Hierarchical micro/nano-structured nanoimprinting stamp fabrication for superhydrophobic application

Abstract

ABSTRACTThe hierarchical micro/nano structure of a real lotus leaf was successfully transferred to a nickel stamp, and it was used as a nanoimprinting stamp for superhydrophobic surface preparation. The hierarchical micro-bump/nano-tubule structure of the lotus leaf was transformed to a nano-wrinkled micro-bump in order to apply the nanoimprinting process and provide superhydrophobicity. Ag nanoparticles (AgNPs) were uniformly coated over the lotus leaf surface to form an electrically conducting seed layer, followed by a nickel electroplating process. A nickel stamp with a well-defined negative structure of a lotus leaf, including even nano-wrinkled microstructure, was thereby successfully fabricated. The micro/nano pattern of the lotus leaf was successfully reduplicated on a poly vinyl chloride (PVC) film by a nanoimprinting process using the nickel stamp. According to contact angle measurements, the nanoimprinted polymer films are rendered hydrophobic. Superhydrophobicity was then obtained by applying a self-assembled monolayers (SAM) coating over the nanoimprinted polymer film.