Research on mixing mechanism of micromixer based on segmented gas-liquid flow

Previous approaches to improve mixing between miscible liquid streams are based on lamination; introducing chaotic advection through patterned channel walls; or through three dimensional (3D) channel networks. A new mixer for miscible liquids based on segmented gas-liquid flow is presented here. It can be operated over a very large range of liquid flow rates and is therefore compatible with nanoparticle growth. In order to explore the mixing mechanism based on segmented gas-liquid flow, a micro-resolution particle image velocimetry (Micro-PIV) is used to measure the flow field in liquid segment (plug) involving liquid species to be mixed. The velocity distributions in the plug can be obtained according to the CCD image. There are two recirculating flows in the plug, which can enhance the mixing efficiency by folding and stretching the liquids occurred deterministically in these regions. Some published results were cited as a comparison. The comparison indicated that present device has a best mixing characteristic at high Peclet number.