Passive micromixer platform for size- and shape-controllable preparation of ultrafine HNS

A passive micromixer platform, with the assistance of controllable mixing performance, was used for the preparation and morphology control of ultrafine explosives. This method is characterized by high mixing efficiency, safe and easy processing, low solvent consumption, and fast preparation and screening. The preparation of hexanitrostibene (HNS) in the micromixer platform has obvious advantages over the beaker in terms of particle size and particle size distribution. The particle size of HNS prepared in the platform ranges from 91 to 255 nm, while that of the HNS prepared in a beaker ranges from 106 to 615 nm with the same antisolvent/solvent ratio. The particle size of HNS can be controlled to about 100, 150, and 200 nm, and the crystal shape can be controlled to nanoscale, two-dimensional nanosheet, and short rod crystal. This study demonstrated the feasibility of a safe and efficient way of controlling the particle size and crystal shape of explosives.