Surface segregation and surface tension at the liquid–vapour interface of a binary mixture of Lennard-Jones fluids

1981 ◽  
Vol 16 (0) ◽  
pp. 45-58 ◽  
Author(s):  
Margarida M. Telo da Gama ◽  
Robert Evans
Keyword(s):  
Surface Tension ◽  
Binary Mixture ◽  
Surface Segregation ◽  
Lennard Jones

scholarly journals Non-equilibrium surface tension of the vapour-liquid interface of active Lennard-Jones particles

2017 ◽  
Vol 147 (8) ◽  
pp. 084902 ◽  
Author(s):  
Siddharth Paliwal ◽  
Vasileios Prymidis ◽  
Laura Filion ◽  
Marjolein Dijkstra
Keyword(s):  
Surface Tension ◽  
Liquid Interface ◽  
Equilibrium Surface ◽  
Lennard Jones ◽  
Equilibrium Surface Tension ◽  
Non Equilibrium

scholarly journals Prediction of the release process of the nitrogen-extinguishant binary mixture considering surface tension

2020 ◽  
Author(s):  
Siyuan Liu ◽  
Yongqi Xie ◽  
Mengdong Chen ◽  
Jianqin Zhu ◽  
Rodney Day ◽  
...  
Keyword(s):  
Surface Tension ◽  
Binary Mixture ◽  
Release Process

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.

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