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

Abstract

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 C@SiO 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 C@SiO 2 NTs have a large loading capacity on IPW (78.6 wt%). Moreover, the coating has good photothermal conversion efficiency (87.6%) due to C@SiO 2 NTs with good light absorption. By the combined effect of C@SiO 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. The fluoride-free superhydrophobic thermal energy storage coating on cloth exhibits excellent flexibility, superhydrophobicity, and photothermal conversion efficiency, offering the possibility of wearability. • Fluoride-free superhydrophobic thermal energy storage coating was designed. • The coating with good flexibility can withstand various deformations. • The coating with good superhydrophobic properties can withstand extreme conditions. • The coating exhibited high photothermal conversion efficiency. • The coating offered the possibility of wearability and thermal therapy.