title: Excess equimolar radius of liquid drops.
abstract: The curvature dependence of the surface tension is related to the excess equimolar radius of liquid drops, i.e., the deviation of the equimolar radius from the radius defined by the macroscopic capillarity approximation. Based on the Tolman [J. Chem. Phys. 17, 333 (1949)] approach and its interpretation by Nijmeijer et al. [J. Chem. Phys. 96, 565 (1991)], the surface tension of spherical interfaces is analyzed in terms of the pressure difference due to curvature. In the present study, the excess equimolar radius, which can be obtained directly from the density profile, is used instead of the Tolman length. Liquid drops of the truncated and shifted Lennard-Jones fluid are investigated by molecular dynamics simulation in the canonical ensemble, with equimolar radii ranging from 4 to 33 times the Lennard-Jones size parameter σ. In these simulations, the magnitude of the excess equimolar radius is shown to be smaller than σ/2. This suggests that the surface tension of liquid drops at the nanometer length scale is much closer to that of the planar vapor-liquid interface than reported in studies based on the mechanical route.
authors.affiliation: Lehrstuhl für Thermodynamik, Fachbereich Maschinenbau und Verfahrenstechnik, Technische Universität Kaiserslautern, Kaiserslautern, Germany. martin.horsch@mv.uni-kl.de
authors.forename: Martin
authors.initials: M
authors.lastname: Horsch
authors.forename: Hans
authors.initials: H
authors.lastname: Hasse
authors.forename: Alexander K
authors.initials: AK
authors.lastname: Shchekin
authors.forename: Animesh
authors.initials: A
authors.lastname: Agarwal
authors.forename: Stefan
authors.initials: S
authors.lastname: Eckelsbach
authors.forename: Jadran
authors.initials: J
authors.lastname: Vrabec
authors.forename: Erich A
authors.initials: EA
authors.lastname: Müller
authors.forename: George
authors.initials: G
authors.lastname: Jackson
mesh_terms: D003198:Computer Simulation; D044085:Microfluidics / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D010316:Particle Size; D012996:Solutions / Q000737:chemistry*; D013500:Surface Tension
chemical_list: D012996:Solutions