Fluorine-Free MWCNTs/Epoxy Superhydrophobic Coatings with Low Interfacial Adhesion for Robust Dust-Resistant...

Superhydrophobic coatings are functional materials with broad application prospects for dust-repellent and self-cleaning properties. In this study, a simple one-step spraying process was employed, using lauric acid (surface energy: 30 mN·m^-1) as a hydrophobic modifier, to prepare a low-cost and environmentally friendly LA-MWCNTs superhydrophobic coating on an aluminum alloy substrate. The coating exhibits excellent superhydrophobicity (WCA = 161.8° ± 1.7°, WSA = 3.7° ± 0.6°) and outstanding self-cleaning performance, capable of efficiently removing adhered dust particles via rolling water droplets. Interfacial energy calculations based on the Owens-Wendt method indicate that, compared to bare aluminum alloy, this coating reduces surface free energy and adhesion energy by 78.19% and 53.56%, respectively, confirming the key role of low interfacial adhesion in dust repellency. Molecular dynamics simulations further demonstrate that the low interfacial energy effectively suppresses water wetting and interfacial aggregation, thereby weakening liquid adhesion. Additionally, the coating maintains stable superhydrophobicity after enduring abrasion (20 cycles), corrosion across a wide pH range, and UV irradiation (48 h), exhibiting exceptional durability suitable for practical dust resistance applications.