Effect of electrode geometry and charge on the production of polymer microbeads by electrostatics

Abstract

AbstractExperimental parameters which are critical for producing small diameter (i.e. 100‐300 μm) polymer microbeads, using electrostatic droplet generation, were investigated with three types of electrodes; a parallel plate, a positively charged needle and a grounded needle with alginate as the polymer. Electrode spacing was a critical factor controlling microbead size, but only for the parallel plate set‐up. While the applied potential affected droplet size in all three set‐ups, the smallest droplet size was produced with the positively charged needle. In some experiments needle oscillation was observed resulting in even smaller microbeads (i.e. < 100 μm). Calculated microbead diameters agreed well with experimental values.