微流控法二乙烯基苯乳液粒子成型机理研究

采用相界面跟踪(V()F)数值模拟方法,研究了轴流型微流控芯片中流速比、界面张力、粘度等对乳液粒子粒径的影响。模拟结果表明:乳液粒子粒径与流速比的对数存在线性关系,在一定范围内,当流速比增大时,粒径变小;当界面张力小于0.025 N/m时,乳液粒径随界面张力增大而增加,当界面张力超过0.03N/m时,乳液粒径变化趋于平缓;分散相粘度对乳液粒径的影响甚微。以聚乙烯醇(PVA)水溶液为连续相,二乙烯基苯(DVB)溶液为分散相,采用自制的聚二甲基硅氧烷(PDMS)轴流型微流控芯进行了DVB乳液粒子成型实验研究,获得了0.5~3.0 mm的DVB乳液粒子。

Divinyl benzene emulsion droplets generation with microfluidic method

The emulsion droplets generation process in co-flowing microfluidic channels was studied by using a volume-of-fluid (VOF) numerical way. The diameter of emulsion droplets was controlled by the parameters including velocity ratio, surface tension and viscosity. Simulation results demonstrated that the diameter could be tuned by logarithm of velocity ratio in linear ways. The diameter increases with the increase of surface tension but becomes steady when surface tension is above 0.03 N/m. And the viscosity of disperse phase has negligible impact on droplet diameter. Furthermore, divinyl benzene (DVB) emulsion droplets with a diameter of 0.5 mm to 3.0 mm were produced in a self-made polydimethylsiloxane (PDMS) microfluidic slab where polyvinyl alcohol (PVA), DVB solution were set as the continuous phase and disperse phase respectively.