Improved combustion performance of solid propellant with sliver nanoparticle decorated Al addition

The oxide layer on the Al particle surface seriously limits application in solid propellants, resulting in low combustion efficiency. This work prepares a series of Al decorated by nano-silver (namely Al/Ag) via in-situ reduction to enhance combustion performance Thanks to silver's smaller specific heat capacity, surplus heat energy is transferred to the Al core through a tight combination with decorated noble metal nanoparticles. Along with the intermetallic reaction, the thermal stress on Al would accelerate the oxide shell rupture to reduce the oxygen gas diffusion barrier during combustion. The oxidation temperature of Al/Ag-2 composites decreases from 1017.3 °C to 982.93 °C. Hence, the combustion performance of solid propellants containing Al/Ag composites is improved with the higher maximum flame temperature and emission spectra intensity. In addition, the thermal decomposition of ammonium perchlorate (AP) is catalyzed via nano-silver. The combustion efficiency of the propellant containing Al/Ag-2 is effectively improved by the synergistic effect in which the potential energy from Al and AP is exploited as far as possible. This work demonstrates that metal surface modification significantly improves the combustion performance of solid propellants.