The objective of this study eas to devleop the capabilities to determine the effect of operational parameters on the morphology of powders proplet was constructed. It allowed for monitoring and recording the images of a drying droplet as a function of time. The experimental drying was carried out for a number of systems that highlighted the effects of different controlling parameters, such as drying temperature and initial solute concentration. The experients demonstrated that the shell structure of a drying droplet played an important role in determining the final dried particle morphology. In addition, the shell structure of a drying droplet varies from material to material, which increases the difficulty in the modeling prediction. Several materials with different physical properties, such as solubility and latent heat of crystallization, were investigated. Two sets of experiemtns, Ca(C_2H_3O_2)_2 versus NaC_2H_3O_2 and K_2CO_3 versus Na_2CO_3, were run to examine the effect of material solubility. The effect of latent heat of crystallization was examined by experiment with NH_4Cl versus NaCl. In summary, low drying temperature and material with high latent heat of crystallization (i.e., endothermic crystallization) were favorable for small, dense, and regularly-shaped particles. Materials that formed an elastic shell structure such as ammonium chloride led to hollow particle formation. Material with high solubility led to small, dense, irregularly-shaped particles. A higher initial solute concentration was favorable for the formation of a large dense particle.
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