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

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 (lambda = 285 nm).

Automated summary

Steel surfaces are prone to corrosion, especially in natural environments with salt solutions and continuous UV exposure. Researchers have developed a polyurethane coating with TiO2 and carbon nanotubes composites to enhance its protective properties. The coated CT3 steel substrates show excellent antibacterial ability against Staphylococcus aureus bacteria and effective protection against corrosion for up to 31 days under harsh environments.