Non-classical crystallization in slow motion: observing Pt nanocrystals forming in a polymeric matrix

In contrast to classic ion-by-ion or molecule-by-molecules crystal growth, non-classical crystallization involves complex multi-step pathways that involve nanoscale amorphous or crystalline precursors phases. While the processes are extremely relevant in biology and materials science, the typical fast kinetics inhibit studies of the underlying mechanism. We have recently established a method to obtain Pt(0) nanocrystals via mild conditions in a polymer matrix with extremely slow kinetics (few hours), and our preliminary data suggest that the process proceeds through the formation and subsequent aggregation of amorphous Pt clusters. We believe that this system represents a unique gateway into studying the details of non-classical crystallization pathways. With the use of high-brilliance small and wide-angle X-ray scattering, we aim to monitor the puzzling features of this mechanism with unprecedented spatial and temporal resolution.