Boushi Youta, Yanagishita Takashi
Department of Applied Chemistry, Tokyo Metropolitan University, Minamiosawa, Hachioji, Tokyo 192-0397, Japan.
Langmuir. 2024 Mar 12;40(10):5455-5461. doi: 10.1021/acs.langmuir.3c04000. Epub 2024 Feb 20.
Water droplets can spontaneously move on surfaces with a wettability gradient, and such surfaces can be used in various functional devices. In this study, surfaces with a wettability gradient were prepared from anodic porous alumina with different pore arrangement regularities. The evaluation of the water droplet transport distance on the surfaces of the prepared samples showed that the pore arrangement regularity of the anodic porous alumina had no effect on the droplet transport distance. It was also shown that the droplet transport distance was affected by the droplet size and the width of the wettability gradient structure. When two water droplets were formed at both ends of the anodic porous alumina with an increasing gradient of pore diameter from the center to both ends, they moved from the ends toward the center and merged. The method reported in this paper shows that by controlling the pore size of anodic porous alumina, one can fabricate a substrate on which droplets can move in any direction. The anodic porous alumina with a wettability gradient as obtained in this study has potential use for various applications such as microfluidic devices and analytical chips.
水滴能够在具有润湿性梯度的表面上自发移动，并且这样的表面可用于各种功能器件。在本研究中，具有不同孔排列规则性的阳极多孔氧化铝制备出了具有润湿性梯度的表面。对制备样品表面上水滴传输距离的评估表明，阳极多孔氧化铝的孔排列规则性对水滴传输距离没有影响。还表明，水滴传输距离受液滴尺寸和润湿性梯度结构宽度的影响。当在阳极多孔氧化铝两端形成两个水滴，且从中心到两端孔径呈递增梯度时，它们会从两端向中心移动并合并。本文报道的方法表明，通过控制阳极多孔氧化铝的孔径，可以制造出液滴能够向任何方向移动的基底。本研究中获得的具有润湿性梯度的阳极多孔氧化铝在微流控器件和分析芯片等各种应用中具有潜在用途。
