Facile fabrication of biometric cellulose-based films with superhydrophobicity and tunable optical performance

[Display omitted] •A cellulosic film with hierarchical structures was prepared via a two-step method.•The hierarchy coordinated optical performance with superhydrophobic properties.•The film exhibited great stability and sustainability. Sustainable and biodegradable products processed from natural biomass offer promising replacement alternatives for nondegradable petrochemical-based plastics. While, the poor water tolerance of biomass is typically insufficient for practical use in applications, such as packaging. This study proposes a simple strategy to imitate the lotus leaf structure. Precision imprinting is performed to construct surface microstructure with simple templates, followed by in situ grafting of low-surface-energy nanoparticles onto the micro-architecture of the cellulose composite film surface. The resulting biometric superhydrophobic cellulosic composite (BSCC) exhibits both stable superhydrophobicity and excellent optical performance (anti-counterfeiting, high transparency (approximately 87%), and high haze (approximately 75%)) owing to the designed microstructure. The BSCC exhibits good self-cleaning behavior, and high tensile strength (>91.4 MPa), and is biodegradable in soil within 87 d. Importantly, this work demonstrates a simple approach to engineering and enhancing cellulose-based materials with superhydrophobicity and tunable optical performance to be able to replace petrochemical plastics.