Effects of oxidation processes and microstructures on the hydrophilicity of copper surface

A rapid, economical method to achieve superhydrophilic copper surfaces is proposed in the present study. Different microstructures could be obtained by different oxidation processes, namely, hydrogen peroxide (H2O2) oxidation, thermal oxidation, and their combination, and the effects of the various processes and microstructures on the hydrophilicity were investigated. The results revealed that an optimal oxidation time and solution concentration enable copper surfaces have superhydrophilicity. The superhydrophilicity, with contact angle close to 0°, was attained on a copper plate surface first by thermal oxidation and then by H2O2 oxidation. However, for a porous wick surface, only H2O2 oxidation is required to achieve excellent superhydrophilicity.