This thesis investigates the effect of pressure on the wettability of water on zirconia and graphite surfaces, in the context of enhancing heat dissipation for energy applications. Understanding how contact angle behaviour responds to pressure is crucial for several engineering applications, many of which operate under high-temperature and -pressure conditions. This is particularly relevant to nuclear reactor cooling, where boiling heat transfer is a key process that is strongly influenced by wetting properties and contact angle, a relationship that is well established in the field. The work of adhesion was computed through Molecular Dynamics (MD) simulations and a Free Energy Perturbation (FEP) approach using the 2021 version of LAMMPS.