Electric-field effects on interfaces: electrospray and electrocoalescence

Recent advances in the application of electric fields to interface modification, leading to drop breakup and coalescence in liquid–liquid dispersions or particle aggregation in solid–liquid suspensions, are reviewed in this article. Potential new applications based on electrospray and electrocoalescence of droplets are discussed. Both of these phenomena may occur under applied electric fields and may apply to drops, particles or bubbles. Several industrial applications take advantage of electric fields. Some of these applications are based on well-understood phenomena, such as normal electrospray of droplets (e.g., as in ink jet printing), while others are less understood (e.g., inverse electrospray). Recent developments of electric-field effects and applications, as well as expected future directions, are discussed.