Metallic hierarchical structures uniformly covered with WC@PDMS composite coatings toward comprehensively durable superhydrophobic surfaces

Abstract

Superhydrophobic surface is one of the most promising materials for the prevention and elimination of ice in daily lives but its durability remains a tremendous problem. Inevitable deterioration on the low-free-energy coating caused by harsh environment restrains their potential applications. Icephobic polymers are more durable than mostly used fluorosilanes for their higher thickness and cohesive strength but difficult to be uniformly modified on rugged micro-nanostructures. In this study, a nanostructured tungsten carbide doped PDMS layer was uniformly covered on aluminum microcones via a hybrid fabrication process combining nanosecond and femtosecond laser ablations and a rotational homogenization process. The prepared superhydrophobic surfaces exhibited excellent water repellency and anti-icing properties in icing-deicing cycles, water flow impacting and freezing-melting cycles. Multiple mechanical/chemical damage tests were performed to test their durability comprehensively. In mechanical tests, the surfaces could withstand linear abrasion length of 240 cm under 5.2 kPa pressure, impacting sand amount of at least 80 g or tape peeling for at least 200 cycles. The chemical durability was elucidated in −40 to 200 °C cycles, 2-day ultraviolet exposure and immersion in different liquids. The proposed hybrid method to form homogenous, ductile and durable superhydrophobic coatings could yield a prospective candidate for applications in anti-fouling and anti-icing.