Liquid-liquid colliding micro-dispersion and general scaling laws in novel T-junction microdevices

Colliding micro-dispersion has been extensively used to generate uniform droplets in liquid-liquid heterogeneous reactions. However, there are few reports on the colliding micro-dispersion. More importantly, only squeezing flow and big size droplets can be generated in the normal colliding micro-dispersion process, and even there exists no general scaling laws for droplet size. We have developed novel T-junction microdevices with new geometric structures to intensify the colliding micro-dispersion and proposed general scaling laws for droplet size in colliding T-junction microdevices. The droplet formation frequency was increased by more than 40 times, and a much wider operating range was allowed in the novel colliding T-junction microdevice. The flow regime distribution under high Weber number was explored for the first time and a complete liquid-liquid flow pattern map under colliding micro-dispersion has been also proposed. We also proved that jetting flow regime can be occurred under high Weber number and low capillary number.