碩士 / 國立成功大學 / 工程科學系碩博士班 / 96 / This study describes the optimal formation of microemulsions with Taguchi method and the generation of monodisperse calcium alginate (Ca-alginate) microcapsules on a microfluidic platform using the commercial optical disc process. Our strategy is based on combining the injection molding process for cross-junction microchannel with the sheath focusing effect to form uniform water-in-oil (w/o) emulsions. These emulsions, consisting of 1.5% (w/v) sodium alginate (Na-alginate), are then dripped into a solution containing 20% (w/v) calcium chloride (CaCl2) creating Ca-alginate microparticles in an efficient manner. This study utilizes Computational Fluid Dynamic (CFD) software to simulate the motion of fluids and emulsions in microfluidic channel. We demonstrate that the size of Ca-alginate microparticles can be controlled from 20 µm to 70 µm in diameter with a variation of less than 10%, simply by altering the relative dispersed/dispersed (sheath/sample) phase flow rate ratio. Experimental data show that for a given fixed dispersed phase flow, the emulsion size decreases as the average flow rate of the continuous phase flow increases. We apply Taguchi method to investigate the influence of other controlled factors on the size of microemulsions except the flow rate ratio, and find that the optimal parameter dispersed phase flow rate in 1 μL/min, flow rate ratio in 10 between continuous/dispersed phases, viscosity of dispersed phase in 27 cP, and span 80 concentration in 2% (v/v) have the smallest emulsion size 19.67 μm lower 23.86% than original design. The proposed microfluidic platform is capable of generating relatively uniform emulsions and has the advantages of active control of the emulsion diameter, a simple and low cost process, and a high throughput.
| Identifer | oai:union.ndltd.org:TW/096NCKU5028005 |
| Date | January 2008 |
| Creators | Ming-Kai Liu, 劉明凱 |
| Contributors | Yu-Cheng Lin, 林裕城 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 122 |
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