Nanoimprint Lithography Enabled Lubricant Infused Nano-Fibrillar Slippery PVDF-HFP for Enhanced Fog Harvesting, Anti-Fouling and Transparency.

The application of Nepenthes-inspired slippery surfaces in practical technologies, e.g., fog harvesting and anti-fouling, is limited by complex fabrication methods, toxic hydrophobizing agents, and limited durability. Here, an intrinsically hydrophobic poly (vinylidene fluoride-co-hexafluoropropylene) film (F-PVDF-HFP) is subjected to nanoimprint lithography to fabricate a super-hydrophobic nanofibrillar PVDF-HFP (N-PVDF-HFP; contact angle of 155° ± 2.2°). Subsequent lubricant infusion into N-PVDF-HFP produced nanofibrillar, slippery PVDF-HFP (L-PVDF-HFP), demonstrating stable lubricant retention due to capillary forces and preferential lubricant wetting on the substrate. Fog harvesting experiments show a 32.1% higher water collection rate for L-PVDF-HFP than F-PVDF-HFP. Furthermore, L-PVDF-HFP exhibits remarkable repellence against common liquid foulants and suppressed E. coli and S. epidermidis adhesion. Additionally, L-PVDF-HFP demonstrates optical transparency with an average total transmittance of 91.7% and a haze of 26.7% across the visible spectrum. Moreover, L-PVDF-HFP retained sliding angles below 17° after storage under ambient conditions (30 days) and elevated temperatures (75°C, 30 days), aqueous shear (10 h), resistance to pH, long-term foulant exposure, repeated immersion-withdrawal cycles, abrasion (20 cycles), and UV exposure (7 h), underscoring its durability. This work enables a time-efficient and potentially scalable approach to slippery-surface fabrication, thereby opening a pathway to real-world use.