"Dynamics of Soft Matter: Neutron Applications" provides an overview of neutron scattering techniques that measure temporal and spatial correlations simultaneously, at the microscopic and/or mesoscopic scale. These techniques offer answers to new questions arising at the interface of physics, chemistry, and biology. Knowledge of the dynamics at these levels is crucial to understanding the soft matter field, which includes colloids, polymers, membranes, biological macromolecules, foams, emulsions towards biological & biomimetic systems, and phenomena involving wetting, friction, adhesion, or microfluidics.

Emphasizing the complementarities of scattering techniques with other spectroscopic ones, this volume also highlights the potential gain in combining techniques such as rheology, NMR, light scattering, dielectric spectroscopy, as well as synchrotron radiation experiments. Key areas covered include polymer science, biological materials, complex fluids and surface science.

Ionomers, that is polymers containing a low concentration of charged units along the chain, have been the subject of increasing interest during the past twenty years. The presence of ionic groups in the poly mer changes some of its properties dramatically. Increases in the modu lus and the viscosity of several orders of magnitude have been observed, and changes in the glass transition of hundreds of degrees are possible. In addition, diffusion coefficients can be modified drastically. These changes are due primarily to the presence of reversible ionic cross links in these materials. Because of the low dielectric constant of most organic polymers, the ions or ionic dipoles tend to aggregate; this aggregation process, however, is limited, because the ionic groups are covalently bonded to the organic chain. Host of the fundamental research done on these materials has been devoted to a determination of the extent of association, the structure of the aggregates, the limi ting factors, and the correlations between molecular and supermolecular structure and the resul ting properties."

Since A. Kowalsky's first report of the spectrum of cytochrome c in 1965, interest in the detection, assignment and interpretation of paramagnetic molecules has surged, especially in the last decade. Two classes of systems have played a key role in the development of the field: heme proteins and iron-sulfur proteins. These two systems are unique in many respects, one of which is that they contain well-defined chromophores, each of which can be studied in detail outside the protein matrix. They are the most successfully studied macromolecules, and the first eight and last six of the seventeen contributions to this book deal with heme and/or iron-sulfur proteins. The middle three chapters survey the progress on, and significant promise of, more difficult systems which do not possess a chromophore, but which have nevertheless yielded remarkable insights into their structure.

Since the discovery that polymer single crystals are composed of chain folded macromolecules in 1957, the crystallization of polymers has attracted considerable interest and still provides fascinating and fruitful areas of research. Only a few books have been fully devoted to the crystallization of polymers in the past. This book contains the proceedings of the NATO ARW devoted to the `Crystallization of Polymers' which took place in September 1992 at the University of Mons-Hainaut (Belgium). In view of the variety of papers devoted to the crystallization of polymers, this book will be used in the next few years as a reference book for scientists concerned in the field of polymer physical chemistry. Crystallization of Polymers is mainly devoted to the experimental and theoretical study of the crystallization of synthetic polymers. As a kinetic study of the growth of polymer crystals should always be preceded by a morphological or a structural investigation, the structure, the morphology of polymer crystals and more particularly the lamellar and supralamellar organizations, as well as the nature of the crystal amorphous interface are reviewed and discussed.

The 25th Jerusalem Symposium represents a most significant highlight in the development and history of these meetings. Living within the decimal system we have celebrated with much pleasure the lath and the 20th Jerusalem Symposia. With this one we experience a feeling of particular satisfaction because 25 years is different from, is more than, two decades and a half. It is a quarter of a century. It seems thus as if we have changed the dimension of our endeavour. In no way do we loose the sense of modesty with respect to the significance of these meetings. For the organizers, however, they do represent a continuity of efforts which we feel happy to have been able to carry out. At this occasion it seems useful to say a few words about the origin of the Jerusalem Symposia and to recall the name of a colleague who played an essential role in their creation and has been a most efficient and devoted co organizer of the seven first of them. This was Professor Ernst Bergmann, one of the most distinguished founders of Israeli Science and a world famous physico-organic chemist.

