scholarly journals Polyphilicity—An Extension of the Concept of Amphiphilicity in Polymers

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 960 ◽  
Author(s):  
Daniel Heinz ◽  
Elkin Amado ◽  
Jörg Kressler
Keyword(s):  
Liquid Crystalline ◽  
Point Of View ◽  
Solid Surfaces ◽  
Random Copolymers ◽  
Click Reactions ◽  
Segmented Copolymers ◽  
Current Trends ◽  
Reversible Deactivation ◽  
Recent Developments ◽  
Reversible Deactivation Radical Polymerization

Recent developments in synthetic pathways as simple reversible-deactivation radical polymerization (RDRP) techniques and quantitative post-polymerization reactions, most notoriously ‘click’ reactions, leading to segmented copolymers, have broadened the molecular architectures accessible to polymer chemists as a matter of routine. Segments can be blocks, grafted chains, branchings, telechelic end-groups, covalently attached nanoparticles, nanodomains in networks, even sequences of random copolymers, and so on. In this review, we describe the variety of the segmented synthetic copolymers landscape from the point of view of their chemical affinity, or synonymous philicity, in bulk or with their surroundings, such as solvents, permeant gases, and solid surfaces. We focus on recent contributions, current trends, and perspectives regarding polyphilic copolymers, which have, in addition to hydrophilic and lipophilic segments, other philicities, for example, towards solvents, fluorophilic entities, ions, silicones, metals, nanoparticles, and liquid crystalline moieties.

Electron microscopy of crystalline structure in thermotropic random copolymers

1991 ◽  
Vol 49 ◽  
pp. 1054-1055
Author(s):  
Afzana Anwer ◽  
S. Eilidh Bedford ◽  
Richard J. Spontak ◽  
Alan H. Windle
Keyword(s):  
Electron Microscopy ◽  
Crystalline Structure ◽  
Liquid Crystalline ◽  
Elevated Temperatures ◽  
Random Copolymers ◽  
Molecular Characteristics ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Identical Monomer ◽  
Periodic Layer

Random copolyesters composed of wholly aromatic monomers such as p-oxybenzoate (B) and 2,6-oxynaphthoate (N) are known to exhibit liquid crystalline characteristics at elevated temperatures and over a broad composition range. Previous studies employing techniques such as X-ray diffractometry (XRD) and differential scanning calorimetry (DSC) have conclusively proven that these thermotropic copolymers can possess a significant crystalline fraction, depending on molecular characteristics and processing history, despite the fact that the copolymer chains possess random intramolecular sequencing. Consequently, the nature of the crystalline structure that develops when these materials are processed in their mesophases and subsequently annealed has recently received considerable attention. A model that has been consistent with all experimental observations involves the Non-Periodic Layer (NPL) crystallite, which occurs when identical monomer sequences enter into register between adjacent chains. The objective of this work is to employ electron microscopy to identify and characterize these crystallites.

Photocontrolled iodine-mediated reversible-deactivation radical polymerization with a semifluorinated alternating copolymer as the macroinitiator

2020 ◽  
Vol 11 (47) ◽  
pp. 7497-7505
Author(s):  
Jiannan Cheng ◽  
Kai Tu ◽  
Enjie He ◽  
Jinying Wang ◽  
Lifen Zhang ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Radical Polymerization ◽  
Room Temperature ◽  
Blue Led ◽  
Led Light ◽  
Alternating Copolymers ◽  
Alternating Copolymer ◽  
Reversible Deactivation ◽  
Novel Strategy ◽  
Reversible Deactivation Radical Polymerization

A novel strategy for preparing block copolymers with semifluorinated alternating copolymers as macroinitiators was established by photocontrolled iodine-mediated RDRP under irradiation with blue LED light at room temperature.

scholarly journals Russia’s Foreign Policy Evolution in the New Balkan Landscape

2020 ◽  
Vol 56 (3-4) ◽  
pp. 179-199
Author(s):  
Ekaterina Entina ◽  
Alexander Pivovarenko
Keyword(s):  
Foreign Policy ◽  
Soviet Union ◽  
Regional Security ◽  
Southeast Europe ◽  
The Balkans ◽  
Current Trends ◽  
The Soviet Union ◽  
Recent Developments ◽  
The Difference

