Changes in the particle morphology are reported as diameter growth factor, Gfd, calculated by Equation , where 𝐷 p is the mobility diameter of the processed (coated, humidified, or coatedhumidified) particles and 𝐷 i is the initial diameter. The relative error in Gfd measurement was less than 1%. Changes in the particle mass are reported as mass growth factor Gfm (Equation ) and mass fraction 𝑓 m (Equation ), where 𝑚 i is the initial particle mass and 𝑚 p is the particle mass after processing. The relative error in 𝑓 m was about 3%.