Particle size distributions was determined by laser granulometry
with a Malvern Mastersizer 2000 diffraction laser particle sizer
(Malvern Instruments, Worcestershire, UK), equipped with a
Scirocco dry powder unit (Malvern Instruments, Worcestershire,
UK). The instrument provides volume weighted size distributions
and particle size parameters, such as volume median diameter
(d50), De Brouckere mean diameter