ItisagreatpleasureforustopresentacollectionofpapersreadattheToyoichiTanaka MemorialSymposiumonGelsheldon10-12September2008inTokyo. ProfessorToyoichi TanakaofMIThasdevelopedgelscienceafterthediscoveryofvolumephasetransition,but unfortunately he passed away so early in 2000. His friends and co-workers decided to organizeasymposiumcommemoratingthe30thanniversaryforthediscoveryofthevolume phasetransitionin1978. ThesymposiumwasheldinastyleofFaradayDiscussions. FullpaperswritteninJapanese weresentbeforehandtoalltheparticipants,anddiscussionswereactiveafterashort(5min) presentationofeachpaper. SinceJapaneselanguageisverydifferentfromEuropeanl- guages,weJapanesecouldspeakfreelywithoutanyhesitation. Althoughalltheparticipants are good at English as proved by their publication of many papers in English, yet the discussionofdelicatenuancescouldbedonebetterinJapanesethaninEnglish. Afterthesuccessfulsymposium,paperswritteninEnglishtakingintoaccountthedisc- sionsduringthesymposiumwerereviewedbyexpertscientists,andthepaperswererevised accordingly. We hope that this collection of papers is interesting and useful for all the scientistsandengineersworkingintheareaofgelsbothinacademiaandindustry. Finally, wethankallthecontributorsandreviewersfortheirenthusiasticefforts. Summer2009 MasayukiTokita KatsuyoshiNishinari v Contents StructureandFunctionalPropertiesofGels CompetitiveHydrogenBondsandCononsolvencyofPoly(N-isopropylacrylamide)s inMixedSolventsofWater/Methanol...1 FumihikoTanaka,TsuyoshiKoga,andFranc,ItisagreatpleasureforustopresentacollectionofpapersreadattheToyoichiTanaka MemorialSymposiumonGelsheldon10-12September2008inTokyo. ProfessorToyoichi TanakaofMIThasdevelopedgelscienceafterthediscoveryofvolumephasetransition,but unfortunately he passed away so early in 2000. His friends and co-workers decided to organizeasymposiumcommemoratingthe30thanniversaryforthediscoveryofthevolume phasetransitionin1978. ThesymposiumwasheldinastyleofFaradayDiscussions. FullpaperswritteninJapanese weresentbeforehandtoalltheparticipants,anddiscussionswereactiveafterashort(5min) presentationofeachpaper. SinceJapaneselanguageisverydifferentfromEuropeanl- guages,weJapanesecouldspeakfreelywithoutanyhesitation. Althoughalltheparticipants are good at English as proved by their publication of many papers in English, yet the discussionofdelicatenuancescouldbedonebetterinJapanesethaninEnglish. Afterthesuccessfulsymposium,paperswritteninEnglishtakingintoaccountthedisc- sionsduringthesymposiumwerereviewedbyexpertscientists,andthepaperswererevised accordingly. We hope that this collection of papers is interesting and useful for all the scientistsandengineersworkingintheareaofgelsbothinacademiaandindustry. Finally, wethankallthecontributorsandreviewersfortheirenthusiasticefforts. Summer2009 MasayukiTokita KatsuyoshiNishinari v Contents StructureandFunctionalPropertiesofGels CompetitiveHydrogenBondsandCononsolvencyofPoly(N-isopropylacrylamide)s inMixedSolventsofWater/Methanol...1 FumihikoTanaka,TsuyoshiKoga,andFranccoiseM. Winnik RheologicalPropertiesofSolutionsofaPolyampholyticBlockCopolymer...9 TomomitsuSekitani,KenjiUrayama,ManabuTsuruta,Masahiko Mitsuzuka,andToshikazuTakigawa Helix-CoilTransitionandAssociationBehaviorofWater-SolublePolypeptides HavingHydrophobicAlkylSideChains...15 KatsuhiroInomata,TomokazuTakai,NoriyoshiOhno,YoshiakiYamaji, ErinaYamada,HidekiSugimoto,andEijiNakanishi EffectsofSurfactantsontheLinearRheologyofTelechelic AssociatingPolymers...23 TsutomuIndei