The role of electrochemical polarization in micro-droplets formation

The effects of electrochemical polarization on the micro-droplets formation were investigated using microscope observation method and electrochemical polarization techniques.It is found that cathodic polarization can initiate and accelerate the formation of micro-droplets, whereas anodic polarization can inhibit the micro-droplets formation, independent of metal type, electrolyte species, composition of air, and environmental humidity, indicating that the electrochemical polarization is the key condition for micro-droplets formation on metal surfaces. Based on above results, it is suggested that both the decrease of liquid/metal interface tension and the cooling of temperature of the three-phase-boundary area which are caused by cathodic polarization, may be the main reason for the micro-droplets formation.