Microgravimetric study on the formation and redox behavior of poly(2-acrylamido-2-methyl-1-propanesulfonate)-doped thin polyaniline layers

• Published in: Electrochimica acta Vol. 56; no. 13; pp. 4803 - 4811
• Main Authors: Lyutov, V., Tsakova, V., Bund, A.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2011; Elsevier
• Subjects: Applied sciences; Buffer solutions; Cationic; EQCM; Exact sciences and technology; Fluxes; Inorganic acids; Neutral solutions; PAMPSA; PANI; Physicochemistry of polymers; Polyanilines; Polymerization; Polymers and radiations; Redox behavior; Thin films; PANI; PAMPSA; Neutral solutions; Redox behavior; EQCM; Oxidation reduction; Doped materials; Neutral solution; Perchlorates; Electrochemical polymerization; Acrylamide derivative polymer; Operating conditions; Conducting polymers; Sulfonate polymer; Inorganic anion; Chlorides; Chronoamperometry; Electrochemical reaction; Formation; Aniline polymer; Quartz microbalance
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2011.03.079

► Incorporation of polyanions in PANI during electrosynthesis in inorganic acids. ► Preserved electroactivity of PANI up to pH 9. ► Small mass fluxes at PANI redox transition in neutral and slightly alkaline solutions. A comparative study on the potentiostatic polymerization of polyaniline (PANI) in inorganic (sulfuric and perchloric) acid and mixed poly(2-acryalamido-2-methyl-1-propane-sulfonic) (PAMPSA)/inorganic acid solutions is carried out through combined electrochemical and microgravimetric techniques. It is established that polymerization in the presence of small amounts of PAMPSA in the mixed solutions results in immobilization of the polyanions in the PANI layers. The redox behavior of the PAMPSA-doped PANI layers, studied in acidic, neutral and slightly alkaline solutions shows that the electroactivity is preserved up to pH 9. PAMPSA seems to operate as a buffer, providing the necessary protons for the PANI layer in the range pH 7 to pH 9. Detailed microgravimetric measurements in buffer solutions with various cationic (Na + and Cs +) and anionic (Cl − and ClO 4 −) species are used to elucidate the ionic transport occurring in the course of the PANI redox transition in neutral solutions. It is found that cations (different than protons) are involved in the early stage of oxidation whereas the participation of anionic species seems to be limited. Small mass fluxes and minor changes in the viscoelastic properties are observed during the redox transition in neutral and slightly alkaline solutions.