The Characterization of Poly ( P-Phenylenediamine ) using Scanning Electron Microscopy Cyclic Voltammetry and Rotating Disc Electrode (original) (raw)
Related papers
Electropolymerization of p-phenylenediamine (pPD) on Pt-electrode from a deoxygenated aqueous acid medium was carried out using cyclic voltammetry technique. The kinetic parameters were calculated by means of electrochemical data. The experimentally obtained kinetic equation was RP,E ¼ kE [monomer]1.23 [acid] 1.24 [electrolyte]0.94 from the value of the anodic current density. The apparent activation energy (Ea) is found to be 65.1 kJ mol 1. The obtained polymer films have been characterized by X-ray diffraction, elemental analysis, scanning electron microscopy, UV–vis, and IR spectroscopy. The conductivity of the polymer pellets is 6.3 10 7 S cm 1. The mechanism of the electrochemical polymerization reaction has been discussed. TGA is used to confirm the proposed structure and determination of the number of water molecules in the polymeric chain unit.
Journal of Applied Polymer Science
Electropolymerization of O-phenylenedi-amine (o-PD) on Pt-electrode from a deoxygenated aqueous acid medium was carried out using cyclic voltammetry technique. The kinetic parameters were calculated by means of electrochemical data. The experimentally obtained kinetic equation was R P , E ¼ k E [monomer] 1.19 [acid] 1.23 [electro-lyte] 0.87 from the value of the anodic current density using cyclic voltammetry technique. The apparent activation energy (E a) is found to be 28.34 kJ mol À1 . The polymer films obtained have been characterized by X-ray diffraction, elemental analysis, scanning electron microscopy, 1 H-NMR, 13 C-NMR, UV-visible, and IR spectroscopy. The mechanism of the electrochemical polymerization reaction has been dis-cussed. TGA is used to confirm the proposed structure and determination of the number of water molecules in the pol-ymeric chain unit. V
Journal of Electroanalytical Chemistry, 2013
The physico-chemical characteristics of thin poly-(ortho-phenylenediamine) (PPD) films, obtained by electrochemical oxidation of the relevant monomer, are investigated using electrochemical, morphological and spectroscopic techniques. In particular, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) techniques are used to collect information concerning the redox, conductivity and double layer capacitance properties of the PPD film. AFM imaging and Raman spectroscopy results are exploited to characterize the film structure. In this respect, Raman spectra of two possible PPD oligomers are calculated at the B3LYP/6-311G ÃÃ level of the theory.
International Journal of Electrochemical Science, 2012
Poly(ortho-Phenylenediamine) was deposited as a thin film by electrochemical impedance spectroscopy (EIS) and compared to cyclic voltammetry (CV) on Teflon insulated Platinum–Iridium (Pt) disk microelectrode (125 μm diameter) in 300 mM phosphate buffer solution (pH 7.2). This study focuses on the electropolymerization process and electrical properties of PoPD-modified microelectrodes, using EIS technique. The estimated thickness of the PoPD film was 31 nm with conductivity of 1.1 x 10 −5 Scm −1 . The initial impedance plot shows a semicircle which characterized the charge-transfer resistance at the microelectrode/polymer interface at higher frequency and a diffusion process at lower frequency. Impedance data were fitted to the Randles and a modified Randles circuit models with χ 2 = 0.12 and χ 2 = 0.06 respectively. The capacitive behavior (phase angle = 83°) of the bare Pt microelectrode was transformed to a resistive behavior (phase angle = 13°) after the formation of PoPD layer a...
Influence of structure of poly(o-phenylenediamine) on the doping ability and conducting property
Ionics, 2016
Poly(o-phenylenediamine) with ladder-type structure was formed in aqueous hydrochloric acid medium below pH 1, while open ring-type amine derivative, i.e., −NH 2 functional group substitution of polyaniline structure, was obtained in 1:1 aqueous sulfuric acid medium from the chemical synthesis of the monomer o-phenylenediamine. However, poly(o-phenylenediamine) having structure like polyaniline derivative with free =NH functional groups was obtained by chemical synthesis in dimethyl sulfoxide medium. The laddertype polymer was almost insoluble but the other two types of synthesized polymers having polar functional group substitutions were well soluble in polar organic solvent like dimethyl sulfoxide, N,N-dimethyl formamide, and tetrahydrofuran. The freestanding films were cast from dimethyl sulfoxide solution of both the soluble functional polymers. The polymers having different structures were doped with inorganic acid by solution doping technique and the doped polymers were characterized by various standard characterizations. In order to explore the electronic uses of the polymers like sensor and actuators, the influences of their structure on the doping ability as well as ionic properties of the sulfuric acid-doped polymers were compared.
