Preparation and evaluation of photocatalytic activity of poly(dimethylsiloxane)–titanium dioxide composites

Abstract

The poly(dimethylsiloxane)–titanium dioxide (PDMS–TiO₂) composites were prepared by emulsion polymerisation of octamethylcyloteterasiloxane (D₄) in the presence of TiO₂ particles modified by [γ-(methacryloxy)-propyl] trimethoxysilane (γ-MPS). The structure of the prepared PDMS–TiO₂ composites was characterised by fourier transform infrared (FTIR) spectra, thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The results show that PDMS is grafted onto the surface of TiO₂ particles via γ-MPS. The photocatalytic activity of PDMS–TiO₂ composites was evaluated by decomposition of methyl orange (MeO). The result indicates that PDMS–TiO₂ composite is one kind of efficient catalyst for MeO decomposition and the decomposition rate constant of MeO for PDMS–TiO₂ composite is ∼3 times of that for TiO₂. UV-vis diffuse reflectance spectra measurements show that the absorbance of PDMS–TiO₂ composites is higher than that of TiO₂ in the visible light range.

Keywords:

• PDMS-TIO2 COMPOSITES
• PREPARATION
• PHOTOCATALYTIC ACTIVITY
• METHYL ORANGE