Self-Propagation Low Temperature Flameless Combustion Synthesis of Ni and Al Nanoparticles: Time-Resolved XRD Study

Abstract

The combustion of cellulose nitrate (NC) in ballasted mixtures containing an organic binder and nickel hydroxycarbonate (NiOHCO3) or silver carbonate (Ag2CO3) as precursors has been found to produce Ni or Ag nanoparticles. Formation of Ni and Ag nanoparticles in the wave of flameless combustion of NC was monitored by the time-resolved X-Ray diffraction (TRXRD) method. During the formation of the Ag nanoparticles, the diffraction patterns exhibited only signals from decreasing amounts of the precursor and newly simultaneously formed 20-30 nm silver particles. It has been detected that in the systems with NiOHCO3 the formation of the Ni 5-10 nm crystals proceeded via some 2-3 seconds diffraction-silent intermediate state of the whole system.