The mass transport in electrokinetically actuated microchannel flow is interesting when the wall reactions influence the wall potential, thereby affecting the hydrodynamics. This is the first work where the electro-osmotic flow is impacted by the chemical reactions. Since the wall potential is non-uniform, we have compared the results of the classical Poisson–Boltzmann equations with the generalized Poisson–Nernst–Planck model and investigated the applicability within the range of the operating conditions of the problem. The results provide fundamental understanding of the velocity profile within the channel and the wall concentration, which is significantly different from the classical species transport. The wall concentration is dependent on the electrokinetic parameters rather than the Reynolds and Peclet number solely. For constant volumetric flow rate, the resultant electro-osmotic velocity profile is not parabolic and exhibits higher convection close to the wall, leading to reduced solute polarization. The overall mass transport rate can be enhanced by more than two times with respect to non-electrical phenomena. The results will be useful in understanding the physics and provide operational know-how of electrokinetic-based applications related to capillary electrophoresis, electrochromatrogaphy and (bio-)chemical sensing.

中文翻译：

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电动微流中的传质与壁反应影响流体动力学

当壁反应影响壁电位从而影响流体动力学时，电动驱动微通道流中的质量传递很有趣。这是电渗流受化学反应影响的第一项工作。由于壁势是非均匀的，我们将经典 Poisson-Boltzmann 方程的结果与广义 Poisson-Nernst-Planck 模型的结果进行了比较，并研究了该问题在操作条件范围内的适用性。结果提供了对通道内速度分布和壁浓度的基本理解，这与经典的物质传输有很大不同。壁浓度取决于电动参数，而不仅仅是雷诺数和佩克莱数。对于恒定的体积流速，所产生的电渗速度分布不是抛物线形的，并且在靠近壁面处表现出更高的对流，从而导致溶质极化降低。相对于非电现象，整体质量传输速率可以提高两倍以上。结果将有助于理解物理学，并提供与毛细管电泳、电色谱和（生物）化学传感相关的基于电动的应用的操作知识。