Electrolyte type and concentration effects on poly(3-(2- aminoethyl thiophene) electro-coated on glassy carbon electrode via impedimetric study

Enhancement of Electrochemical Stability Window and Electrical Properties of CNT-Based PVA-PEG Polymer Blend Composites

New polymer blend composite electrolytes (PBCEs) were prepared by the solution casting technique using poly(vinyl alcohol) (PVA)-polyethylene glycol (PEG), sodium nitrate (NaNO₃) as a doping salt and multiwalled carbon nanotubes (MWCNTs) as fillers. The X-ray diffraction pattern confirms the structural properties of the polymer blend composite films. FTIR investigations were carried out to understand the chemical properties and their band assignments. The ionic conductivity of the 10 wt % MWCNTs incorporated PVA-PEG polymer blend was measured as 4.32 × 10^-6 S cm^-1 at 20 °C and increased to 2.253 × 10^-4 S/cm at 100 °C. The dependence of its conductivity on temperature suggests Arrhenius behavior. The equivalent circuit models that represent the R _s(Q₁(R₁(Q₂(R₂(CR₃))))) were used to interpret EIS data. The dielectric behavior of the samples was investigated by utilizing their AC conductance spectra, dielectric permittivity, dielectric constant (εⁱ and ε^r), electric modulus (Mⁱ and M^r), and loss tangent tan δ. The dielectric permittivity of the samples increases due to electrode polarization effects in low frequency region. The loss tangent's maxima shift with increasing temperature; hence, the peak height rises in the high frequency region. MWCNTs-based polymer blend composite electrolytes show an enhanced electrochemical stability window (4.0 V), better transference number (0.968), and improved ionic conductivity for use in energy storage device applications.

Electrochemical copolymerization of acrylic acid and acrylamide on the carbon fiber surface

Electrochemical polymerization of acrylic acid and acrylamide on carbon fiber was carried out by using cyclic voltammogram in the presence of sulfuric acid (H2SO4) as electrolyte. Cycles, monomer mass ratio, scan rate, and H2SO4 concentration had an effect on the electropolymerization, and electrochemical impedance spectroscopic behavior of modified carbon fiber was studied. Systematic experiments were conducted to determine the tensile strength of carbon fiber/epoxy resin composites before and after modification. As a result, the tensile strength of modified carbon fiber/epoxy resin composites was improved greatly. Surface morphology of the polymer films on carbon fiber was investigated by using scanning electron microscopy. It was found that voltammograms of electrodes prepared showed irreversible oxidation–reduction of the polymer films and capacitive behaviors of coated carbon fiber were defined using Nyquist plots, Bode magnitude plot and Bode phase plot at low-frequency region.

Comparative analysis of poly(N-methylpyrrole) and its titanium dioxide nanocomposite film formations against equivalent electrical circuit model for the their corrosion-inhibition effects

Conducting polymers have been used for many years as coating materials against corrosion. However, the coated materials absorb water over time resulting in reduction of resistivity and anticorrosion properties. In this study, poly( N-methylpyrrole) (P( N-MPy)) and P( N-MPy)/titanium dioxide ((TiO2) nanocomposite films were synthesized in 0.5 M oxalic acid solution on Al 1050 electrode by chronoamperometric method. The modified electrodes were characterized by scanning electron microscopy–energy dispersive X-ray analysis, Fourier transform infrared–attenuated transmission reflectance, electrochemical impedance spectroscopy (EIS), and Tafel extrapolation techniques. The corrosion tests results were obtained in 3.5% sodium chloride (NaCl) solution by Tafel plots. In addition, the equivalent electrical circuit model of P( N-MPy) and P( N-MPy)/TiO2 nanocomposite films were investigated in 3.5% NaCl solution at different time periods. The EIS study of the polymer and nanocomposite were analyzed by Matlab program and for the first time Tina, the equivalent electrical circuits program, was used.