State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Academy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology, Harbin, Heilongjiang 150090, P. R. China.
ACS Appl Mater Interfaces. 2012 Nov;4(11):5826-32. doi: 10.1021/am3014746. Epub 2012 Oct 31.
Water permeation is an important issue in both fundamental research and industrial applications. In this work, we report a novel strategy to realize the controllable water permeation on the mixed thiol (containing both alkyl and carboxylic acid groups) modified nanostructured copper mesh films. For acidic and neutral water, the film is superhydrophobic, and the water cannot permeate the film because of the large negative capillary effect resulting from the nanostructures. For basic water, the film shows superhydrophilic property, and thus the water can permeate the film easily. The permeation process of water can be controlled just by simply altering the water pH. A detailed investigation indicates that nanostructures on the substrate and the appropriate size of the microscale mesh pores can enhance not only the static wettability but also the dynamic properties. The excellent controllability of water permeation is ascribed to the combined effect of the chemical variation of the carboxylic acid group and the microstructures on the substrate. This work may provide interesting insight into the new applications that are relevant to the surface wettability, such as filtration, microfluidic device, and some separation systems.
水渗透是基础研究和工业应用中都非常重要的问题。在这项工作中，我们报告了一种在混合硫醇（同时含有烷基和羧酸基团）修饰的纳米结构铜网薄膜上实现可控水渗透的新策略。对于酸性和中性水，由于纳米结构导致的大负毛细效应，薄膜表现出超疏水性，水无法渗透薄膜。对于碱性水，薄膜表现出超亲水性，因此水可以很容易地渗透薄膜。只需简单地改变水的 pH 值，就可以控制水的渗透过程。详细的研究表明，基底上的纳米结构和微尺度网孔的适当尺寸不仅可以增强静态润湿性，还可以增强动态性能。水渗透的优异可控性归因于羧酸基团的化学变化和基底上的微观结构的综合影响。这项工作可能为与表面润湿性相关的新应用提供有趣的见解，例如过滤、微流控器件和一些分离系统。
