Preparation of CL-20 with Controllable Particle Size Using Microfluidic Technology.

As a typical high-energy-density material, the sensitivity of CL-20 severely limits its application in explosives and propellants. Adjusting its structure at the microscopic level can effectively solve such problems. In this study, a microfluidic recrystallization technique was used to prepare ε-CL-20 with three different particle sizes, with narrow particle size distributions (D50 = 2.77 μm, 17.22 μm and 50.35 μm). The prepared samples had fewer surface defects compared to the raw material. As the particle size decreased, the density of CL-20 increased and its impact sensitivity was significantly reduced. The activation energy of the CL-20 prepared using microfluidic technology increased with increases in particle size. Laser ignition experiments revealed that smaller CL-20 particles had the highest energy release efficiency, while larger particles exhibited a higher energy density and more stable energy release. The combustion performance and safety of CL-20 can be effectively improved by improving the crystal size distribution and surface morphology. Controllable preparation of multiple particle sizes of CL-20 was achieved using microfluidic recrystallization technology, which provides a reference for the preparation of multiple particle sizes of other energetic materials.