1303.3117 (Shuxi Dai et al.)

Biomimetic fabrication and tunable wetting properties of
three-dimensional hierarchical ZnO structures by combining soft lithography
templated with lotus leaf and hydrothermal treatments    [PDF]

Shuxi Dai, Dianbo Zhang, Qing Shi, Xiao Han, Shujie Wang, Zuliang Du

Three-dimensional hierarchical ZnO films with lotus-leaf-like micro/nano structures were successfully fabricated via a biomimetic route combining sol-gel technique, soft lithography and hydrothermal treatments. PDMS mold replicated from a fresh lotus leaf was used to imprint microscale pillar structures directly into a ZnO sol film. Hierarchical ZnO micro/nano structures were subsequently fabricated by a low-temperature hydrothermal growth of secondary ZnO nanorod arrays on the micro-structured ZnO film. The morphology and size of ZnO hierarchical micro/nano structures can be easily controlled by adjusting the hydrothermal reaction time. Wettability of hierarchical ZnO thin films was found to convert from superhydrophilicity to hydrophobicity after a low-surface-energy fluoroalkylsilane modification. Improved wetting properties from hydrophobic to superhydrophobic can be tuned by increasing the growth of ZnO nanorods structures.

View original: http://arxiv.org/abs/1303.3117