Ice Nucleation in the Presence of Electric Fields: An Experimental Study

In the present study, ice nucleation in sessile water drops during continuous cool down is studied experimentally under the impact of a constant electric field, to determine its influence on heterogeneous nucleation. The experimental setup enables simultaneous observation of multiple drops under well-defined conditions with and without an electric field and at temperatures down to -40 °C. A single experimental run contains 40 drops exposed to the same conditions. Drops with a well-defined size are produced employing a drop-on-demand drop generator. Based on multiple experimental runs using the same drops, the nucleation behavior is analyzed using statistical methods to determine the drop survival curves and nucleation site densities for varying conditions. Besides the influence of the electric field, the influence of different drop ensembles is investigated for a constant cooling rate of 5 K/min. A comparison of the experiments with and without an electric field is used to elaborate its influence on heterogeneous ice nucleation.