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Books > Science & Mathematics > Chemistry > Organic chemistry > Polymer chemistry
The Xth European Colloid and Interface Society (ECIS) Conference
was conducted jointly with its Finnish counterpart (PKS-YKS) in Abo
(Turku), Finland, in September 1996.
The focus was placed on the following topics:
- Properties of microemulsion systems; - Structure and interactions
in thin films; - Biocolloids and vesicles; - Structure and
interactions in dispersions; - Polymers at solid interfaces; -
Polymers in solutions.
This volume presents a balanced and representative selection of the
papers presented at the conference.
"Imagination and shrewd guesswork are powerful instruments for
acquiring scientific knowledge . . . " 1. H. van't Hoff The last
decades have witnessed a rapid growth of quantum chemistry and a
tremendous increase in the number of very accurate ab initio
calculations of the electronic structure of molecules yielding
results of admirable accuracy. This dramatic progress has opened a
new stage in the quantum mechanical description of matter at the
molecular level. In the first place, highly accurate results
provide severe tests of the quantum mecha nics. Secondly, modern
quantitative computational ab initio methods can be synergetically
combined with various experimen tal techniques thus enabling
precise numerical characterization of molecular properties better
than ever anticipated earlier. However, the role of theory is not
exhausted in disclosing the fundamental laws of Nature and
production of ever increasing sets of data of high accuracy. It has
to provide additionally a means of systematization, recognition of
regularities, and ratio nalization of the myriads of established
facts avoiding in this way complete chaos. Additional problems are
represented by molecular wavefunctions provided by the modern
high-level computational quantum chemistry methods. They involve,
in principle, all the information on molecular system, but they are
so immensely complex that can not be immediately understood in
simple and physically meaningful terms. Both of these aspects,
categorization and interpretation, call for conceptual models which
should be preferably pictorial, transparent, intuitively appealing
and well-founded, being sometimes useful for semi quantitative
purposes."
Dedicated to Professor Manfred Gordon on the Occasion of His 70th
Birthday
The word Polyethylene was probably first pronounced in a lecture
which M. P. E. Berthelot delivered on April ,27, 1863 to the
Chemical Society in Paris, reporting on the "polymerization" of
various simple organic compounds (1). Much later this work appeared
twice in the literature before the classical ICI breakthrough in
the 1930's which is so colorfully described in Ballard's lecture.
Once it came up at the end of the last century when H. von Pechmann
obtained "a white flocculant material" from the decomposition of
diazomethane which, one year later, was termed to be
"polymethylene" - (CH ) - from E. Bamberger 2 and F. Tschiemer (1).
At that time the investigators were disappointed about this product
because it was not what they had expected to find in their
experiments. As a result any further work was discontinued. The
second time that the word polyethylene appeared in the literature
to describe a "white solid powder" was in 1930 when C. S. Marvel
and M. E. P. Friedericks (2) attempted to prepare alkylated As
compounds in which all five valencies were covalently bonded to
five monovalent-aTkyl groups. They reacted Tetra-ethyl-arsenium
bromide with butyllithium and expected to get tetra ethyl butyl
arsenium. Instead they obtained LiBr + AsEt3 + gaseous products.
Delicate and somewhat time-consuming analysis gave a surprising
result: ethane and C 's were there in the 4 expected quantities but
ethylene was missing - or almost missing - in the gas mixture.
Epoxy resins are regarded as thermosetting resins and have found
various c- mercial applications after crosslinking with adequate
curing agents [1-3]. H- ever, some epoxy resins have been used as
thermoplastic resins without curing agents. Figure 1 shows the
applications of epoxy resins that are classi?ed to three
categories: thermosets in combination with curing agents,
thermoplastics wi- out curing agents, and raw materials for
modi?cation. The use in thermoplastics is not popular compared with
the two other applications. Typical thermoplastic applications are
found in stabilizers for vinyl resins, toners for copying - chines,
?re retardants for engineering plastics, and sizing material for
glass or carbon ?bers. The epoxy resin most frequently used is the
oligomer of the diglycidyl ether of bisphenol-A (DGEBA) whose
chemical structure is shown below [1-3]. The DGEBA is composed of
linear molecules with different molecular weights according to the
variation of the repeated number (n) in the structural formula.
