Bio-Inspired Fabrication and Performance of Flexible Superhydrophobic Films

Abstract

The lotus leaf, paradigmatic in superhydrophobic research, exhibits a water contact angle of θ = 160.4˚ ± 1.5˚ and a sliding angle of 2˚ ± 1˚, enabled by its micro-/nano-hierarchical architecture. Herein, we report a facile two-step protocol—micro-texture replication followed by fluorination—to fabricate flexible, low-adhesion, superhydrophobic films. Using polydimethylsiloxane (PDMS, part A) and curing agent (part B) as the matrix, biomimetic micro-cones were faithfully duplicated from a master mold, with matched elastic modulus, thermal stability which can withstand extreme conditions of 300˚C, as well as inert chemical stability (100% ethanol resistance). Subsequent vapor-phase grafting of 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (PFDS) yielded robust fluorocarbon chains oriented outward, minimizing surface energy. The resulting film possesses a static water contact angle of 158.3˚ ± 1.2˚ and a sliding angle of 3.1˚ ± 0.4˚, surpassing the conventional benchmarks (WCA ≥ 150˚, SA ≤ 10˚). The material demonstrates significant potential for self-cleaning solar panels, anti-icing aircraft coatings, and corrosion-resistant marine surfaces.