Abstract:In order to improve the compatibility of HMX to liquid bonding agents, octogen(HMX)/TiO2 composites with reversible wettability were prepared by electrostatic deposition method and then modified by hexadecyltrimethoxysilane. The morphology, polymorph of HMX/TiO2 composites and the element content on the surface of HMX/TiO2 composites were tested by scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscope, respectively. Results show TiO2 coating with rough structure is constructed on the surface of HMX. The characteristic peaks of HMX/TiO2 composites in the XRD spectra are attributed to the β-HMX and anatase TiO2, and strong Ti2p signal appears on the XPS spectra, which further proves that TiO2 coates on the surface of HMX. The analysis of thermogravimetry-differential scanning calorimetry (TG-DSC) indicates the phase transition temperature of HMX is increased by 8.4 ℃ after coated by TiO2, and the TiO2 coating can improve the thermostability of the HMX particles. The water contact angles of HMX/TiO2 composites treated by hexadecyltrimethoxylsilane is 160.4°, which achieves superhydrophobicity. More interesting, the water contact angles turns to 0° after ultraviolet radiation for 45min, and reversed to 147.9° after dark storage at 80 ℃ for 17 d. So, reversible transformation of surface wettability of HMX/TiO2 composites is achieved.