Molecular dynamics simulation of a Gold nanodroplet in contact with graphene

The liquid Gold (Au) Nanodroplet spreading on a graphene substrate was studied by molecular dynamics (MD) simulation technique. The EAM interatomic potential and Tersoff many body potential have been used for Au-Au and C-C interactions respectively, and Lenard-Jones potential has been employed for Au-C interaction. The temperature of nanodroplet and substrate were controlled by Nose-Hoover thermostat in canonical ensemble. The cross-section snapshots of the nanodroplet were used to study contact angle and wettability of nanodroplet. Upon alteration of nanodroplet size is changed and no obvious effect on the contact angle was seen in the nanodroplet on the graphene surface. Moreover, we investigated effect of graphene temperature, the number of graphene layers and cooling rate of nanodroplet on the contact angle. Our MD results showed that the contact angle decreased with the increase of number of graphene layers and increased with increase of cooling rate and graphene temperature. It means that, the wettability of Au nanodroplet is independent of nanodroplet size and is dependent on substrate temperature and cooling rate. (C) 2016 Elsevier B.V. All rights reserved.