Hybrid materials based on azopolymer and sol–gel synthesized silver-containing titanium oxide nanoparticles with photoinduced birefringence

Abstract

The main goal of this work was the development of novel nanocomposite films with different optical properties. A non-toxic water soluble azopolymer was modified with TiO₂ nanoparticles and silver-containing TiO₂ nanoparticles. The thermal stability and glass transition temperature were enhanced in the silver-containing hybrid materials. Birefringence can be optically induced and erased in the azopolymer and the nanocomposites with and without silver. However, the photoorientation rate and the maximum and remaining birefringence values varied depending on the concentration of azopolymer in the nanocomposites and the presence of silver-containing nanoparticles. In nanocomposites with low concentrations of azopolymer the presence of silver in the nanocomposite films improved dramatically the induced birefringence level. Moreover, the semiconductive properties of the developed hybrid materials were studied by electrostatic force microscopy, applying both positive and negative voltages.