Hydrothermal synthesis of organic hybrid BaTiO3 nanoparticles using a supercritical continuous flow reaction system

Barium titanate (BaTiO3 BT) nanoparticles were synthesized by the hydrothermal method in the presence of dispersants using a continuous supercritical flow reaction system The reactants of TiO2 sol/Ba(NO3)(2) mixed solution and KOH solution were used as starting materials and that was heated quickly up to 400 degrees C under the pressure of 30 MPa for 8 ms as reaction time The dispersant solution such as polyacrylic acid (PAA) and polyoxyethylene(20) sorbitan monooleate (Tween 80) was injected in the cooling process after the reaction The crystal phase of the obtained particles was identified as perovskite cubic BaTiO3 by X-ray diffractometry (XRD) and Raman spectroscopy Raman spectra and thermogravimetric data revealed that PAA and Tween 80 fabricated hybrid BT nanoparticles Primarily particle size of the BaTiO3 nanoparticle was determined by means of BET surface area as small as loss than 10 nm irrespective of dispersants In contrast dispersed particle size in solution measured by dynamic light scattering (DLS) technique decreased from 282 nm to less than 100 nm depending on the dispersant Aggregation of BaTiO3 nanoparticles might be depressed in the presence of dispersants especially PAA is the most effective among the dispersants examined (C) 2010 Elsevier BV All rights reserved