Analysis of Droplet Formation Near Onset Voltage of Aqueous Electrosprays

There is a lot of research on liquid atomization by means of electrospray, particularly because of its many practical applications. Nevertheless, the full understanding and control of the electrospray mechanisms are still incomplete. An experimental setup was developed in order to investigate the frequency characteristics of droplet formation and ejection at the tip of Taylor’s cone of aqueous electrosprays. Droplet formation and oscillations are monitored using a Kodak Ektapro high-speed camera. The frequency of droplet formation at the tip of the capillary needle is analyzed. Droplet frequency formation appears to exhibit three distinct regimes with an abrupt transition from one regime to another. Droplet formation is recorded at different needle-plate electrode distances. Based on the analysis of experimental data a scaling law for droplet formation was found.