Fabrication of robust superhydrophobic micro-nano hierarchical surface structure using compression molding with carbon soot nanoparticles and thermoplastic polymer

The fragility of superhydrophobic surfaces limits applicability; therefore, development of hierarchical surface structure is an important strategy to achieve more robust superhydrophobic surfaces. Here, two-level micro-nano hierarchical polymer surfaces were fabricated by compression molding. Microstructured aluminum molds were produced through laser beam machining and then coated with carbon soot nanoparticles from acetone combustion. The nanostructure of soot nanoparticles combined with the mold microstructure was transferred onto the polypropylene sheet by compression molding. The replicated surface demonstrated superhydrophobicity with contact angles greater than 170° and sliding angles less than 10°. The mechanical robustness was confirmed with abrasion tests and adhesion tests. • We fabricated easily two-level micro-nano hierarchical polymer surfaces based on carbon soot nanoparticles and thermoplastic polymer. • Replicated surfaces performed good water repellence with the contact angle above 170° and the sliding angle under 6°. • Mechanical robustness of replicated surfaces was due to the upper micro-nanostructures as the protective microstructures that preserved the lower micro-nanostructures and the lowest nanostructures.