The Function Researche Of Conducting Polyaniline、Polypyrrole

The conducting polymers has the special structure,the physical and chemistry performance, and has the widespread application prospect in domains of optoelectronic devices, electromagnetic shield, molecular device, sensor, metal anticorrosion, battery and life science. Polyaniline （Pani） and polypyrrole （PPy） are easily to synthesize, stable to the environment, excellent reversibility and so on merits, therefore, has the important applied research value. This work prepared the conducting polypyrole take acetonitrile and water as solvent, has prepared PPy and the Pani copolymerization membrane in the oxalic acid peroxide solution and in the different water content’s acetonitrile resolver has prepared the PPy electric conduction high polymer. Used scanning electronic microscope, elementary analysis, infrared spectroscopy, potentiodynamic polarization curves, corrosion potential-time curve and electrochemistry impedance spectrum studied the conducting polymers electrochemistry performance and the stainless steel corrosion preventing performance.The PPy film was prepared in the 0.1 mol/L pyrrole that as the high polymer monomer by the cyclic voltammetry, and take acetonitrile and water as the solvent and 0.2 mol/L NaClO₄ as the supports electrolyte. Observed the PPy film superficial appearance which using the scanning electronic microscope, used the potentiodynamic polarization curves, the corrosion potential-time curve and the electrochemistry impedance spectrum studied the protective function of the PPy membrane in 1 mol/L H2SO₄ to the stainless steel. As it turned out, the corrosion potential is moved to 0.8 V compared to the bare stainless steel, the corrosion current density from the bare stainless steel’s 3580μA/cm² drops separately to 40μA/cm² （water solution） and 9μA/cm² （acetonitrile solution）, the protection time to the stainless steel of PPy membrane prepared in acetonitrile solution is longer than prepared in water solution. In the soaking time, PPy （acetonitrile solution） interface charge shift resistance Rct is bigger than PPy （water solution） Rct. Therefore the protection effect of PPy （acetonitrile solution） is good than PPy （water solution）. The continuous current charging and discharging curve indicates PPy in 0.2 mol/L H2SO₄ the electrical energy strength compared to PPy （water solution） is obvious enhanced. This possibly is PPy prepared in the water that H+ are excessively much in the polymerization process, the side reaction intensifies, has affected PPy （water solution） the stack way and causes PPy（water solution） the inherent drawback to increase causes the structural change, thus causes charging and discharging ability drops.The conducting polymer film was prepared in py and aniline as the high polymer monomer, 0.3 mol/L oxalic acid as the supports electrolyte prepared the compound electric conduction polymerization membrane which was composed of Pani and PPy by the cyclic voltammetry. The infrared spectrum indicated that the compound electric conduction polymerization membrane is composed of Pani and PPy. In 1 mol/L H2SO₄, PPy or Pani has the redox reaction with the stainless steel substrate, promotes the stainless steel surface to have the deactivation. In 3.5% NaCl, the Plunges’ Cl- to the stainless steel surface induces the stainless steel to have the corrosion to respond that under the both’s combined action, the metal surface has the deactivation and the corrosion process. The result indicated that when the aniline and the pyrrole concentration is 1:3, the prepared compound electric conduction polymerization membrane protected stainless steel’ the corrosion current is minimum, and the corrosion potential is highest, and the protected time is longest. After the conducting polymers film constant potential anodic and cathodic polarization in 3.5%NaCl solution electrochemistry impedance spectrum indicated that the polypyrrole and polyaniline has the redox reaction with the stainless steel substrate, promotes the stainless steel surface passivation; at the same time Cl- plunges to the stainless steel surface, the destruction deactivation membrane causes the stainless steel to corrode. The conducting polymer film was prepared in 0.1 mol/L py as the high polymer monomer, 0.2mol/L NaClO₄ as the support electrolyte and content the water respectively 0%, 3%, 6%, 9% （volume fraction） acetonitrile solution by the cyclic voltammetry. Use the X-ray energy spectrometer analysis the PPy films elemental composition. Results indicate that support electrolyte NaClO₄ by the ClO₄- form dopes in the pyrrole polymerization chain. Has studied the PPy membrane electrochemical properties using tconstant current charge/discharge techniques, and compared the PPy membrane quality specific capacity and the energy density. When the charging and discharging current density increased from 0.001A/cm² to 0.005A/cm², the PPy（0%）, PPy（3%）, PPy（6%）, PPy（9%） quality specific capacity dropped 73.5%, 54.6%, 21.6%, 64.7% separately.In the electrochemistry impedance spectrum of SS/PPy（0%） and SS/PPy（3%）, because of SS/PPy（3%） and SS/PPy（0%） membrane’s polymerization degree compares ambassador, the ion removed in PPy migration is prevented, the system may think approximately is the semi-infinite diffusion control by the PPy/solution and the SS/PPy two contact surfaces turned to PPy/solution contact surface. The displayed in the electrochemistry impedance diagram for the diffusion of ions process control occupied the majority of frequency range. SS/PPy（6%） and SS/PPy（9%） membrane when preparation supports electrolyte NaClO₄ the doping to enable the PPy membrane interior to include the massive ClO₄- ion high, the ion is quick in the PPy membrane internal diffusion process, therefore has the Warburg diffusion process in the electrochemistry impedance spectrum, in the low frequency area main performance is the PPy membrane capacitive character.