title: Water droplet bouncing and superhydrophobicity induced by multiscale hierarchical nanostructures.
abstract: Superhydrophobicity of multiscale hierarchical structures and bouncing phenomenon of a water droplet on the superhydrophobic surface were studied. The multiscale hierarchical structures of carbon nanotube/ZnO and ZnO/carbon nanofiber were produced by the hydrothermal method. The multiscale hierarchical structure showed superhydrophobicity with a static contact angle (CA) larger than 160° due to increased air pockets in the Cassie-Baxter state. The water bouncing effect observed on the multiscale hierarchical nanostructure was explained by the free energy barrier (FEB) analysis and finite element simulation. The multiscale hierarchical nanostructure showed low FEBs which provoke high CA and bouncing phenomenon due to small energy dissipation toward receding and advancing directions.
authors.affiliation: Research Institute of Advanced Materials, Department of Materials Science and Engineering, Seoul National University, Daehak-Dong, Gwanak-Gu, Seoul 151-744, Korea.
authors.forename: Doo Jin
authors.initials: DJ
authors.lastname: Lee
authors.forename: Hyung Min
authors.initials: HM
authors.lastname: Kim
authors.forename: Young Seok
authors.initials: YS
authors.lastname: Song
authors.forename: Jae Ryoun
authors.initials: JR
authors.lastname: Youn
mesh_terms: D003460:Crystallization / Q000379:methods*; D057927:Hydrophobic and Hydrophilic Interactions; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013499:Surface Properties; D014867:Water / Q000737:chemistry*; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D046911:Macromolecular Substances; D037742:Nanotubes, Carbon; D014867:Water; D015034:Zinc Oxide