Rationally Micropatterned Antifogging Hydrogels Counteracting Extreme Condensation

Abstract

Abstract Loss of transparency due to water vapor condensation, is a widespread problem across diverse applications such as windows, eyewear, displays, vehicles, and kitchenware. Conventional antifogging strategies relying on hydrophilic, or hydrophobic coatings, based on chemistry and/or nano-topography, can counteract up to mild water deposition, but lose functionality at excessive condensation environments. Here, we present a passive approach, rationally micropatterning an inherently hydrophilic hydrogel to maintain high transparency under supersaturation. Guided by optics and wetting theory, and employing a diffusion model to calculate related timescales of water film formation, we engineer a wicking structure on poly(ethylene glycol) diacrylate hydrogel, facilitating long-term sustainable filmwise condensation. Employing quantitative optical clarity measurements and visualization, we show that our approach clearly outperforms state of the art antifogging alternatives, retaining high optical clarity even in boiling environments. Facile fabrication and superior performance establish our microstructured hydrogel as an excellent choice for sustaining transparency under extreme condensation.