Time-DependentFlowPropertiesofTransientHydrogelswith TemporalNetworkJunctions...3 1 IsamuKaneda,TsuyoshiKoga,andFumihikoTanaka StressGrowthinTransientPolymerNetworksunderStartup ShearFlow...39 TsuyoshiKoga,FumihikoTanaka,andIsamuKaneda Self-assemblingStructuresandSol-GelTransitionofOptically ActiveandRacemic12-HydroxystearicAcidsinOrganicSolvents...47 HiroyukiTakeno,TomomitsuMochizuki,KazutoYoshiba,ShingoKondo, andToshiakiDobashi TheGelPointandNetworkFormationinthePolymerisation ofanEpoxy-AmineSystemIncludingRingFormation...55 YutakaTanaka,JohnL. Stanford,andRobert. F. T. Stepto TheEffectiveSurfaceRoughnessScalingoftheGelationSurface PatternFormation...63 T. Mizoue,M. Tokita,H. Honjo,H. J. Barraza,andH. Katsuragi DiscontinuousGrowthofOnionStructureUnderShear...69 ShujiFujii vii viii Contents StudyonSelf-AssemblyofTelechelicHydrophobicallyModi?ed Poly(N-isopropylacrylamide)inWater...77 TaisukeFujimoto,EmiYoshimoto,andMasahikoAnnaka SomeThoughtsontheDe?nitionofaGel...87 KatsuyoshiNishinari SwellingofGels StructuralTransitionofNon-ionicPoly(acrylamide)Gel...95 Sada-atsuMukai,HirohisaMiki,VasylGaramus,Regine Willmeit,andMasayukiTokita SwellingEquilibriumofaGelinBinaryMixedSolvents...1 01 HirohisaMiki,ShinYagihara,Sada-atsuMukai,andMasyukiTokita RevisittoSwellingKineticsofGels...107 KenjiUrayama,NaokiMurata,ShojiNosaka,MasahiroKojima, andToshikazuTakigawa EffectofResidualSwellingSolventonNanoporeFormationinReplication ofSwollenHydrogelNetwork...113 Ken-ichiKurumada,AtsushiSuzuki,EmikoOtsuka,SusumuBaba,Youhei Seto,KeisukeMorita,andTakanoriNakamura SwellingPropertiesofPhysicallyCross-linkedPVAGelsPrepared byaCast-dryingMethod...121 EmikoOtsukaandAtsushiSuzuki In?uenceofHeatingTemperatureonCookingCurveofRice...127 KunioNakamura,AtsukoAkutsu,AyumiOtake,andHatsueMoritaka IndustrialandbiomedicalApplication EffectsofThicknessandCurvatureontheAdhesionProperties ofCylindricalSoftMaterialsbyaPointContactMethod...135 D. Sakasegawa,M. Goto,andA. Suzuki ElectrophoresisofDyesandProteinsinPoly(Acrylamide)GelContaining ImmobilizedBilayerMembranes...143 HirokiIshihara,GohMatsuo,TakanoriSasaki,YukoSaito,MakotoDemura, andKaoruTsujii AnApplicationofMicrocapsulesHavingEnzyme-degradableGel MembraneToCellCulture...149 ToshiakiDobashi,MichiruKoike,KentaroKobayashi,YasuyukiMaki, TakaoYamamoto,andSusumuTanaka DevelopmentofaNovelHydrogeltoPreventBacterial InfectiousDiseases...1 55 NorihiroKato,AzumiKobayashi,HiroshiMotohashi,YuOzonoe,Tomohiro Morohoshi,andTsukasaIkeda EffectofParticlesAlignmentonGiantReductioninDynamic ModulusofHydrogelsContainingNeedle-ShapedMagneticParticles...163 TetsuMitsumata,YuheiKosugi,andShunsukeOuchi Contents ix MolecularDiffusioninPolysaccharideGelSystemsasObservedbyNMR...171 ShingoMatsukawa,DaisukeSagae,andAkikoMogi ChainReleaseBehaviorofGellanGels...177 KhandkerS. HossainandKatsuyoshiNishinari GelFormationofRecombinantFibrinogenLackingaCTermini...187 KenjiKuboa,YukaMasuda,YoshiharuToyama,NobukazuNameki, NobuoOkumura,andMasanoriOchiai DynamicLightScatteringStudyofPigVitreousBody...195 ToyoakiMatsuura,NaokazuIdota,YoshiakiHara,andMasahikoAnnaka TheRelationshipBetweentheChangesinLocalStiffnessofChicken Myo?brilandtheTendernessofMuscleDuringPostmortemAging...205 T. Iwasaki,Y. Hasegawa,K. Yamamoto,andK. Nakamura Index...211 ProgrColloidPolymSci(2009)136:1-8 DOI:10. 1007/2882_2009_1 CompetitiveHydrogenBondsandCononsolvency ofPoly(N-isopropylacrylamide)sinMixedSolvents ofWater/Methanol 1 1 2 FumihikoTanaka ,TsuyoshiKoga ,andFranc,oiseM.

