This work improves our understanding of detonation nanodiamonds. We have applied the innovated salt-assisted ultrasonic de-aggregation (SAUD) process on three commercially available ND powders (two DNDs and one LND; laser nanodiamond). By correlation of spectroscopic, microscopic, and thermal analysis techniques we revealed a size and shape inhomogeneity of primary DND particles, also affecting aggregation strength. By elemental analysis of the fractions, we also show that nitrogen content is systematically higher in the smaller primary DND particles of all three ND samples. The observed size and nitrogen inhomogeneity evidence a compositional and kinetic inhomogeneity in the reaction zone during detonation synthesis. The presented study underlines the importance of complex processing and analysis approaches to detonation nanodiamonds for a better understanding of their formation and properties.
