Electrodeposition of PTFE superhydrophobic coatings: MgCl2-mediated micro-nano structuring for multifunctional anti-icing performance

Abstract

This study develops an optimized electrodeposition method for fabricating superhydrophobic polytetrafluoroethylene (PTFE) coatings by regulating magnesium chloride (MgCl₂) concentration (0.04–0.20 g/L). Systematic experiments and mechanism analysis reveal MgCl₂ plays a dual role in controlling micro-nano structure evolution and enhancing interfacial stability. The coating maintains superhydrophobicity after 300 tape-peeling cycles, 2000 mm linear abrasion, and 60 min water jet impact. XRD analysis confirms the formation of magnesium oxychloride cement phase (5 Mg(OH)₂·MgCl₂·8H₂O) acting as an effective binder to improve interfacial adhesion and mechanical strength. Charge neutralization induced by Mg²⁺ governs electrophoretic dynamics: insufficient coverage occurs at 0.04 g/L while particle agglomeration emerges at 0.20 g/L. The optimized 0.12 g/L concentration enables dense PTFE deposition and stabilizes Cassie-Baxter state, achieving a water contact angle of 166.9° with a sliding angle of 2°. Compared with bare aluminum, the optimal coating exhibits 47-fold delayed freezing time (278 s vs 6 s) and 76.5 % reduced ice adhesion strength (38.3 kPa vs 163.3 kPa). It suppresses 81.8–83.5 % ice accumulation under glaze (−3 °C) and rime (−13 °C) icing conditions. Dynamic freezing rain simulations demonstrate effective prevention of supercooled droplet retention even at low temperatures. This work advances fundamental understanding of ion concentration-mediated structural engineering and provides practical solutions for developing energy-efficient anti-icing systems in power transmission and aerospace applications under extreme climates.