Computationally Probing the Cybotactic Region in Gas-Expanded Liquids

Molecular dynamics simulations;Supercritical fluids;Gas-expanded liquids;Carbon dioxide;Separations

Shukla, Charu L. ; Chemical Engineering

University:Georgia Institute of Technology

Department:Chemical Engineering

关键词: Molecular dynamics simulations;    Supercritical fluids;    Gas-expanded liquids;    Carbon dioxide;    Separations;   

Others  :  https://smartech.gatech.edu/bitstream/1853/14510/1/shukla_charu_l_200705_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

Gas-expanded liquids (GXLs) arenovel and environmentally benign solvent systems with applications in reactions, separations, nanotechnology, drug delivery, and microelectronics. GXLs are liquid mixtures consisting of an organic solvent combined with a benign gas, such as CO2, in the nearcritical regime.In this work, molecular dynamics simulations have been combined with experimental techniques to elucidate the cybotactic region or local environment in gas-expanded liquids. Molecular dynamics simulations show clustering of methanol molecules in carbon dioxide-methanol mixtures. This clustering was not observed in carbon dioxide-acetone mixtures. Furthermore, addition of carbon dioxide enhances diffusivity of solutes in gas-expanded media as shown by both simulations and Taylor-Aris dispersion experiments. Finally, local structure and local compositions around pyrene in carbon dioxide-methanol and carbon-dioxide acetone were investigated using simulations and UV-vis spectroscopy.