Synthesis of CuO nanopowders by high-energy ball-milling method and investigation of their catalytic activity on thermal decomposition of ammonium perchlorate particles

Abstract

In this research, nearly spherical CuO nanopowders (NPs) were synthesized in a high-energy ball-milling method at room temperature for different milling times (20 and 40 h) at dry medium. The structure, particle size, purity and morphology of the resulting CuO NPs were characterized by X-ray diffraction, inductively coupled plasma and scanning electron microscopy (SEM) techniques. The results showed that the NPs obtained after 40 h have the smallest particle with only 31 nm. These NPs were studied as an additive for promoting the thermal decomposition of ammonium perchlorate (AP) particles. The photographs of field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy showed that the surface of CuO NPs was successfully coated with AP particles. Also, differential scanning calorimetry (DSC) and thermogravimetry analysis (TG) techniques were used to investigate the thermal decomposition of pure and AP + CuO nanocomposites. The DSC/TG results showed that CuO NPs with 31 nm had an excellent catalytic effect on the AP thermal decomposition property and by adding 2 and 5 % additive, decomposition temperatures decreased by 81.9 and 90.4 °C, and the heat of decomposition increased by 707.6 and 839.9 J g−1, respectively. Finally, the apparent activation energy (E), ΔG #, ΔH #, ΔS # of thermal decomposition processes of pure and treated samples were obtained by non-isothermal methods proposed by Kissinger and Ozawa.