Liquids (Jan 2023)

Density and Dynamic Viscosity of Perfluorodecalin-Added <i>n</i>-Hexane Mixtures: Deciphering the Role of Fluorous Liquids

  • Deepika,
  • Siddharth Pandey

DOI
https://doi.org/10.3390/liquids3010005
Journal volume & issue
Vol. 3, no. 1
pp. 48 – 56

Abstract

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Fluorous solvents are deputed as prominent solvent systems owing to their salient features, unique physical properties, and ecological importance. In this study, the temperature- and composition-dependence of physical properties, density (ρ/g·cm−3), and dynamic viscosity (η/mPa·s), of neat perfluorodecalin (PFD) and PFD-added n-hexane mixtures with select compositions are reported. Density follows a linear decrease with temperature and a quadratic increase with the mole fraction of PFD. The sensitivity or dependence of density on temperature increases with an increase in PFD mole fraction. The temperature-dependence of the dynamic viscosity of the investigated mixtures follows the Arrhenius-type expression from which the resultant activation energy of the viscous flow (Ea,η) is determined. Interestingly, the composition-dependence of dynamic viscosity shows exponential growth with an increase in PFD mole fraction. Excess molar volumes (VE) and deviation in the logarithmic viscosities ∆(ln η) of the mixtures are calculated to highlight the presence of strong repulsive interactions between the two mixture components.

Keywords