T型微通道中液液相微反应器微流控装置的研究
文献类型：学位论文
| ; | |
| 作者 | 刘志鹏 |
| 学位类别 | 硕士 |
| 答辩日期 | 2008-05-31 |
| 授予单位 | 中国科学院广州能源研究所 |
| 授予地点 | 广州能源研究所 |
| 导师 | 徐进良 |
| 关键词 | 液滴 破裂 排列 界面不稳定性 微通道 微反应器 |
| 其他题名 | Study of droplet formation as liquid-liquid microreactors in a microfluidic T-junction device |
| 中文摘要 | Technology of liquid-liquid microreactors is a rapid developing and widely used by chemical and biological engineering, which is widely applied onto life science and other related fields. In the present work, two kinds of new microfluidic T-junction device have been put forward on the basis of the synthetical analysis of the previously reported microreactor microfluidics, in which a series of experiments and analysis of microreactor formation have been performed. For the microreactor microfluidics based on the T-junction device, droplet formation in a 30μm high, 800μm wide microfluidic T-junction device, which is used as liquid-liquid microreactors, were investigated experimentally using water as the dispersed phase and silicone oil as the continuous phase. The production of micron size droplets with a perfectly controllable diameter is affected by flow dynamics of both the dispersed and the continuous phase. Experimental results, including the relation between diameter and flow rates, and the change of the velocity and pressure at drop break-up process, had been analyzed in detail. As the conclusion, the break-up is dominated by shear-stress force and surface tension force. We reported the periodic process of droplet generation in a microfluidic device, which was found that the ratio of the length to the width of the ellipse, biscuit droplet keeps linearly increasing versus time during a full cycle, and develop a scaling law for the droplet frequencies and sizes. Depending on the Oh number, the droplet may or may not breakup into smaller ones when it enters the downstream 120μm deep microchannel. For the non-breaking up cases, three self-assembled, ordered droplet patterns, reverse droplet, pearl necklace, single droplet, appear. For large relative flow rate, droplet breakup occurs in branched microchannel network by two different mechanisms with the two liquids flow in parallel along the shallow channel segment. For the microreactor instabilities based on the T-junction device, droplet formation in a 40μm high, 200μm wide microfluidic T-junction device were investigated experimentally using n-Octane as the dispersed phase and water as the continuous phase. Depending on flow dynamics of both the dispersed and the continuous phase, two different droplet formation mechanisms are distinguished: jetting and dripping. Experimental results, included the relation among surface tension force, shear-stress force and inertial stress force, and instabilities of interface in two mechanisms of droplet formation had been analyzed in detail. Experimental observations support the break-up is dominated by interfacial instabilities, and larger shear-stress force could trigger this instability in advance. Consequently, Marangoni effect which is caused by the change of the surfactant concentration on the droplet properties had be analyzed. |
| 语种 | 中文 |
| 公开日期 | 2011-07-14 ; 2011-07-15 |
| 页码 | 64 |
| 源URL | [http://ir.giec.ac.cn/handle/344007/5802]  |
| 专题 | 中国科学院广州能源研究所 |
| 推荐引用方式 GB/T 7714 | 刘志鹏. T型微通道中液液相微反应器微流控装置的研究, Study of droplet formation as liquid-liquid microreactors in a microfluidic T-junction device[D]. 广州能源研究所. 中国科学院广州能源研究所. 2008. |
入库方式： OAI收割
来源：广州能源研究所
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