Electrosynthesis and In Situ Spectroelectrochemistry of Conductingo-aminophenol-p-aminophenol Copolymers in Aqueous Solution

Abstract

Copolymerization of o-aminophenol (o-AP) and p-aminophenol (p-AP) in aqueous sulfuric acid solution was electrochemically performed using cyclic voltammetry on gold electrode. Copolymerization was carried out at different feed concentrations of homo monomers. The obtained films were characterized with cyclic voltammetry, in situ resistivity measurements, in situ UV-Vis-spectroscopy, FT-IR spectroscopy, and scanning electron microscopy (SEM). Cyclic voltammetry study shows that the onset potentials for o-AP, p-AP and o-AP + p-AP are located at the different values. The results from the electrochemical copolymerization of o-AP with p-AP demonstrate that the CVs of copolymers films growth are different from those of homopolymers, and are strongly affected by the amount of monomers. The in situ resistivity of copolymers measured from −0.20 V to 0.95 V vs. SCE decreased with increasing the [o-AP]/[p-AP] concentration ratio. In situ UV-visible and ex situ FT-IR spectra of homopolymers and copolymers results show intermediate spectroscopic behavior between homopolymers and copolymers. SEM micrographs of the samples show fundamental differences between the morphology of the homo-and copolymers.

Novel conducting poly (p-nitro aniline-co-N-methyl aniline): Electrosynthesis, mechanism and in situ spectroelectrochemical characterization

“…Minimum resistivity values was observed between 0.35 and 0.80 V. The obvious in situ conductivity differences between the homopolymers and copolymers as well as between the different copolymers were indicated the effect of concentration of comonomers in the polymer backbone. The results of in situ conductivity and the effect of concentration on the conductivity of the polymer and copolymer films are in good agreement with other published results [26][27][28]. With increasing the concentration of each monomers in the monomer feeds, the conductivity of the resulting copolymers were changed to lower or higher values.…”

“…In order to test reversibility, spectra were recorded in the negative-going potential direction. In the selected potential ranges, the stability of the optical response was checked frequently [26,27]. Cyclic voltammograms (CVs) were recorded using a Behpajoh model BHP/2062 and an Autolab model PGSTAT 20 potentiostat/ galvanostat.…”

“…Polymer and copolymer films were scraped off from the electrode and were dried. Then polymer and copolymer films were milled with KBr, and were pressed into pellets [26,27].…”

“…conductivity, solubility and optical behavior) for homopolymers and copolymer were observed comparatively [25]. Electropolymerization of copolymers of aniline with three nitroaniline isomers (ortho, meta-or para) were reported [26]. Electrocopolymerization offers the advantages of preparing a wide array of materials with good stability, varying conductivity and redox activity [27].…”

“…Electrocopolymerization offers the advantages of preparing a wide array of materials with good stability, varying conductivity and redox activity [27]. Electrochemical synthesis and in situ spectroelectrochemistry characterization of conducting ortho amino phenolco-para amino phenol, para nitro aniline-co-para amino phenol and N-methyl aniline-co-ortho aminophenol have already been reported [26][27][28]. According to our best knowledge, the electrochemical studies of nitroaniline electrochemically deposited on solid electrode surfaces in nonaqueous and aqueous is very difficult [9,19,20].…”