Electroosmotic flow in nanofluidic channels.
Electroosmotic flow in nanofluidic channels.
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DOI：
10.1021/ac502596m
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发表时间：
2014-11-18
影响因子：
7.4
通讯作者：
Jacobson, Stephen C.
中科院分区：
文献类型：
--
作者：
Haywood, Daniel G.;Harms, Zachary D.;Jacobson, Stephen C.
我们报道了在具有矩形横截面的纳米流体通道中的电渗迁移率的测量，并将我们的结果与理论进行了比较。用聚焦离子束仪器将纳米流体通道直接研磨到两个紧密间隔的微通道之间的硼硅酸盐玻璃中，并且纳米通道具有27、54和108 nm的半深（h）和265 nm的相同半宽。我们分别测量了德拜长度（κ-1）为30至0.4 nm的0.1至500 mM NaCl溶液中的电渗迁移率。实验电渗迁移率定量比较从一个非线性的解决方案的泊松-玻尔兹曼方程的通道与平行板的几何形状计算的迁移率。在计算中，使用了在半深为2.5 μm的微通道中测量的Δ-电位，对于500至0.1 mM NaCl，Δ-电位的范围分别为−6至−73 mV。对于κh > 50，Smoluchowski方程准确地预测了纳米通道中的电渗迁移率。然而，对于κh < 10，双电层延伸到纳米通道中，并且由于通道内的限制，平均电渗迁移率降低。在κh = 4时，27、54和108 nm通道中的电渗迁移率表现出最大值，在0.1 mM NaCl时，27 nm通道中的电渗迁移率（κh = 1）比2.5 μm通道中的电渗迁移率（κh = 100）低5倍。
We report the measurement of electroosmotic mobilities in nanofluidic channels with rectangular cross sections and compare our results with theory. Nanofluidic channels were milled directly into borosilicate glass between two closely spaced microchannels with a focused ion beam instrument, and the nanochannels had half-depths (h) of 27, 54, and 108 nm and the same half-width of 265 nm. We measured electroosmotic mobilities in NaCl solutions from 0.1 to 500 mM that have Debye lengths (κ–1) from 30 to 0.4 nm, respectively. The experimental electroosmotic mobilities compare quantitatively to mobilities calculated from a nonlinear solution of the Poisson–Boltzmann equation for channels with a parallel-plate geometry. For the calculations, ζ-potentials measured in a microchannel with a half-depth of 2.5 μm are used and range from −6 to −73 mV for 500 to 0.1 mM NaCl, respectively. For κh > 50, the Smoluchowski equation accurately predicts electroosmotic mobilities in the nanochannels. However, for κh < 10, the electrical double layer extends into the nanochannels, and due to confinement within the channels, the average electroosmotic mobilities decrease. At κh ≈ 4, the electroosmotic mobilities in the 27, 54, and 108 nm channels exhibit maxima, and at 0.1 mM NaCl, the electroosmotic mobility in the 27 nm channel (κh = 1) is 5-fold lower than the electroosmotic mobility in the 2.5 μm channel (κh = 100).
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影响因子：
7.4
作者：
Kovarik, Michelle L.;Jacobson, Stephen C.
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