title: On interfacial properties of tetrahydrofuran: Atomistic and coarse-grained models from molecular dynamics simulation.
abstract: We have determined the interfacial properties of tetrahydrofuran (THF) from direct simulation of the vapor-liquid interface. The molecules are modeled using six different molecular models, three of them based on the united-atom approach and the other three based on a coarse-grained (CG) approach. In the first case, THF is modeled using the transferable parameters potential functions approach proposed by Chandrasekhar and Jorgensen [J. Chem. Phys. 77, 5073 (1982)] and a new parametrization of the TraPPE force fields for cyclic alkanes and ethers [S. J. Keasler et al., J. Phys. Chem. B 115, 11234 (2012)]. In both cases, dispersive and coulombic intermolecular interactions are explicitly taken into account. In the second case, THF is modeled as a single sphere, a diatomic molecule, and a ring formed from three Mie monomers according to the SAFT-γ Mie top-down approach [V. Papaioannou et al., J. Chem. Phys. 140, 054107 (2014)]. Simulations were performed in the molecular dynamics canonical ensemble and the vapor-liquid surface tension is evaluated from the normal and tangential components of the pressure tensor along the simulation box. In addition to the surface tension, we have also obtained density profiles, coexistence densities, critical temperature, density, and pressure, and interfacial thickness as functions of temperature, paying special attention to the comparison between the estimations obtained from different models and literature experimental data. The simulation results obtained from the three CG models as described by the SAFT-γ Mie approach are able to predict accurately the vapor-liquid phase envelope of THF, in excellent agreement with estimations obtained from TraPPE model and experimental data in the whole range of coexistence. However, Chandrasekhar and Jorgensen model presents significant deviations from experimental results. We also compare the predictions for surface tension as obtained from simulation results for all the models with experimental data. The three CG models predict reasonably well (but only qualitatively) the surface tension of THF, as a function of temperature, from the triple point to the critical temperature. On the other hand, only the TraPPE united-atoms models are able to predict accurately the experimental surface tension of the system in the whole temperature range.
authors.affiliation: Departamento de Ingeniería Química, Universidad de Concepción, POB 160-C Concepción, Chile.
authors.forename: J M
authors.initials: JM
authors.lastname: Garrido
authors.affiliation: Laboratorio de Simulación Molecular y Química Computacional, CIQSO-Centro de Investigación en Química Sostenible and Departamento de Física Aplicada, Universidad de Huelva, 21007 Huelva, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Algaba
authors.affiliation: Laboratoire des Fluides Complexes et Leurs Reservoirs, Université de Pau et des Pays de l'Adour, CNRS, TOTAL-UMR 5150, Avenue de l'Université, B.P. 1155, Pau F-64013, France.
authors.forename: J M
authors.initials: JM
authors.lastname: Míguez
authors.affiliation: Laboratoire des Fluides Complexes et Leurs Reservoirs, Université de Pau et des Pays de l'Adour, CNRS, TOTAL-UMR 5150, Avenue de l'Université, B.P. 1155, Pau F-64013, France.
authors.forename: B
authors.initials: B
authors.lastname: Mendiboure
authors.affiliation: Laboratorio de Simulación Molecular y Química Computacional, CIQSO-Centro de Investigación en Química Sostenible and Departamento de Geología, Universidad de Huelva, 21007 Huelva, Spain.
authors.forename: A I
authors.initials: AI
authors.lastname: Moreno-Ventas Bravo
authors.affiliation: Departamento de Física Aplicada, Universidade de Vigo, E36310 Vigo, Spain.
authors.forename: M M
authors.initials: MM
authors.lastname: Piñeiro
authors.affiliation: Laboratorio de Simulación Molecular y Química Computacional, CIQSO-Centro de Investigación en Química Sostenible and Departamento de Física Aplicada, Universidad de Huelva, 21007 Huelva, Spain.
authors.forename: F J
authors.initials: FJ
authors.lastname: Blas