An efficient approach to derive hydroxyl groups on the surface of barium titanate nanoparticles to improve its chemical modification ability.

Abstract Highly hydroxylated barium titanate (BaTiO 3 ) nanoparticles have been prepared via an easy and gentle approach which oxidizes BaTiO 3 nanoparticles using an aqueous solution of hydrogen peroxide (H 2 O 2 ). The hydroxylated BaTiO 3 surface reacts with sodium oleate (SOA) to form oleophilic layers that greatly enhance the dispersion of BaTiO 3 nanoparticles in organic solvents such as tetrahydrofuran, toluene, and n -octane. The results of Fourier transform infrared spectroscopy confirmed that the major functional groups on the surface of H 2 O 2 -treated BaTiO 3 nanoparticles are hydroxyl groups which are chemically active, favoring chemical bonding with SOA. The results of transmission electron microscopy of SOA-modified BaTiO 3 nanoparticles suggested that the oleate molecules were bonded to the surfaces of nanoparticles and formed a homogeneous layer having a thickness of about 2 nm. Furthermore, the improved dispersion capability of the modified BaTiO 3 nanoparticles in organic solvents was verified through analytic results of its settling and rheological behaviors.