Incorporation of titanium dioxide particles into polymer matrix using block copolymer micelles for fabrication of high refractive and transparent organic–inorganic hybrid materials

Abstract

AbstractWe report a novel strategy for incorporation of titanium dioxide (TiO2) particles into poly(methyl methacrylate) (PMMA) to exploit high refractive and transparent organic–inorganic hybrid materials. Formation of TiO2 particles of around 20 nm was conducted within hydrophilic core of block copolymer micelles of poly(methyl methacrylate‐block‐acrylic acid) (PMMA‐b‐PAA) in toluene via sol–gel process from titanium isopropoxide and hydrochloric acid. Subsequently, incorporation of TiO2 particles into PMMA matrix was carried out by casting toluene solution of TiO2 precursor‐loaded copolymer micelles, prepared from PMMA350‐b‐PAA93 and the precursor of mole ratio Ti4+/carboxyl 4.0, and PMMA. Hybrid films of TiO2/PMMA exhibited high transparency to achieve transmission over 87% at 500 nm at 30 wt % of TiO2 content. The refractive index of resulting hybrid films at 633 nm linearly increased with TiO2 content to attain 1.579 at 30 wt % TiO2, which was 0.1 higher than that of PMMA. Cross‐sectional transmission electron microscope images of TiO2/PMMA hybrid films showed existence of TiO2 clusters less than 100 nm, which were probably formed by aggregation or agglutination of TiO2 particles during a drying process. It was also observed that decomposition temperature of the hybrid films elevated with increasing TiO2 content. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011