Strontium aluminate (SrAl2O4) spinel nanoparticles were synthesized by microemulsion method using micro-reactors made of different nonionic surfactants (Span 20, Span 40 and Span 60) in a nonpolar solvent cyclohexane. 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). The average particles size was estimated by XRD and transmission electron microscope (TEM) with using software of IMAGE J. The effect of different surfactants on the particles size and morphology was determined. It was found that the average particles size was decreased by decreasing HLB (Hydrophilic-Lipophilic Balance) of surfactants and also the average particles size was decreased from 31 to 21 nm. HLB of surfactants is a major factor in controlling the final particles size of SrAl2O4 powder. Dislocation of peaks (2θ) in XRD with decreasing HLB of surfactant was decreased slightly. The XRD analysis of all the powders indicated the formation of singlephase spinel structure on calcinations.

Keywords: Strontium aluminate, Nanoparticle, Span 20, 40 and 60, X-ray diffraction, Hydrophilic-lipophilic balance of surfactant