Zou Ruiqing, Wang Jian, Tang Jianbin, Zhang Xin, Zhang Yaocheng
School of Materials Science and Engineering, Xihua University, Chengdu 610039, People's Republic of China.
School of Automotive Engineering, Changshu Institute of Technology, Jiangsu 215500, People's Republic of China.
ACS Appl Mater Interfaces. 2021 Mar 24;13(11):13848-13860. doi: 10.1021/acsami.1c01360. Epub 2021 Mar 14.
The anisotropic surface prepared by the top-down etching technology shows unique advantages in terms of functional superhydrophobicity. However, it still has a shackle of the smallest etching size, which largely restricts the development of better superhydrophobicity. Therefore, it is still a huge challenge to realize the stepless size adjustment of an anisotropic surface in order to achieve better functionalization. In this work, a bottom-up approach inspired via the modular segmented preparation technology has been used to successfully build an anisotropic, locally ordered functionalized unique superhydrophobic structure, whose contact and rebound time of water droplets is extremely short. Furthermore, this structure with artfully arranged "tracks", which has a relatively large contact angle value, not only lasts more than 15 consecutive bounce cycles in the same direction, where the droplets after merging still bounce, but also exhibits a significant anisotropic sliding behavior, which is presented in different sliding angles, toward droplets rolling in different directions and has lower adhesion work and better self-cleaning and anti-fouling performance. Besides, some mechanisms such as the reduction-replacement-reduction cycle and repulsion-adhesion-switching have been proposed especially in modular preparation and anisotropic sliding behavior. More importantly, this sorted bottom-up structure has great potential for achieving higher efficiency of functionalized superhydrophobicity and other related applications.
通过自上而下蚀刻技术制备的各向异性表面在功能性超疏水性方面展现出独特优势。然而，它仍存在最小蚀刻尺寸的限制，这在很大程度上制约了更好超疏水性的发展。因此，实现各向异性表面的无级尺寸调整以实现更好的功能化仍是一项巨大挑战。在这项工作中，受模块化分段制备技术启发的自下而上方法已被用于成功构建一种各向异性、局部有序的功能化独特超疏水结构，其水滴的接触和反弹时间极短。此外，这种具有巧妙排列“轨道”的结构具有相对较大的接触角值，不仅在同一方向上能连续反弹超过15个周期，合并后的水滴仍能反弹，而且还表现出显著的各向异性滑动行为，即朝着不同方向滚动的水滴呈现出不同的滑动角度，具有较低的粘附功以及更好的自清洁和防污性能。此外，特别是在模块化制备和各向异性滑动行为方面，还提出了诸如还原 - 置换 - 还原循环和排斥 - 粘附转换等一些机制。更重要的是，这种分类的自下而上结构在实现更高效率的功能化超疏水性及其他相关应用方面具有巨大潜力。
