2.2.2. Mean Particle Size, Particle Size Distribution, and Morphology of Microspheres

Mean particle size and particle size distribution were measured by static light scattering (Microtrac S3500, Montgomeryville, PA, USA). Samples were prepared by suspending microspheres in distilled water. Microsphere morphology was evaluated by scanning electron microscopy (SEM; Jeol, JSM-6335F, Tokyo, Japan). Prior to that, each powder sample was spread on a double-sided carbon tape mounted on an aluminum stub to be gold-coated under vacuum (K550X ion sputter, Emitech, UK) for 3 min at 25 mA. SEM images were recorded at an acceleration voltage of 5.0 kV and 2500× magnification.