The feasibility of polyaniline-TiO2 coatings for photocathodic antifouling: antibacterial effect
By Wen, Bo; Waterhouse, Geoffrey I. N.; Jia, Meng-Yang; Jiang, Xiao-hui; Zhang, Zhi-Ming; Yu, Liang-min
Published in Synthetic Metals
2019
Abstract
This study explores the feasibility of polyaniline-TiO2 coatings for photocathodic antifouling: antibacterial effect. PANI-TiO2 composites were prepared by chemical polymerization of polyaniline (PANI) in the presence of anatase TiO2, followed by dispersion of the resulting PANI-TiO2 composite in an acrylic resin for coating applications. The incorporation of PANI resulted in sensitization of the TiO2 to visible light, resulting in efficient electron and hole transfer between the PANI and TiO2 components. Under UV–vis illumination, the balanced potential of the PANI-TiO2 coating on 316 L stainless steel in a 3.5 wt.% NaCl solution was lowered to −0.4 V (vs. a saturated calomel electrode), sufficient to achieve cathodic protection of the stainless steel. The PANI-TiO2 coating also possessed good antimicrobial activity under UV–vis illumination for 30 min (efficiency > 70%). The antibacterial properties of the PANI-TiO2 coating can be attributed to the generation of H2O2 or other reactive oxygen species through photovoltaic effects, which cause oxidative damage to E. coli cells. This work confirms the feasibility of using PANI-TiO2 coatings to prevent biofouling (especially for fouling raised by the bacterial) of steels in marine environments.