Critical Angle for Electrically Driven Coalescence of Two Conical Droplets

作     者：James C. Bird William D. Ristenpart Andrew Belmonte Howard A. Stone 

作者机构：School of Engineering and Applied Sciences Harvard University Cambridge Massachusetts 02138 USA Department of Chemical Engineering and Materials Science and Department of Food Science and Technology University of California at Davis Davis California 95616 USA W.G. Pritchard Laboratories Department of Mathematics Pennsylvania State University University Park Pennsylvania 16802 USA 

出 版 物：《Physical Review Letters》 (Phys Rev Lett)

年 卷 期：2009年第103卷第16期

页      面：164502-164502页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

基　　金：NSF via the Harvard MRSEC [DMR-0820484] IGERT Direct For Mathematical & Physical Scien Division Of Materials Research Funding Source: National Science Foundation 

主　　题：Drops 

摘      要：Oppositely charged drops attract one another and, when the drops are sufficiently close, electrical stresses deform the leading edges of each drop into cones. We investigate whether or not the liquid cones coalesce immediately following contact. Using high-speed imaging, we find that the coalescence behavior depends on the cone angle, which we control by varying the drop size and the applied voltage across the drops. The two drops coalesce when the slopes of the cones are small, but recoil when the slopes exceed a critical value. We propose a surface energy model (volume-constrained area minimization) to describe the transition between these two responses. The model predicts a critical cone angle of 30.8°, which is in good agreement with our measurements.