Department of Mechanical Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
Illinois Mathematics and Science Academy , 1500 W. Sullivan Rd., Aurora, Illinois 60506, United States.
Langmuir. 2017 Mar 21;33(11):2911-2919. doi: 10.1021/acs.langmuir.6b04432. Epub 2017 Mar 7.
Superhydrophobic surfaces submerged in liquids are susceptible to permanently becoming wet. This is especially true when the ambient liquid is pressurized or undersaturated with air. To gain insight into the thermodynamics of restoring underwater superhydrophobicity, nucleation theory is applied to the design of spontaneously dewetting conical pores. It is found that, for intrinsically hydrophobic materials, there is a geometric constraint for which reversible superhydrophobic behavior may occur. Molecular dynamics simulations are implemented to support the theory, and steered molecular dynamics simulations are used to investigate the energy landscape of the dewetting process. The results of this work have implications for the efficacy of underwater superhydrophobicity and enhanced nucleation sites for boiling heat transfer.
浸入液体中的超疏水表面容易永久润湿。当环境液体受压或与空气未饱和时，尤其如此。为了深入了解恢复水下超疏水性的热力学，成核理论被应用于设计自发去湿的锥形孔。研究发现，对于本征疏水材料，存在一个几何约束条件，在此条件下可能会出现可逆的超疏水性行为。通过分子动力学模拟来支持这一理论，并采用定向分子动力学模拟来研究去湿过程的能量景观。这项工作的结果对水下超疏水性的效果以及沸腾传热的增强成核点具有重要意义。
