Paper Number
SE7                         My Program 

Session
Rheology and Sustainability for Energy and Production

Title
Thermodynamic insights into shear flow-mediated crystallization

Presentation Date and Time
October 23, 2025 (Thursday) 9:05

Track / Room
Track 2 / Sweeney Ballroom B

Authors (Click on name to view author profile)

  1. Willis, L. Connor (FAMU-FSU College of Engineering, Chemical and Biomedical Engineering)
  2. Rao, Rekha R. (Sandia National Laboratories)
  3. Liu, Leo (FAMU-FSU College of Engineering, Chemical and Biomedical Engineering)

Author and Affiliation Lines (in printed abstract book)
L. Connor Willis1, Rekha R. Rao2 and Leo Liu1
1Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL 32311; 2Sandia National Laboratories, Albuquerque, NM 87123

Speaker / Presenter 
Willis, L. Connor

Keywords
theoretical methods; computational methods; advanced manufacturing; colloids; industrial applications; methods; particualte systems; production; selft-assemblies; sustainability; techniques

Text of Abstract
During scalable perovskite solar cell processing, many of the roll-to-roll manufacturing techniques, such as blade-coating or slot-die coating, rely on understanding many simultaneous phenomena: fluid dynamics, crystal nucleation and growth, evaporation, and resulting film morphology. To optimize the process and consistently produce high-quality films, the synergy of these concurrent phenomena must be further investigated. To address the limited knowledge in how the fluid dynamics during processing could impact crystallization, we utilize a novel simulation technique to probe the early stages of crystal nucleation and growth in the presence of a flowing Newtonian fluid. The technique, known as the Hydrodynamic Structural Phase Field Crystal (HXPFC) method, is a grid-based method that represents crystallizing colloidal particles interacting via attractive hard-sphere potentials. Direct access to thermodynamic quantities, such as the chemical potential and free energy, is one of the greatest strengths of the method. By extending the free energy functional, other thermodynamic potentials, such as the entropy, can also be probed. Fundamental nucleation behavior is first recovered to connect the mesoscopic level crystallization behaviors to the atomic level encountered during perovskite crystallization. Then, various scenarios, governed by the HXPFC dimensionless parameters, are analyzed to draw conclusions that are applicable to full-scale processing. In addition, the energetic and entropic contributions to early-stage crystallization are probed as the velocity is increased.