The theme and contents of this book have assumed a new significance in the light of recent ideas on nanoscience and nanotechnology, which are now beginning to influence developments in food research and food processing. The fabrication of nanoscale structures for food use relies on an in-depth understanding of thermodynamically driven interactions and self-assembly processes involving the major food structure-forming components: proteins and polysaccharides. This understanding has the potential to provide thermodynamically inspired approaches that can be used to manipulate food structures rationally in order to enhance the nutritional and health-promoting properties of foods and beverages.

This is the second volume in a series which presents the state of the art in chosen sectors of oil and fat chemistry, including its relevance to the food and pharmaceutical industries. The text in this book aims to provide an authoritative account of the use of a wide range of spectroscopic methods in the analysis of lipids, with an emphasis on topics that have attracted special attention.

This IMA Volume in Mathematics and its Applications AMORPHOUS POLYMERS AND NON-NEWTONIAN FLUIDS is in part the proceedings of a workshop which was an integral part of the 1984-85 IMA program on CONTINUUM PHYSICS AND PARTIAL DIFFERENTIAL EQUATIONS We are grateful to the Scientific Committee: Haim Brezis Constantine Dafermos Jerry Ericksen David Kinderlehrer for planning and implementing an exciting and stimulating year-long program. We espe cially thank the Program Organizers, Jerry Ericksen, David Kinderlehrer, Stephen Prager and Matthew Tirrell for organizing a workshop which brought together scientists and mathematicians in a variety of areas for a fruitful exchange of ideas. George R. Sell Hans Weinberger Preface Experiences with amorphous polymers have supplied much of the motivation for developing novel kinds of molecular theory, to try to deal with the more significant features of systems involving very large molecules with many degrees offreedom. Similarly, the observations of many unusual macroscopic phenomena has stimulated efforts to develop linear and nonlinear theories of viscoelasticity to describe them. In either event, we are confronted not with a well-established, specific set of equations, but with a variety of equations, conforming to a loose pattern and suggested by general kinds of reasoning. One challenge is to devise techniques for finding equations capable of delivering definite and reliable predictions. Related to this is the issue of discovering ways to better grasp the nature of solutions ofthose equations showing some promise."

This is the first volume of a two-volume work which summarizes in an edited format and in a fairly comprehensive manner many of the recent technical research accomplishments in the area of Elastomers. Advances in Elastomers discusses the various attempts reported on solving these problems from the point of view of the chemistry and the structure of elastomers, highlighting the drawbacks and advantages of each method. It summarize the importance of elastomers and their multiphase systems in human life and industry, and covers all the topics related to recent advances in elastomers, their blends, IPNs, composites and nanocomposites.

This first volume focuses on advances on the blends and interpenetrating networks (IPNs) of elastomers.

The purpose of the preface is to explain the book's objectives and how to use it; give warnings, disclaimers, and the like.* The main objective of Protein and Peptide Analysis by Mass Spec trometry is quite straightforward-to present authoritative, up-to-date, and practical accounts of the use of mass spectrometry in the analysis of pep tides and proteins. How to use it? Every reader will have their own particular interests and will surely be drawn toward the chapters that cover these interests. Within the remaining chapters, however, techniques are described with analytical possibilities that such a reader can then only guess at. So, read the book fully. Again, as is customary in the Methods in Molecular Biology series, the chapter format (Introduction, Materials, Methods, and Notes) allows the authors to introduce the techniques, to explain their relevance and applicability, and, above all, to provide detail-detail that represents each author's accumulated experience and enables the reader to use and benefit from these methods. So, read the book fully, and read it diligently. Warnings and disclaimers: Mass spectrometry today offers the pro tein chemist ready access to a wealth of information that is otherwise avail able only with great difficulty, or perhaps not at all. With this goal in sight, any warnings and disclaimers will almost surely be ignored. So, a warning anyway; the use of mass spectrometry might be habit forming."

