Asymmetric diblock copolymers-phase behaviour and kinetics of structure formation

1997 ◽  
Vol 275 (4) ◽  
pp. 341-351 ◽  
Author(s):  
M. Schwab ◽  
B. Stühn
Keyword(s):  
Structure Formation ◽  
Diblock Copolymers ◽  
Phase Behaviour ◽  
Kinetics Of

Adsorption Kinetics of Diblock Copolymers from a Micellar Solution on Silica and Titania

1998 ◽  
Vol 31 (26) ◽  
pp. 9281-9294 ◽  
Author(s):  
H. D. Bijsterbosch ◽  
M. A. Cohen Stuart ◽  
G. J. Fleer
Keyword(s):  
Adsorption Kinetics ◽  
Micellar Solution ◽  
Diblock Copolymers ◽  
Kinetics Of ◽  
Silica And Titania

scholarly journals FEATURES OF QUANTITATIVE MEASUREMENTS OF THE DYNAMIC MODULE OF ELASTICITY OF BINDERS IN OPTIMIZATION OF PRODUCTION TECHNOLOGY SEROGYPSUM COMPOSITE

2021 ◽  
pp. 86-92
Author(s):  
V.I. Tarasevych ◽  
◽  
Yu.G. Gasan ◽  
V.B. Dolgoshey ◽  
◽  
...  
Keyword(s):  
Time Dependence ◽  
Structure Formation ◽  
Elastic Properties ◽  
Physicochemical Characteristic ◽  
Resonance Method ◽  
Acoustic Resonance ◽  
Mechanical Action ◽  
Bending Vibrations ◽  
Damping Decrement ◽  
Kinetics Of

The paper considers the issues of studying the structure formation of binders during hardening to determine the optimal moments of mechanical action on gypsum concrete specimens, which makes it possible to optimize the technology of their impregnation with sulfur melt. The time dependence of the elastic modulus of a hardening, binder is its important physicochemical characteristic, since it is used to objectively identify the stages of structure formation, to simulate the processes occurring at each of the stages. It is noted that the method of acoustic resonance of bending vibrations, in the case of hardening binders, needs correction with respect to the measurement technique and interpretation of the results obtained. The kinetics of the resonance frequency of a sample consisting of a rigid cell and a dispersion poured into it is a function of the elastic properties of the cell, the dispersion itself, the contact zone of the dispersion with cell and therefore cannot be used for either qualitative or quantitative analysis of the kinetics of hardening. Taking into account the elasticity of cuvette is necessary to obtain reliable information. It has been established that in the presence of shrinkage or significant expansion of the binder, the study of structure formation by the resonance method should be carried out in plastic cuvettes. Regardless of shrinkage, the use of a cuvette requires compulsory consideration of its elastic properties. It is advisable to objectively distinguish the stages of structure formation on the basis of the kinetics of not the dynamic modulus of elasticity itself, but the rate of its change. The time dependence of the logarithmic damping decrement is also an important characteristic of the concrete structure. The studies carried out make it possible to obtain serogypsum composites with the necessary performance characteristics and to manufacture elements of architectural décor, wall fencing products of increased aesthetics, durability and reliability from them.

Side-Chain LC Block Copolymers with Well Defined Structures Prepared by Living Anionic Polymerization. 2: Effect of the Glass Transition Temperature of Amorphous Segments on the Phase Behaviour and Structure of the LC Segment

1998 ◽  
Vol 10 (1) ◽  
pp. 131-138 ◽  
Author(s):  
Masayuki Yamada ◽  
Tomomichi Itoh ◽  
Akira Hirao ◽  
Sei-Ichi Nakahama ◽  
Junji Watanabe
Keyword(s):  
Glass Transition ◽  
Anionic Polymerization ◽  
Diblock Copolymers ◽  
Domain Size ◽  
Phase Behaviour ◽  
Side Chain ◽  
Isotropic Phase ◽  
Transition Temperatures ◽  
Living Anionic Polymerization ◽  
Methyl Styrene

We have prepared two classes of LC diblock copolymers, OcSt-b-LC and MeStb-LC, by living anionic polymerization. These are composed of the side-chain LC polymer as one segment and two different amorphous polymers, poly(octyl styrene) (OcSt) and poly(α-methyl styrene) (MeSt), as the other segment. OcSt and MeSt segments have glass transition temperatures of −60 °C and 160 °C respectively, which are relatively lower and higher than the transition temperatures of crystal–SA (∼90 °C) and SA–isotropic (∼130 °C) in the LC segment. In OcSt-b-LC the lamellar domain size decreases gradually from that of the crystal phase to that of the isotropic phase, indicating that the global conformation of the backbone changes throughout the SA temperature region. In MeSt-b-LC, in contrast, no change in the lamellar size is observed and the crystallinity of the LC segment is reduced in comparison with that in OcSt-b-LC while the liquid crystal is well formed. Such a distinction between two copolymer systems, arising from an interplay between the LC and amorphous segments, shows that the global conformation of the backbone is significant for understanding the phase behaviour and structure of side-chain LC polymers.

