Enhancement of Micromixing Tees Using Ultrasound Energy

摘要

Microfluidic opposed mixing tees were tested with hydraulic diameters of 100 μm, 177 μm, and 254 μm. Mixing performance was characterized by feeding one stream with hydrochloric acid and another stream with sodium hydroxide and dimethoxypropane. Under ideal mixing conditions, the instantaneous neutralization of sodium hydroxide with hydrochloric acid would prevent the catalytic hydrolysis of dimethoxypropane. Therefore, higher conversions of dimethoxypropane in this fast, competitive reaction is an indication of lower mixing performance. For a constant Reynolds Number, the mixing performance was increased by decreasing the channel dimensions. Ultrasound energy was externally applied to all three reactors and was found to increase mixing performance. Challenges in sealing the 100 μm mixer precluded operation at comparable pressures achieved with the 177 and 254 μm mixers. The highest mixing performance was observed with the 177 μm diameter mixer using a combination of pump work and ultrasound energy. A combination of ultrasound energy and pump work was demonstrated to be the most efficient mode of providing mixing for the 254 μm system. Therefore, externally applied ultrasound energy can be an effective and efficient means of improving the mixing performance of microfluidic systems.