Analysis of non-Newtonian liquids using a microfluidic capillary viscometer
Analysis of non-Newtonian liquids using a microfluidic capillary viscometer
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DOI：
10.1021/ac0518046
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发表时间：
2006-03-01
影响因子：
7.4
通讯作者：
Burns, MA
中科院分区：
文献类型：
--
作者：
Srivastava, N;Burns, MA
我们已经使用了自校准的微型毛细管粘度计来分析非牛顿幂律流体。毛细管粘度计可以在单次实验运行期间产生宽范围的剪切速率，从而能够快速准确地分析非牛顿液体。粘度的测量是基于监测流体样品的毛细管压力驱动的运动，其平均速度和剪切速率随时间变化。该装置已成功地测试了准确性和鲁棒性与稀释以及半稀释溶液的柔性弹性聚合物，包括聚（环氧乙烷）和水解聚丙烯酰胺的水溶液的硬棒状聚合物分子的黄原胶，一种流行的乳化剂和食品增稠剂，以及与喷墨印刷油墨。在1-600 cP的范围内的粘度进行了测量，并从5到1000 s（-1）变化的剪切速率已获得与当前的几何形状和通道尺寸的微型粘度计。总测量时间在2和8分钟之间变化，需要小于1 μ L的样品体积。这种微加工毛细管粘度计可能应用于质量控制和制造，其中需要使用有限的样品体积进行快速和重复的测量。
We have used a self-calibrating microfabricated capillary viscometer to analyze non-Newtonian power law fluids. The capillary viscometer can generate a wide range of shear rates during a single experimental run enabling quick and accurate analysis of non-Newtonian liquids. The measurement of viscosity is based on monitoring the capillary pressure-driven movement of fluid sample whose mean velocity and, therefore, shear rate varies with time. The device has been successfully tested for accuracy and robustness with dilute as well as semidilute solutions of flexible elastic polymers including poly(ethylene oxide) and hydrolyzed polyacrylamide to an aqueous solution of a stiff rodlike polymer molecule of xanthan gum, a popular emulsifier and food thickener, as well as with ink-jet printing inks. Viscosities in the range of 1-600 cP were measured, and shear rates varying from 5 to 1000 s(-1) have been obtained on the microfabricated viscometer with the current geometry and channel dimensions. The total measurement time varied between 2 and 8 min and less than 1 mu L of sample volume was required. Such a microfabricated capillary viscometer would have possible applications in quality control and manufacturing where rapid and repeated measurements need to be made using limited sample volume.