Ultrasound and ionic-liquid-assisted synthesis and characterization of polyaniline/Y2O3 nanocomposite with controlled conductivity.

A sonochemical method has been employed to prepare polyaniline-Y(2)O(3) nanocomposite with controlled conductivity with the assistance of an ionic liquid (IL). Ultrasound energy and the IL replace conventional oxidants and metal complexes in promoting the polymerization of aniline monomer for the first time. Structural characterization has revealed that the resulting nanocomposite consists of microspheres of average diameter 3-5 microm. The products were found to consist of regular solid microspheres covered with some 40 nm nanoparticles. Under certain polymerization conditions, polyaniline nanofibers and nanosheet were obtained. The method may open a new pathway for the preparation of nanoscale conducting polymer nanocomposites with the aid of ILs. The conductivity of the product varies with the mass ratio of aniline monomer to Y(2)O(3) and IL. TG curves of the products suggest that the thermal degradation process of the PANI/Y(2)O(3) composites proceeds in two steps and that the composites are more thermally stable than pure PANI. The reaction conditions have been optimized by varying parameters such as the aniline/Y(2)O(3) ratio and the type and amount of IL used. The effect of the ultrasonic irritation time and frequency on the morphology, conductivity and yield were discussed.