EFFECT OF ELECTRODE GEOMETRY AND CHARGE ON THE PRODUCTION OF POLYMER MICROBEADS BY ELECTROSTATICS

Experimental parameters which are critical for producing small diamete r (i.e. 100-300 mum) polymer microbeads, using electrostatic droplet g eneration, were investigated with three types of electrodes; a paralle l plate, a positively charged needle and a grounded needle with algina te as the polymer. Electrode spacing was a critical factor controlling microbead size, but only for the parallel plate set-up. While the app lied potential affected droplet size in all three set-ups, the smalles t droplet size was produced with the positively charged needle. In som e experiments needle oscillation was observed resulting in even smalle r microbeads (i.e. < 100 mum). Calculated microbead diameters agreed w ell with experimental values.