Fig. 3.
SEM of electrosprayed composite microspheres prepared using different core and shell polymer concentrations. The nozzle voltage (4.5 kV), the core/shell flow rates ((a) to (b): 0.5/2.5 ml/h; (c) to (d): 1.0/5.0 ml/h) and the nozzle-to-collector distance (15 cm) were maintained. Scale bar = 25 μm.