Fabrication of flexible superhydrophobic films by lift-up soft-lithography and decorationwith Ag nanoparticles

Abstract

Superhydrophobic films with excellent flexibility have been fabricated bycombining the lift-up soft-lithography technique and chemical reduction of[Ag(NH3)2]+ ions to Ag nanoparticles (NPs) on the surface of silica spheres which are patterned on thepolydimethylsiloxane (PDMS) films. Scanning electron microscopy (SEM) images revealthe presence of raspberry-like hierarchical structures on the PDMS films. The influence ofthe amount of Ag NPs and the size of the silica spheres on the wettability of the softfilms is investigated carefully. Because PDMS films are elastomeric materials, oursuperhydrophobic films offer great flexibility. The resulting films can be easily transferredfrom one substrate surface to another without destroying their superhydrophobicity. Theseflexible and superhydrophobic films can be used repeatedly to satisfy a wide range ofapplications.