on 2017 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Physics of Polymers written by Gert R. Strobl and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymer physics is one of the key courses not only in polymer science but also in material science. In his textbook Strobl presents the elements of polymer physics to the necessary extent in a very didactical way. His main focus is on the concepts and major phenomena of polymer physics, not just on mere physical methods. He has written the book in a personal style evaluating the concepts he is dealing with. Every student in polymer and materials science will be happy to have it on his shelf.
Download or read book Polymer Physics written by Michael Rubinstein and published by OUP Oxford. This book was released on 2003-06-26 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymer Physics provides and introduction to the field for upper level undergraduates and first year graduate students. Any student with a working knowledge of calculus, physics and chemistry should be able to read this book. The essential tools of the polymer physical chemist or engineer are derived in this book without skipping any steps.