This book comprehensively covers researches on enzymatic polymerization and related enzymatic approaches to produce well-defined polymers, which is valuable and promising for conducting green polymer chemistry. It consists of twelve chapters, including the following topics: The three classes of enzymes, oxidoreductases, transferases and hydrolases, have been employed as catalysts for enzymatic polymerization and modification; Well-defined polysaccharides are produced by enzymatic polymerization catalyzed by hydrolases and transferases; Hydrolase-catalyzed polycondensation and ring-opening polymerization are disclosed to produce a variety of polyesters; Polyesters are synthesized by in-vivo acyltransferase catalysis produced by microorganisms; Enzymatic polymerization catalyzed by appropriate enzymes also produces polypeptides and other polymers; Poly(aromatic)s are obtained by enzymatic polymerization catalyzed by oxidoreductases and their model complexes; Such enzymes also induce oxidative polymerization of vinyl monomers; Enzymatic modification of polymers is achieved to produce functionalized polymeric materials; The enzymatic polymerization is a green process with non-toxic catalysts, high catalyst efficiency, green solvents and renewable starting materials, and minimal by-products; Moreover, renewable resources like biomass are potentially employed as a starting substrate, producing useful polymeric materials. This book is not only educative to young polymer chemists like graduate students but also suggestive to industrial researchers, showing the importance of the future direction of polymer synthesis for maintaining a sustainable society.

The book provides a unique collection of 15 contributions by 15 internationally recognized scientists performing intensive research activity on the preparation and characterization of complex and multiphase materials based on macromolecules as well as on the evaluation and simulation of structure/properties relations. The topic is assuming a general increasing importance as providing a highly sustainable and modern approach to the present and future development of the important area of materials science and technology. The scientific route along the successive contributions goes from the controlled preparation of functional MM both by innovative polymerization reactions and preformed polymers modification (intramacromolecular complexity), to their combination with other MMs and materials to give blends and composites where new properties are conveniently achieved by morphologic complexity. The synergic behaviour of the different components in these last is obtained by reactive processing producing the necessary interfacial adhesion. Even if most examples deal with man-made MMs, biopolymers are also included. The various chapters provide in most cases an exhaustive fundamental description assisted by an up- to-date and broad list of relevant references The book is therefore an excellent informative and formative instrument for those involved in complex materials preparation and application in research and industry.

-On the Mechanisms Leading to Exfoliated Nanocomposites Prepared by Mixing By C. D. Han -Phase Behavior and Phase Transitions in AB- and ABA-type Microphase-Separated Block Copolymers By J. K. Kim, C. D. Han -New Class Materials of Organic Inorganic Hybridized Nanocrystals/Nanoparticles, and Their Assembled Microand Nano-Structure Toward Photonics By H. Oikawa, T. Onodera, A. Masuhara, H. Kasai, H. Nakanishi -Poly(substituted Methylene) Synthesis: Construction of C C Main Chain from One Carbon Unit By E. Ihara"

Analytical ultracentrifugation (AUC) is a powerful method for the characterization of polymers, biopolymers, polyelectrolytes, nanoparticles, dispersions, and other colloidal systems. The method is able to determine the molar mass, the particle size, the particle density and interaction parameters like virial coefficients and association constants. Because AUC is also a fractionation method, the determination of the molar mass distribution, the particle size distribution, and the particle density distribution is possible. A special technique, the density gradient method, allows fractionating heterogeneous samples according to their chemical nature that means being able to detect chemical heterogeneity. The book is divided into chapters concerning instrumentation, sedimentation velocity runs, density gradient runs, application examples and future developments. In particular, the detailed application chapter demonstrates the versatility and power of AUC by means of many interesting and important industrial examples. Thus the book concentrates on practical aspects rather than details of centrifugation theory.

Both authors have many years of experience in an industrial AUC research laboratory of a world leading chemical company.

