Continuous flow resonance acoustic mixing technology: a novel and efficient strategy for preparation of nano energetic materials

Recently, microfluidic technology has been widely applied to the preparation of nano-energetic materials. The mixing efficiency of fluid is one of the significant factors which could affect the particle size and particle size distribution (PSD) of products. In this report, a novel strategy to enhance the mixing performance of fluid is developed by combining continuous flow microfluidic and resonant acoustic mixing (RAM) technologies. The results of the fluid visualization and 3D-Computational fluid dynamics (CFD) simulation showed that the new continuous flow resonance acoustic mixing (CFRAM) technology has better mixing efficiency than the traditional microfluidic approach. To demonstrate the utility of this CFRAM technology, it was implemented in the continuous preparation of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) nanoparticles. Compared with previous reported results, nano TATB prepared by CFRAM technology has a smaller average particle size (D50 = 50.8 nm) and a narrower particle size distribution (D10 = 33.0 nm; D90 = 69.6 nm). The XRD spectrum shows that the crystal structure of nano TATB has not changed. DSC test results show that the apparent activation energy of nano TATB is 177.8 kJ/mol, which is 6.5 kJ/mol lower than the raw TATB, and has good thermal stability. We expect that this strategy may open a new avenue for the efficient preparation of nano energetic materials with narrow PSD.