Universal scaling laws for the disintegration of electrified drops
Universal scaling laws for the disintegration of electrified drops
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DOI：
10.1073/pnas.1213708110
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发表时间：
2013-03-26
影响因子：
11.1
通讯作者：
Basaran, Osman A.
中科院分区：
文献类型：
--
作者：
Collins, Robert T.;Sambath, Krishnaraj;Basaran, Osman A.
受到强电场作用的水滴会从其尖头发射出带电射流。这种射流分解成由带电液滴组成的喷雾对于电喷雾电离质谱、印刷和涂层过程以及雷雨云中的雨滴来说是常见的。目前，关于这些小电喷雾液滴的尺寸和电荷存在相互矛盾的理论和测量结果。我们使用理论和模拟来表明，可以调整电导率以产生液滴半径和电荷的三种缩放机制，这是以前的研究遗漏的发现。电喷雾液滴携带的电荷量 (Q) 决定了它们是库仑稳定且带电低于瑞利稳定性极限 ((Q) 超过波浪线 (R)) 还是不稳定，因此一旦形成就容易进一步爆炸。先前的实验报告了液滴电荷值的范围从 10% 到超过波浪号 (R) 的 (Q)。模拟明确表明，电喷雾液滴在产生时是库仑稳定的，并且存在液滴电荷的通用缩放定律，(Q) 与波形符 = 0: 44 (Q) 与波形符 (R)。
Drops subjected to strong electric fields emit charged jets from their pointed tips. The disintegration of such jets into a spray consisting of charged droplets is common to electrospray ionization mass spectrometry, printing and coating processes, and raindrops in thunderclouds. Currently, there exist conflicting theories and measurements on the size and charge of these small electrospray droplets. We use theory and simulation to show that conductivity can be tuned to yield three scaling regimes for droplet radius and charge, a finding missed by previous studies. The amount of charge (Q) over tilde that electrospray droplets carry determines whether they are coulombically stable and charged below the Rayleigh limit of stability ((Q) over tilde (R)) or are unstable and hence prone to further explosions once they are formed. Previous experiments reported droplet charge values ranging from 10% to in excess of (Q) over tilde (R). Simulations unequivocally show that electrospray droplets are coulombically stable at the instant they are created and that there exists a universal scaling law for droplet charge, (Q) over tilde = 0: 44 (Q) over tilde (R).