1 Department of Mechanical Engineering, Technical University of Denmark 2 Fluid Mechanics, Coastal and Maritime Engineering, Department of Mechanical Engineering, Technical University of Denmark 3 Universidad de Concepcion 4 NASA Ames Research Center 5 Universidad de Concepcion 6 NASA Ames Research Center
Wepresent a force field forMolecular Dynamics (MD) simulations ofwater and air in contactwith an amorphous silica surface. We calibrate the interactions of each species present in the systemusing dedicated criteria such as the contact angle of a water droplet on a silica surface, and the solubility of air in water at different pressures. Using the calibrated force field, we conduct MD simulations to study the interface between a hydrophilic silica substrate and water surrounded by air at different pressures. We find that the static water contact angle is independent of the air pressure imposed on the system. Our simulations reveal the presence of a nanometer thick layer of gas at the water–silica interface. We believe that this gas layer could promote nucleation and stabilization of surface nanobubbles at amorphous silica surfaces. © 2014 Elsevier B.V. All rights reserved.
Journal of Molecular Liquids, 2014, Vol 198
Molecular dynamics; Wetting; Nanodroplets; Contact angle; Solid–liquid–gas interactions
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