Compositional analysis of organic–inorganic semiconductor composites

Abstract

Compositional analysis of composite powders containing organic and inorganic semiconductor components was performed by thermogravimetric analysis (TGA). Two model composites, consisting of poly(aniline) (PAN) as the matrix and either WO₃ or TiO₂ particles dispersed therein, were used to illustrate the analytical methodology. In both cases, the oxide semiconductor component asymptotically approached a saturation level in the composite, as the initial medium content was varied from 0 to 120 mg (per 15 ml). Chemical polymerization was used to prepare the PAN–WO₃ and PAN–TiO₂ composites. Cyclic voltammetric data mainly reflect the PAN component in the composite although voltammograms acquired under chopped illumination of the working electrode reveal the photoactivity of the oxide component. The TGA data were linearly correlated with compositional assays as performed by laser Raman spectroscopy for the PAN–WO₃ case . The relative analytical merits of the two techniques for the analysis of composite samples are discussed.