Symposium
Editor, Yuli
Ya Gotlib
Wiley-VCH, 1999, pp. 1-273
Preface
The 3rd International
Symposium "Molecular Mobility and Order in Polymer Systems" continues
the series of Saint Petersburg meetings organized by the Institute of
Macromolecular Compounds of Russian Academy of Sciences (RAS) and the
Department of General and Technical Chemistry of RAS. The Symposium
was sponsored by the International Union of Pure and Applied Chemistry
and supported by the Russian Foundation of Basic Research and St. Petersburg
Research Center of RAS.
The present Symposium
(as well as the first one in 1994) was oriented more towards dynamical
and relaxation phenomena whereas the discussion at the previous 2nd
Symposium (May, 1996) was mainly focused on the problems of structure
and order. Of course, these shifts in the subject of Symposiums were
never too dramatic: mobility in polymer physics and physical chemistry,
just like in real life, is inseparable from the order (or disorder!)
of the system.
The main topics
of the Symposium include:
- conformation
and mobility of macromolecules in solutions, melts, and networks in
strong external fields
- structure and
properties of liquid-crystalline polymers - block copolymers
- polymer layers,
brushes and micelles - polymer complexes and membranes
- structure and
dynamics of branched polymer systems, stars, dendrimers and networks
All the systems
considered share a common general feature: the order present in them
is "soft", and there exists a pronounced molecular mobility.
The Symposium included
18 invited plenary lectures, 32 contributed lectures and 180 poster
presentations. This meeting was a truly international one: lectures
and posters were submitted by scientists from Canada, Czech Republic,
Finland, France, Germany, Greece, Hungary, Italy, Israel, Japan, Kazakhstan,
Lithuania, The Netherlands, Portugal, Russia, Spain, Sweden, Turkey,
USA, Uzbekistan, Ukraine, and UK.
A short account
of the materials presented at the Symposium was published in the Book
of Abstracts.
The plenary and
contributed lectures were presented by eminent scientists, classics
of polymer science (Sam Edwards, Tatiana Birshtein, Victor Kabanov ...
), and also by well-known active researchers of younger generations.
The Symposium featured
a dynamic poster session which included presentations by many participants,
especially young scientists, and was accompanied by very lively discussions.
Regrettably, this
volume does not cover all the new and interesting results discussed
at the Symposium since not all the authors were able to present their
lectures for publication in this volume (some of the materials had been
published earlier or submitted elsewhere). However, it provides a good
representation of the scope of the meeting and the main topics of the
discussion.
Because of the close
interconnection between the different topics we preferred a less detailed
classification of papers than that given in the original topics of the
Symposium. The classification accepted in this Volume i.e. "Mobility=Structure=Order"
or "Structure-Order-Properties" is still of a somewhat conditional character
and is based on the most characteristic features of the investigation
in a given paper.
Mobility-Structure-Order
The lectures devoted
to polymer dynamics describe various types of relaxation phenomena on
different time and length scales (from nano-scale to macroscopic) investigated
by a broad variety of experimental, theoretical and computer simulation
methods. Polarized luminescence provides information on the molecular
mobility in the nanosecond range which can be used to characterize molecular
structure for copolymers of various chemical structure (Anufrieva et
al.). An extensive set of methods: DSC, interferometric spectroscopy,
TGA, dielectric relaxation spectroscopy, and thermally stimulated depolarization
were applied to study molecular dynamics in nano-structured polyimide
silicon materials (Bershtein et al.). Dybal and coworkers investigated
the structure and mobility in polycarbonates and polycarbonate-PEO mixtures
by NMR and vibrational spectroscopy. The relaxation of poly (4-oligodimethylsiloxanyl)
styrene as seen by solid state 29Si NMR was discussed by
Kawakami in connection with the gas permeation behavior of the polymer
membranes. Quasi-elastic neutron scattering, X-ray and dielectric spectroscopy
were applied to the investigation of the super- structure, order and
segmental dynamics of carbosilane dendrimers in bulk and solution (Stuehn
et al.). Mechanical strength, ion conductivity, gas permeability, and
ion exchange capacity were studied for new polymer membranes used for
low-temperature fuel cells (Sundholm et al.). Rheo-optical FT-IR spectroscopy
was used for investigating the intra- and intermolecular hydrogen-bonding
and its effect on the local mobility in solid poly(acrylic acid) films
(Mavinkurve and Heyvelmans-Wijdenes). The mechanical and electrical
degradation processes of polymer composites and the application of the
Zhurkov thermofluctuation theory were studied by Mamedov et al.
Some papers were
devoted to the theory and computer simulation of the molecular mobility.