Featuring practical strategies and exciting experiments, Teaching Innovations in Lipid Science addresses lipid education at a range of levels from the novice to the graduate student and teacher. Peer-reviewed contributions from internationally known specialists, describe several methods and approaches designed to create new lipid courses, modify existing courses, and serve as a basis for pursuing novel avenues of instruction. Divided into two sections, the first focuses on teaching strategies and outlines some of the barriers that lipid science specialists face when transmitting accurate information. It emphasizes the development and implementation of creative programs that foster interest in lipid science, and presents novel problem-solving approaches. It discusses strategies for involving and evaluating independent study students and explains the successful use of sample cards to teach oilseed and cereal processing. This section also provides generalized accounts of biotechnology and crop improvement and isoprenoid biochemistry, including improvement of oilseed crops and tips on explaining DNA science and crop biotechnology. The second section begins with simple demonstrations on the physical properties of lipids suitable for middle- and high school students. It follows with more complex experiments on analyzing lipids in food oils, plasma, and milk utilizing thin layer chromatography, gas chromatography, and high performance liquid chromatography. Contributions include information on convenient enzyme test kits with exercises that can translate to a lab course beginning with chromatographic methods for lipid analysis. The final chapter presents theory and experiments for studying lipid metabolism in the plastid by describing preparation methods, studying metabolite uptake, and pathway analysis.

Structure formation in crystallizing polymers, as occurring during processing, has not been treated so far in a coherent form. This fact explains, why this monograph is written as the ?rst book devoted to this subject. A quarter of a century ago the underdevelopment of this subject was obvious. Trial and error dominated. In fact, other apposite subjects as polymer melt rheology or heat transfer, had reached high levels. A great number of books has been devoted to them. Mold ?lling of amorphous polymers and the solidi?cation of these polymers by vitri?cation can nowadays be simulated numerically with a high degree of accuracy. In the solidi?ed sample even residual stresses and corresponding birefringence effects can accurately be 1 calculated . However, semicrystalline polymers, which form the majority of industrial po- mers, have been excluded from these considerations for good reasons. In fact, great uncertainties existed about the formation of quality determining crystalline str- tures. In particular, polyole?ns suffered from this shortcoming. In 1983 this fact instigated the polymer research group at the Johannes Kepler University in Linz to start with pertinent activities. The urgency of this kind of studies becomes evident, if advantages and hitches of these polymers are considered. 1. Versatility of processing: Injection molding into a great variety of shapes and sizes, from thin walled beakers to garden chairs, not to forget pipe and pro?le extrusion, cable coating, ?ber spinning, ?lm blowing. 2. Product qualities: Ductility, low density, good electric insulation, corrosion resistance, surface quality.

Hansen solubility parameters (HSPs) are used to predict molecular affinities, solubility, and solubility-related phenomena. Revised and updated throughout, Hansen Solubility Parameters: A User's Handbook, Second Edition features the three Hansen solubility parameters for over 1200 chemicals and correlations for over 400 materials including polymers, inorganic salts, and biological materials.

To update his groundbreaking handbook with the latest advances and perspectives, Charles M. Hansen has invited five renowned experts to share their work, theories, and practical applications involving HSPs. New discussions include a new statistical thermodynamics approach for confirming existing HSPs and how they fit into other thermodynamic theories for polymer solutions. Entirely new chapters examine the prediction of environmental stress cracking as well as absorption and diffusion in polymers. Highlighting recent findings on interactions with DNA, the treatment of biological materials also includesskin tissue, proteins, natural fibers, and cholesterol. The book also covers the latest applications of HSPs, such as ozone-safe "designer" solvents, protective clothing, drug delivery systems, and petroleum applications.

Presenting a comprehensive survey of the theoretical and practical aspects of HSPs, Hansen Solubility Parameters, Second Edition concludes with a detailed discussion on the necessary research, future directions, and potential applications for which HSPs can provide a useful means of prediction in areas such as biological materials, controlled release applications, nanotechnology, and self-assembly.

