Tang Zhen, Yang Dan, Guo Hengyu, Lin Shiquan, Wang Zhong Lin
Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 101400, P. R. China.
School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Adv Mater. 2024 Jun;36(25):e2400451. doi: 10.1002/adma.202400451. Epub 2024 Apr 2.
Wettability significantly influences various surface interactions and applications at the liquid-solid interface. However, the understanding is complicated by the intricate charge exchange occurring through contact electrification (CE) during this process. The understanding of the influence of triboelectric charge on wettability remains challenging, especially due to the complexities involved in concurrently measuring contact angles and interfacial electrical signals. Here, the relationship is investigated between surface charge density and change of contact angle of dielectric films after contact with water droplets. It is observed that the charge exchange when water spared lead to a spontaneous wetting phenomenon, which is termed as the contact electrification induced wetting (CEW). Notably, these results demonstrate a linear dependence between the change of contact angle (CA) of the materials and the density of surface charge on the solid surface. Continuous CEW tests show that not only the static CA but also the dynamics of wetting are influenced by the accumulation charges at the interface. The mechanism behind CEW involves the redistribution of surface charges on a solid surface and polar water molecules within liquid. This interaction results in a decrease in interface energy, leading to a reduction in the CA. Ab initio calculations suggest that the reduction in interface energy may stem from the enhanced surface charge on the substrate, which strengthens the hydrogen bond interaction between water and the substrate. These findings have the potential to advance the understanding of CE and wetting phenomena, with applications in energy harvesting, catalysis, and droplet manipulation at liquid-solid interfaces.
润湿性显著影响液固界面处的各种表面相互作用和应用。然而，在此过程中通过接触起电（CE）发生的复杂电荷交换使这种理解变得复杂。对摩擦电荷对润湿性影响的理解仍然具有挑战性，特别是由于同时测量接触角和界面电信号所涉及的复杂性。在此，研究了介电薄膜与水滴接触后表面电荷密度与接触角变化之间的关系。观察到水滴接触时的电荷交换会导致自发润湿现象，这被称为接触起电诱导润湿（CEW）。值得注意的是，这些结果表明材料的接触角（CA）变化与固体表面的表面电荷密度之间存在线性关系。连续的CEW测试表明，不仅静态CA，而且润湿动力学也受界面处积累电荷的影响。CEW背后的机制涉及固体表面的表面电荷和液体内极性水分子的重新分布。这种相互作用导致界面能降低，从而导致CA减小。从头算计算表明，界面能的降低可能源于基底上增强的表面电荷，这加强了水与基底之间的氢键相互作用。这些发现有可能推进对CE和润湿现象的理解，并应用于能量收集、催化以及液固界面处的液滴操纵。
