A new technique for measuring the Fickian diffusion coefficient in binary liquid solutions
A new technique for measuring the Fickian diffusion coefficient in binary liquid solutions
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DOI：
10.1016/s0894-1777(98)10006-7
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发表时间：
1998-09
影响因子：
3.2
通讯作者：
Massimo Capobianchi;T. Irvine;N. Tutu;G. Greene
中科院分区：
文献类型：
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作者：
Massimo Capobianchi;T. Irvine;N. Tutu;G. Greene
本研究详细介绍了一种新技术的发展，用于测量的菲克扩散系数在二元液体溶液中，并报告了使用这种新技术的两个电解系统获得的系数。这种新方法称为衰减脉冲技术，它利用了暴露于瞬态浓度脉冲的半无限系统的行为。该方法允许简单，直接和绝对的扩散系数的测定，只需要测量时间和距离。它适用于许多不同类型的流体对，并且不需要溶液性质的知识。衰减脉冲技术用于测量氯化钾在水中和氯化钠在水中在18.5、25.0和30.0°C下的平均扩散系数。将当前的实验结果与其他已发表的研究结果进行了比较，发现通常在当前测量的预测不确定度± 7.6%范围内一致。
The present study details the development of a new technique for measuring the Fickian diffusion coefficient in binary liquid solutions, and reports the coefficients obtained using this new technique for two electrolytic systems. The new method, called the decaying pulse technique, takes advantage of the behavior of a semi-infinite system exposed to a transient concentration pulse. The method permits simple, direct, and absolute determination of the diffusion coefficient, and requires measurement of only time and distance. It is applicable to many different types of fluid pairs, and requires no knowledge of solution properties. The decaying pulse technique was used to measure the average diffusion coefficient of potassium chloride in water and sodium chloride in water, at 18.5, 25.0, and 30.0°C. The current experimental results were compared to those from other published investigations, and were generally found to agree within the predicted uncertainty of the current measurements ±7.6%.