Fig. 2: Multi-stage annealing protocol produces stable particles of programmable size.

a Hydrodynamic radius R_H of protected particles with displaceable and non-displaceable corona (see Fig. 3a) as measured as a function of growth time t_g using differential dynamic microscopy (DDM) (Bottom). Particle size can be prescribed by tuning t_g. Data are shown as mean ± standard deviation calculated over 3 (non-displaceable) and 4 (displaceable) independent repeats, each point representing the R_H value depicted in panel (b) at the delay time of 60 min. Dashed lines are fits to a diffusion-reaction growth model (see Supplementary Discussion 1). (Top) Bright-field snapshots from the videos used in the DDM analysis, showing visibly larger aggregates for increasing t_g. Contrast has been enhanced to enable visualization. Scale bars 5 μm. b Time dependence of R_H in protected particles with displaceable and non-displaceable corona as measured with DDM at room temperature. Data are shown as mean ± standard deviation as in panel (a). A limited increase in size is observed, demonstrating particle stability against coalescence. Supplementary Fig. 7 proves longer-term particle stability. c TEM micrographs of protected particles assembled at two different t_g values. Selected micrographs represent data obtained in a single experiment. Scale bars 200 nm. d Confocal micrograph of a large aggregate assembled via a slow quenching protocol (see Methods), highlighting the core–shell structure. Scale bar 2 μm. e Confocal micrograph of a core–shell aggregate displaying polyhedral morphology, indicative of an underlying crystalline structure of the aggregate core, as previously demonstrated with other C-star designs^35,36,37. Crystallization was achieved through slow cooling at −0.01 ^∘C min⁻¹ (see Methods). Scale bar 2 μm. In (d) and (e) core motifs are labeled with fluorescein (cyan) and outer corona motifs with Alexa Fluor 647 (red). For both (d) and (e) image acquisition was performed twice independently.