Simulation-guided construction of solar thermal coating with enhanced light absorption capacity for effective icephobicity

A finite difference time domain (FDTD) simulation was adopted to initially illuminate a neglected phenomenon that SiO2 nanospheres in superhydrophobic layer could enhance the light absorption capacity of the layer itself, and of the contiguous photothermal semiconductor simultaneously. Guided by this simulation, a solar thermal coating (STC) composed of superhydrophobic SiO2 nanospheres and CuFeMnO4/PDMS was assembled to achieve highly efficient icephobicity. The accurate tests illustrated the temperature rise originated from the semiconductor layer by photothermal effect and superhydrophobic layer by self-heating effect, which was consistent with the simulation results. Depending on the high photothermal conversion efficiency, the freezing temperature of droplets on STC dropped to −35 °C, the ice adhesion strength decreased from 78.5 kPa to 12.1 kPa and an ice layer was removed within 99 s under the light illumination. Furthermore, STC could be further adopted in a cold natural environment, and deicing in 12 min. The simulation-guided construction of STC provides a new design strategy for icephobic coatings and new insights on energy management analysis in superhydrophobic photothermal composite coating.