Preparation of a Cu Surface with the Hierarchical Structure of a Lotus Leaf via Electroplating and Its Superhydrophobicity

Abstract

A lotus leaf exhibits excellent superhydrophobic properties because of its hierarchical microstructure and a waxy hydrophobic material covering its surface. Herein, the lotus leaf was used as a template and a copper surface layer with a microstructure similar to the lotus leaf was prepared by electroplating. Experimental results show that the plating samples saved micron-sized structure of the lotus leaf, such as papillae. At the same time, owing to the specificity of the electroplating method, smaller grains were formed as the second-level structure on the papillae, forming a hierarchical structure that makes it possible to obtain a superhydrophobic surface. The plated copper surface exhibited excellent hydrophobic properties with a contact angle of 160°, which is higher than that of the lotus leaf (157°) and also much higher than that of smooth copper covered with an identical fluroalkyl silane (112°). This affords a novel idea for preparing of superhydrophobic surfaces.

Fig. 3 A schematic diagram of the change in surface microstructure during the preparation processes. (a) Lotus leaf, (b) carbon derived from lotus leaf, (c) electroplated copper, and (d) the changing of a papilla.