Synergistic effect of substrate heating and coupling agent on electrosprayed superhydrophobic coatings

Electrospraying is an attractive technique for fabricating multifunctional superhydrophobic coatings; however, limited durability impedes their practical use. To overcome this limitation, we propose coupling substrate heating with silane coupling agent (KH550) modification in poly(vinylidene fluoride)/carbon black (PVDF/CB) slurry. Results demonstrate that the coatings fabricated from PVDF/150 wt% CB slurry containing 1 wt% KH550 and deposited at 100 °C (Sample-DM) exhibit optimal superhydrophobicity, mechanical/chemical durability, self-cleaning capability, and oil/water separation efficacy compared to the counterparts employing either strategy individually. This enhancement arises from synergistic mechanisms: (1) KH550 hydrolysis establishes covalent bonding with CB nanoparticles, PVDF chains, and the substrate; (2) in situ substrate heating concurrently optimizes hierarchical topography while strengthening interparticle cohesion and coating-substrate adhesion. This dual-functional approach provides a robust methodology for fabricating high-durability electrosprayed superhydrophobic surfaces, advancing their technological deployment.