Abstract:
Controlled directional spreading of a droplet on a smart high-adhesion surface was made possible by simply controlling anodic oxidation. The wettability gradient of the surface was controlled from 0.14 to 3.38° mm(-1) by adjusting the anodic oxidation conditions. When a water droplet made contact with the substrate, the droplet immediately spread in the direction of the wettability gradient but did not move in other directions, such as those perpendicular to the gradient direction, even when the surface was turned upside down. The spreading behavior was mainly controlled by the wettability gradient. Surfaces with a V- or inverse-V-shaped wettability gradient were also formed by the same method, and two droplets on these surfaces spread either toward or away from one another as designed. This method could be used to oxidize many conductive substrates (e.g., copper, aluminum) to form surfaces with variously shaped wettability gradients. It has potential for application in microfluidic devices.
摘要:
通过简单地控制阳极氧化,可以使液滴在智能高附着力表面上的受控定向扩散。通过调整阳极氧化条件,将表面的润湿性梯度控制在0.14至3.38°mm(-1)。当水滴与基材接触时,液滴立即在润湿性梯度的方向上扩散,但没有在其他方向上移动,比如那些垂直于梯度方向的,即使表面被颠倒了。铺展行为主要受润湿性梯度控制。也通过相同的方法形成具有V形或反V形润湿性梯度的表面。这些表面上的两个液滴按照设计相互靠近或远离。该方法可用于氧化许多导电基板(例如,铜,铝)以形成具有各种形状的润湿性梯度的表面。它具有应用于微流体装置的潜力。