NTNU Nanomechanical Lab, Department of Structural Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway.
Phys Chem Chem Phys. 2018 Oct 3;20(38):24759-24767. doi: 10.1039/c8cp03256d.
Water adhesion underlies wettabilities, and thus hydrophobicities, and defines surface properties like self-cleaning, icephobicity and many others. The nanomechanics of water adhesion, especially in the dynamic dewetting processes, has not been fully investigated. Here in this article, atomistic modeling and molecular dynamics simulations were utilized to probe the adhesion mechanics of water droplets on nanopillars and flat surfaces, covering dewetting in the Wenzel and the newly discovered monostable Cassie-Baxter states. The simulations were able to identify intermediate dewetting states on rough surfaces, and resolve the transition between wetting states under force. The results revealed characteristic features of dynamic water adhering stress underpinning dewetting on the nanoscale, which provided deeper knowledge on surface dewetting mechanics. This work complements nanoscale dewetting experiments for new fundamental insights in studies including nanoroughness design, enhanced oil recovery, anti-icing and others.
水的附着力是润湿性的基础，因此也是疏水性的基础，并定义了自清洁、抗冰等表面特性。水的附着力的纳米力学，特别是在动态去湿过程中，尚未得到充分研究。在本文中，利用原子建模和分子动力学模拟来探测液滴在纳米柱和平面上的附着力学，涵盖了在 Wenzel 和新发现的单稳态 Cassie-Baxter 状态下的去湿过程。模拟能够在粗糙表面上识别中间去湿状态，并在力的作用下解析润湿状态之间的转变。结果揭示了纳米尺度上去湿过程中动态附着应力的特征，为表面去湿力学提供了更深入的认识。这项工作为包括纳米粗糙度设计、提高采油率、抗冰等在内的研究提供了纳米尺度去湿实验的新基础见解。