The article reflects on the issue of the foreign policy strategy of modern Russia in the Balkans region. One of the most significant aspects of this problem is the difference in views between Russia and the West. Authors show how different interpretations of the events in former Yugoslavia in the 1990s and the beginning of the 2000s predetermined the sense of mutual suspicion and mistrust which spread to other regions such as the post-Soviet space. Exploring differences between the Russian and the Western (Euro-Atlantic) views on the current matters, authors draw attention to fundamental differences in terminology: while the Western narrative promotes more narrow geographical and political definitions (such as the Western Balkan Six), traditional Russian experts are more inclined to wider or integral definitions such as “the Balkans” and “Central and Southeast Europe”. Meanwhile none of these terms are applicable for analysis of the current trends such as the growing transit role of the Balkans region and its embedding in the European regional security architecture. Therefore, a new definition is needed to overcome the differences in vision and better understand significant recent developments in the region. Conceptualizing major foreign policy events in Central and Southeast Europe during the last three decades (the 1990s, 2000s and 2010s), authors demonstrate the significance of differences in tools and methods between the Soviet Union and the modern Russia. Permanent need for adaptation to changing political and security context led to inconsistence in Russian Balkan policy in the 1990s. Nevertheless, Russia was able to preserve an integral vision of the region and even to elaborate new transregional constructive projects, which in right political circumstances may promote stability and become beneficial for both Russia and the Euro-Atlantic community.

Metaphor Research and the Hebrew Bible

2021 ◽  
Vol 19 (3) ◽  
pp. 235-285
Author(s):  
Mason D. Lancaster
Keyword(s):  
Hebrew Bible ◽  
Conceptual Metaphor ◽  
Future Research ◽  
Conceptual Metaphor Theory ◽  
Current Trends ◽  
Metaphor Theory ◽  
Recent Developments

This article provides an overview of metaphor theories and research on their own terms, as well as their use in Hebrew Bible (HB) studies. Though metaphor studies in the HB have become increasingly popular, they often draw upon a limited or dated subset of metaphor scholarship. The first half of this article surveys a wide variety of metaphor scholarship from the humanities (philosophical, poetic, rhetorical) and the sciences (e.g., conceptual metaphor theory), beginning with Aristotle but focusing on more recent developments. The second half overviews studies of metaphor in the HB since 1980, surveying works focused on theory and method; works focused on specific biblical books or metaphor domains; and finally noting current trends and suggesting areas for future research.

scholarly journals GRIBOV PROBLEM FOR GAUGE THEORIES: A PEDAGOGICAL INTRODUCTION

2004 ◽  
Vol 01 (04) ◽  
pp. 423-441 ◽  
Author(s):  
GIAMPIERO ESPOSITO ◽  
DIEGO N. PELLICCIA ◽  
FRANCESCO ZACCARIA
Keyword(s):  
Cross Sections ◽  
Gauge Theories ◽  
Functional Integral ◽  
Point Of View ◽  
Spherically Symmetric ◽  
Abelian Gauge ◽  
Gauge Transformations ◽  
Recent Developments ◽  
Gribov Ambiguity ◽  
Gribov Copies

The functional-integral quantization of non-Abelian gauge theories is affected by the Gribov problem at non-perturbative level: the requirement of preserving the supplementary conditions under gauge transformations leads to a nonlinear differential equation, and the various solutions of such a nonlinear equation represent different gauge configurations known as Gribov copies. Their occurrence (lack of global cross-sections from the point of view of differential geometry) is called Gribov ambiguity, and is here presented within the framework of a global approach to quantum field theory. We first give a simple (standard) example for the SU(2) group and spherically symmetric potentials, then we discuss this phenomenon in general relativity, and recent developments, including lattice calculations.

Copolymerization of simple methacrylates by Cu(0)-mediated reversible deactivation radical polymerization

2018 ◽  
Vol 51 (5) ◽  
pp. 449-459 ◽  
Author(s):  
Jongwon Choe ◽  
Woo Jung Lee ◽  
Han Gyeol Jang ◽  
Youngjoo Song ◽  
Jae Hyun Sim ◽  
...  
Keyword(s):  
Radical Polymerization ◽  
Reversible Deactivation ◽  
Reversible Deactivation Radical Polymerization
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