Discover the Fascinating World of Crystal Nucleation: A Cutting-Edge Confocal Microscopy Investigation on Colloidal Hard Sphere Systems

Abstract

This research study focuses on the experimental evolution of the crystallization process in colloidal hard spheres using advanced techniques such as confocal microscopy and image analysis. The colloidal system used in this study is a fluorescently labeled PMMA-PHSA system, where the particles have been precisely characterized in terms of size, mass density, and refractive index. The research highlights the importance of suppressing heterogeneous nucleation, which is achieved through careful sample cell preparation, including coating the sidewalls and base of the sample cell. Confocal microscopy is used to study the structure and dynamics of the colloidal suspension in three dimensions, providing detailed information about the system's behavior. The study also focuses on image analysis techniques to accurately determine particle positions and local structures at the single-particle level. This information is used to investigate the crystallization process in colloidal hard spheres by observing the system's structural behavior in a wide volume fraction range. The research finds that some systems exhibit hard-sphere-like behavior, while others show discrepancies. Experimental 3D radial distribution functions are modeled using analytical theory and computer simulations, considering polydispersity and experimental position uncertainty. The study also investigates the discrepancy between experimental and theoretical data in crystal nucleation rate densities. The research finds that the cause of this discrepancy is due to shortcomings of the Classical Nucleation Theory (CNT), concluding that temporal evolution of phonons is essential for the crystal nucleation process. Furthermore, the research examines the kinetics involved in the crystallization of colloidal hard spheres using CDL and TCE. Single-particle level measurements on the kinetics of three-dimensional colloidal crystallization for symmetry and density transformations are reported. The study identifies the kinetics during the transition process and sheds light on the dynamics involved during crystallization.