Preparation and Characterizations of Tantalum Pentoxide (Ta2O5) Nanoparticles and UV-Curable Ta2O5-Acrylic Nanocomposites

Tantalum pentoxide (Ta2O5) nanoparticles with the sizes in the range of 20-50 nm were prepared via a chemical route in which the oleic acid (OLEA) was adopted as the surfactant for the synthesis process. X-ray diffraction (XRD) revealed the as-synthesized Ta2O5 transforms from amorphous to hexagonal and ortho-rhombic structures at the temperatures of 700 degrees C and 750 degrees C, respectively, illustrating the suppression of recrystallization temperature of Ta2O5 due to the particle size reduction. UV-curable nanocomposites containing the Ta2O5 nanoparticles and acrylic matrix were also prepared. Thermogravimetry analysis (TGA) found an about 10-20 degrees C improvement on the 5% weight-loss thermal decomposition temperatures (T(d)s). Dielectric measurement showed that the dielectric constant of nanocomposite increases with the increase in the filler loading without severe deterioration of dielectric loss. The increment of dielectric constants was ascribed to the addition of high-dielectric inorganic fillers as well as the presence of interfacial polarization at the organic/inorganic interfaces. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 1252-1259, 2010