期刊
JOURNAL OF COLLOID AND INTERFACE SCIENCE
卷 263, 期 1, 页码 133-143出版社
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/S0021-9797(03)00282-0
关键词
microfluidics; electrokinetic flow; electroosmosis; zeta potential; polarization; vorticity
Due to electric field leakage across sharp corners, the irrotational character of Ohmic electroosmotic flow is violated. Instead, we demonstrate experimentally and theoretically evidence of electrolyte depletion and vortex separation in electroosmotic flow around a junction between wide and narrow channels. When the penetration length of the electric field exceeds the width of the narrow channel and if the electric field is directed from the narrow to the wide channel, the electromigration of ions diminishes significantly at the junction end of the narrow channel due to this leakage. Concentration depletion then develops at that location to maintain current balance but it also increases the corner zeta potential and the local electroosmotic slip velocity. A back pressure gradient hence appears to maintain flow balance and, at a sufficient magnitude, generates a pair of vortices. (C) 2003 Elsevier Science (USA). All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据