Effects of microstructure design on aluminum surface hydrophobic and ice-retarding properties

The poor mechanical strength of superhydrophobic surface limits its use in civil aviation. In this work, superhydrophobic surfaces with open and closed microstructure design were prepared, and their hydrophobicity and icephobicity over icing/de-icing cycles were thoroughly studied. For all samples, contact angle decreased and contact angle hysteresis increased over time. However, surface with interconnected hollow honeycomb microstructure design kept its Cassie-Baxter state even after 20 times icing/de-icing cycles, while surface with repeated individual post microscopic unit lost its superhydrophobicity only after six times icing/de-icing cycles. The interconnected hollow honeycomb microstructure design strengthened surface mechanical strength by lowering the damage to microscopic unit. The freezing time for water droplet on surface with interconnected hollow honeycomb microstructure design was only slightly shortened over time. The difference in water/ice-solid contact area for surfaces with different nano-microscale design also led to the difference in wetting and ice-retarding ability. Surface with interconnected hollow honeycomb microstructure design showed the strongest ice-retarding ability followed by surface with interconnected hollow brick, ladder type, and triangle shape microstructure design. (c) 2017 Curtin University of Technology and John Wiley & Sons, Ltd.