Molecular manipulation of nano- and microstructures paves the way
to produce organic polymer materials by design. Such architectures
comprise both the synthesis and the kinetics and thermodynamics of
macromolecular organization and is the theme of this volume. The
book consists of four articles reviewing living polymerization to
produce precisely defined linear polyesters, comparing them to
other living polymerization techniques. The articles also deal with
the synthesis of polymeric dendrimers, either by the convergent or
divergent approach; block copolymers synthesis, to define
micromorphology in high performance polymers; and thereby tailoring
their thermal, chemical, mechanical and dielectrical properties,
and finally kinetics and thermodynamics for microstructural
organization in macroporous thermosets.
Organometallic chemistry is a well established research area at the
interface of organic and inorganic chemistry. In recent years this
field has undergone a ren aissance as our understanding of
organometallic structure, properties and mechanism has opened the
way for the design of organometallic compounds and reactions
tailored to the needs of such diverse areas as medicine, biology,
materials and polymer sciences and organic synthesis. For example,
in the de velopment of new catalytic processes, organometallic
chemistry is helping meet the challenge to society that the
economic and environmental necessities of the future pose. As this
field becomes increasingly interdisciplinary, we recognize the need
for critical overviews of new developments that are of broad
significance. This is our goal in starting this new series Topics
in Organometallic Chemistry. The scope of coverage includes a broad
range of topics of pure and applied or ganometallic chemistry,
where new breakthroughs are being achieved that are of significance
to a larger scientific audience. Topics in Organometallic Chemistry
differs from existing review series in that each volume is
thematic, giving an overview of an area that has reached a stage of
maturity such that coverage in a single review article is no longer
possible. Furthermore, the treatment addresses a broad audience of
researchers, who are not specialists in the field, starting at the
graduate student level. Discussion of possible future research
directions in the areas covered by the individual volumes is
welcome."
With the aim of providing a deeper insight into possible mechanisms
of biological self-organization, this thesis presents new
approaches to describe the process of self-assembly and the impact
of spatial organization on the function of membrane proteins, from
a statistical physics point of view. It focuses on three important
scenarios: the assembly of membrane proteins, the collective
response of mechanosensitive channels and the function of the twin
arginine translocation (Tat) system. Using methods from equilibrium
and non-equilibrium statistical mechanics, general conclusions were
drawn that demonstrate the importance of the protein-protein
interactions. Namely, in the first part a general aggregation
dynamics model is formulated, and used to show that fragmentation
crucially affects the efficiency of the self-assembly process of
proteins. In the second part, by mapping the membrane-mediated
forces into a simplified many-body system, the dynamic and
equilibrium behaviour of interacting mechanosensitive channels is
derived, showing that protein agglomeration strongly impacts its
desired function. The final part develops a model that incorporates
both the agglomeration and transport function of the Tat system,
thereby providing a comprehensive description of this
self-organizing process.
Block Copolymer Surfactant Mixtures in Aqueous Solution: Can we
Achieve Size and Shape Control by Co-Micellization?, by Thomas
Hellweg; Non-ionic Thermoresponsive Polymers in Water, by Vladimir
Aseyev, Heikki Tenhu and Francoise Winnik; From Coordination
Polymers to Hierarchical Self-Assembled Structures, by Yun Yan,
Arie de Keizer, Martien A. Cohen Stuart and Nicolaas A. M.
Besseling; Processes of Ordered Structure Formation in Polypeptide
Thin Film Solutions, by Ioan Botiz, Helmut Schlaad and Gunter
Reiter; Amphiphilic Polymers at Interfaces, by Katarzyna
Kita-Tokarczyk, Mathias Junginger, Serena Belegrinou and Andreas
Taubert;"
The second edition of this textbook is identical with its fourth
German edi tion and it thus has the same goals: precise definition
of basic phenomena, a broad survey of the whole field, integrated
representation of chemistry, physics, and technology, and a
balanced treatment of facts and comprehen sion. The book thus
intends to bridge the gap between the often oversimpli fied
introductory textbooks and the highly specialized texts and
monographs that cover only parts of macromolecular science. The
text intends to survey the whole field of macromolecular science.