Russian Journal of Electrochemistry, 2000
Electrochemical behavior of poly-o -phenylenediamine (P o PhD) films in lithium perchlorate and perchloric acid solutions of different pH and constant ionic strength is studied using cyclic voltammetry, low-amplitude chronoamperometry, chronopotentiometry, and faradaic-impedance spectroscopy. The experimental results point to the diffusion-migration kinetics of charge transfer processes in redox-active P o PhD films and show that two such processes occur during oxidation-reduction of P o PhD. The processes are separated most fully at low concentrations of hydronium ions. Effect of the electrode potential and electrolyte composition on these processes is examined. Different methods yield similar results and permit their more reliable interpretation.
Electrochemistry Communications, 2008
In attempts to improve the permselective properties of poly(o-phenylenediamine), PoPD, for biosensor applications, its electrosynthesis was carried out in the presence and absence of a variety of background electrolytes. Surprisingly, not only was electropolymerization efficient when no charge carriers were added to the monomer solution, the selectivity of the PoPD generated under this condition was superior to other published forms. Interpretation of these findings in terms of ion entrapment also supports the hypothesis that self-blocking by biosensor interference species present in solution is involved in determining PoPD permeability, which increases selectivity in bio-monitoring applications.
Composite Material–Based Conducting Polymers for Electrochemical Sensor Applications: a Mini Review
BioNanoScience, 2020
Conducting polymers (CPs) represent a sizeable range of useful organic substances. Their unique electrical, chemical, and physical properties; reasonable price; simple preparation; small dimensions; and large surface area have enabled researchers to discover a wide variety of uses, including sensors, supercapacitors, solar cells, batteries, biochemical applications, and electrochromic devices. To promote the success of CPs, unique composite materials have been prepared with metals or steel oxides. The goal of this overview is to characterize the electrochemical sensor utility of CPs and their composites and to categorize future components of electrochemical sensing materials. CPs have been comprehensively applied over a wide range of variable industrial fields; such CPs have used many new materials with diverse compositions that are utilized as electrochemical sensors and biosensors. These materials have been fabricated inside numerous analytical instruments that are applied in healthcare settings and clinical, environmental, food, and pharmaceutical laboratories. Electrochemical sensors are essentially based on CPs and/or their corresponding composite materials. Therefore, the present work provides a brief illustration of electrochemical sensor and biosensor applications for the most important conducting polymer composite materials. Polyaniline (PANI), poly(o-toluidine) (PoT), and poly(o-anisidine) (PoAN) were considered in this study. Moreover, the most important electrochemical properties of these conducting polymer composite materials are discussed.
Electropolymerization features of o-phenylenediamine on carbon electrode with developed surface
Synthetic Metals, 2010
Carbonized tissue (CT) was used for the first time to prepare developed surface coated with electroactive polymer. A stable monolayer of electroactive heteropolyacid was found to result from CT impregnation with silicododecamolybendic acid (SiMo) solution. Successful electrochemical oxidation of o-phenylenediamine (OPD) was first demonstrated both on pure carbonized tissue and on the tissue coated with SiMo monolayer, while the oxidation potential on both pure and impregnated CT is shifted by 0.6 V more cathode from the OPD oxidation potential on "smooth" electrodes. OPD oxidation was found to yield primarily water-soluble oligomers on pure CT and solid PPD layer on SiMo-modified tissue.
Journal of the Electrochemical Society, 2013
The electropolymerization of o-Phenylenediamine (oPDA), both in the absence and presence of Fe 3+ in solution, was investigated in detail using cyclic voltammetry concurrently with the quartz crystal microbalance (QCMB) technique. It is shown that a set of redox peaks (A 1 /C 1), seen between 0.05 and 0.4 V is characteristic of the phenazine-like PoPDA polymer, produced by the irreversible radical oxidation of the oPDA monomer at a Au surface and forming an oPDA radical cation that initiates the polymerization step at >0.8 V vs. RHE. The QCMB results showed that ca. 20% of the oxidized product deposits on the Au surface as a redox-active polymer film, with charge compensation by H + injection/expulsion along with some inhalation/exhalation of water. The presence of Fe 3+ in solution during electropolymerization led to very similar electrochemistry, with ca. 50% of the oxidized product forming the redox-active polymer film. The PoPDA films are very smooth and uniform, while films formed in the presence of Fe 3+ are coated with Fe-containing nodules ca. 0.8 μm in diameter, which hinder the further growth of the PoPDA film.