The PSD was evaluated by light scattering (Malvern Mastersizer
2000 with Hydro 2000s, Malvern instruments Ltd, UK). Droplets of the
sample were slowly added into a sample compartment, already filled
with distilled water (at room temperature), until obscurity was around
10. The mean diameter was also evaluated based for both particle
volume (D[4,3]; Eq. (1)) and the particle surface area (D[3,2]; Eq. (2)).
This is useful since the particles are not ideal spheres, and the D[3,2] is
more influenced by the smaller particles,while the D[4,3] ismore influenced
by the larger ones