Title: Biomimetic Submicroarrayed Cross-Linked Liquid Crystal Polymer Films with Different Wettability via Colloidal Lithography

Author: Yuanyuan Zhan, Jianqiang Zhao, Wendong Liu, Bai Yang, Jia Wei, Yanlei Yu*

Journal: ACS Appl. Mater. Interfaces, 2015, 7(45), 25522–25528

Abstract:

Photoresponsive cross-linked liquid crystal polymer (CLCP) films with different surface topographies, submicropillar arrays, and submicrocone arrays were fabricated through colloidal lithography technique by modulating different types of etching masks. The prepared submicropillar arrays were uniform with an average pillar diameter of 250 nm and the cone bottom diameter of the submicrocone arrays was about 400 nm, which are much smaller than previously reported CLCP micropillars. More interestingly, these two species of films with the same chemical structure represented completely different wetting behavior of water adhesion and mimicked rose petal and lotus leaf, respectively. Both the submicropillar arrayed film and the submicrocone arrayed film exhibited superhyrophobicity with a water contact angle (CA) value of 144.0 ± 1.7° and 156.4 ± 1.2°, respectively. Meanwhile, the former demonstrated a very high sliding angle (SA) greater than 90°, and thus, the water droplet was pinned on the surface as rose petal. On the contrary, the SA of the submicrocone arrayed CLCP film consisting of micro- and nanostructure was only 3.1 ± 2.0°, which is as low as that of lotus leaf. Furthermore, the change on the wettability of the films was also investigated under alternating irradiation of visible light with two different wavelengths, blue light and green light.

论文链接：https://pubs.acs.org/doi/10.1021/acsami.5b09013

PDF链接：Biomimetic Submicroarrayed Cross-Linked Liquid Crystal Polymer Films with Different Wettability via Colloidal Lithography.pdf

本研究采用胶体光刻技术制备了表面形貌可控、润湿性不同的亚微柱阵列交联液晶聚合物（CLCP）膜和亚微锥阵列CLCP膜。微阵列柱和锥的平均直径分别为250 nm和400 nm，比以往报道的要小得多。由于表面化学和表面形态设计以获得优良的疏水性，亚微柱阵列薄膜表现出疏水性和高的水粘附力，类似于玫瑰花瓣。而亚微锥阵列膜具有层次结构，具有与荷叶相媲美的疏水性能。蓝、绿光交替照射时，两种微阵列膜均在超疏水区发生接触角（CA）的可逆变化。不仅如此，亚微柱阵列始终保持高的水附着力，而蓝、绿光交替照射后，亚微锥阵列膜的水滑动角（SA）产生了3.1 ± 2.0°~ 6.1 ± 2.2°的可逆变化。我们认为，这种胶态光刻方法与CLCP相结合，可以通过在整个制作过程中调控蚀刻掩模，制备具有更强动态表面润湿性的各类表面形貌。