Its organization results from the following considerations. The
chemical structure of macromolecular compounds should be inde
pendent of the method of synthesis, at least in the ideal case.
Part I is thus concerned with the chemical and physical structure
of polymers. Properties depend on structure. Solution properties
are thus discussed in Part II, solid state properties in Part III.
There are other reasons for dis cussing properties before
synthesis: For example, it is difficult to understand equilibrium
polymerization without knowledge of solution thermodynamics, the
gel effect without knowledge of the glass transition temperature,
etc. Part IV treats the principles of macromolecular syntheses and
reactions.
The liquid crystalline state may be identified as a distinct and
unique state of matter which is characterised by properties which
resemble those of both solids and liquids. It was first recognised
in the middle of the last century through the study of nerve myelin
and derivatives of cholesterol. The research in the area really
gathered momentum, however, when as a result of the pioneering work
of Gray in the early 1970's organic compounds exhibiting liquid
crystalline properties were shown to be suitable to form the basis
of display devices in the electronic products. The study of liquid
crystals is truly multidisciplinary and has attached the attention
of physicists, biologists, chemists, mathematicians and electronics
engineers. It is therefore impossible to cover all these aspects
fully in two small volumes and therefore it was decided in view of
the overall title of the series to concentrate on the structural
and bonding aspects of the subject. The Chapters presented in these
two volumes have been organised to cover the following fundamental
aspects of the subiect. The calculation of the structures of liquid
crystals, an account of their dynamical properties and a discussion
of computer simulations of liquid crystalline phases formed by Gay
Berne mesogens. The relationships between molecular conformation
and packing are analysed in some detail. The crystal structures of
liquid crystal mesogens and the importance of their X ray
scattering properties for characterisational purposes are
discussed.
The 13th Conference of the European Colloid and Interface Society
(ECIS 99) was held in September 1999 in Dublin, Ireland. It brought
together scientists from academic research and industry within the
field of physics and chemistry of colloids and interfaces. The
Conference focused on the following topics: - Surfactant
colloids;
- Polymer colloids and solid particles;
- Food colloids;
- Soft matter interfaces;
- Biosystems;
- Rheology;
- Experimental methods in colloid and interface science.
Das Buch enthalt Kapitel uber: N. Kinjo, M. Ogata, Ibaraki-ken; K.
Nishi, Tokyo; A. Kaneda, Yokohama, Japan: Epoxyd-Formmassen als
Einschlussmaterialien fur mikroelektronische Gerate Yu.S. Lipatov,
T.E. Lipatova, L.F. Kosyanchuk, Kiev, UdSSR: Synthese und Struktur
struktureller Makromolekule K. Horie, I. Mita, Tokyo, Japan:
Reaktionen und Photodynamik in polymeren Festkorpern Yu.K.
Godovsky, V.S. Papkov, Moskau, UdSSR: Thermotrope Mesophasen
elementorganischer Polymere
This monograph gives a detailed introductory exposition of research
results for various models, mostly two-dimensional, of directed
walks, interfaces, wetting, surface adsorption (of polymers),
stacks, compact clusters (lattice animals), etc. The unifying
feature of these models is that in most cases they can be solved
analytically. The methods used include transfer matrices,
generating functions, recurrence relations, and difference
equations, and in some cases involve utilization of less familiar
mathematical techniques such as continued fractions and q-series.
The authors emphasize an overall view of what can be learned
generally of the statistical mechanics of anisotropic systems,
including phenomena near surfaces, by studying the solvable models.
Thus, the concept of scaling and, where known, finite-size scaling
properties are elucidated. Scaling and statistical mechanics of
anisoptropic systems in general are active research topics. The
volume provides a comprehensive survey of exact model results in
this field.
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