Lobelia-Inspired Photothermal Storage Flexible Film for Efficient Deicing

Abstract

The insufficient density and discontinuity of solar energy of photothermal superhydrophobic flexible film seriously affect the practical application. Light energy harvesting and heat energy storage are effective ways to solve this problem. Inspired by the viscous temperature-regulating material within the inflorescence of Lobelia telekii and the arrangement of bracts on its surface, a flexible film for photoheat storage is proposed that integrated a three-order photoheat trap and one-order heat storage. The surface of the flexible film features microcone array with micro-grooves, modified carbon nanotubes (MCNTs), and layered structures on microcapsules, forming a three-level photoheat trap. The generated heat increases the surface temperature and is partially absorbed by the heat storage material inside the microcapsule. The stable photothermal temperature of polyurethane films with microcone structure (S_x) was elevated by 3–5 °C compared to without it (Flat-S_x), while the stable photothermal temperature of MCNTs-S_x (Flat-S_x with MCNTs) exceeds that of S_x by 2–6 °C. The ice particles on the MCNTs-S_0.45 completely dissolved within 180 s under xenon lamp light source. Meanwhile, MCNTs-S_x demonstrated superhydrophobicity and outstanding anti-fouling capabilities. The fabricated MCNTs-S_x realized biomimicry of Lobelia telekii in both structure and performance, providing a strategy for biomimetic photothermal de-icing.