Thermally programmed disassembly and reconstruction of 2D polymer platelets via melting-governed crystallization-driven self-assembly

Crystallization-driven self-assembly (CDSA) has emerged as a powerful methodology to precisely control the morphology and size of polymer nanostructures, enabling the formation of 1D and 2D nanomaterials. Yet, the melting behavior of polymer crystals grown in solution using this technique has remained largely unexplored. Here, we show that melting temperature is a structurally sensitive descriptor and an active design parameter for 2D poly(ε-caprolactone) platelets formed by seeded living CDSA. Using nano differential scanning calorimetry, we establish quantitative thickness-melting correlations consistent with Gibbs-Thomson theory for finite, solution-grown lamellae. Leveraging these insights, we engineer multilayer platelets with programmed thermal stability gradients that undergo rapid, selective disassembly under mild conditions (37 °C), yielding uniform hollow architectures within minutes. Upon cooling, released polymer chains undergo spatially confined recrystallization, allowing reversible reconstruction and self-healing of the platelet framework. This work establishes melting as a powerful thermodynamic handle for probing and reconfiguring CDSA-derived nanostructures in solution.