Spaepen, FransWeitz, DavidWang, Zizhao2026-07-0720252025-11-202025Wang, Zizhao. 2025. Homogeneous Nucleation of Nearly-hard-sphere Colloidal Crystals from the Liquid: Measurements and Modeling. Doctoral Dissertation, Harvard University Graduate School of Arts and Sciences.32241017https://dash.harvard.edu/handle/1/42744054Understanding crystal nucleation in colloidal systems remains fundamentally challenging de- spite decades of research, with persistent discrepancies between experimental measurements and theoretical predictions. Using confocal microscopy, we directly observe homogeneous crystal nucleation in nearly hard-sphere colloids and compare this results with Brownian dynam- ics simulations. Our measurements of critical nucleus size, interfacial energy, and nucleation rates demonstrate excellent agreement between experiment and simulation, validating Classical Nucle- ation Theory (CNT) without requiring enhanced sampling techniques. Moreover, crystal morphol- ogy analyzes reveal a branched crystal phase before transitioning to compact spherical nuclei, which is different from the CNT assumption10. Our findings resolve long-standing nucleation rate dis- crepancies in this system while highlighting that experimental approaches currently provide a wider data window than computationally practical simulations, especially for rare nucleation events near melting conditions.application/pdfenPhysicsThesis or Dissertation2026-07-070000-0001-7116-5222