Charge limits on droplets during evaporation
Charge limits on droplets during evaporation
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DOI：
10.1021/la047973n
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发表时间：
2005-04-26
期刊：
影响因子：
3.9
通讯作者：
Ray, AK
中科院分区：
文献类型：
--
作者：
Li, KY;Tu, HH;Ray, AK
我们研究了悬浮在电动天平中的单个蒸发微滴的电荷稳定性极限。基于光学共振的高精度光散射技术用于确定电荷不稳定性引起的破裂时液滴的尺寸和尺寸变化。破裂时的电荷水平和电荷损失是从破裂之前和之后平衡液滴所需的do电压获得的。对邻苯二甲酸二乙酯 (DEP)、二甘醇 (DEG)、三甘醇 (TEG) 和十六烷液滴的结果表明，由于电荷不稳定性，在瑞利电荷极限处会发生破裂。观察到的破碎过程中电荷损失范围从十六烷液滴的约 15.3% 到 TEG 液滴的约 41.1%。十六烷液滴损失了约 1.5% 的质量，而 DEP 液滴损失了约 2.3%。在 0.03% 的检测限内，DEG 和 TEG 液滴破碎期间未观察到质量损失。观察到极低的质量损失伴随着 DEG 和 TEG 液滴的高电荷损失，这表明 DEG 和 TEG 液滴的破碎过程与 DEP 和十六烷液滴的破碎过程不同。结果分析表明，DEP 和十六烷液滴的破碎导致形成一些大的子代液滴，而 TEG 和 DEG 液滴则产生数千个细小的子代液滴。
We have examined charge stability limits of single evaporating microdroplets that were suspended in an electrodynamic balance. A high precision light scattering technique based on optical resonances was used to determine the size and the size change of a droplet at a charge instability induced breakup. The charge level and the charge loss at the breakup were obtained from the do voltages required to balance the droplet prior to and following the breakup. The results on droplets of diethyl phthalate (DEP), diethylene glycol (DEG), triethylene glycol (TEG), and hexadecane show that breakups due to the charge instability occur at the Rayleigh charge limit. The observed charge losses during breakups range from about 15.3% for hexadecane droplets to about 41.1% for TEG droplets. Hexadecane droplets lose about 1.5% of their mass, while DEP droplets, about 2.3%. Within the detectable limit of 0.03%, no mass losses were observed during breakups of DEG and TEG droplets. The observation of extremely low mass losses that accompany high charge losses from DEG and TEG droplets suggests that the process of breakups of DEG and TEG droplets is distinct from that of DEP and hexadecane droplets. An analysis of the results indicates that breakups of DEP and hexadecane droplets result in the formation of a few large progeny droplets, while TEG and DEG droplets produce thousands of fine progeny droplets.