MOLECULAR WEIGHr CHANGES AND NE1WORK FORMATION BY SCISSION AND CROSSUNKING A. Charlesby 1 Introduction Main Chain Scission of Polymers ____________________________ _ ________________________ _ 1 Crosslinking ______ . . . . . . . . . . . . . . . . . . . . . . _ . . . . . . . _ . . . . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . __ . . . . _ . . . . . . . . . . . _ . . . . . . . . ___ . . _. __ . . . . _. _. _____ . _____ . _ 4 5 Random Crosslinking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Enhanced Crosslinking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Other Forms of Crosslinking . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . _. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Combined Crosslinking and Scission ___________ _________________ ______ _ ______________ . _. _. 11 Antioxidants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Fillers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . . . . . . . . . __ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . __ . . . 12 Crosslinking of Polymers in Solution ________________________________ . . ______________ . . . . __ 12 References _. __ _ 13 HIGH ENERGY RADIATION-AND UV UGHr-INDUCED CROSSLINKING AND CHAIN SCISSION w. Schnabel Introduction 15 Importance of Radiation-Induced Crosslinking and Main-Chain Scission in Linear Polymers ___________________________ _________________ 15 TYPes of Radiation and Radiation Sources _. ___________________________ . . . . . . . . . _ . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . . . . . . . . . _. _. _ . . __ . . . 16 Absorption of Radiation . . _ . . . . _ . . . . . . _ . . _ . . __ . _ . . . . . . . . ____ . . . _ . . . . . . . . . . . . __ . . . . _ . . . . . . . . . _ . . . . _ . . . . . . _ . . . _ . . _ . . . . . . . . . . . . . . . . . . . . . _ . . . . . __ . . . . . . . . . . . _ . . . . . _____ . . . . . . . . . ___ . . . 16 General Aspects Concerning XL and CS in Linear Polymers ______________________ . _________ . _____ . _____ 22 Random and Specific Site Attacks . . . . . . . _. ____ . _ . . . _ . . . . . . . . . . __ . . . . . . . . . . . . . _ . . ___ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . . . . _ . . . . . __ . . . . _ . . . . . . _ . . . . __ . ___ . . . . . . . . . . __ . . _ 22 Detection of XL and CS . . . _. _ . . . . . . . . . . . . . . . _. __ . . . _ . . . . . . . . . . . . ___ . . . . . . . __ . . . _ . . . _ . . . . . . . . ____ . . . . . . . . . . . . . . . . . . _ . . . . _ . . . . . _ . . . . . . . . . . . . . . . . . . . . __ . . . . . _ . . . . _ . . . . . _. _ . . . . _ . . . . . . . 22 Simultaneous XL and CS Mechanisms 25 Ion Beam-Induced Radiation Effects In Linear Polymers ____________________________________________________ .

This book presents a comprehensive study on a new class of branched polymers, known as hyperbranched polymers (HBPs). It discusses in detail the synthesis strategies for these particular classes of polymers as well as biocompatible and biodegradable HBPs, which are of increasing interest to polymer technologists due to their immense potential in biomedical applications. The book also describes the one-pot synthesis technique for HBPs, which is feasible for large-scale production, as well as HBPs' structure-property relationship, which makes them superior to their linear counterparts. The alterable functional groups present at the terminal ends of the branches make HBPs promising candidates in the biomedical domain, and the book specifically elaborates on the suitable characteristic properties of each of the potential biological HBPs' applications. As such, the book offers a valuable reference guide for all scientists and technologists who are interested in using these newly developed techniques to achieve faster and better treatments.

This series presents critical reviews of the present and future trends in polymer and biopolymer science including chemistry, physical chemistry, physics and materials science. It is addressed to all scientists at universities and in industry who wish to keep abreast of advances in the topics covered.

Impact Factor Ranking: Always number one in Polymer Science. More information as well as the electronic version of the whole content available at: www.springerlink.com

Silicon Based Polymers presents highlights in advanced research and technological innovations using macromolecular organosilicon compounds and systems, as presented in the 2007 ISPO congress. Silicon-containing materials and polymers are used all over the world and in a variety of industries, domestic products and high technology applications.