This treatise is a compendium of refereed papers based on invited talks presented at the American Chemical Society Symposium on Electrorheological (ER) Materials and Fluids. ER fluids were first investigated 50+ years ago. These fluids, which change rheology when placed in an electric field, were recognized, from the beginning, for allowing an extremely efficient interface between electrical control and mechanical devices. Critical problems, however, existed with the initial fluids, which prevented them from serious consideration for large-scale applications. While over time some of the critical problems have been solved and activity in ER technology has increased, commercial success has remained elusive. A recent Department of Energy report concluded that a primary reason for the failure to commercialize this promising technology is due to a lack in understanding the physics and chemistry of how the materials work. The goal of the symposium was to address the issue of understanding how ER materials work and how they can be used. One of the outcomes of the symposium, which we hope is conveyed in this book, is a feeling that if the mechanism of ER is to be fully understood and improved, expertise from diverse fields must be applied to the problem.

Microgels by Precipitation Polymerization: Synthesis, Characterization, and Functionalization, by A. Pich and W. Richtering * Hydrogels in Miniemulsions, by K. Landfester and A. Musyanovych * Nano- and Microgels Through Addition Reactions of Functional Oligomers and Polymers, by K. Albrecht, M. Moeller, and J. Groll * Synthesis of Microgels by Radiation Methods, by F. Krahl and K.-F. Arndt * Microgels as Nanoreactors: Applications in Catalysis, by N. Welsch, M.s Ballauff, and Y. Lu

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

These volumes, 3 and 4, of Fracture Mechanics of Ceramics con stitute the proceedings of an international symposium on the frac ture mechanics of ceramics held at the Pennsylvania State Univer sity, University Park, PA on July 27, 28, and 29, 1977. Volumes 1 and 2 were published previously as the proceedings of a sympo sium of the same name held July 11, 12, and 13, 1973, also at Penn State. All four volumes published to date concentrate on the fracture aspects of the mechanical behavior of brittle'ceramics in terms of the characteristics of cracks. The program chairmen gratefully acknowledge the financial as sistance for the symposium provided by the Office of Naval Re search, the Energy Research and Development Administration, and the Army Research Office. Without their support the quality and mag nitude of this conference simply would not have been possible. Numerous individuals contributedto the success of the con ference, but unfortunately they cannot all be listed here. However the program chairmen would especially like to recognize the contri butions of Penn State Conference Coordinator, Mr. Ronald Avillion, whose expertise in planning and organization was indispensable; Dr. Fred R. Matson for his interesting after dinner speech; and Drs. A. M. Diness, J. C. Hurt, and D. W. Readey for their en couragement and valuable suggestions regarding the program. Finally, we wish to also thank our joint secretaries for the patience and help in bringing these proceedings to press."

The goal of this monograph is to summarize the different quantum mechanical methods developed in the last 20 years to treat the electronic structure of polymers. Owing to the nature of the problem, these methods consist of a mixture of quantum-chemical and solid-state physical tech niques. The theory described in Part I treats, besides the Hartree-Fock problem, the. electron correlation, and it has also been developed for disordered polymeric systems. Though for obvious reasons the book could not include all the existing calculations, each new method des cribed is illustrated by a few applications, with a discussion of the numerical results obtained. Far more details see the Introduction to Part I. The second part contains the theoretical calculation of different properties of polymers based on the methods systematically introduced in the first part. The properties calculated include the electronic and vibrational spectra of polymers, and the computation of their transport, magnetic, and mechanical properties. In cases where reliable ex perimental data are available, the theoretical results are compared with them."

