Biomimetic Design of Photothermal Superhydrophobic Surfaces with Robust Mechanical Stability and Self-defrosting/Deicing Performance

Abstract

Superhydrophobic surfaces have attracted extensive attention due to their unique nonwettability and good anti-icing/deicing potential but often experience significant performance degradation due to poor mechanical robustness and low humidity tolerance. Here, we developed a composite architecture (M-PNPs-T) by integrating a honeycomb-inspired thin-walled metallic frame into a polydimethylsiloxane (PDMS)-based matrix with the photothermal superhydrophobic (PNPs-T) surface, where the superhydrophobic property was achieved through laser-fabricating hierarchical micro/nanostructures on PNPs-T and the metallic frame acted as an ‘armor’ to protect the superhydrophobic PNPs-T surface from potential damage. This design allowed the PNPs-T surface to remain superhydrophobicity even after the M-PNPs-T surface underwent mechanical abrasion against a 600 grit SiC sandpaper for 1100 m at a pressure of 2.65 kPa. The composite M-PNPs-T surface exhibited good self-defrosting and self-deicing performance under both large temperature-difference (–14 ± 0.5 to 26 ± 0.5 °C) and low-temperature (–14 ± 0.5 °C) conditions. Particularly, the frost layer and the ice droplets formed on the M-PNPs-T surface completely melted after light irradiation for merely 60 and 186 s, respectively. The melted droplets easily slid off the M-PNPs-T surface under gravity with the help of lubrication and guidance provided by a thin water layer on the metallic frame surface. Moreover, the superior photothermal conversion performance of PNPs-T enabled the M-PNPs-T surface to maintain a high temperature (>22 °C) so as to exhibit good anti-icing/frosting properties under a low-temperature environment. Our design strategy provides an effective and facile route to prepare photothermal superhydrophobic surfaces with robust stability for potential deicing/defrosting applications.