The role of polarization effect on the hydrophobicity of graphene and graphene-based devices: Theoretical and computational studies

Abstract The wettability of graphene and graphene-based devices are the main topics discussed in many literatures which have recently been published. The polar nature of water molecules leads us to focus more on this question that how much polarization influences on the interactions between a water droplet and graphene. However, owing to the challenges which maybe occurred following the consideration of the polarization effect, most researchers have ignored it. We have answered the mentioned question by developing a theory that reveals polarization has an essential role and should not be neglected. Notably, limitation of the atomic thickness and 2D structure of graphene lead us to use suitable substrates such as metal, in graphene-based devices. Although the type of substrates may change graphene electric behavior, some metals such as Cu, Ag and, Au due to higher equilibrium distance from the graphene layer and weaker adsorption energy do not change the intrinsic electronic property of graphene. Interestingly, our developed theory also predicts the water contact angles on these substrates and despite the heavy calculations, the obtained results are close to the experimental data. Additionally, we have extended this theory to multi-layer graphene to investigate how increasing the number of layers changes the wettability.