Micromixing of miscible liquids in segmented gas-liquid flow
Micromixing of miscible liquids in segmented gas-liquid flow
复制标题
DOI：
10.1021/la0482406
复制
发表时间：
2005-02-15
期刊：
影响因子：
3.9
通讯作者：
Jensen, KF
中科院分区：
文献类型：
--
作者：
Günther, A;Jhunjhunwala, M;Jensen, KF
我们提出了一种集成的微流控系统，通过引入气相，形成分段的气液(弹状流)流，并在平面毛细管分离器中完全分离混合的液和气流，实现了两种可混溶液体流之间的有效混合。与分段流动相关的回流运动增强了直线微通道中的对流，而不需要额外的制造步骤。用显微粒子图像测速仪(MuPIV)对瞬时速度场进行了定量。垂直于流道方向的速度约为液体段内体积液体速度的30%。该值仅弱地依赖于液体段的长度。通过脉冲激光荧光显微镜和共聚焦扫描显微镜测量得到了空间浓度场和混合程度(EOM)。与以前报道的使用三维微通道网络或图案化墙壁的混沌微混合器相比，混合长度缩短了2-3倍。分段的气液微流动允许混合时间在毫秒和秒时间尺度之间的几个数量级内变化。
We present an integrated microfluidic system that achieves efficient mixing between two miscible liquid streams by introducing a gas phase, forming a segmented gas-liquid (slug) flow, and completely separating the mixed liquid and gas streams in a planar capillary separator. The recirculation motion associated with segmented flow enhances advection in straight microchannels without requiring additional fabrication steps. Instantaneous velocity fields are quantified by microscopic particle image velocimetry (muPIV). Velocities in the direction normal to the channel amount to approximately 30% of the bulk liquid velocity inside a liquid segment. This value depends only weakly on the length of a liquid segment. Spatial concentration fields and the extent of mixing (EOM) are obtained from pulsed-laser fluorescence microscopy and confocal scanning microscopy measurements. The mixing length is reduced 2-3-fold in comparison with previously reported chaotic micromixers that use three-dimensional microchannel networks or patterned walls. Segmented gas-liquid microflows allow mixing times to be varied over several orders of magnitude between milliseconds and second time scales.