作　　者： ; ; ;

机构地区： 中国科学院广州能源研究所

出　　处： 《微纳电子技术》 2008年第5期275-281,共7页

摘　　要： 以辛烷为分散相、水为连续相,对宽度为200μm、深度为40μm的T型交错微通道内水包油型液液相微反应器的形成进行了实验研究。通过改变分散相和连续相流量比例,在T型节点的下游发现射流状液滴和滴状液滴两种液滴形成方式。比较了两种液滴形成过程中界面张力、黏性剪切力和惯性力的关系,分析了形成两种液滴的界面不稳定性,得到界面不稳定是微尺度下液滴形成的主要原因,而较大的黏性剪切力可以提前激发界面失稳。最后,分析了由表面活性剂的质量分数引起的Marangoni效应对液滴形成的影响。 Droplet formation in a 40μm high, 200μm wide microfluidic T-junction device, which is used as liquid-liquid microreactors, was investigated experimentally using n-octane as the dispersed phase and water as the continuous phase. Depending on flow dynamics of the dispersed phase and the continuous phase, two different droplet formation mechanisms, jetting and dripping, were distinguished. Experimental results among surface tension force, shear-stress force were analyzed. The results include the relation and inertial stress force, and instabilities of interface in two mechanisms of droplet formation. Experimental observations support that the break-up is dominated by interfacial instabilities, and larger shear-stress force could trigger this instability in advance. Consequently, Marangoni effect caused by the change of the surfactant concentration on the droplet properties was analyzed.

关 键 词： 微通道 液滴 流型分布 界面不稳定性 微反应器

领　　域： [机械工程] [机械工程] [理学] [理学]