Mai Van Cuong, Hou Shuai, Pillai Praveen Raghuram, Lim Teik-Thye, Duan Hongwei
School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637457, Singapore.
School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
ACS Nano. 2021 Apr 27;15(4):6977-6986. doi: 10.1021/acsnano.0c10871. Epub 2021 Mar 23.
Mixtures of immiscible liquids are commonly found in the scenarios of environmental protection and many industrial applications. Compared to widely explored water-oil mixtures, small differences in the surface energy of organic liquids, especially for those in multiphase mixtures, make their separation a formidable challenge. Here, a family of versatile coatings based on the reactions between plant polyphenols and 3-aminopropyl triethoxysilane is introduced to regulate the wetting behavior of substrates by forming stable liquid-infused interfaces. The key finding is that when a coated substrate is prewetted with a liquid forming a stable liquid-infused interface, it becomes repellent to any other immiscible liquids. This phenomenon is independent of the surface energy of the initial wetting liquid. This exclusive wetting behavior can lead to distinctive repellency toward almost any liquid by the infusion of an immiscible liquid, even if the difference of surface energy and dielectric constant of a liquid pair is as small as 2.0 mJ m and 1.8, respectively, resulting in universal and switchable omni-repellency. Of particular importance is that the as-prepared coating makes possible the on-demand separation of multiphase liquid mixtures by both continuous membrane filtration and static absorption, presenting a green and cost-effective approach to addressing this major environmental and industrial challenge.
在环境保护和许多工业应用场景中，常常会遇到不互溶液体的混合物。与被广泛研究的水 - 油混合物相比，有机液体表面能的微小差异，尤其是多相混合物中的有机液体，使得它们的分离成为一项艰巨的挑战。在此，我们引入了一类基于植物多酚与3 - 氨丙基三乙氧基硅烷反应的多功能涂层，通过形成稳定的液体注入界面来调节基底的润湿性。关键发现是，当涂覆的基底用形成稳定液体注入界面的液体进行预润湿后，它会对任何其他不互溶液体产生排斥作用。这种现象与初始润湿液体的表面能无关。这种独特的润湿行为通过注入不互溶液体，能够对几乎任何液体产生独特的排斥性，即使液体对的表面能差和介电常数差分别小至2.0 mJ/m²和1.8，从而实现通用且可切换的全排斥性。特别重要的是，所制备的涂层通过连续膜过滤和静态吸附实现了多相液体混合物的按需分离，为应对这一重大环境和工业挑战提供了一种绿色且经济高效的方法。
