A facile approach for preparing biomimetic polymer macroporous structures with petal or lotus effects

Abstract

In this paper, three kinds of superhydrophobic polymethylmethacrylate (PMMA) macroporous membranes with controlled adhesion were fabricated by a simple hierarchical alumina template wetting method. This alumina template was obtained through a convenient one-step anodization method, achieving a hierarchical structure combining the upper macroporous structure and lower nanopore topography. These final PMMA products perfectly replicate the original macroporous structure of the template. By simply controlling the reaction temperature, we can obtain the different PMMA surfaces with diverse topographies. The testing results confirm that the PMMA samples not only could achieve superhydrophobicity after the post-modification treatment but also present huge differences in adhesive abilities. The shallow bowl-shape structure presents a slippery property, which has a low sliding angle (SA) of 3°; the deep bowl-shape morphology possesses a SA of 30°, presenting a little sticky performance; the deep honey-comb texture possesses a large SA, which can hold a 10 μL water droplet even upside down, totally showing strong sticky water adhesion. Noticeably, the as-prepared superhydrophobic PMMA samples have remarkable resistivity to acid/alkali, various organic solvents and a long-time period. Moreover, the approach in this work can also be applied to any other soluble polymers. It is believed that our work provide a convenient and promising method to prepare polymer superhydrophobic surfaces with controlled adhesion, which has been rarely reported up to now.