Molecular dynamics simulations for estimating surface tension of ionic liquid nano-drops

Molecular dynamics simulations of the nano droplets of the ionic liquid 1-ethyl-3-ethylimidazolium tetrafluroborate (EMIM-BF4) subjected to large external electric field were performed. It is believed that under external electric field the rearrangement of liquid molecules alters the intermolecular interactions and the forces developed influence the surface tension. With this intention we have calculated the surface tension using Irving-Kirkwood pressure tensor method. Surface tension has been estimated for various sized nano-droplets and it is observed that, there is a decrease in the values of the surface tension with a decrease in the drop size. The study also confirmed Rayleigh limit by calculating the number of surface charge present at every time step, which indeed denotes an instance of ion emission from droplet.