Electrostatic droplet-formation in water/oil flow in a microchannel system

Electrostatic atomization has been studied to inject charged water droplets into oil in a microchannel reactor system. With a negative DC voltage, Taylor cone was formed and the droplets were injected into oil within 1/30 sec. The injection took place periodically with interval of a few seconds when the DC voltage was maintained. Using water, droplets of 10.7 /spl mu/m average diameter with standard deviation of 3.8 /spl mu/m were injected into rapeseed oil. When 50% glycerol was used, droplets of 6.7 /spl mu/m diameter with SD of 2 /spl mu/m were generated. The electrostatic atomization was proved to be effective in a microchannel system to produce charged fine droplets into oil. This will provide a pump-free system as the droplets can be manipulated using electrical force. The results require further improvement to produce more monodisperse droplets.