Ultrasonically initiated, in situ emulsion polymerization was used to prepare multiwalled carbon nanotube/polyaniline composites (MWNTs/PANI). Transmission electron microscopy (TEM) showed that the nanotubes were coated with a PANI layer, with the thickness of this coating varying with the content of carbon nanotubes and polymerization conditions. Whereas polyaniline/carbon nanotube composite particles prepared by the conventional stirring method have a highly structured, nodular morphology, ultrasonic initiation leads to long, thin, polymer-wrapped tubes. In the case of ultrasonically initiated in situ emulsion polymerization, Fourier transform infrared (FTIR) spectra suggested that siteselective interactions between the quinoid ring of the PANI and the MWNTs facilitate charge-transfer between the two components. In such composites, CNT improved the polymer properties, such as thermal stability, as determined by thermogravimetric analysis and conductivity measured using the four-probe method.

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New oxadiazole-based polymeric materials have been synthesized either as side chain copolymers with polymethacrylate or as main chain copolymers carrying solubilizing elements such as hexafluoropropylidene or meta-linked aromatic spacer units. Many of these materials exhibit blue luminescence in the solid state. The materials have been evaluated by photoluminescence and cyclic voltammetry studies, and as the electron transporting layer in a two-layer electroluminescent device with poly(p-phenylenevinylene) (PPV) as the emissive layer. The major conclusion is that these materials function by providing large heterojunction offsets at the Highest Occupied Molecular Orbital (HOMO) which block the passage of holes through the device.

Polypyrrole (Ppy) was prepared by a photoelectropolymerization technique using different current densities on Ru-dye sensitized titanium dioxide nanoporous films. Solar cells were constructed using gold as the counter electrode with Ppy acting as the hole conductor and current–voltage characteristics were measured revealing initial efficiencies of 0.06%. Time–current profiles and x-ray photoelectron data confirmed that Ppy growth occurs within the TiO2 pores and not at the extreme surface. Efficiency measurements of solar cells increased over one month and stabilized to nearly 1% this phenomenon being attributed to the intercalation of Li+ ions during the preparation step, which involved a dedoping process at a reduced potential and a soaking in LiClO4 solution.

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