Rheology of liquid n-triacontane: Molecular dynamics simulation

31st International Conference on Equations of State for Matter

Kondratyuk, N.D.^1 ; Norman, G.E.^1 ; Stegailov, V.V.^1

Joint Institute for High Temperatures of the Russian Academy of Sciences, Izhorskaya 13, Moscow

125412, Russia^1

关键词: Atomic liquids;    Diffusion process;    Force field parameters;    Green-Kubo methods;    Green-Kubo relations;    Low temperatures;    Molecular crowding;    Molecular dynamics simulations;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/774/1/012039/pdf
DOI  :  10.1088/1742-6596/774/1/012039

来源: IOP

【 摘 要 】

Molecular dynamics is applied to calculate diffusion coefficients of n-triacontane C30H62using Einstein-Smoluchowski and Green-Kubo relations. The displacement Δr2(t) has a subdiffusive part Δr2∼ tα, caused by molecular crowding at low temperatures. Longtime asymptotes of v(0)v(t) are collated with the hydrodynamic tail t-3/2demonstrated for atomic liquids. The influence of these asymptotes on the compliance of Einstein-Smoluchowski and Green-Kubo methods is analyzed. The effects of the force field parameters on the diffusion process are treated. The results are compared with experimental data.