The growing public concern about environmental matters has prompted widespread discussion in the media. Unfortunately much of this public debate has been characterized more by ardour than by information, and often the wildest speculations are pro mulgated with the same appearance of veracity as hard scientific facts. It is an important, and often neglected, duty of scientific societies to make sure that the public is properly informed regard ing the technical aspects of matters of public interest, and to assure that policy decisions of governmental and other agencies are made with due regard to the scientific and technical facts, so far as they are ascertainable. For a variety of reasons, not all of which are related to the magnitude of the problems, a great deal of public attention has been focused on the environmental aspect s of the chemical industry. Because of this the American Chemical Society has wisely decided to sponsor a number of symposia at national scientific meetings where these issues can be raised and information supplied regarding their technical and scientific aspects."

These volumes, 3 and 4, of Fracture Mechanics of Ceramics con stitute the proceedings of an international symposium on the frac ture mechanics of ceramics held at the Pennsylvania State Univer sity, University Park, PA on July 27, 28, and 29, 1977. Volumes 1 and 2 were published previously as the proceedings of a sympo sium of the same name held July 11, 12, and 13, 1973, also at Penn State. All four volumes published to date concentrate on the fracture aspects of the mechanical behavior of brittle ceramics in terms of the characteristics of cracks. The program chairmen gratefully acknowledge the financial as sistance for the symposium provided by the Office of Naval Re search, the Energy Research and Development Administration, and the Army Research Office. Without their support the quality and mag nitude of this conference simply would not have been possible. Numerous individuals contributed to the success of the con ference, but unfortunately they cannot all be listed here. However the program chairmen would especially like to recognize the contri butions of Penn State Conference Coordinator, Mr. Ronald Avillion, whose expertise in planning and organization was indispensable; Dr. Fred R. Matson for his interesting after dinner speech; and Drs. A. M. Diness, J. C. Hurt, and D. W. Readey for their en couragement and valuable suggestions regarding the program. Finally, we wish to also thank our joint secretaries for the patience and help in bringing these proceedings to press."

The first edition of this book (1958) described an analytical situation which had existed for a number of years for maintaining quality control on vulcanizates of natural rubber although the situation had recently been disturbed by the introduction of a range of synthetic rubbers which required identification and quantitative estimation. For the former purpose 'wet' chemistry, based on various imperfectly understood organic reactions, was pressed into service. Alongside this was the first introduction of instrumental analysis, using the infrared spectra of either the polymers or, more usually, their pyrolytic products to 'fingerprint' the material. The identification of a range of organic accelerators, antioxidants and their derivatives which had been intro duced during the 1920s and 30s was, in the first edition, dealt with by a combination of column chromatography and infrared spectroscopy or by paper chromatography. Quantitative procedures were, however, still classical in the tradition of gravimetric or volumetric assays with an initially weighed sample yielding, after chemical manipulation, a carefully precipitated, dried and weighed end product, or a solution of known composition whose weight or titre, as a percentage of the initial sample, quantified the function being determined. The second edition of this work (1968) consolidated the newer techni ques which had been introduced in the first without adding to them although, in other applications of analytical chemistry, instrumental analysis had already brought about a transformation in laboratory practice."

In a way the MOTECC-89 project started in the early sixties at the IBM Research Laboratory in San Jose, California. The six years of post-doctoral research, first with Giulio Natta on conductive polymers, with Michael Kasha on spin-orbit effects, with Kenneth S. Pitzer on high temperature molecules and thermo dynamics and with R. S. Mulliken in the quantum chemistry of small molecules had demonstrated pragmatically the importance of a broad-based research and also let me taste some of the excitement to be derived from interdisciplinarity. Thus when I started to gather a department in the newly opened IBM Research Laboratory in San Jose, California, I purposely named it "Large Scale Scientific Computation Department," avoiding reference to chemistry, physics, statistical mechanics or fluid dynamics, which were our main tasks. In the sixties interdisciplinarity was more and more recognized as a most important if not nec essary avenue to cope with the technical needs of our society. However, at that time interdisciplinarity was synonymous with "team work," and true interdisciplinarity was a formidably difficult objective. Although I headed an excellent group of scientists with different backgrounds and there was much progress and creativity, still each one of us was more or less conducting his own research in his own field with occasional cross-field partnerships and with some of the computational techniques as our common base. Later, in 1974, I made a second attempt, this time starting a new department at the Donegani Institute, Montedison, in Novara, Italy."

