This indeed favors a highly uniform product. The scanning electron microscopy (SEM) images in Figure suggest that the obtained PBFS polymer nanospheres show good colloid stability and uniformity in particle sizes (for dynamic light scattering data, see SI Figure S2). Interestingly, self-assembled periodic structures with close-packed planes arranged along the (111) direction are observed, indicating a good monodispersity of the obtained polymer nanospheres.