Stainless Steel Poly(3,4-ethylenedioxythiophene) Antifouling Coating Marine Corrosion Conducting Polymer

External authors:

• Javiera Aguirre ( Pontificia Universidad Catolica de Chile )
• Leslie K. Daille ( Pontificia Universidad Catolica de Chile )
• Diego Fischer ( Pontificia Universidad Catolica de Chile )
• Carlos Galarce ( Pontificia Universidad Catolica de Chile )
• Rodrigo De la Iglesia ( Pontificia Universidad Catolica de Chile , Marine Energy Res & Innovat Ctr )
• Francisco Armijo ( Pontificia Universidad Catolica de Chile , Marine Energy Res & Innovat Ctr )

Abstract:

In this work the poly(3,4-ethylenedioxythiophene) (PEDOT) was evaluated to mitigate biocorrosion of conventional stainless steel (SS), grade AISI 304, under exposure to natural seawater. PEDOT was obtained electrochemically onto the steel and coated coupons were immersed in flow-through exposure rig fed with fresh seawater. Corrosion performance of the coupons SS and SS/PEDOT was characterised using electrochemical analysis of open circuit potentials and polarization curves measured on samples retrieved after 7, 35 and 210 days of exposure. For the same retrieval times, the evolution of the biofilm was inspected by scanning electron microscopy (SEM), and microbiological analysis by denaturing gradient gel electrophoresis (DGGE) and fluorescence microscopy. Results indicate that PEDOT delays the growth of the biofilm on the modified steel surface by at least 35 days, producing a less variable bacterial community over time as compared to the uncoated steel surface. In addition, PEDOT retains electrochemical stability throughout the exposure, which is mainly attributed to the intrinsic properties of the conducting polymer.