Ejection Of Single Flexible Polymer Chains From A Disc Like Confined Space Through A Nano Channel To A Nano Slit Studied By Molecular Dynamics Simulations

The behavior of polymer solutions in simple shear flows has been the subject of considerable research in the past. On the other hand, reports on polymers in elongational flow have appeared comparatively recently in the literature. Elongational flow with an inherent low vorticity is known to be more effective in extending polymer chains than simple shear flow and thus is more interesting from the point of view of basic (molecular chain dynamics at high deformation) and applied polymer science (rheology, fiber extrusion, drag reduction, flow through porous media). Undoubtly, one landmark in the field of polymer dynamics in elongational flow was the notion of critical strain-rate for chain extension, initially put forward by A. Peterlin (1966) and later refined into the "coil-stretching" transition by P. G. de Gennes and H. Hinch (1974). In the two decades which followed, significant progress in the understanding of chain conformation in "strong" flow has been accomplished through a combination of advances in instrumentation, computation techniques and theoretical studies. As a result of the multidisciplinary nature of the field, information on polymer chains in "strong" flow is accessible only from reviews and research papers scattered in disparate scientific journals. An important objective of this book is to remedy that situation by providing the reader with up-to-date knowledge in a single volume. The editors therefore invited leading specialists to provide both fundamental and applied information on the multiple facets of chain deformation in elongational flow.

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.

Academic and industrial research around polymer-based colloids is huge, driven both by the development of mature technologies, e.g. latexes for coatings, as well as the advancement of new materials and applications, such as building blocks for 2D/3D structures and medicine. Edited by two world-renowned leaders in polymer science and engineering, this is a fundamental text for the field. Based on a specialised course by the editors, this book provides the reader with an invaluable single source of reference. The first section describes formation, explaining basic properties of emulsions and dispersion polymerization, microfluidic approaches to produce polymer-based colloids and formation via directed self-assembly. The next section details characterisation methodologies from microscopy and small angle scattering, to surface science and simulations. The final chapters close with applications, including Pickering emulsions and molecular engineering for materials development. A comprehensive guide to polymer colloids, with contributions by leaders in their respective areas, this book is a must-have for researchers and practitioners working across polymers, soft matter and chemical and molecular engineering.

The second edition of Extrusion is designed to aid operators, engineers, and managers in extrusion processing in quickly answering practical day-to-day questions. The first part of the book provides the fundamental principles, for operators and engineers, of polymeric materials extrusion processing in single and twin screw extruders. The next section covers advanced topics including troubleshooting, auxiliary equipment, and coextrusion for operators, engineers, and managers. The final part provides applications case studies in key areas for engineers such as compounding, blown film, extrusion blow molding, coating, foam, and reprocessing. This practical guide to extrusion brings together both equipment and materials processing aspects. It covers basic and advanced topics, for reference and training, in thermoplastics processing in the extruder. Detailed reference data are provided on such important operating conditions as temperatures, start-up procedures, shear rates, pressure drops, and safety. A practical guide to the selection, design and optimization of extrusion processes and equipment Designed to improve production efficiency and product quality Focuses on practical fault analysis and troubleshooting techniques

Early History of the Recognition of Molecular Biochirality, by Joseph Gal, Pedro Cintas Synthesis and Chirality of Amino Acids Under Interstellar Conditions, by Chaitanya Giri, Fred Goesmann, Cornelia Meinert, Amanda C. Evans, Uwe J. Meierhenrich Chemical and Physical Models for the Emergence of Biological Homochirality, by son E. Hein, Dragos Gherase, Donna G. Blackmond Biomolecules at Interfaces: Chiral, Naturally, by Arántzazu González-Campo and David B. Amabilino Stochastic Mirror Symmetry Breaking: Theoretical Models and Simulation of Experiments, by Celia Blanco, David Hochberg Self-Assembly of Dendritic Dipeptides as a Model of Chiral Selection in Primitive Biological Systems, by Brad M. Rosen, Cécile Roche, Virgil Percec Chirality and Protein Biosynthesis, by Sindrila Dutta Banik, Nilashis Nandi

Nanoscience is not physics, chemistry, engineering or biology. It is all of them, and it is time for a text that integrates the disciplines. This is such a text, aimed at advanced undergraduates and beginning graduate students in the sciences. The consequences of smallness and quantum behaviour are well known and described Richard Feynman's visionary essay 'There's Plenty of Room at the Bottom' (which is reproduced in this book). Another, critical, but thus far neglected, aspect of nanoscience is the complexity of nanostructures. Hundreds, thousands or hundreds of thousands of atoms make up systems that are complex enough to show what is fashionably called 'emergent behaviour'. Quite new phenomena arise from rare configurations of the system. Examples are the Kramer's theory of reactions (Chapter 3), the Marcus theory of electron transfer (Chapter 8), and enzyme catalysis, molecular motors, and fluctuations in gene expression and splicing, all covered in the final Chapter on Nanobiology. The book is divided into three parts. Part I (The Basics) is a self-contained introduction to quantum mechanics, statistical mechanics and chemical kinetics, calling on no more than basic college calculus. A conceptual approach and an array of examples and conceptual problems will allow even those without the mathematical tools to grasp much of what is important. Part II (The Tools) covers microscopy, single molecule manipulation and measurement, nanofabrication and self-assembly. Part III (Applications) covers electrons in nanostructures, molecular electronics, nano-materials and nanobiology. Each chapter starts with a survey of the required basics, but ends by making contact with current research literature.

This book is meant to serve as a textbook for beginners in the field of nanoscience and nanotechnology. It can also be used as additional reading in this multifaceted area. It covers the entire spectrum of nanoscience and technology: introduction, terminology, historical perspectives of this domain of science, unique and widely differing properties, advances in the various synthesis, consolidation and characterization techniques, applications of nanoscience and technology and emerging materials and technologies.