Obtaining A Unified Picture of Heterogeneous and Homogeneous Crystallization with Kinetic Transition Rate

Abstract Heterogeneous and homogeneous crystallization exhibit distinct phase transition kinetics. However, due to the difficulty of realizing both heterogeneous and homogeneous crystallization under an identical thermodynamic condition, an independent comparison of the two remains lacking. In this work, we experimentally realize a continuous tuning from heterogeneous to homogeneous crystallization under an identical thermodynamic condition, capture the entire colloidal crystallization process of each particle, and discover a universal picture of the two modes. In the heterogeneous crystallization regime, we reveal an unexpected variation of critical nucleus size with boundary disorderness instead of contact angle, which violates the classical nucleation theory but enables the system tuning. Moreover, analogous to reaction rates in chemical reactions, we propose and measure the kinetic transition rates of crystallization, which quantify the transition probabilities between any two intermediate structures. To our surprise, regardless of heterogeneous or homogeneous crystallization, all 42 kinetic transition rates fall onto universal master curves, which unifies the two distinct crystallization modes into a universal picture.