Chengdu Green Energy and Green Manufacturing Technology R&D Center, Chengdu Development Center of Science and Technology, China Academy of Engineering Physics, Chengdu, 610200, China.
Small. 2017 May;13(19). doi: 10.1002/smll.201602353. Epub 2017 Mar 17.
With the rapid development of stretchable electronics, functional textiles, and flexible sensors, water-proof protection materials are required to be built on various highly flexible substrates. However, maintaining the antiwetting of superhydrophobic surface under stretching is still a big challenge since the hierarchical structures at hybridized micro-nanoscales are easily damaged following large deformation of the substrates. This study reports a highly stretchable and mechanically stable superhydrophobic surface prepared by a facile spray coating of carbon black/polybutadiene elastomeric composite on a rubber substrate followed by thermal curing. The resulting composite coating can maintain its superhydrophobic property (water contact angle ≈170° and sliding angle <4°) at an extremely large stretching strain of up to 1000% and can withstand 1000 stretching-releasing cycles without losing its superhydrophobic property. Furthermore, the experimental observation and modeling analysis reveal that the stable superhydrophobic properties of the composite coating are attributed to the unique self-adaptive deformation ability of 3D hierarchical roughness of the composite coating, which delays the Cassie-Wenzel transition of surface wetting. In addition, it is first observed that the damaged coating can automatically recover its superhydrophobicity via a simple stretching treatment without incorporating additional hydrophobic materials.
随着可拉伸电子产品、功能纺织品和柔性传感器的快速发展，需要在各种高柔性基底上构建防水保护材料。然而，由于混合微纳尺度的分层结构在基底的大变形下很容易被破坏，保持超疏水表面的抗湿仍然是一个巨大的挑战。本研究报道了一种通过在橡胶基底上简单喷涂碳黑/聚丁二烯弹性体复合材料，然后进行热固化制备的高拉伸和机械稳定的超疏水表面。所得的复合涂层在高达 1000%的超拉伸应变下仍能保持其超疏水性（水接触角≈170°，滑动角<4°），并且可以承受 1000 次拉伸-释放循环而不失去超疏水性。此外，实验观察和建模分析表明，复合涂层稳定的超疏水性归因于复合涂层 3D 分级粗糙度的独特自适应变形能力，这延迟了表面润湿的 Cassie-Wenzel 转变。此外，首次观察到通过简单的拉伸处理，无需添加额外的疏水材料，受损的涂层可以自动恢复其超疏水性。
