Tuning the wettability of metal surface with electrodeposited porous copper and graphene coatings

Abstract

Electrodeposition of porous copper is an interesting type of coating that is emerging for various applications. However, the understanding of the relationships between copper surface wettability control and electrodeposition parameters and post-electrodeposition storage conditions is quite limited. Furthermore, it is worthwhile to explore how nanomaterials such as graphene would interact with porous copper to provide surface wettability modifications. This work therefore aims to develop a framework for the relationship of copper and graphene deposition processes, storage conditions, and the wetting behavior of copper surfaces. The research work performed in this study is divided into 2 parts: (i) effects of plating and storage conditions on the wettability of electrodeposited porous copper surfaces, (ii) tailoring the wettability of copper surfaces by dropping of graphene solutions. From a wide range of characterization methods and analysis to investigate the microstructure of porous copper and graphene, and corresponding wetting properties of their surfaces, the key findings of the study are that the concentration of copper electrolyte and current density largely influence the microstructure of the porous copper which subsequently lead to the variations of contact angles in the hydrophilic regime. Furthermore, whereas the air storing condition promote hydrophobicity, the water and saline storage conditions are found to induce hydrophilicity. Finally, deposition of graphene using a solution dropping technique allows tuning of the surface wettability in a wide range, spanning superhydrophilic to superhydrophobic, depending on copper surface porosity and graphene solutions’ concentration and dispersing level. Graphene is thus demonstrated as a promising top-coat layer to tune the wettability of copper surfaces