Mixture of fuels approach for solution combustion synthesis of nanoscale MgAl2O4 powders

Nanoscale MgAl2O4 powders were synthesized via a microwave-assisted solution combustion process using various mixtures of urea, glycine and starch as fuel. The effects of starch addition on characteristics (e.g. specific surface area and crystallite size) of the as-resulted powders were also investigated. The experimental results revealed that the specific surface area of the powders was significantly increased as the starch content rose from 0 to 35.6 wt.%, followed by a slight decrease when it was further raised to 54.7 wt.%. The scanning electron microscope micrographs disclosed that starch addition also affected the morphology of porous nanoparticles’ agglomerates and was remarkably beneficial to dissipate the as-produced nanoparticles. Higher degree of dissipation and larger specific surface area of the powders resulted from starch addition were mainly attributed to a larger amount of gases evolved during combustion and/or lower combustion temperature.