Dependence of diffusivity on density and solute diameter in liquid phase: A molecular dynamics study of Lennard-Jones system

摘要: Investigations into the variation of self-diffusivity with solute radius, density, and degree disorder host medium is explored. The system consists a binary mixture relatively smaller sized solute, whose size varied larger solvent interacting via Lennard-Jones potential. Calculations have been performed at three different reduced densities 0.7, 0.8, 0.933. These simulations show that diffusivity exhibits maximum for some intermediate when diameter varied. found same all which variance prediction levitation effect. In order to understand this anomaly, additional were carried out in has while keeping density constant. results gradually disappears increase disorder. Disorder characterized by means minimal spanning tree. Simulations also constant only altered. from these now shifts distances decrease density. This agreement changes void neck distribution medium. are excellent predictions They suggest effect shift towards radius it radius. Thus, real systems where lower higher vice versa, due opposing influences. confirmed seen velocity autocorrelation function, self part scattering function activation energy.