Improved pressure discharge property of surface modified Al/Bi₂O₃ composites

Al/Bi₂O₃ nanothermites were prepared via a self-assembly method using poly-4-vinylpyridine and surface modification of particles by a kind of binder oleic acid respectively. The structures, morphology, and energetic properties were characterized. The pressure discharge properties were studied by a closed bomb. The peak pressures and pressurization rates of Al/Bi₂O₃/P4VP and Al/Bi₂O₃/OA were 5590 kPa, 13.976 GPa s^–1 and 4858 kPa, 12.146 GPa s^–1, respectively, better than those of Al/Bi₂O₃ prepared by normal ultrasonic method (4559 kPa, 11.397 GPa s^–1). However, the decreased ignition delay time for self-assembled method and the increased one for modifying with oleic acid suggested different mechanism in accelerating the reaction of Al/Bi₂O₃. Moreover, the effect of mass fraction of oleic acid on nanothermite reaction was demonstrated.