Thermodynamic model of extraction equilibrium in cylindrical nanopores validated with molecular dynamics simulation. (2nd February 2022)

• Record Type: Journal Article
• Authors: Kanda, Hideki; Wahyudiono, ; Goto, Motonobu
• Is Part Of: Chemical engineering science. Volume 248:Part A(2022)
• Publication Date: 2022-02-02
• Subjects: Extraction -- Adsorption -- Phase equilibrium -- Thermodynamic model -- Nanopores -- Molecular dynamics simulation; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2021.117115
• Languages: English
• ISSNs: 0009-2509

Abstract

Graphical abstract: Highlights: Extraction equilibrium of Lennard-Jones fluid in cylindrical nanopore was examined. Molecular dynamics (MD) determined the equilibrium for various pore sizes. Bulk concentration where equilibrium was observed in the pore was lower for smaller pore. Prediction by thermodynamic model was consistent with the MD results. The thermodynamic model does not contain any tuneable parameters. Abstract: Capillary phase separation (CPS) of two partially mixed Lennard-Jones (LJ) liquids in cylindrical nanopores was investigated by molecular dynamics (MD) simulations. The purpose of MD is not to reproduce reality, but to represent an ideal system that incorporates the effect of nanopores to compare it with a proposed thermodynamic equation. CPS is observed in the extraction equilibrium state, where extraction can no longer occur, and the solutes that are strongly bound to the nanopores cannot be extracted even if the solute concentration in the solvent is lower than the saturation solubility. At higher solute concentrations, the pores are filled with the solute. At lower solute concentrations, the solute was only adsorbed onto the pore wall surfaces. The CPS concentrations in various pore diameters obtained by MD were successfully predicted by the thermodynamic equation that considers interfacial tension between solvent and solute and potential from pore wall, without any adjustable parameters.