Viscosity, Interfacial Tension, and Density of Binary-Liquid Mixtures of n‑Hexadecane with n‑Octacosane, 2,2,4,4,6,8,8-Heptamethylnonane, or 1‑Hexadecanol at Temperatures between 298.15 and 573.15 K by Surface Light Scattering and Equilibrium Molecular Dynamics Simulations
This work contributes to the characterization of three binary liquid hydrocarbon-based mixtures via the determination of density, viscosity, and interfacial tension over the entire concentration range up to temperatures of 573.15 K. The oscillating-tube method, surface light scattering (SLS), and eq...
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| Published in: | Journal of chemical and engineering data Vol. 66; no. 5; pp. 2264 - 2280 |
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| Main Authors: | , , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
American Chemical Society
13-05-2021
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| Online Access: | Get full text |
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| Summary: | This work contributes to the characterization of three binary liquid hydrocarbon-based mixtures via the determination of density, viscosity, and interfacial tension over the entire concentration range up to temperatures of 573.15 K. The oscillating-tube method, surface light scattering (SLS), and equilibrium molecular dynamics (EMD) simulations are applied to analyze the influences of chain length, branching, and hydroxylation on the aforementioned thermophysical properties. For probing these effects, the three binary systems of n-hexadecane (1) with n-octacosane (2), 1-hexadecanol (2), or 2,2,4,4,6,8,8-heptamethylnonane (2), each with mole fraction of x 1 = 0.25, 0.5, or 0.75, are investigated in macroscopic thermodynamic equilibrium at or close to saturation conditions at temperatures between 298.15 and 573.15 K. Based on the experimental results for the liquid densities, liquid viscosities, and interfacial tensions with average expanded uncertainties (k = 2) of 0.10, 2.0, and 1.8%, respectively, our previously published modification to the optimized potentials for the liquid simulations (OPLS) force field for long hydrocarbons (L-OPLS) is evaluated for its transferability to liquid mixtures in EMD simulations. Considering all simulation results, the average absolute relative deviations for the density, viscosity, and interfacial tension are 0.74, 27, and 14%, respectively. Experimental results are also applied for the evaluation of simple prediction models based on pure-component properties. Especially at high temperatures, such simple mixing rules perform well. At lower temperatures, however, nonidealities like surface enrichment or the formation of molecule clusters in the mixture are more likely to dominate fluid behavior, leading to a failure of the simple mixing rules. To explain this observation, partial-density profiles and radial distribution functions from simulations, giving access to the fluid structure on a microscopic level, are evaluated. |
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| ISSN: | 0021-9568 1520-5134 |
| DOI: | 10.1021/acs.jced.1c00108 |