A new device for monitoring deformation dynamics and droplet shrinkage kinetics (during drying) of a charged droplet suspended in air

Abstract

In this study, a new device was developed to study the deformation kinetics of a pendant droplet under controlled drying conditions and in the presence of an electric field (EF). It has made it possible to investigate the deformation and air-drying kinetics of conductive and electrically charged pendant CuSO₄.5H₂O droplets. Various EF intensities (0–800 kV/m) and solid content concentrations (0–25 % wt/wt) are applied. Results show significant reduction (up to 42 %) in interfacial tension with increasing EF, along with a quadratic relationship between EF intensity and interfacial tension. Droplet surface area expansion and deformation are influenced by the EF intensity and the solution solids content. It has also been shown that, during drying, EF application can influence the deformation kinetics and shrinkage rate during the early drying stages, particularly at higher solid concentrations and high EF intensity, revealing new insights into droplet dynamics under EF.