title: Reversible superhydrophobic-superhydrophilic transition of ZnO nanorod/epoxy composite films.
abstract: Tuning the surface wettability is of great interest for both scientific research and practical applications. We demonstrated reversible transition between superhydrophobicity and superhydrophilicity on a ZnO nanorod/epoxy composite film. The epoxy resin serves as an adhesion and stress relief layer. The ZnO nanorods were exposed after oxygen reactive ion etching of the epoxy matrix. A subsequent chemcial treatment with fluoroalkyl and alkyl silanes resulted in a superhydrophobic surface with a water contact angle up to 158.4° and a hysteresis as low as 1.3°. Under UV irradiation, the water contact angle decreased gradually, and the surface eventually became superhydrophilic because of UV induced decomposition of alkyl silanes and hydroxyl absorption on ZnO surfaces. A reversible transition of surface wettability was realized by alternation of UV illumination and surface treatment. Such ZnO nanocomposite surface also showed improved mechanical robustness.
authors: School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332-0245, United States.
authors: Yan
authors: Y
authors: Liu
authors: Ziyin
authors: Z
authors: Lin
authors: Wei
authors: W
authors: Lin
authors: Kyoung Sik
authors: KS
authors: Moon
authors: C P
authors: CP
authors: Wong
mesh_terms: D000042:Absorption; D004853:Epoxy Resins / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D053761:Nanocomposites / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods; D043942:Nanotubes / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014466:Ultraviolet Rays; D014867:Water / Q000737:chemistry; D017155:Wettability; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D004853:Epoxy Resins; D012821:Silanes; D013501:Surface-Active Agents; D014867:Water; D015034:Zinc Oxide