Engineering the electrocapillary behavior of electrolyte droplets on thin fluoropolymer films

This study presents methods for engineering the electrocapillary behavior of fluoropolymer surfaces through the use of surfactants and an external insulating liquid. By the scaling of the appropriate surface energies, electrocapillary behavior is obtained at a record low voltage, with contact angle changes in excess of 100 degrees at 4 V. A consistent description of electrocapillary saturation is presented, identifying three separate regimes: breakdown, thermodynamic instability, and relaxation. Methods for identifying and mitigating some of the saturation behaviors are discussed. Finally, the parameters influencing the observed voltage of zero charge are summarized.