A Capsule-Like Encapsulation Strategy for Waterborne Fabrication of Ultradurable Superhydrophobic Coating with Multifunctionality

Despite urgent demands for eco-friendly superhydrophobic coatings, solvent-free waterborne fabrication combining robust durability and multifunctionality remains challenging, primarily due to the inherent incompatibility between low-surface-energy hydrophobic filler and high-surface-energy water solutions. Hydrophobic fillers tend to aggregate or stratify spontaneously in water spontaneously. Herein, a fully waterborne, ultradurable superhydrophobic coating is stably fabricated via a capsule-like encapsulation strategy. The superhydrophilic diatomite scaffold stabilizes fluorinated SiO₂ nanoparticles (F-SiO₂) within waterborne polyurethane (WPU) by pore encapsulation, obtaining a uniform and stable emulsion. Upon curing, mechanical abrasion triggers "damage-responsive" F-SiO₂ migration, enabling enhanced surface roughness and self-repairing superhydrophobicity. Strong interface interactions between WPU and diatomite synergistically endow the coating with harsh environmental resilience (-40∼200 °C; pH 1∼13; UV; plasma) and outstanding wear resistance (>2500 Taber abrasion cycles). Multifunctionality is further unlocked through colorability and anti-icing and active de-icing capabilities. The coating displays comprehensive superiority in solvent-free processing, water repellency, durability, aesthetics, reparability, and de-icing. This breakthrough addresses the persistent waterborne fabrication-durability trade-off in superhydrophobic coatings, establishing a generalized platform for sustainable adaptive surface engineering.