Molecular dynamics study of the solution of semiflexible telechelic polymer chains with strongly associating end-groups

1999 ◽  
Vol 110 (12) ◽  
pp. 6039-6049 ◽  
Author(s):  
Pavel G. Khalatur ◽  
Alexei R. Khokhlov ◽  
Julia N. Kovalenko ◽  
Dmitrii A. Mologin
Keyword(s):  
Molecular Dynamics ◽  
Polymer Chains ◽  
End Groups ◽  
Telechelic Polymer

scholarly journals Ab initio molecular dynamics study of AlCl4− adsorption on PEDOT conducting polymer chains

2021 ◽  
Vol 7 ◽  
pp. 111-119
Author(s):  
Ben Craig ◽  
Chris-Kriton Skylaris ◽  
Carlos Ponce de Leon ◽  
Denis Kramer
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Conducting Polymer ◽  
Polymer Chains ◽  
Ab Initio Molecular Dynamics

Quantification of the Surface Morphology of Lubricant Films With Polar End Groups Using Molecular Dynamics Simulation: Periodic Changes in Morphology Depending on Film Thickness

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Susumu Ogata ◽  
Hedong Zhang ◽  
Kenji Fukuzawa ◽  
Yasunaga Mitsuya
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Surface Morphology ◽  
Film Thickness ◽  
Film Surface ◽  
Dynamics Simulation ◽  
Molecular Probe ◽  
Coarse Grained ◽  
End Groups ◽  
Lubricant Films

Using a coarse-grained molecular dynamics simulation based on the bead-spring polymer model, we reproduced the film distribution of molecularly thin lubricant films with polar end groups coated on the disk surface and quantified the film-surface morphology using a molecular-probe scanning method. We found that the film-surface morphology changed periodically with increasing film thickness. The monolayer of a polar lubricant that entirely covers the solid surface provides a flat lubricant surface by exposing its nonpolar backbone outside of the monolayer. By increasing film thickness, the end beads aggregate to make clusters, and bulges form on the lubricant surface, accompanying an increase in surface roughness. The bulges continue to grow even though the averaged film thickness reaches or exceeds the bilayer thickness. With further increases in film thickness, the clusters start to be uniformly distributed in the lateral direction to clearly form a third layer. As for the formation of fourth and fifth layers, the process is basically the same as that for the second and third layers. Through our calculations of the intermolecular potential field and the intermolecular force field, these values are found to change periodically and are synchronized with the formation of molecule aggregations, which explains the mechanism of forming the layered structure that is inherent to a polar lubricant.

scholarly journals Effect of Chitin Whiskers on the Molecular Dynamics of Carrageenan-Based Nanocomposites

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1083 ◽  
Author(s):  
Marta Carsi ◽  
Maria J. Sanchis ◽  
Clara M. Gómez ◽  
Sol Rodriguez ◽  
Fernando G. Torres
Keyword(s):  
Molecular Dynamics ◽  
Casting Process ◽  
Polymer Chains ◽  
Dielectric Relaxation Spectroscopy ◽  
Solution Casting ◽  
Fragility Index ◽  
Relaxation Dynamics ◽  
Dynamic Mobility ◽  
Chitin Nanowhiskers ◽  
Chitin Whiskers

Films of carrageenan (KC) and glycerol (g) with different contents of chitin nanowhiskers (CHW) were prepared by a solution casting process. The molecular dynamics of pure carrageenan (KC), carrageenan/glycerol (KCg) and KCg with different quantities of CHWs as a filler was studied using dielectric relaxation spectroscopy. The analysis of the CHW effect on the molecular mobility at the glass transition, Tg, indicates that non-attractive intermolecular interactions between KCg and CHW occur. The fragility index increased upon CHW incorporation, due to a reduction in the polymer chains mobility produced by the CHW confinement of the KCg network. The apparent activation energy associated with the relaxation dynamics of the chains at Tg slightly increased with the CHW content. The filler nature effect, CHW or montmorillonite (MMT), on the dynamic mobility of the composites was analyzed by comparing the dynamic behavior of both carrageenan-based composites (KCg/xCHW, KCg/xMMT).

scholarly journals Interface Characteristics of Neat Melts and Binary Mixtures of Polyethylenes from Atomistic Molecular Dynamics Simulations

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1059
Author(s):  
Sanghun Lee ◽  
Curtis W. Frank ◽  
Do Y. Yoon
Keyword(s):  
Molecular Dynamics ◽  
Surface Tension ◽  
Molecular Dynamics Simulations ◽  
Binary Mixtures ◽  
Surface Segregation ◽  
Surface Region ◽  
Polymer Chains ◽  
Methyl Groups ◽  
Free Standing ◽  
Dynamics Simulations

Molecular dynamics simulations of free-standing thin films of neat melts of polyethylene (PE) chains up to C150H302 and their binary mixtures with n-C13H28 are performed employing a united atom model. We estimate the surface tension values of PE melts from the atomic virial tensor over a range of temperatures, which are in good agreement with experimental results. Compared with short n-alkane systems, there is an enhanced surface segregation of methyl chain ends in longer PE chains. Moreover, the methyl groups become more segregated in the surface region with decreasing temperature, leading to the conclusion that the surface-segregation of methyl chain ends mainly arises from the enthalpic origin attributed to the lower cohesive energy density of terminal methyl groups. In the mixtures of two different chain lengths, the shorter chains are more likely to be found in the surface region, and this molecular segregation in moderately asymmetric mixtures in the chain length (C13H28 + C44H90) is dominated by the enthalpic effect of methyl chain ends. Such molecular segregation is further enhanced and dominated by the entropic effect of conformational constraints in the surface for the highly asymmetric mixtures containing long polymer chains (C13H28 + C150H3020). The estimated surface tension values of the mixtures are consistent with the observed molecular segregation characteristics. Despite this molecular segregation, the normalized density of methyl chain ends of the longer chain is more strongly enhanced, as compared with the all-segment density of the longer chain itself, in the surface region of melt mixtures. In addition, the molecular segregation results in higher order parameter of the shorter-chain segments at the surface and deeper persistence of surface-induced segmental order into the film for the longer chains, as compared with those in neat melt films.

Molecular Dynamics of Polymer Chains and Alkyl Groups in Solution

1980 ◽  
pp. 119-145 ◽  
Author(s):  
GEORGE C. LEVY ◽  
PETER L. RINALDI ◽  
JAMES J. DECHTER ◽  
DAVID E. AXELSO ◽  
LEO MANDELKERN
Keyword(s):  
Molecular Dynamics ◽  
Polymer Chains ◽  
Alkyl Groups

Molecular dynamics simulation study of adsorption of polymer chains with variable degree of rigidity. I. Static properties

1996 ◽  
Vol 104 (12) ◽  
pp. 4806-4813 ◽  
Author(s):  
E. Yu. Kramarenko ◽  
R. G. Winkler ◽  
P. G. Khalatur ◽  
A. R. Khokhlov ◽  
P. Reineker
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Simulation Study ◽  
Polymer Chains ◽  
Dynamics Simulation ◽  
Variable Degree ◽  
Static Properties

UV-reversible chain extendable polymers from thymine functionalized telechelic polymer chains

2014 ◽  
Vol 52 (18) ◽  
pp. 2557-2561 ◽  
Author(s):  
Gagan Kaur ◽  
Arthur Bertrand ◽  
Julien Bernard ◽  
Toby D. M. Bell ◽  
Kei Saito
Keyword(s):  
Polymer Chains ◽  
Telechelic Polymer
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