Facile fabrication of tear-film-inspired durable hyaluronic acid hydrogel films for persistent anti-fogging

Hydrophilic anti-fogging coatings face dual challenges of insufficient water resistance and poor weathering durability in practical applications. To address these issues, we propose a natural composite coating system integrating hyaluronic acid (HA), glycerol (Gly), FeCl 3 , and zinc oxide nanoparticles (ZnO-NPs) via a facile mixing strategy. Inspired by the mucin-mediated hydration dynamics of tear films, the HA framework constructs a self-replenishing layer to inhibit fogging while achieving underwater oleophobicity through surface hydration, effectively repelling oily contaminants. Glycerol maintains flexibility and hydration equilibrium through hydrogen-bonded water retention, whereas FeCl 3 crosslinking enhances mechanical strength and water stability via dynamic coordination bonds emulating tear film's ion-modulated self-repair, thereby resisting hydration-induced degradation. ZnO-NPs further endow the coating with photo-induced hydrophilicity. The optimized coating exhibits exceptional water resistance, weathering durability, and mechanical robustness, retaining high transmittance and stable hydrophilicity after 120 h of water immersion, 120 h of xenon lamp irradiation, 40 adhesion cycles, and 300 abrasion tests. Remarkably, the coating demonstrates rapid self-healing within 10 s and superior self-cleaning performance. This study proposes a sustainable strategy to synergistically enhance water resistance and weathering resistance.