Fractal Surfaces of Molecular Crystals Mimicking Lotus Leaf with Phototunable Double Roughness Structures

• DOI: 10.1021/jacs.6b05562
• Publication Date: 2016-07-25T14:38:20Z
• Authors: Ryo Nishimura; Kengo Hyodo; Haruna Sawaguchi; Yoshiaki Yamamoto; Yoshimune Nonomura; Hiroyuki Mayama; Satoshi Yokojima; Shinichiro Nakamura; Kingo Uchida
• Keywords: Light; Molecular Structure; Surface Properties; Ultraviolet Rays; Water; 02 engineering and technology; 01 natural sciences; Nanostructures; 0104 chemical sciences; Plant Leaves; Fractals; Biomimetic Materials; Lotus; Microscopy, Electron, Scanning; Pressure; Wettability; Crystallization; 0210 nano-technology

Double roughness structure, the origin of the lotus effect of natural lotus leaf, was successfully reproduced on a diarylethene microcrystalline surface. Static superwater-repellency and dynamic water-drop-bouncing were observed on the surface, in the manner of natural lotus leaves. Double roughness structure was essential for water-drop-bouncing. This ability was not observed on a single roughness microcrystalline surface showing the lotus effect of the same diarylethene derivative. The double roughness structure was reversibly controlled by alternating irradiation with UV and visible light.