Chemical Synthesis and Characterization of Highly Oil Dispersed MgO Nanoparticles

Abstract

Preparation of highly oil dispersed MgO nanoparticles (NPs) was carried out at room temperature via precipitation of Mg(OH)2 from aqueous media using Mg(NO3)2 as a starting precursor and NaOH as a precipitant. The Mg(OH)2 precursor was converted into MgO particles having face-centered cubic structures through calcination treatment in air at 500 o C for 4 h. The freshly calcined material had a high specific surface area (91.4 m 2 /g). An SEM study revealed the presence of nanoparticles of spherical shape (20~50 nm). The NPs of MgO remained dispersed in oil through the capping action of oleic acid after heating them under reflux at 160 o C in organic solvent. An IR study indicated the presence of hydroxyl (OH - ) groups at the surface of the MgO particles; these units interact with the carboxylate groups of oleic acid molecules to cap the MgO particles and, thus, to help disperse them in a given solvent. The results are quite reproducible and the dispersion stability was maintained for long durations.