Mechanism of wettability transition in copper metal foams: From superhydrophilic to hydrophobic

► We corrected a misconception on the role of oxides on wettability in heat pipes. ► Time of spreading of a droplet is used to measure the rate of hydrophilicty loss. ► Samples in ambient air become hydrophobic but not in pure air or nitrogen. ► XPS and TOF-SIMS show carbon content increases when samples are in ambient air. ► We show the link between increasing the carbon and hydrophobicity in foams.