Electrodeposition of polypyrrole films on aluminum from tartrate aqueous solution

Abstract

A síntese eletroquímica de filmes de polipirrol em superfícies de alumínio, em meio aquoso contendo ácido tartárico e pirrol, foi realizada através da técnica galvanostática e por voltametria cíclica. Um mecanismo que considera o crescimento de uma camada porosa de óxido de alumínio em paralelo com a eletrodeposição do filme de polipirrol foi proposto. Foi observado que quanto mais homogênea a distribuição dos poros na camada de óxido, menor a resistência oferecida para o crescimento dos filmes de polipirrol. Também foi observado que os filmes de polipirrol depositados por voltametria cíclica são menos uniformes do que aqueles formados galvanostaticamente. Filmes eletrodepositados galvanostaticamente a maiores densidades de corrente são mais propensos ao processo de superoxidação, como mostram os resultados de FTIR. Além disso, filmes de polipirrol depositados a 2,5 mA cm -2 apresentam um melhor desempenho na proteção de superfícies de alumínio contra corrosão.The electrochemical synthesis of polypyrrole films on aluminum surfaces from aqueous solutions containing tartaric acid and pyrrole was performed using cyclic voltammetry and galvanostatic techniques. A mechanism that considers a porous aluminum oxide layer growing in parallel with the polymeric film explains the polypyrrole electrodeposition on aluminum surfaces. The more homogeneous the distribution of pores on the aluminum oxide layer, the smaller is the resistance offered to the polypyrrole film growth. Polypyrrole films deposited by cyclic voltammetry are much less uniform than those galvanostatically formed. Polymeric films galvanostatically deposited at higher current densities were more susceptible to overoxidation processes than those films formed at lower current densities, as demonstrated by FTIR analyses. Furthermore, films formed at low current density perform better on protecting aluminum surfaces against corrosion.

The effect of dopant pKa and the solubility of corresponding acid on the electropolymerisation of pyrrole

“…4, it appears that it is the lowest NaDF concentration that gives rise to the highest charge and the more efficient rate of electropolymerisation. Again, this is somewhat different to the majority of reports which show an increase in the rate of electropolymerisation with increasing concentrations of dopant [11,27]. However, the data in Fig.…”

Electrodeposition of polypyrrole films on aluminum surfaces from a p-toluene sulfonic acid medium

“…Doped films can be deposited depending on the synthesis conditions, such as electrolyte, pH, and deposition potential 15,16 . The electrolyte plays an important role in determining the porosity of the oxide film formed under the PPy film.…”

Chemical Precipitation Synthesis of Fe, Ni, and Co Doped Zinc Sulphide Nanoparticles

“…[14] After autoclaving this was allowed to cool for bearable temperature then it was poured into sterile petriplates. The petripltes were allowed to solidification.…”