Among them, silicones are certainly the most wella "known, however there are still new properties discovered and preparative processes developed all the time, therefore adding to their potential. Less known, but in preparation for the future, are other silicon containing-polymers which are now close to maturity and in fact some are already available like polysilsesquioxanes and polysilanes.

All these silicon based materials can adopt very different structures like chains, dendrimers, hyperbranched and networks, physical and chemical gels. The result is a vast array of materials with applications in various areas such as optics, electronics, ionic electrolytes, liquid crystals, biomaterials, ceramics and concrete, paints and coatings a ] all needed to face the environmental, energetical and technological issues of today. Some industrial aspects of the applications of these materials will also be presented.

The free-radical retrograde-precipitation polymerization (FRRPP) process was introduced by the author in the early 1990s as a chain polymerization method, whereby phase separation is occurring while reactive sites are above the lower cr- ical solution temperature (LCST). It was evident that certain regions of the product polymer attain temperatures above the average ?uid temperature, sometimes rea- ing carbonization temperatures. During the early stages of polymerization-induced phase separation, nanoscale polymer domains were also found to be persistent in the reacting system, in apparent contradiction with results of microstructural coarsening from constant-temperature modeling and experimental studies. This mass con?- ment behavior was used for micropatterning, for entrapment of reactive radical sites, and for the formation of block copolymers that can be used as intermediates, surf- tants, coatings, coupling agents, foams, and hydrogels. FRRPP-based materials and its mechanism have also been proposed to be relevant in energy and environmentally responsible applications. This technology lacks intellectual appeal compared to others that have been p- posed to produce polymers of exotic architectures. There are no special chemical mediators needed. Control of conditions and product distribution is done by p- cess means, based on a robust and ?exible free-radical-based chemistry. Thus, it can readily be implemented in the laboratory and in production scale.

The production and application of polymeric materials based on poly(butylene terephthalate) (PBT) has increased dramatically. The main reason for this is that PBT and its composites have a number of profitable properties, such as increased mechanical characteristics, good resistance to chemicals and water, processability, etc. This volume gives an analysis of recent achievements in the field of synthesis, structural investigations, and properties of PBT. Furthermore, the mechanism of PBT synthesis by equilibrium polycondensation reaction is described together with the used reagents, catalysts and stabilizers.

Synthetic Polymers is a comprehensive introduction to the technologies involved in the synthesis of the main classes of engineering high polymers used in such materials as plastics, fibers, rubbers, foams, adhesives and coatings. Besides the basic processes, this volume includes information on physical, chemical and mechanical characteristics - key factors with respect to obtaining the right end products. It also focuses on the main application of synthetic polymers in different engineering areas and gives data on production and consumption. Over 60 technological flowcharts are presented in a clear and concise manner, to provide the reader with essential information on relevant operations.

To the biochemist, water is, of course, the only solvent worthy of consideration, because natural macromolecules exhibit their remarkable conformational properties only in aqueous media. Probably because of these remarkable properties, biochemists do not tend to regard proteins, nucleotides and polysaccharides as polymers in the way that real polymer scientists regard methyl methacrylate and polyethylene. The laws of polymer statistics hardly apply to native biopolymers. Between these two powerful camps, lies the No-man's land of water soluble synthetic polymers: here, we must also include natural polymers which have been chemically modified. The scientific literature of these compounds is characterized by a large number of patents, which is usually a sign of little basic understanding, of 'know-how' rather than of 'know-why'. Many of the physical properties of such aqueous solutions are intriguing: the polymer may be completely miscible with water, and yet water is a 'poor' solvent, in terms of polymer parlance. ~kiny of the polymers form thermorever sible gels on heating or cooling. The phenomena of exothermic mixing and salting-in are common features of such systems: neither can be fully explained by the available theories. Finally, the eccentric behaviour of polyelectrolytes is well documented. Despite the lack of a sound physico-chemical foundation there is a general awareness of the importance of water soluble vinyl, acrylic, polyether, starch and cellulose derivatives, as witnessed again by ~he vast patent literature.