Preparation, optimization and properties of FOX-7@Al microparticles via spray drying

In this laboratory, FOX-7@Al composites were developed by spray-drying technique. The effects of inlet temperature, feed rate and nitrogen flow rate and their interactions on the morphology and yield of FOX-7@Al were investigated by response surface methodology (RSM). Corresponding empirical equations were derived to show these interactions. The optimum process conditions determined by RSM were as follows: inlet temperature of 90°C, nitrogen flow rate of 450 L·h−1 and feed rate of 4.25 mL·min−1. The crystal structure, surface element distribution and thermal decomposition performance of FOX-7@Al in optimal condition were researched. Small crystallinity and low crystallinity of FOX-7 were observed in the XRD pattern, which were caused by the recrystallization of FOX-7 during the spray drying process. FOX-7@Al exhibited a concentrated energy release efficiency and a uniformed component distribution. The surface of aluminum nanoparticle was covered by FOX-7 and Viton, which effectively suppressed the agglomeration of aluminum nanoparticles and enhanced the heat and mass transfer properties. The work present here not only gives information for predicting, optimizing and improving the preparation conditions of energetic composites, but also provides a spray drying method for dealing with the materials distribution and thermal decomposition performance of composite aluminized explosives.