Hydrophilic modification of superhydrophobic coatings induced by surface dielectric barrier discharge plasma

Abstract The combination of surface dielectric barrier discharge (surface-DBD) plasma and a superhydrophobic coating has been proposed as an effective approach for enhancing the anti-icing capability of wind turbine blades. However, direct plasma exposure may alter the chemical composition and morphology of the coating, potentially reducing its hydrophobicity and could thereby undermine the synergistic effect. This work investigates three typical superhydrophobic coatings, examining how surface wettability, chemistry and morphology evolve after surface-DBD treatment and how they age. The results demonstrate that surface-DBD plasma rapidly switches the coating surface from superhydrophobic to highly hydrophilic within 60 s, with the water contact angle of all three coatings decreasing from ~ 160° to ~ 20°. XPS analysis reveals that defluorination is the dominant chemical mechanism of this modification, accompanied by oxidation and exposure of the underlying hydrophilic inorganic skeleton; this is evidenced by a significant decrease in fluorine content and reduced intensities of fluorinated carbon peaks. Morphology analysis shows that physical etching of the micron-scale rough structure is limited; nevertheless, the rough structure provides a larger effective reaction area, which may facilitate the chemical modification. Aging tests indicate that the water contact angle partially recovers to approximately 70°–78° after 10 days, but the original superhydrophobicity is not restored, indicating irreversible chemical damage. This study elucidates the hydrophilic modification mechanism and aging effect of superhydrophobic coatings induced by surface-DBD plasma. These findings suggest that the negative impact of plasma on the intrinsic properties of the coating should be considered in their combined application.