scholarly journals Kinetics of structure formation of a composite mortar with nano-additives based on aluminium

2020 ◽  
Vol 161 ◽  
pp. 01099
Author(s):  
S.Yu. Efremova ◽  
M.I. Panfilova ◽  
N.I. Zubrev ◽  
O.V. Novoselova
Keyword(s):  
Structure Formation ◽  
Temporal Evolution ◽  
Initial Period ◽  
Control Sample ◽  
Injection Efficiency ◽  
Evolution Of Structure ◽  
Nano Additives ◽  
Kinetics Of

This paper discusses the possibility of using aluminum-containing nano-additives as structure modifiers of composite mortar in order to ensure safety and durability of rubble foundation. Higher injection efficiency can be achieved by integrating the composite mortar into the foundation body. The temporal evolution of structure formation in composite mortar with various contents of boehmite and aluminosilicate nanotubes (ANT) was studied. The optimal concentrations of additives were determined at which the rate of structure formation reaches its maximum. It was revealed that ANT additives accelerate the hardening time of the composite mortar by 1.3 times in comparison with boehmite additives. The greatest impact on accelerating the structure formation in the initial period is achieved by adding 0.125% aluminosilicate tubes to the mass of cement. It was found that in this case, the duration of flowability loss of the composite mortar is reduced by a factor of three compared with that of the control sample.

scholarly journals Transient Structure Formation Kinetics of Monomeric Alpha-Synuclein Derived from MD Simulations

2020 ◽  
Vol 118 (3) ◽  
pp. 216a
Author(s):  
Reinhard Klement ◽  
Timo Graen ◽  
Asaf Grupi ◽  
Elisha Haas ◽  
Helmut Grubmueller
Keyword(s):  
Structure Formation ◽  
Md Simulations ◽  
Alpha Synuclein ◽  
Formation Kinetics ◽  
Kinetics Of ◽  
Transient Structure

Self-assembly of highly asymmetric, poly(ionic liquid)-rich diblock copolymers and the effects of simple structural modification on phase behaviour

2019 ◽  
Vol 10 (6) ◽  
pp. 751-765 ◽  
Author(s):  
Alyssa W. May ◽  
Zhangxing Shi ◽  
Dilanji B. Wijayasekara ◽  
Douglas L. Gin ◽  
Travis S. Bailey
Keyword(s):  
Ionic Liquid ◽  
Phase Behavior ◽  
Self Assembly ◽  
Structural Modification ◽  
Diblock Copolymers ◽  
Alkyl Substituent ◽  
Phase Behaviour ◽  
Phase Boundaries ◽  
Poly Ionic Liquid

A series of ATRP-synthesized poly(IL) diblock copolymers exhibit morphological phase behavior with shifted phase boundaries and alkyl substituent dependent segregation.

Interfacial Segregation Effects in Mixtures of Homopolymers with Copolymers.

1989 ◽  
Vol 171 ◽  
Author(s):  
Vijay S. Wakharkar ◽  
Thomas P. Russell ◽  
Vaughn R. Deline
Keyword(s):  
Mass Spectroscopy ◽  
Diblock Copolymers ◽  
Large Range ◽  
Surface Enrichment ◽  
Molecular Weights ◽  
Polymer Interface ◽  
Segregation Process ◽  
Interfacial Segregation ◽  
Kinetics Of ◽  
Secondary Ion

ABSTRACTSecondary Ion Mass Spectroscopy (SIMS) has been used to study the surface and interfacial segregation of diblock copolymers in mixtures of the copolymer in the homopolymer. Symmetric, diblock copolymers of polystyrene (PS) and poly(methyl methacrylate) (PMMA), in either the PS or the PMMA homopolymers were investigated. In mixtures of the copolymer with the PS homopolymer, systematic surface enrichment of the copolymer as well as segregation of the copolymer to the polymer/Si interface or in the case of bilayered filmsto the polymer/polymer interface occurs with annealing treatments. These segregation effects persist over a large range of homopolymer molecular weights with changes in the kinetics of the segregation process being predominant.

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