Congratulations to Dr. Zizhao (Will) Wang on Successfully Defending His PhD Dissertation!

Congratulations to Dr. Zizhao (Will) Wang on Successfully Defending His PhD Dissertation!

May 29, 2025

We are excited to announce that Zizhao (Will) Wang has successfully defended his doctoral dissertation entitled “Homogeneous Nucleation of Nearly Hard-sphere Colloidal Crystals from the Liquid: Measurements and Modeling” at Harvard University’s School of Engineering and Applied Sciences.

Under the guidance of advisors Professors Frans Spaepen and David A. Weitz, Will’s work addresses a long-standing fundamental challenge in condensed matter physics: resolving the discrepancies between theoretical predictions and experimental measurements of homogeneous nucleation rates in hard-sphere colloidal systems.

Utilizing advanced confocal microscopy combined with large-scale Brownian dynamics simulations, Will’s research provides the first direct 3D observations and quantitative comparisons of nucleation phenomena in nearly hard-sphere colloids. His measurements of critical nucleus size, interfacial energy, and nucleation rates exhibit remarkable agreement with simulations, validating Classical Nucleation Theory without the need for enhanced sampling techniques.

Additionally, Will uncovered a novel nucleation pathway characterized by branched crystal structures during early growth stages—offering new insights into the kinetics of crystal formation and explaining previously observed rate discrepancies near melting conditions.

This comprehensive study sets a new benchmark for quantitative testing of fundamental theories of phase transitions and offers valuable guidance for future research in soft condensed matter and materials science.