Studies on the Interaction of Emeraldine Base Polyaniline with Cu(II), Fe(III), and Zn(II) Ions in Solutions and Films

Abstract

The interaction of emeraldine base polyaniline (EB) with Cu(II), Fe(III), and Zn(II) in 1-methyl-2-pyrrolidinone (NMP) solution was monitored using electronic UV−vis−NIR, resonance Raman, and electron paramagnetic resonance (EPR) spectroscopies. The films prepared from these solutions were also spectroscopically characterized. It was demonstrated that the nature of the products (semiquinone and quinone segments) formed from the interaction of EB and metal ions is strongly dependent on the nature of the cation, the metal/EB molar ratio, and the concentration of the components. The presence of semiquinone segments (radical cation) in EB solutions with Cu(II) and Fe(III) was undoubtedly confirmed by the observation of an electronic absorption band at ca. 900 nm, a characteristic Raman band at ca. 1330 cm-1 (νC - N •+ ), and also an EPR signal at g = 2.006. The influences of metal/EB molar ratio and metal ion concentration on the formed species were investigated in Cu(II) and Fe(III) solutions, and it was verified that diluted solutions favor the formation of oxidized segments (pernigraniline) instead of doped ones (emeraldine salt). No matter the nature of metal ion solutions, all the polymeric films show a spectroscopic behavior of ES (doped polymer) according to electronic and Raman spectroscopic data.

Highly efficient adsorbents of poly(o-phenylenediamine) solid and hollow sub-microspheres towards lead ions: A comparative study

“…Recently, PANI has attracted considerable attention for removal of various pollutions from water due to its unique properties of easy of preparation, high environmental stability, special doping mechanisms and particular low cost. For instance, PANI or PANI composites have been employed as adsorbents for the removal of sulfonated dyes [18,19], fluoride [20,21] or transition metal salts [22,23] through doping. In particular, adsorption of heavy-metal ions by PANI has attracted increasing attention due to its functional amine and imine groups that can interact with heavy-metal ions.…”

Pleated Surface Morphology of C60Fullerene Nanowhiskers Incorporated by Polyaniline inN-Methyl-2-Pyrrolidone

“…The C 60 fullerene acts as the electron acceptor and Pleated Surface Morphology of C 60 Fullerene Nanowhiskers 711 the NMP serves as donor since it has a nitrogen atom with lone pair electrons. The PAni that has been dispersed in NMP further promotes the CT complexes due to the lone pair electrons of imine nitrogen atoms that are present in its chain backbone (23). The lone pair electrons present in both NMP and PAni caused dissolution inside the whisker to produce a hybrid with tubular structure.…”

One-pot synthesis of polyaniline doped with transition metal ions using H2 O2 as oxidant

“…45% and 74% of imine nitrogen atoms coordinated to Zn 2+ and Cu 2+ , respectively. However, the complexation occurs preferentially at imine nitrogen of PANI for Zn 2+ doping by a pseudo‐protonation mechanism, while the complexation appears at both imine and amine for Cu 2+ doping by pseudo‐protonation and redox mechanism . The electrical conductivities ( σ ) of H‐PANI, Zn‐PANI and Cu‐PANI were measured and listed together in Table .…”

“…The most general method of obtaining conducting PANI is chemical oxidative polymerization with ammonium peroxydisulfate (APS) in the presence of inorganic or organic Brønsted acids, in which the imine nitrogen preferentially gets protonated and the electrical conductivity varies over a wide range as a function of the pH of the acid used for doping. Doping has also been achieved by using Lewis acids such as SnCl 4 , GaCl 3 , AlCl 3 , FeCl 3 , CuCl 2 and EuCl 3 . In recent years, the doping of PANI with transition metal ions has attracted more and more research interest owing to the distinctive electron exchange property of the combination, higher specific capacitance values and thermal stability .…”