Fabrication of microspherical Hexanitrostilbene (HNS) with droplet microfluidic technology

Spherical explosives had regular shape and smooth surface, which gave them low sensitivity, excellent flowability, and high bulk density, thereby yield good charging performance. Traditional spherization methods always resulted in irregular shape, low sphericity, and uneven size. In this paper, a novel droplet microfluidic technology was used to fabricate hexanitrostilbene (HNS) microspherical with nitrocellulose (NC) as adhesive. The farication process (e. g., HNS concentration, NC concentration, flow rate) was fully investigated in pursuing for the ideal farication condition. The chemical structures, crystalline structures, and thermal stability of HNS were preserved. Meanwhile, the flowability and bulk density of HNS microspheres were significantly improved (Repose angle: HNS microsphere vs raw HNS, 33.1 vs 39.2°; bulk density: HNS microsphere vs raw HNS, 0.466 vs 0.301 g cm−3), which enhanced the charging and pressing performance of HNS. [Display omitted] •Droplet microfluidics was firstly used for the spheroidization of HNS.•HNS microspheres with arrow size distribution were successfully synthesized.•The flowability of HNS microspheres were superior to that of raw HNS.•This work provided a novel method for the spheroidization of explosives.