Barium aluminate (BaAl2O4) spinel nanoparticles were prepared by a reverse micelle method using micro-reactors made of different nonionic surfactants (Span 20, Span 40 and Span 60) in a nonpolar solvent benzene. The synthesized nanomaterials were characterized by X-ray diffraction (XRD) technique. The morphology of the synthesized materials was studied by field emission scanning electron microscope (FESEM). Particle size was estimated by XRD and transmission electron microscope (TEM) with using software of ImageJ. The effect of different surfactants on the particles size and morphology was determined. The results revealed, that particle size was increased by decreasing HLB (Hydrophilic-Lipophilic Balance) of surfactants and also particle size was increased from 23 to 35 nm. HLB of surfactants is a major factor in controlling the final particles size of BaAl2O4 powder. The X-ray powder diffraction analysis indicated, all the formation of hexagonal phase on calcinations. Dislocation of peaks (2θ) in XRD with decreasing HLB of surfactant was decreased slightly.

Keywords: Barium aluminate, Reverse micelle, Nanoparticle, Span 20, 40 and 60, X-ray diffraction, Hydrophilic-lipophilic balance