Alloy is a term commonly associated with metals and implies a composite which may be sinqle phase (solid solution) or heterophase. Whichever the case, metallic alloys generally exist because they exhibit improved properties over the base metal. There are numer ous types of metallic alloys, including interstitial solid solutions, substitutional solid solutions, and multiphase combinations of these with intermetallic compounds, valency compounds, electron compounds, etc. A similar situation exists with polymers. There are numerous types of composites, or "alloys" of polymers in existence today with new ones being created continuously. Polyblends are simple physical mixtures of the constituent polymers with no covalent bonds occuring between them. As with metals, these may be homogeneous (single phase) solid solytions or heterogeneous (multiple phase) mixtures. With polymers, the latter case is by far the most prevalent situation due to the thermodynamic incompatibility of most polymers. This is due to the relatively small gain in entropy upon mixing the polymers due to contiguity restrictions imposed by their large chain length."

The biological and biomedical applications of polymeric materials have increased greatly in the past few years. This book will detail some, but not all, of these recent developments. There would not be enough space in this book to cover, even lightly, all of the major advances that have occurred. Some earlier books and summaries are available by two of this book's Editors (Gebelein & Carraher) and these should be consul ted for additional information. The books are: "Bioactive Polymeric Systems" (Plenum, 1985); "Polymeric Materials In Medication" (Plenum, 1985); "Biological Acti vi ties of Polymers" (American Chemical Society, 1982). Of these three, "Bioacti ve Polymeric Systems" should be the most useful to a person who is new to this field because it only contains review articles written at an introductory level. The present book primarily consists of recent research results and applications, with only a few review or summary articles. Bioactive polymeric materials have existed from the creation of life itself. Many firmly believe that life could not even exist unless poly meric materials are used to form the basic building blocks. Although this assumption can not be rigorously proven, it is a fact that most, if not all, of the major biochemical pathways involve polymeric species, such as the proteins (including enzymes), polysaccharides and nucleic acids."

Photochromism is the reversible phototransformation of a chemical species between two forms having different absorption spectra. During the phototransformation not only the absorption spectra but also various physicochemical properties change, such as the refractive index, dielectric constant, oxidation/reduction potential, and geometrical structure. The property changes can be applied to photonic equipment such as erasable memory media, photo-optical switch components, and display devices. This book compiles the accomplishments of the research project titled "New Frontiers in Photochromism" supported by the Ministry of Education, Culture, Sports, Science and Technology of Japan. The project focused not only on the above-mentioned classical subjects in photochromism, such as color changes, optical memory, and optical switches, but also on fundamental physicochemical studies and unprecedented application fields that have not yet been explored in photochromism. The latter topics include light-driven mechanical motion, photocontrol of surface wettability, metal deposition on solid materials, photocontrol of chiral properties, ultrafast decoloration dyes, and femtosecond laser experiments, among others.

Both an introductory course to broadband dielectric spectroscopy and a monograph describing recent dielectric contributions to current topics, this book is the first to cover the topic and has been hotly awaited by the scientific community.

