(555f) Multiscale Modeling and Experiments to Understand Crystallization Pathways for Trans-Stilbenes

Digital manufacturing, where we design and optimize a process in silico, can significantly reduce build/test cycles and product waste streams while ensuring rapid prototyping and agility for traditional manufacturing processes. Crystallization of organic molecules from solution, though critical to applications from consumer projects to pharmaceutical production, is still a trial-and-error process where the morphology of the product is unknown until significant laboratory testing is carried out as a function of processing variables such as temperature, temperature ramp, concentration, and seeding. While classical crystallization proceeds via nucleation-and-growth in simple systems, more complicated molecular crystallization may follow a number of nonclassical transition pathways with more complex intermediate structures such as aggregated nanoparticles or mesocrystals. In this paper, we discuss multiscale models and experiments to understand solution crystallization of trans-Stilbenes, namely resveratrol (3,5,4’-trihydroxy-trans-stilbene), a prototypical trans-stilbene molecule with pharmaceutical interest due to its antioxidant and antimicrobial properties. We examine complex crystal growth and surface kinetics in resveratrol with a number of computational and experimental methods. Computationally, we will first introduce (1) a coarse-graining approach for trans-stilbene geometries to implement crystal growth models in on-lattice kinetic Monte Carlo and (2) associated software development in the Stochastic Parallel PARticle Kinetic Simulator (SPPARKS) package. We also present a computational fluid dynamics model of a crystallizer coupled to a population balance equation to predict crystal size distribution as a function of time and space. Finally, single crystal studies of resveratrol growth are studied using microscopy. Early results show that in favorable solvent systems, such as water and ethanol, needle-like crystal morphologies are formed similar to what is seen in the kinetic Monte-Carlo models.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.