abstract
Molecular dynamics (MD) simulations were employed to compute tracer diffusion coefficients (D-12) of propanone, butanone, 2-pentanone and 3-pentanone in supercritical CO2, which are in quite good agreement with experimental data available in the literature. It was confirmed that D-12 is enhanced by pressure decrease, temperature increase, and solute size reduction. The radial distribution functions, spatial distribution functions, and coordination numbers derived from the simulations were further employed to understand how molecular structure specificities affect D-12. The simulations proved that the molecular structuring of the solvent around the solute is similar for all ketones, which implies their diffusivities are essentially affected by their size and volume and, to a less extent, by the position of the carbonyl group in the carbon chain. The good agreement between calculated and measured data validates the MD simulations as a cheap and fast alternative to predict D-12 values of ketones in supercritical CO2. (C) 2015 Elsevier B.V. All rights reserved.
keywords
ATOM FORCE-FIELD; CARBON-DIOXIDE; MONTE-CARLO; PRESSURE RANGE; LENNARD-JONES; WIDE RANGES; HARD-SPHERE; FLUIDS; LIQUID; MODEL
subject category
Chemistry; Engineering
authors
Vaz, RV; Gomes, JRB; Silva, CM
our authors
Carlos Manuel Silva
Associate Professor
Graça Raquel Veiga Vaz
PhD Student
José R. B. Gomes
Principal ResearcherGroups
G4 - Renewable Materials and Circular Economy
G6 - Virtual Materials and Artificial Intelligence
acknowledgements
R.V. Vaz thanks PhD grant SFRH/BD/69257/2010 provided by Fundacao para a Ciencia e a Tecnologia, Portugal. This work was developed in the scope of the project CICECO-Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement.