Electrical charging of a conducting water droplet in a dielectric fluid on the electrode surface
Electrical charging of a conducting water droplet in a dielectric fluid on the electrode surface
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DOI：
10.1016/j.jcis.2008.04.019
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发表时间：
2008-06-15
影响因子：
9.9
通讯作者：
Kang, In Seok
中科院分区：
文献类型：
--
作者：
Jung, Yong-Mi;Oh, Hyun-Chang;Kang, In Seok
据设想，由库仑力驱动的带电液滴可用作基于液滴的微反应器。作为此类应用的基础研究，对导电水滴的充电进行了实验研究。研究了电场、介质粘度和液滴尺寸的影响。研究发现，带电量随着液滴尺寸和电场的增加而增加。然而，介质粘度在本研究范围内没有显着影响。从实验结果推导出比例定律。与完美导体的情况不同，水滴的估计电荷量 (Q(est)) 与水滴半径 (R) 的 1.59 次方和电场强度 (E) 的 1.33 次方成正比。 （对于球形完美导体，Q 与 R-2 和 E 成正比。）为了理解这些差异，对完美导体的理想化液滴进行了数值模拟。数值结果与实验结果的比较表明，差异主要是由于电极电化学反应和水相对较低的电导率的综合作用导致水滴不完全带电。 (C) 2008 Elsevier Inc. 保留所有权利。
It has been conceived that a charged droplet driven by Coulombic force can be used as a droplet-based microreactor. As a basic research for such applications, electrical charging of a conducting water droplet is studied experimentally. The effects of electric field, medium viscosity, and droplet size are investigated. It is found that the amount of electrical charging increases with the droplet size and the electric field. However, the medium viscosity does not have a significant effect in the range of the present study. A scaling law is derived from the experimental results. Unlike the case of a perfect conductor, the estimated amount of electrical charge (Q(est)) of a water droplet is proportional to the 1.59 power of the droplet radius (R) and the 1.33 power of the electric field strength (E). (For a spherical perfect conductor, Q is proportional to R-2 and E.) In order to understand these differences, numerical simulations are performed for the idealized droplets of perfect conductor. Comparison of the numerical and experimental results suggests that the differences are mainly due to incomplete charging of a water droplet resulted from the combined effect of electrochemical reaction at electrode and the relatively low conductivity of water. (C) 2008 Elsevier Inc. All rights reserved.