Contact Angle Dependence on the Fluid−Wall Dispersive Energy

Menisci of the truncated and shifted Lennard-Jones fluid between parallel planar walls are investigated by molecular dynamics simulation. Thereby, the characteristic energy of the unlike dispersive interaction between fluid molecules and wall atoms is systematically varied to determine its influence on the contact angle. The temperature is varied as well, covering most of the range between the triple-point temperature and the critical temperature of the bulk fluid. The transition between obtuse and acute angles is found to occur at a temperature-independent magnitude of the fluid-wall dispersive interaction energy. On the basis of the present simulation results, fluid-wall interaction potentials can be adjusted to contact angle measurements.