Modular Chemistry: the First Steps In recent years, there has been increasing interest among chemists, physicists, materials scientists, biologists, engineers, and others in the assembly of well defmed, relatively large functional structures from repetitive units that themselves are molecules of some complexity. Using the dictionary defmition of a module (a detachable section, compartment, or unit with a specific purpose or function, and in electronics, a compact assembly functioning as a component of a larger unit) [1], we feel that this newly emerging field of endeavor could be called "modular chemistry" [2]. The NATO Advanced Research Workshop on Modular Chemistry that was held on September 9 to 12, 1995, at Aspen Lodge near Estes Park, Colorado, was meant to bring together prominent contributors to modular chemistry as it is being born, and to examine the associated birth pangs. It was concluded that although real, these are not nearly as bad as giving birth to a hedgehog tail first, and that the ultimate rewards were likely to be far more satisfying in terms of new ideas and enabling methodology. The level of excitement about the possibilities that are opening up for modular chemists, and also the challenge involved, are perhaps best documented by noting that the planned discussion periods at the workshop were as long as the oral presentation periods, and yet, each discussion ran over the allocated time.

The study of the electrical properties of polymers constitutes a substantial fraction of the total research interest in macro molecular behavior. Because of the increasing attention now being paid to theoretical and experimental aspects of the phenomena encountered, a symposium focusing particularly on dielectric behavior was held at the l6lst National Meeting of the American Chemical Society in Los Angeles, California, March, 1971. The authoritative papers in this volume were all presented at this symposium, which was sponsored by the Polymer Division of the American Chemical Society. An obvious advantage of such a collection is that it keep together closely related material which would otherwise tend to be dispersed amongst different journals; a further factor of which most authors represented here have taken advantage is that it gives an opportunity to present research in less attenuated form than is now normally possible in journals. I wish to thank all the authors for their uniformly excellent contributions and for their cooperation in the publication of this volume. Thanks are also due to Dr. S. Matsuoka for chairing one of the sessions at the symposium. September, 1971 Frank E. Karasz v LIST OF CONTRIBUTORS B. Baysal, Department of Chemistry, Dartmouth College, Hanover, New Hampshire Richard H. Boyd, Department of Chemical Engineering and Division of Materials Science and Engineering, University of Utah, Salt Lake City, Utah M. G. Broadhurst, Institute for Materials Research, National Bureau of Standards, Washington, D. C."

The International Winter School on Electronic Properties of Polymers and Re- lated Compounds, held March 11-18, 1989, in Kirchberg (Austria), was a sequel to two meetings on similar subjects held there two and four years be- fore. The 1989 winter school was again organized in cooperation with the "Bundesministerium flir Wissenschaft und Forschung" in Austria, and with the "Bundesministerium fUr Forschung und Technologie" in the Federal Republic of Germany. The basic idea of the meeting was to provide an opportunity for experienced scientists from universities and industry to discuss their most recent results and for students and young scientists to become familiar with the present status of research and applications in the field. Like the previous winter schools, this one concentrated on the electronic structure and application potentialities of polymers. A purely tutorial contribu- tion on high-temperature supercondutors was included. Special attention was paid this time to our present theoretical understanding of the electronic struc- ture of polymers in general, the role of disorder and the nature of the doping process in particular. Accordingly, two discussion meetings were held on the stability of quasiparticles in conjugated polymers and on the thermochromic phase transition in alkylated thiophenes. As a general result, disorder and con- jugation length were recognized as fundamental properties, not only for the stability of the quasiparticles but also for linear and nonlinear optics, transport, phototransport, magnetic properties, lattice dynamics, etc.

Nuclear magnetic resonance spectroscopy, which has evolved only within the last 20 years, has become one of the very important tools in chemistry and physics. The literature on its theory and application has grown immensely and a comprehensive and adequate treatment of all branches by one author, or even by several, becomes increasingly difficult. This series is planned to present articles written by experts working in various fields of nuclear magnetic resonance spectroscopy, and will contain review articles as well as progress reports and original work. Its main aim, however, is to fill a gap, existing in literature, by publishing articles written by specialists, which take the reader from the introductory stage to the latest development in the field. The editors are grateful to the authors for the time and effort spent in writing the articles, and for their invaluable cooperation. The papers presented here are condensed versions of the main contributions to the 7th Colloquium on Nuclear Magnetic Resonance Spectroscopy, which was made possible by the generous support of the Freunde der Aachener Hoch schule (FAHO). The RWTH is indebted to the FAHO and to all the participants who contributed to the success of the Colloquium."

