A new replication method for fabricating hierarchical polymer surfaces with robust superhydrophobicity and highly improved oleophobicity

Abstract

In this paper, we reported a very interesting replication method to fabricate various kinds of chemically stable and mechanically durable superhydrophobic and highly oleophobic polymer surfaces by using hierarchical aluminum (H-Al) as the template. The H-Al template that consisted of microsteps and nanoplatelets was obtained by acid etching and subsequent boiling water treatment. Five polymers including acrylonitrile butadiene styrene (ABS), polycarbonate (PC), polymethyl methacrylate (PMMA), polystyrene (PS), and polyurethane (PU) were demonstrated to successfully replicate the hierarchical morphology of the H-Al. When coated with PDES, the final hierarchical polymer surfaces showed excellent superhydrophobicity and much improved oleophobicity to hexadecane. Most importantly, these polymer duplicates with coating displayed outstanding chemical stability and excellent mechanical durability. The resultant polymer surfaces showed stability even when immersed in HCl/NaOH solutions for as long as 144h, exposed to organic solvent immersion for 168h, irradiated with UV-light for 24h, and placed under air condition for 8 months. The surfaces also impressively presented good mechanical durability after being severely scratched by sharp blade, multiply peeled by adhesive tape, and circularly rubbed under quantitative weight. This strategy can also be applied to any other dissolvable polymers. It is believed that this work provides a simple replicating method to create hierarchical polymer surfaces, and then further realize superhydrophobicity and oleophobicity. Specially, the excellent stability and durability of the resultant surfaces are believed to find promising outdoor applications.