Experimental study of the effect of gas discharge on ionic liquid electrospray

Electrospray is a technique used to break and atomize a liquid medium via electric force. This technique holds significant potential for various applications, particularly in the field of ionic liquid electrospray (ILE) technology. However, when ILE is conducted in high-voltage atmospheric environments, gas discharge phenomena often occur. These phenomena disrupt the normal operation of electrospray and the measurement of experimental parameters. In this study, electrospray experiments were conducted on the ionic liquid EMI-BF4. The observations revealed that the operating modes of the ionic liquid depend on the voltage polarity at high voltages. Additionally, a correspondence between the operating mode of ILE and the current signal in the circuit was established. The shape of the liquid cone formed at the needle tip bore a striking resemblance to the plume of corona discharge, suggesting that the motion trajectory of electrons influenced the curvature of the liquid cone. Steamer theory provided a clear explanation for the change in curvature as the voltage increased.