Ultrasonic approach to the synthesis of HMX@TATB core–shell microparticles with improved mechanical sensitivity

To improve the safety of sensitive explosive HMX while maintaining explosion performance, a moderately powerful but insensitive explosive TATB was used to coat HMX microparticles via a facile ultrasonic method. By using Estane as surface modifier and nano-sized TATB as the shell layer, the HMX@TATB core–shell microparticles with a monodisperse size and compact shell structure were successfully constructed. Both scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) results confirmed the formation of perfect core–shell structured composites. Based on a systematic and comparative study of the effect of experimental conditions, a possible formation mechanism of core–shell structure was proposed in detail. Moreover, the perfect core–shell HMX@TATB microparticles exhibited a unique thermal behavior and significantly improved mechanical sensitivity compared with that of the physical mixture.