Surface tension of hydrocarbon chains at the liquidvapour interface

Molecular dynamics simulations were performed at constant temperature to obtain the surface tension of hydrocarbon chains at the liquidvapour interface. The Ewald sum was used to calculate the dispersion forces of the LennardJones potential to take into account the full interaction. The NERD and TraPPE_UA flexible force field models were used to simulate molecules from ethane to hexadecane along the coexistence curve. The simulation results for the TraPPE_UA model are in good agreement with experimental data, whereas the NERD model predicts slightly higher values.