Superhydrophobic Graphene/Nafion Nanohybrid Films with Hierarchical Roughness

Abstract

The micro- and macroscopic structures of functional films strongly influence the critical properties, such as superhydrophobicity, which exhibits super water repellency with a water contact angle (CA) larger than 150° for self-cleaning and antimicrobial surfaces. However, it is difficult to achieve the structural hierarchy of two-dimensional graphene for superhydrophobicity. Herein, we report the fabrication of superhydrophobic graphene/Nafion nanohybrid films by controlling the structures with respect to the chemical composition from an interpenetrating networked and compactly interlocked structure (surface area of 9.56 m2 g–1) to the hierarchical petal-like, porous structure (surface area of 413.46 m2 g–1). The superhydrophobicity of hybrid thin films with a CA of ∼161° was derived from the petal-like structure with hierarchical roughness, where microscale roughness was produced in the lateral direction of hybrid sheets while nanoscopic roughness was created on the edges of hybrid sheets. Furthermore, the wettability and optical and electrical properties of hybrid thin films can be controlled by manipulating the micro- and macroscale structures through the composition-dependent structural changes.