Effect of Divalent Ions on Electroosmotic Flow in Microchannels.
Effect of Divalent Ions on Electroosmotic Flow in Microchannels.
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DOI：
10.1016/j.mechrescom.2008.07.006
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发表时间：
2009-01
影响因子：
2.4
通讯作者：
Yoda M
中科院分区：
文献类型：
--
作者：
Datta S;Conlisk AT;Li HF;Yoda M
实验发现，当将痕量的含有二价阳离子Ca 2+和Mg 2+的盐加入到在具有带负电荷的壁的通道中流动的恒定离子强度背景电解质溶液（BGE）中时，熔融石英微通道中的电渗流（electroosmotic flow，简称电渗）速率降低。此外，观察到的效果是定量不同的两种离子Ca 2+和Mg 2+。由于静电相互作用对于以点电荷建模的相同价离子是相同的，因此仅基于泊松-玻尔兹曼方程的双电层（EDL）的描述不能解释这些实验观察。本文报道了在Ca ~（2+）和Mg ~（2+）存在下电渗流的新的实验观察结果。一个网站绑定模型，占BGE离子与二氧化硅表面的化学相互作用的开发。该模型的预测是在良好的协议与二价阳离子的实验观察，以及从文献中的数据，如pH值和离子强度如何影响电渗透流速的BGE与一价阳离子。
The electroosmotic flow (EOF) rate in fused silica microchannels is experimentally found to decrease when trace quantities of salts containing the divalent cations Ca2+ and Mg2+ are added to a constant ionic strength background electrolytic solution (BGE) flowing in a channel having negatively charged walls. Moreover, the observed effect is quantitatively different for the two ions Ca2+ and Mg2+. Since electrostatic interactions are identical for ions of the same valence modeled as point charges, a description of the electric double layer (EDL) based on the Poisson-Boltzmann equation alone cannot account for these experimental observations. New experimental observations on electroosmotic flow in presence of Ca2+ and Mg2+ are reported in this work. A site binding model that accounts for the chemical interactions of the BGE ions with the silica surface is developed. The model predictions are in good agreement with the experimental observations on divalent cations as well as data from the literature on how properties such as pH and ionic strength affect electroosmotic flow rates for a BGE with monovalent cations.
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影响因子：
2.9
作者：
Zheng, Z;Hansford, DJ;Conlisk, AT
通讯作者：
Conlisk, AT
影响因子：
3.7
作者：
Sadr, R;Yoda, M;Conlisk, AT
通讯作者：
Conlisk, AT
影响因子：
3.4
作者：
DUKER, A;LEDIN, A;ALLARD, B
通讯作者：
ALLARD, B
影响因子：
15
作者：
Mammen, M;Carbeck, JD;Whitesides, GM
通讯作者：
Whitesides, GM
影响因子：
3.9
作者：
Revil, A;Pezard, PA;Glover, PWJ
通讯作者：
Glover, PWJ