The theoretical approach to the viscoelasticity of polymer melt and
cross-linked system as a function of frequency and cross-linking was
developed by Edwards and Takano, in the framework of tube model. The
topology of the system and closing of the tube at cross-links were taken
into account. The influence of the long-range hydrodynamic interactions
between polymer network and effective viscous medium on the cooperative
relaxation spectra was considered by Gotlib. Borodin and Khazanovich
proposed a non-standard alternative approach to hydrodynamic interactions
in polymer solutions applied to the calculation of the diffusion coefficient
and intrinsic viscosity of polymer solutions. An application of the
mode-coupling theory to the dynamics of the DNA macromolecules and proteins
and its effects on the NMR relaxation was treated by La-Penna and coworkers.
Fatkullin and Kimmich considered the problems of intra- and interchain
relaxation in entangled polymer melts using memory function formalism
and treated also the visco-elastic properties of polymer melts with
the help of renormalized Rouse formalism. Ngai presented an improved
theory of the concentration dependence of the cooperative polymer dynamics
in solutions based on the general coupling model explaining the stretched
exponential time dependence of correlation functions and the same type
of the stretched exponential dependence of relaxation times on concentration.
The conformational change and the kinetics of the coil-stretch transition
in polymer chains in a steady elongational flow were investigated by
computer simulation (de la Torre and Ciffe). Oleinik and coworkers performed
a detailed computer modeling of the local structure and rotational mobility
of ethylene-(a-olefin copolymers in n-paraffin
crystals.
Thus the theoretical
work and computer simulations emphasize a detailed study of the collective
motions in complex many-chain systems and the effects of strong external
or internal fields (as in crystalline phases).
Structure- Order-Properties
The papers of this
part of the Symposium were devoted to the study of the interconnection
between chemical constitution, morphology and order for a broad class
of macromolecular systems mentioned in the topics of the Symposium.
New types of mesophases (e.g., aperiodic layer mesophases) in rigid-chain
copolymers and co-(poly)esteramides appearing in the two-phase semicrystalline
materials were considered by Antipov, Plate, and Levchenko. Experimental
electron microscopic structure investigations of organic molecules with
non-linear optical properties and ab initio quantum-mechanical structure
determination were carried out by Voigt-Martin and coworkers. In the
paper of Koyun et al. the effects of the molecular and supermolecular
structure of polyolefin on some mechanical properties of plastics used
for manufacturing pipes were investigated. The structure of hydrophobically
modified poly(ethylene oxide), association and ordering effects, formation
of aggregates and rheological behavior was considered by Francois et
al. The interconnection between the polymer structure and optical properties
(in IR and UV spectra) for polymer composite films was investigated
by Boydag et al. Zaitsev and coworkers have studied the structure and
properties of polymethylsiloxane monolayers with styrene and poly styrene-poly
siloxane latexes and monolayer films. The group of papers was devoted
to the properties of the neutral and charged hydrogels, their interaction
with incorporated particles and surfactants (Starodoubtsev, Khokhlov
et al.), the complexes between gels and organic dyes (Nastmova, Makhaeva,
Khokhlov) and problems of the ion aggregation in hydrogels (Philippova,
Khokhlov et al.).
Theory and computer
simulation of the structure-order problem was also represented extensively
on the Symposium. The theory of mixed superstructures with different
morphology formed in mixtures of ABC-triblock and AB-, AC- and BC-diblock
polymers was presented by Birshtein, Amoskov and Polotskii. Johner,
Vilgis and Joanny considered the behavior of polyelectrolyte gels in
poor solvent chain on the basis of the single chain elasticity using
the necklace model of polyelectrolyte. Paul, Weber and Binder considered
the competition between local LC ordering and glassy-freezing in melts
of semiflexible polymers using the MC computer simulation of the bond-fluctuation
model. A simulation of a specific structure ally ordered phase intermediate
between the crystalline and amorphous phases was performed by Ludovice
et. al. Conformational structure and some dynamic characteristics of
charged polyelectrolyte brushes (anchored chains) were studied by molecular
dynamics method by Seidel and Csaika. Lukasheva, Darinskii et al. studied
(by molecular mechanics method) the conformation of polyisocyanates
with helical structure, investigated the mechanisms of helix reversal
and the comparative role of breaks and librations in the chain flexibility
of PIC. The microstructure and collapse transition of protein-like AB-copolymer
globules was investigated by computer simulation by Ivanov et al.
This brief review
of the materials of the Symposium including those presented in this
volume shows that the main interest in the investigation of the "structureorder-properties"
problem lies in the domain of systems with complex chemical constitution
and morphology like polyelectrolytes, copolymers, mesophases, glassy
states with local ordering etc.
We believe that
the 3rd International Symposium contributed significantly to the understanding
of the interconnection of mobility and order in the polymer systems.
Yuli
Ya. Gotlib
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