Preparation Of Nano-composite Oxides And Applied Research

Nano-CuFe2O4 was prepared by solution combustion method. The optimal preparation conditions were explored, including the ratio of reductant to oxidant (Cit/NO3), calcination temperature; in order to enhance the dispersity dispersion and specific surface area, inorganic salt was introduced as dispersant. The product with good distribution was prepared via salt-assisted solution combustion method. And the crystal structure, particle size, specific surface area of the samples, respectively, are analyzed by Infrared spectroscopy (IR), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Brunnauer Emmet Teller(BET).The results showed that the nano composite oxide was a new material through the complex process of crystal change; not a simple physical mixture. The nanocrystal composite oxides had good dispersity with an average diameter about 15nm and their surface areas were close to or more than 100m2/g at at the optimal reaction conditions (Cit/NO3=5/8, Tcal.=400℃,KC1/M=1)Functional composite particles (CuFe2O/AP,NiFe2O4/AP and CoFe2O4/AP) were prepared by grinding method. The influence of nano-composite oxides on catalyzing AP thermal decomposition was measured by DTA method. The results showed that the three nano-composite oxides all had significant catalytic effects on thermal decomposition of ammonium perchlorate so that the low temperature decomposition peak and the high temperature decomposition peak were almost coincident, as well as the apparent decomposition heat was also notably improved. Among the three nano-composite oxides, copper ferrite (CuFe2O4) had the best catalytic effect which made the high-temperature exothermic peak be advanced to 297℃, and the decomposition activation energy be decreased significantly. The results also showed that composite oxides were better than the corresponding single oxides in terms of the catalytic effects on the thermal decomposition of AP. Comparison of catalytic effects:CuFe2O4>CoFe2O4>NiFe2O4.The reaserch of nano-composite oxides for catalyzing RDX thermal decomposition was measured by DTA method, the result show that the three nano-composite oxides all had notable influence. Among the three nano-composite oxides, copper ferrite (CuFe2O4) had the best catalytic effect, and the peak temperature of thermal decomposition of RDX shift 23℃downward, the well catalytic effects had been show.