Electrosynthesis of poly(o-phenylenediamine) in a room temperature ionic liquid (original) (raw)
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Ionic Liquid based polymer electrolytes for electrochemical sensors
Materials Science, 2015
Amperometric NO2 sensors with a new type of printed solid polymer electrolyte and printed carbon working electrodes were developed. The electrolytes consisted of the ionic liquids 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide [EMIM][N(Tf)2], 1-butyl-3-methylimidazolium trifluoromethanesulfonate [BMIM][CF3SO3], and 1-ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF4], which were immobilized in a poly(vinylidene fluoride) (PVDF) matrix. The analyte, gaseous nitrogen dioxide, was detected by reduction at-500 mV vs. the platinum pseudoreference electrode. The sensors showed linear behavior over the whole tested range, i.e., 0-5 ppm, and their sensitivities were in the order of hundreds of nanoamperes per one ppm of NO2. The sensor sensitivity was influenced by the electrical conductance of the electrolyte; the higher the conductance, the greater the sensor sensitivity. The rise/recovery times were of the order of tens of seconds. The use of screen printing technology for the preparation of the solid electrolyte and the carbon working electrode simplifies sensor fabrication without a negative effect on sensor performance.
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.
Electrochimica Acta, 2010
Room temperature ionic liquids (RTILs) were used in electrochemical polymerization and in doping studies (oxidation and reduction) of poly(para-phenylene) (PPP). Cyclic voltammetry was used simultaneously with Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy. Electropolymerization and doping of PPP were done by potential scanning in acetonitrile (ACN + 0.1 M TBAPF 6 ), 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF 6 ]) and butylmethylpyrrolidinium bis (trifluoromethylsulfonyl) imide ([BMP][Tf 2 N]). The cyclic voltammograms recorded during polymerization of the PPP film indicate that the best film growth was achieved in [BMIM] [PF 6 ]. The films made in [BMP][Tf 2 N] were more stable than films made in ACN (0.1 M TBAPF 6 ). Results from p-doping studies show that doping can be made at higher potentials in RTILs than in ACN (0.1 M TBAPF 6 ). It was also found that n-doping can be performed in RTILs at higher negative potentials (−2.2 V) than in ACN (0.1 M TBAPF 6 ) (−1.8 V). The best n-doping response was achieved in [BMP][Tf 2 N]. Also, n-doping in [BMIM] [PF 6 ] was better than in ACN (0.1 M TBAPF 6 ). The in situ ATR-FTIR spectroscopy was used to study p-and n-doping of PPP films. During both p-and n-doping the spectra indicated formation of infrared active vibration bands (IRAV) in the wavenumber region 1600-800 cm −1 . The obtained IRAV bands correlate to the theoretical modes calculated by Zerbi and co-workers according to the effective conjugation coordinate theory (ECC). All these results indicate that RTILs are good solvents in spectroscopic and electrochemical studies of conducting polymers.
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...
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
2014
Electropolymerization and electro-co-polymerization of 3-methoxythiophene (MOT) and 3, 4ethylenedioxythiophene (EDOT) in the ionic liquids (ILs) 1-butyl-3-methylimidazolium terafluoroborate (BMIm + BF4 ) and 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (OMIm + Tf2N ) as well as the voltammetric, UV/Vis absorption spectroelectrochemical and micromorphological properties of the resulting polymer films are compared and contrasted. MOT was oxidized at a lower potential than EDOT in the hydrophilic BMIm + BF4 , but the reverse being true in the hydrophobic OMIm + Tf2N . The MOT/EDOT mixture’s oxidation-onset potentials were similar in the two ILs. Post-electropolymerization cyclic voltammograms (CVs) showed the deposition of electroactive thin films which didn’t dissolve-off. Among the other observations are that UV/Vis absorption spectra indicated OMIm + Tf2N resulted in polymer molecules with higher degree of conjugation and more heterogeneous polymer films than did BM...
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.
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.
Polypyrrole (pPy) thin films were synthesized electrochemically by a pulse method on platinum electrodes in N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ionic liquid (PYR 14 TFSI). The pulse deposition method allowed the synthesis of well adherent pPy layers on Pt that are attractive for the realization of sensors and biosensors because of their good selectivity with respect to the most common interferants. The EIS (Electrochemical Impedance Spectroscopy) response to hydrogen peroxide and biological interferants indicated pPy as a highly sensitive electrochemical platform for the impedimetric sensing of H 2 O 2 . The polymer was overoxidized (opPy) before the characterization to prevent its electrochemical contribution in aqueous solution. Then opPy was functionalized by glucose oxidase enzyme and the device was assembled and tested as a impedimetric biosensor. This technique showed to have great chances to substitute classic detection methods.
Conducting and Electrochemically Generated Polymers in Sensor Design (Mini Review)
Procedia Engineering, 2012
Various nanotechnological methods and high number of nanostructured materials including polymer nanocomposites (PNCs) become extremely important in sensor and biosensor technology. Conducting polymers as artificial versatile materials seem very suitable for the development of various analyte-recognizing parts of sensors and biosensors. This contribution is reviewing major fabrication methods of conducting polymer-based nanocomposites for biosensorics. Experience of authors in application of various electrochemically generated polymers in design of biosensors is presented. The influence of fabrication method on sensor characteristics is overviewed. Major types of biosensors based on conducting polymers including catalytic biosensors, DNA-sensors, immunosensors and molecularly imprinted polymer-based affinity sensors is discussed. Conducting and electrochemically generated polymers that are mostly used in sensor design are presented.