Fabrication of conducting polyaniline-multiwalled carbon nanotube nanocomposites and their use as templates for loading gold nanoparticles

A new and effective route to synthesize conducting polyaniline-multiwalled carbon nanotube (PANI -f-MWNT) nanocomposites (where 'f' denotes that the MWNTs have been functionalized) starting with amine-protected 4-aminophenol is reported. Aminophenol-functionalized MWNTs were initially synthesized by functionalizing acyl chloride-terminated nanotubes with N-(tert-butoxycarbonyl)-4-aminophenol followed by the in situ chemical oxidative grafting of aniline in the presence of ammonium persulfate as an oxidizing agent. Control of the morphology and thickness of the polymer-MWNT nanocomposites was achieved by varying the weight ratios of aniline monomers and MWNTs in the polymerization process. Fourier transform infrared spectroscopy was employed to characterize the initial changes in surface functionalities which also confirmed that PANI was covalently grafted to the MWNTs. Electron microscopy and UV-visible absorption spectroscopy were employed to characterize the morphology and chemical structure of the resulting hybrids. The results obtained indicate that the structure of the MWNTs was not perturbed by the incorporation of PANI. The content of the polymer in the nanocomposites was determined thermogravimetrically, while the electrical conductivity was obtained using four-probe measurements. The PANI -f-MWNT nanocomposites were adopted as templates for further decoration with gold nanoparticles in solution, thus opening new possibilities for their prospective technological applications