Microfluidic strategy for rapid and high-quality control of crystal morphology of explosives

The crystal morphology of explosives has a great influence on their detonation performance and safety. In order to realize the crystal morphology control of explosives, a new strategy based on microfluidics was proposed. The new strategy consisting of morphology predictions and microfluidic verification experiments has the characteristics of excellent accuracy, less sample consumption, and fast verification. The shapes and sizes of explosives were predicted by simulations and theoretical analysis with different solvents, respectively. Considering an ideal crystallization environment for verification experiments, the parameters of the microfluidic platform were optimized. Under the optimal parameters, the verification experiments were conducted using a microfluidic platform. Here, we used hexanitrohexaazaisowurtzitane (HNIW, also known as CL-20) as a sample to study the applicability of the new strategy for crystal morphology control of explosives. The optimized flow rate ratio and number of chambers were adapted to the verification experiments. It was found that the thicknesses of HNIW have positive correlation with the polarities of the solvents and the sizes have negative correlation with the concentrations, which is in line with predictions. This study demonstrates the feasibility of an efficient, accurate strategy to realize the crystal morphology control of explosives based on a microfluidic platform.