The 1992 Chinese Peptide Symposium was held at Hangzhou, China on November 3--6, 1992 with 152 participants, including 46 from abroad, representing 10 countries. The three days conference was both intense and spiritually rewarding. The Biennial Chinese Peptide Symposium was aimed to provide a forum for advancing the exchange of knowledge, cooperation and friendship between the international and Chinese scientific communities. In order to exchange ideas and review the latest progress in depth, the scientific sessions were held at the mornings and evenings, while afternoons were devoted to social interaction and sightseeing of the unparalleled beauty of Westlake. For realizing the goal to catch up with a fast evolving and fascinating field, the Program Committee arranged eight sessions with 45 oral presentations and 72 posters on topics relating to peptide conformation, design, hormone and bioactive peptides, neuropeptides, recognition, synthesis and methodology in the Symposium and selected 94 articles for publication in this proceedings. As an organizer I was greatly encouraged by the active response of invited speakers and moved by enthusiastic cooperation and excellent contributions which led to the great success of the Symposium, since their presentations were of high quality and represented the latest advances in all aspects of peptide chemistry and peptide biology. Many authors concentrated their attention to a great challenge which peptide chemists have nowadays to face, i. e.

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.

Microbes are known to live in an enormous range of environments. Their ability to survive and proliferate in diverse industrial systems is often a surprise to those not exposed to these problems in their work. These systems contain a range of potential carbon sources, one common theme being surfactants. Surfactants are often not the components most prone to spoilage since some systems contain highly susceptible natural components, such as starch and xanthum gum, but the surfactant is a key part of the formulation, and its extensive breakdown usually means that the material is beyond recovery. The aim of this book is to describe in detail all aspects of the preservation of surfactant containing materials. The book should be viewed as being in three discrete sections. * chapters 1-5 deal with and summarise essential background information * chapters 6-11 discuss in detail various end use applications * chapters 12-15 outline the regulatory and toxicology implication associated with the safe handling of preservatives Given the format of the book there is inevitably some duplication of information in the middle section with different authors describing essentially the same phenomena but on different substrates. I hope the reader will find that although different chapters touch on the same topics the information around these areas is sufficiently different to justify their inclusion in this book and to be of interest. It should also demonstrate what can be the most useful source of information, the hard practical experience of the authors.

Materials that can mold the ?ow of elastic waves of certain energy in certain directions are called phononic materials. The present thesis deals essentially with such phononic systems, which are structured in the mesoscale (\1 lm), and with their individual components. Such systems show interesting phononic properties in the hypersonic region, i.e., at frequencies in the GHz range. It is shown that colloidal systems are excellent model systems for the realization of such phononic materials. Therefore, different structures and particle architectures are investigated by Brillouin light scattering, the inelastic scattering of light by phonons. Both the mechanical properties of the individual colloidal particles, which manifest in their resonance vibrations (eigenmodes), as well as the acoustic propagation in colloidal structures have been investigated. The measurement of the eigenmodes allows for new insights into physical properties at the mesoscale, e.g., con?nement effects, copolymer behavior, or the non-destructive determination of nanomechanical properties of core-shell particles, supporting the working groups aim to achieve a deeper understanding of 'soft mechanics' at small length scales. Another novel contribution assigned to this thesis is the ?rst experimental rea- zation of a phononic band gap arising from the interaction of these particle - genmodes with the effective medium band (hybridization gap). This ?nding already gave new impulses to the whole ?eld of phononics.

Keynote and lectures from invited speakers given at the Se- cond Pacific Polymer Conference in Otsu, Japan, are collec- ted in this book. Eminent Polymer Scientists from both aca- demic and industrial fields around the Pacific Basin contri- buted on the following topics: - Polymer Synthesisand Ractions - Polymer Characterization - Structure-Property-Relationships - High Performance Polymers - Bio-Related Polymers With contributions by H.R. Allcock, R.G. Davidson, T. Inoue, Y.H. Kim, E.A. McCullough, J.E. McGrath, G.F. Meijs, T. Nishi, Y.Nishida, I. Noda, R.M. Nowak, M. Okamoto, R.E. Prud'homme, J.P. Riggs, D.N. Schulz, D.H. Solomon, J. Sunamoto, M. Takayanagi, a.o.