Molecular dynamics simulation is used for studying the contact angle ofnanoscale sessile drops on a planar solid wall in a system interacting via thetruncated and shifted Lennard-Jones potential. The entire range between totalwetting and dewetting is investigated by varying the solid--fluid dispersiveinteraction energy. The temperature is varied between the triple point and thecritical temperature. A correlation is obtained for the contact angle independence of the temperature and the dispersive interaction energy. Sizeeffects are studied by varying the number of fluid particles at otherwiseconstant conditions, using up to 150 000 particles. For particle numbers below10 000, a decrease of the contact angle is found. This is attributed to adependence of the solid-liquid surface tension on the droplet size. Aconvergence to a constant contact angle is observed for larger system sizes.The influence of the wall model is studied by varying the density of the wall.The effective solid-fluid dispersive interaction energy at a contact angle of90 degrees is found to be independent of temperature and to decrease linearlywith the solid density. A correlation is developed which describes the contactangle as a function of the dispersive interaction, the temperature and thesolid density. The density profile of the sessile drop and the surroundingvapor phase is described by a correlation combining a sigmoidal function and anoscillation term.
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