Date of Thesis
Spring 2026
Description
Polymorphism, the ability for a compound to have multiple crystalline structures, plays an important role in determining the physical properties and performance of pharmaceutical materials. In particle formation processes that occur under rapid, non-equilibrium conditions, such as aerosol-based techniques, crystallization pathways can differ significantly from those observed in bulk systems. As a result, understanding how processing conditions influence particle formation and crystal structure is critical for controlling material properties. This work examines how the solution environment and initial solution conditions influence crystallization behavior during the drying of aerosolized droplets. Particles were generated via atomization and characterized with respect to both polymorphic outcome and size distribution to investigate the relationship between particle formation pathways and the resulting crystal structure. As in bulk conditions, results indicate that both solvent identity and initial molar concentration play a key role in determining crystallization behavior; however, at higher concentrations, specific differences emerge, leading to larger particle sizes and shifts in nucleation and growth dynamics. Distinct solvent-dependent polymorphic trends were observed. In water, ethanol, and methanol, the fraction of the metastable polymorph present in the sample generally decreased with increasing initial molar concentration. Across all conditions, ethanol consistently favored formation of the beta polymorph, while methanol favored formation of the alpha polymorph. On the other hand, isopropanol exhibited non-monotonic behavior, with %α increasing from approximately 36% to 99% at 3.33 g/L, then decreasing back to approximately 57% at 10 g/L. SMPS measurements showed corresponding changes in particle size distributions, with increasing concentration generally leading to larger particle diameters, and, in some cases, transitions between bimodal and unimodal distributions. These results indicate that polymorph selection is governed by both nucleation timing and particle growth during droplet drying, providing insight into the crystallization under non-equilibrium conditions and informing the design of particle-engineering processes in pharmaceutical and related industries.
Keywords
Polymorphism, Materials Science, Atomization, Crystallization, Aerosols, Chemical Engineering
Access Type
Honors Thesis
Degree Type
Bachelor of Science in Chemical Engineering
Major
Chemical Engineering
Minor, Emphasis, or Concentration
Computer Science
First Advisor
Ryan Snyder
Second Advisor
Dabrina Dutcher
Recommended Citation
Burek, Victoria I., "Solvent and Concentration Effects on Polymorphic Forms of Glutaric Acid via Atomization" (2026). Honors Theses. 776.
https://digitalcommons.bucknell.edu/honors_theses/776