Polyaniline And Its Derivatives Hollow Structure Of The Controllable Synthesis And Applications In Catalysis, Adsorption

As one of the conducting polymer, PANI has been investigated due to their special advantages. Scientists take more attention to the nanostructure of PANI, such as nanopaticle, nanowire, nanopalte and nanosphere, etc. Except for the properties of conducting polymer, PANI also has parcial potential due to their nanoinches and morphology. Rencently, some articles report the use of PANI on the adsorption, catalys, electrodes and biology sensors. However, the reports are seldom, that is about the effect of the morphology on the applied potential. Therefore, in this article, we obtain the poly(o-phenylenediamine) hollow and solid microspheres, PANI one-dimention hollow nanotubes and there-dimention microspheres by chemical oxidation. Base on this structure, we can synthes metal catalyst and adsorbent, which is of great value in the future. The main results are as follows:(1) Two kinds of different-shaped poly(o-phenylenediamine)(PoPD) polymer:solid sub-microspheres and hollow sub-microspheres with opening in each surface with both size of about700nm synthesized by a simple chemical polymerization solution route without any additional directing agents, were employed as efficient adsorbents for removal of Pb(â…¡) ions from water. Firstly, chemical structures of PoPD sub-microspheres were characterized by Fourier-transform infrared (FT-IR), Uv-vis,1H NMR spectra, and X-ray diffraction (XRD) patterns. When used as adsorbents, both PoPD hollow and solid sub-microspheres showed high adsorptivity and adsorption capacity towards Pb(â…¡) ions in water, and mechanisms of adsorption behaviors were revealed by XRD and X-ray photoelectron spectra (XPS). PoPD hollow sub-microspheres also showed good adsorptivity for other heavy-metal ions, such as Hg(â…¡), Cd(â…¡) and Cu(â…¡), which implies their potential applications as effective adsorbents for heavy-metal ions in water. (2) A large area of well-defined and individual polyaniline (PANI) nanotubes have been synthesized by the oxidative polymerization of aniline in the presence of low-concentration cationic surfactant cetyltrimethylammonium bromide (CTAB). By changing the concentration of CTAB, the molar ratio of aniline to APS, the irregular and smooth nanotubes can be obtained. PANI/Au composits can be synthesised by adding HAuCl4to the aqueous solution with PANI nanotube.Control over the size of noble metal nanoparticles, typical Au nanoparticles, that uniformly supported on PANI nanotubes had been realized by introducing a functional doping acid as additional stabilizer. In addition, PANI nanotube/Au nanoparticle composites were found to serve as effective catalysts to activate the reduction of4-nitrophenol (4NP) in the presence of NaBH4, and effect of catalyst size on catalytic activity was also investigated.(3) With the doping effect of citric acid, a novel porous polyaniline microsphere can be synthesyed by HAuCl4oxidation in aqueous solution. Different concentration of citric acid can affect the morphology of the PANI, as well as the molar ratio of aniline and HAuCl4After the discussion of the morphology changing with time, the formation mechanism of the porous microspheres can be proposed.