A fabrication of CNTs/TiO2/polyurethane films toward antibacterial and protective coatings

Abstract

Steel is a commonly used material in the construction field but the steel's surface is easily corroded under natural conditions and especially in the environments containing a salt solution and continuous UV illumination. The fabrication and modification of polyurethane (PU) coatings toward a protection of the steel surface have been received much more special attention. The TiO2 and carbon nanotubes (CNTs) composites are synthesized by a ball milling method toward the enhancing properties for the smart PU coating. The modified PU coatings, which are coated on the CT3 steel substrates (abbreviation: CNTs/TiO2/PU films), also express a highly effective antibacterial ability (over 95%) against Staphylococcus aureus (S. aureus) bacteria. By the electrochemical analysis of the CNTs/TiO2/PU films, we found that 1%wt CNTs/TiO2/PU film has the most excellent protection for the CT3 steel surface. In detail, the physical and the mechanical strength assessments demonstrate that the 1%wt CNTs/TiO2 composite is 1.67 times, 1.48 times, and 1.70 times higher than that of the purity PU in a comparision of the adhesion, tensile strength, and impact strength, respectively. Moreover, the 1%wt CNTs/TiO2/PU film effectively protects against the corrosion of the steel surface up to 31 days under the environments containing 1 M Na2SO4 solution and continuous UV illumination (λ = 285 nm).