Zero-Discharge Fluid-Dynamic Gauging for Studying the Swelling of Soft Solid Layers
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- 作者：Shiyao Wang ; D. Ian Wilson
- 刊名：Industrial & Engineering Chemistry Research
- 出版年：2015
- 出版时间：August 19, 2015
- 年：2015
- 卷：54
- 期：32
- 页码：7859-7870
- 全文大小：648K
- ISSN：1520-5045
文摘
A benchtop fluid-dynamic gauging device to study the swelling or shrinking of soft solid layers immersed in a liquid environment in situ and in real time is demonstrated. A particular feature is that the volume of liquid is isolated, hence the name zero-net-discharge fluid-dynamic gauging (ZFDG), which renders ZFDG suitable for aseptic operation. For the 1.78 mm nozzle diameter used here, calibration tests gave a resolution of 卤5 渭m and an uncertainty of 卤10 渭m. Computational fluid dynamics simulations indicated that the shear stress imposed on a layer being gauged differed between the successive suction and ejection stages in ZFDG. The swelling of poly(vinyl acetate) (PVA) layers (about 1 mm dry thickness) and gelatin films (50鈥?0 渭m dry thickness) in aqueous solutions is reported as a demonstration of ZFDG application. There was good agreement with more cumbersome gravimetric methods. The gelatin swelled noticeably faster at high pH, above the pKa values of proline and hydroxyproline. Fitting the gelatin swelling data to a power law model indicated 鈥榮ub-Fickian鈥?behavior with a 鈥榙iffusion index鈥?that increased with the pH.