Contact angles and wetting velocity measured electrically
Contact angles and wetting velocity measured electrically
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DOI：
10.1063/1.1149976
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发表时间：
1999-08
影响因子：
1.6
通讯作者：
H. Verheijen;Mwj Menno Prins
中科院分区：
文献类型：
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作者：
H. Verheijen;Mwj Menno Prins
我们描述了两种新的测量技术来研究液体在表面上的润湿行为。首先，我们通过测量导电液滴与地下对电极之间的电容来测量液滴的接触角。对于60°至120°范围内的接触角，测量接触角的估计误差为2%。在第二种测量技术中，我们检测电流作为时间的函数，这提供了有关液滴润湿衬底的动力学信息。时间积分电流与液滴的基面积有关。因此，我们可以推导出液滴三相线的径向速度。测量技术的时间分辨率受到初始电容充电时间的限制，在我们的情况下，充电时间约为0.5ms。
We describe two new measurement techniques for studying the wetting behavior of a liquid on a surface. First, we measure the contact angle of a droplet, by measuring the capacitance between a conducting droplet and a subsurface counter electrode. The estimated error in the measured contact angle is 2% for contact angles in the range between 60° and 120°. In the second measurement technique, we detect the current as a function of time, which provides information about the dynamics of a droplet wetting the substrate. The time-integrated current is related to the base area of the droplet. Consequently, we can derive the radial velocity of the three-phase line of the droplet. The time resolution of the measurement technique is limited by the charging time of the initial capacitance, in our case approximately 0.5 ms.