title: Atomistic Insight into Tetraalkylphosphonium Bis(oxalato)borate Ionic Liquid/Water Mixtures. 2. Volumetric and Dynamic Properties.
abstract: Atomistic molecular dynamics simulations have been performed to investigate volumetric quantities and dynamic properties of binary trihexyltetradecylphosphonium bis(oxalato)borate ([P6,6,6,14][BOB]) ionic liquid (IL)/water mixtures with different water concentrations. The predicted liquid densities for typical [P6,6,6,14][BOB] IL/water mixtures are consistent with available experimental data with a relative discrepancy of less than 3%. The liquid densities and excess molar volumes of all studied [P6,6,6,14][BOB] IL/water mixtures are characterized by concave and convex features, respectively, within full water concentration range. The dynamic properties of [P6,6,6,14] cations, [BOB] anions, and water molecules are particularly analyzed through calculation of velocity autocorrelation functions, diffusion coefficients, and reorientational autocorrelation functions and correlation times. The translational and reorientational mobilities of three species become faster upon increasing water concentration in [P6,6,6,14][BOB] IL/water mixtures and present complex dynamical characteristics arising from three distinct microscopic diffusion features within the full water concentration range. The obtained striking volumetric quantities and particular dynamic properties are well correlated to microscopic liquid structural organization and distinct local ionic environment of all studied [P6,6,6,14][BOB] IL/water mixtures.
authors.forename: Yong-Lei
authors.initials: YL
authors.lastname: Wang
authors.affiliation: Chemistry of Interfaces, Luleå University of Technology , SE-971 87 Luleå, Sweden.
authors.forename: Manishkumar R
authors.initials: MR
authors.lastname: Shimpi
authors.affiliation: Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University , SE-106 91 Stockholm, Sweden.
authors.forename: Sten
authors.initials: S
authors.lastname: Sarman
authors.affiliation: Chemistry of Interfaces, Luleå University of Technology , SE-971 87 Luleå, Sweden.
authors.forename: Oleg N
authors.initials: ON
authors.lastname: Antzutkin
authors.affiliation: Department of Mechanical Construction and Production, Ghent University , B-9000 Ghent, Belgium.
authors.forename: Sergei
authors.initials: S
authors.lastname: Glavatskih
authors.forename: Lars
authors.initials: L
authors.lastname: Kloo
authors.affiliation: Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University , SE-106 91 Stockholm, Sweden.
authors.forename: Aatto
authors.initials: A
authors.lastname: Laaksonen