Real-time label-free imaging of living crystallization-driven self-assembly

Living crystallization-driven self-assembly (CDSA) of semicrystalline block copolymers is a powerful method for the bottom-up construction of uniform polymer microstructures with complex hierarchies. Improving our ability to engineer such complex particles demands a better understanding of how to precisely control the self-assembly process. Here, we apply interferometric scattering (iSCAT) microscopy to observe the real-time growth of individual poly(ε-caprolactone)-based fibers and platelets. This label-free method enables us to map the role of key reaction parameters on platelet growth rate, size, and morphology. Furthermore, iSCAT provides a contrast mechanism for studying multi-annulus platelets formed via the sequential addition of different unimers, offering insights into the spatial distribution of polymer compositions within a single platelet.