Preparation Of Bromo-Substituted Polyaniline And Its Application In Antibacterial, Protective And Antifouling Coatings

Corrosion and biofouling of materials usually have serious negative effect on performance of related equipments.Here,multifunctional conductive polymers?bromo-substituted polyaniline,Br-PANI?were prepared and their applications in antibacterial and protective/antifouling coatings were characterized.First,aniline,KBr,KBrO₃ and ammonia persulphate were used as the reactants to prepared Br-PANI.The mentioned products were prepared by a new one-step strategy and polymerization followed by bromo-substituted two-step process,respectively.The conditions for preparation Br-PANI were optimized and the influences of bromination degree on polymer morphology,structure,stability and hydrophilic properties were characterizied.Under the optimum condtions,Br-PANI can be prepared by the developed two strategies with higher yields and lower costs than that of conventional bromoaniline polymerization method.The antibacterial effects of Br-PANIs and their blend films were characterized by plate counting method,minimal inhibitory concentration?MIC?method,minumun bactericidal concentration?MBC?method and film attach method.The experimental results demonstrate that the bactericidal ability of Br-PANI increases with the increase of bromination degrees,and has no close relation to their doping degree.The MBC of Br-PANI?Br/N molar ratio is 1.22?is 0.40 mg/mL which is much lower than that of conventional products.2.0 wt%Br-PANI can give the blend films a good antibacterial property.Finally,the protective and antifouling performances of epoxy resin coatings with2.0 wt%of dedoped Br-PANI were scharacterized by water adsorption test,wet adhesion test,salt immersion test?95?,12.0 wt%NaCl?,EIS measurement,XPS analysis,field test and so on.The experimental results indicate that with the increase of bromination degree of Br-PANI,the coating's wettability will be decreased,the adhesion strength will be enhanced,and the protecrtive performances will be improved.XPS analysis proves that dedoped Br-PANI can facilitate the formation of Fe₂O₃/Fe₃O₄ passivation layer,which effectively prevents the metal from further corrosion.What's more,antibacterial test and 60 days'of panel test show that dedoped Br-PANI composite coatings have stable and long-term antibacterial/antifouling abilities,and the abilities also enhanced with the increase of bromination degrees.