Droplet Pattern Formation and Translation in New Microfluidic Flow- Focusing Devices  

流动聚焦型微流控体系中的液滴的图案化排列和转变模式

作　　者：徐华国[1] 梁好均[1,2] 

机构地区：[1]中国科学技术大学高分子科学与工程系,合肥230026 [2]中国科学技术大学合肥微尺度物质科学国家实验室(筹),合肥230026

出　　处：《Chinese Journal of Chemical Physics》2014年第6期679-684,I0003,I0004,共8页化学物理学报（英文）

基　　金：This work was supported by the National Natural Science Foundation of China （No.20934004 and No.91127046） and the National Basic Research Program of China （No.2012CB821500 and No.2010CB934500）.

摘　　要：We conducted experiments on specially designed microfluidic chips that generate droplets through a microfluidic ow-focusing approach. The fluid flow in the microfluidic channel produced a shear flow field at low Reynolds numbers. The droplets in the microfluidic system exhibited special droplet pattern formations similar to periodic crystal-like lattices because of the competition between shear forces and surface tension. By adjusting the flow rate ratio of the water （droplet phase） to oil （continuous phase） phases and changing the outlet channel widths, the droplets formed monolayer dispersion to double-layer formation to monolayer squeezing when the outlet channel widths were 250 or 300 μm. We also obtained droplets with monolayer dispersion, three-layer arrangements, double-layer squeezing, and monolayer squeezing when the outlet channel width was 350 μm. The outlet channel width was increased to 400 μm, and four-layer arrangements were observed. We also studied the translation of droplet formation, which resulted in a detailed strategy to control drop size and droplet pattern formation for emulsi cation in microfluidic devices. We expect that our strategy can provide theoretical guidance to synthesize dispersion or polydisperse colloid particles.

关 键 词：Microfluidic flow-focusing device Droplet pattern formation TRANSITION 

分 类 号：O[理学]