Poly(glycidyl methacrylate)-polyaniline bilayer-modified mild steel for combating biocorrosion in seawater

Abstract

An environmentally friendly approach in inhibiting corrosion of mild steel (MS) and in rendering its surface biocidal for reducing bacterial adhesion, biofilm formation, and biocorrosion in seawater is described. Surface-initiated atom transfer radical polymerization (ATRP) of glycidyl methacrylate from the MS surface-coupled trichlorosilane, containing the benzyl sulfonic chloride ATRP initiator, was first carried out, followed by thermal curing with polyaniline (PANI) and N -alkylation of PANI. The modified MS surfaces were characterized by X-ray photoelectron spectroscopy analysis and water contact angle measurement. The adhesion and viability of bacteria on the pristine and surface-modified MS coupons were revealed by scanning electron microscopy. The electrochemical behavior and protective properties of the polymeric bilayer-modified MS surface in simulated seawater medium were evaluated from Tafel polarization curves and by electrochemical impedance spectroscopy. The MS surface with a firmly coupled electroactive bilayer exhibits high inhibition efficiency (up to 95%) against the attack of corrosive environment and significantly reduces bacteria adhesion and biocorrosion. With the good antibacterial and anticorrosion capabilities of the quaternized bilayer coating, the functionalized MS is potentially useful in harsh marine environments. © 2009 The Electrochemical Society.