Print Email Facebook Twitter Two-phase equilibrium conditions in nanopores Title Two-phase equilibrium conditions in nanopores Author Rauter, Michael T. (Norwegian University of Science and Technology (NTNU)) Galteland, O. (Norwegian University of Science and Technology (NTNU)) Erdös, M. (TU Delft Engineering Thermodynamics) Moultos, O. (TU Delft Engineering Thermodynamics) Vlugt, T.J.H. (TU Delft Engineering Thermodynamics) Schnell, Sondre K. (Norwegian University of Science and Technology (NTNU)) Bedeaux, Dick (Norwegian University of Science and Technology (NTNU)) Kjelstrup, Signe (Norwegian University of Science and Technology (NTNU)) Date 2020 Abstract It is known that thermodynamic properties of a system change upon confinement. To know how, is important for modelling of porous media. We propose to use Hill’s systematic thermodynamic analysis of confined systems to describe two-phase equilibrium in a nanopore. The integral pressure, as defined by the compression energy of a small volume, is then central. We show that the integral pressure is constant along a slit pore with a liquid and vapor in equilibrium, when Young and Young–Laplace’s laws apply. The integral pressure of a bulk fluid in a slit pore at mechanical equilibrium can be understood as the average tangential pressure inside the pore. The pressure at mechanical equilibrium, now named differential pressure, is the average of the trace of the mechanical pressure tensor divided by three as before. Using molecular dynamics simulations, we computed the integral and differential pressures, ̂p and p, respectively, analysing the data with a growing-core methodology. The value of the bulk pressure was confirmed by Gibbs ensemble Monte Carlo simulations. The pressure difference times the volume, V, is the subdivision potential of Hill, (p − ̂p)V = ɛ. The combined simulation results confirm that the integral pressure is constant along the pore, and that ɛ/V scales with the inverse pore width. This scaling law will be useful for prediction of thermodynamic properties of confined systems in more complicated geometries. Subject ConfinementEquilibriumHills-thermodynamicsInterfaceNanoporePorePressureSmall-systemThermodynamic To reference this document use: http://resolver.tudelft.nl/uuid:15a29546-6aa6-4b18-b9d9-5e6cb614e84c DOI https://doi.org/10.3390/nano10040608 ISSN 2079-4991 Source Nanomaterials, 10 (4) Part of collection Institutional Repository Document type journal article Rights © 2020 Michael T. Rauter, O. Galteland, M. Erdös, O. Moultos, T.J.H. Vlugt, Sondre K. Schnell, Dick Bedeaux, Signe Kjelstrup Files PDF nanomaterials_10_00608.pdf 1.32 MB Close viewer /islandora/object/uuid:15a29546-6aa6-4b18-b9d9-5e6cb614e84c/datastream/OBJ/view