Preparation of polyaniline/TiO2 hybrid microwires in the microchannels of a template

Polyaniline (PANI)/TiO2 hybrid microwires with diameter of 160-180 nm were prepared through the sol-gel process of TiO2 and in situ polymerization of aniline in the microchannels of anodic aluminum oxide (AAO) template. The structure, morphology and properties of the microwires were characterized with scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), fluorescence spectroscopy (FL), ultraviolet-visible spectroscopy (UV-vis) and X-ray photoelectron spectroscopy (XPS). The results show that the regular arrangement of microwires, with well-dispersed inorganic phase in the organic matrix is formed. Also, the shape of the hybrid microwires is similar to that of the template channel and the diameter of microwires is smaller than that of the template channels due to the shrinkage of volume during the sol-gel process. XPS analysis confirms that there are a lot of leftover OH groups in the hybrid system owing to the lower treatment temperature of TiO2 gel and interactions between PANI and TiO2, which is consistent with the results of UV-vis and FL analysis. The XRD data confirms that no obvious diffraction peak is observed in hybrid microwires at the reported treatment temperature (180 degrees C). FL spectra shows that the interaction and energy band match between PANI and TiO2 cause in the blue shift of the emission peaks of hybrid microwires. It is obvious that with the applied approach, the organic/inorganic hybrid materials with slight phase separation, equable distribution, well-ordered structure and unique function can be prepared easily. (c) 2007 Elsevier B.V. All rights reserved.