Droplet coalescence process under electric fields in an immiscible polymer blend

The droplet coalescence process was investigated in immiscible polymer blends when subjected to a step electric field. We present sequential three-dimensional images captured during the process with a confocal scanning laser microscope. Characteristic lengths parallel and perpendicular to the electric field were obtained from the spatial correlation functions of the images. It was found that the droplet growth rate increased with both the electric field and the volume fraction of droplets. A function describing the droplet growth rate was derived from theory using the "hierarchical model" and was found to be in good agreement with the experimental results.