Synthesis of hollow platelet polymer particles by spontaneous precision fragmentation

The creation of anisotropic core–shell nanoparticles using the living crystallization-driven self-assembly method results in colloidally stable solid particles. The fragmentation or degradation of crystallization-driven self-assembly nanomaterials is currently accessible only when intensive external stimuli are exerted. Controlling the stability of the crystalized core material may also allow structural evolution and fragmentation to be achieved. Here we report that two-dimensional (2D) platelets containing less stable domains specifically fragment upon ageing, providing a simple method to create hollow platelet polymer particles in one step. Mechanistic studies reveal that a high concentration of low-molecular-weight homopolymer in 2D platelet that crystallizes at low temperatures results in less stable domains, which fragment upon ageing. To illustrate the utility of spontaneous fragmentation, spatially selective fragmentation of 2D segmented platelets is used to prepare 2D hollow platelets that are usually inaccessible from a thermodynamic process.