Minerva González-Melchor

arXiv2023

Novel force field of [Bmim][Nf$_2$T] and its tranferability in a mixture with water

In this work, a new force field is presented for the ionic liquid 1-butyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide, [Bmim][Nf$_2$T]. As a part of the εforce field, the acronym IL/εis used to refer to this ionic liquid. This new force field reproduces the dielectric constant, the density, and the entalphy of vaporization, with an error of less than 3%, being posible to generate new force fields for ionic liquids, based on the flexibility of the molecule. In addition, a study of the [Bmim][Nf$_2$T]-H$_2$O mixture is performed from pure IL to pure water, passing through various concentrations.

cond-mat.soft↗

arXiv2020

Equation of state, structure and diffusion coefficients of Gay-Berne fluids: the cases $κ'$ = 5; 10; 15; 20

We performed extensive molecular dynamics simulations to obtain pressure-density phase diagram, orientational order parameter, pair correlation functions and translational diffusion coefficients of Gay-Berne fluids. Different sets of parameters were employed for the Gay-Berne potential, in particular we studied the cases $κ'=5, 10, 15, 20$ and $κ=3$, $μ=2$, $ν=1$ at different conditions of density and temperature. The structure was analyzed in terms of the order parameter and the pair correlation functions. We found that for the highest value $κ'=20$ the region where pressure increases with density is significantly reduced at low temperatures; additionally the pressure shows several decays with density as an indicative that several structural phases can take place. These effects are discussed in terms of the pair correlation functions. For higher temperatures the pressure shows only two decays for all $κ'$'s studied. As this parameter increases its value those decays are shifted to lower densities.

cond-mat.soft↗