A novel flexible and fluoride-free superhydrophobic thermal energy storage coating for photothermal energy conversion

The development of advanced multifunctional phase change materials (PCMs) for solar energy harvesting and storage is an important alternative to conventional energy sources. Herein, a novel flexible superhydrophobic thermal energy storage (FSTES) coating without fluoride is prepared by spraying mesoporous [email protected]2 nanotubes (NTs) supporting materials, PCMs (industrial paraffin wax, IPW), and adhesives (polydimethylsiloxane, PDMS) on the cloth. The coating has a high enthalpy (107.29 J/g) because the mesoporous [email protected]2 NTs have a large loading capacity on IPW (78.6 wt%). Moreover, the coating has good photothermal conversion efficiency (87.6%) due to [email protected]2 NTs with good light absorption. By the combined effect of [email protected]2 NTs with hierarchical roughness and PDMS with low surface energy, the coating achieved excellent fluorine-free superhydrophobicity with good corrosion resistance, UV irradiation resistance, and self-cleaning properties, which ensures the sustainably photothermal conversion efficiency and extends the life of the coating. In addition, the coating has excellent flexibility and offers the possibility of wearability. This research provides ideas for the preparation of flexible superhydrophobic coating, which are close to practical application.