Effect of nanoparticles on the conjugated polymer in the PPV/TiO2 nanocomposites

The poly(p-phenylenevinylene) (PPV)/TiO2 nanocomposites were prepared by using the particulate sol method, and investigated in terms of the optical properties and chemical structures. When the elimination reaction of tetrahydrothiophene was done at 120 C, the conjugation length of the polymer increased with an increase of TiO2 weight fraction because of the polymer chain ordering due to TiO2 nanoparticles. In case of the elimination reaction at 200 degreesC, the conjugation length of PPV was slightly longer than that of the nanocomposites because TiO2 nanoparticles impeded the elimination reaction of tetrahydrothiophene. The enhancement of zero-phonon vibronic transition and the increase of vibronic splitting energy with an increase of TiO2 content were induced by the reduction of torsional disorder. (C) 2003 Elsevier B.V, All rights reserved.