Molecular dynamics study of wetting of alkanes on water: From high temperature to the supercooled region and the influence of second inflection points of interfacial tensions

Author(s):  
Pauf Neupane ◽  
Gerald Wilemski

To explore the wetting behavior of alkanes on bulk water interfaces, molecular dynamics simulations were carried out to determine the temperature dependence of (1) the surface tension of alkanes (octane,...

2015 ◽  
Vol 17 (42) ◽  
pp. 28364-28371 ◽  
Author(s):  
Luca Pavan ◽  
Francesca Baletto ◽  
Rada Novakovic

Melting temperature dependence on the radius of CuPt clusters by CALPHAD and atomistic molecular dynamics simulations. The formation of a supercooled region for 3 nm particle is highlighted by the huge hysteresis during the freezing process.


RSC Advances ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 5507-5515
Author(s):  
Liang Song ◽  
Feng-Qi Zhao ◽  
Si-Yu Xu ◽  
Xue-Hai Ju

The bimolecular and fused ring compounds are found in the high-temperature pyrolysis of NONA using ReaxFF molecular dynamics simulations.


Author(s):  
Kenji Mochizuki

Abstract Molecular dynamics simulations are carried out for a heterogeneous system composed of bulk water and pure-silica zeolites of the AFI type. Our simulations show, for the first time, the...


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1059
Author(s):  
Sanghun Lee ◽  
Curtis W. Frank ◽  
Do Y. Yoon

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.


2014 ◽  
Vol 16 (46) ◽  
pp. 25573-25582 ◽  
Author(s):  
Mirza Galib ◽  
Gabriel Hanna

Ab initio molecular dynamics simulations of carbonic acid (H2CO3) at the air–water interface yield a lower dissociation barrier than in bulk water.


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