Dynamic coalescence of two charged droplets with deflected angles in the presence of electric fields

• Dynamic electrocoalescence of charged droplets with deflected angles is studied. • Effects of field strengths, deflected angles, and ions on electrocoalescence dynamics are focused. • The critical electric field influences the electrocoalescence dynamics. • The dissolved ions are responsible for the appearance of secondary droplets. The electrocoalescence dynamics of two charged droplets with different deflected angles are studied via molecular dynamics simulations. The simulated results show that under a weak electric field, these adjacent droplets can realize the complete coalescence at the deflected angles of 0° and 50°, but cannot realize that at the deflected angle of 90°. As the electric field strength increases to a critical value, owing to escaped ions, a secondary droplet is ejected from coalescing droplet, namely the partial coalescence. However, as the field strength far exceeds the critical field strength, charge transfer appears between these adjacent droplets by the liquid bridge. These two droplets with enough opposite charges move towards the opposite directions, respectively, such that the formed liquid bridge breaks at the interface again, leading to the appearance of non-coalescence. As a result, the complete-to-non coalescence transition is triggered by the strong electric field.