Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, 100191, Beijing, P. R. China.
Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, 100190, Beijing, P. R. China.
Nat Commun. 2019 Mar 14;10(1):1212. doi: 10.1038/s41467-019-09201-1.
Materials with in situ reversible wettability have attractive properties but remain a challenge to use since the inverse process of liquid spreading is normally energetically unfavorable. Here, we propose a general electrochemical strategy that enables the in situ reversible superwetting transition between underwater superoleophilicity and superoleophobicity by constructing a binary textured surface. Taking the copper/tin system as an example, the surface energy of the copper electrode can be lowered significantly by electrodeposited tin, and be brought back to the initial high-energy state as a result of dissolving tin by removing the potential. Tin atoms with the water depletion layer inhibit the formation of a hydrogen-bonding network, causing oil droplets to spread over the surface, while copper atoms, with a high affinity for hydroxyl groups, facilitate replacing the oil layer with the aqueous electrolyte. The concept is applicable to other systems, such as copper/lead, copper/antimony, gold/tin, gold/lead and gold/antimony, for both polar and nonpolar oils, representing a potentially useful class of switchable surfaces.
具有原位可逆润湿性的材料具有吸引人的特性，但由于液体扩展的逆过程通常在能量上不利，因此仍然难以使用。在这里，我们提出了一种通用的电化学策略，通过构建二元织构表面来实现水下超亲油性和超疏油性之间的原位可逆超润湿转变。以铜/锡系统为例，通过电沉积锡可以显著降低铜电极的表面能，并且通过去除电势溶解锡可以使表面能恢复到初始高能状态。具有耗水层的锡原子抑制氢键网络的形成，导致油滴在表面上扩展，而对羟基具有高亲和力的铜原子则有利于用电解质溶液取代油层。该概念适用于其他系统，例如铜/铅、铜/锑、金/锡、金/铅和金/锑，适用于极性和非极性油，代表了一类潜在有用的可切换表面。
