Obtaining highly crystalline barium sulphate nanoparticles via chemical precipitation and quenching in absence of polymer stabilizers

Abstract

Here we report the synthesis of barium sulphate (BaSO 4) nanoparticles from Ba(OH) 2 /BaCl 2 solutions by a combined method of precipitation and quenching in absence of polymer stabilizers. Transmission electron microscopy (HRTEM), Fourier transforms infrared spectroscopy (FTIR), and X-ray diffraction (XRD) were employed to characterize the particles. The Scherrer formula was applied to estimate the particle size using the width of the diffraction peaks. The obtained results indicate that the synthesized material is mainly composed of nanocrystalline barite, with nearly spherical morphology, and diameters ranging from 4 to 92 nm. The lattice images of nanoparticles were clearly observed by HRTEM, indicating a high degree of crystallinity and phase purity. In addition, agglomerates with diameters between 20 and 300 nm were observed in both lattice images and dynamic light scattering measurements. The latter allowed obtaining the particle size distribution, the evolution of the aggregate size in time of BaSO 4 in aqueous solutions, and the sedimentation rate of these solutions from turbidimetry measurements. A short discussion on the possible medical applications is presented.