Studies on coatings containing nano‐zinc oxide for steel protection

Abstract

Zinc oxide (ZnO) nanoparticles (NPs) were synthesized using the coprecipitation method. The resulting NPs were characterized by X‐ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. The surface morphology of the coatings has been characterized by scanning electron microscopy (SEM). SEM images show a uniform and homogeneous distribution of ZnO‐NPs in polyurethane (PU) coatings while aggregates appear in epoxy coatings. Using tensile stress–strain test, the effect of the addition of ZnO‐NPs on the mechanical properties of PU and epoxy coatings was examined. The addition of ZnO‐NPs has enhanced the Young's modulus and the tensile strength of PU and epoxy coatings. Through the open‐circuit potential and electrochemical impedance spectroscopy measurements, the anticorrosive properties of PU‐ or epoxy‐coated mild steel panels containing ZnO‐NPs have been investigated in 0.5 M NaCl solution. Nyquist impedance plots for PU and epoxy coatings in PU‐ or epoxy‐coated mild steel panels containing ZnO‐NPs were tested in the absence and presence of ZnO‐NPs have different responses. It has been shown that the dispersion of ZnO‐NPs significantly improves the anticorrosive performance of PU coatings. A PU coating containing 700 mg/kg ZnO‐NPs is recommended to achieve better mechanical properties and corrosion resistance.

Biodegradable polysaccharide grafted polyacrylamide inhibitor for corrosion in CO2- saturated saline solution

“…Studies have documented the efficient role of organic chemicals containing nitrogen as CO 2 corrosion inhibitors when injected internally in pipelines [ [11] , [12] , [13] , [14] ]. A competent CI possesses electron donor sites owing to existing heteroatoms (N, O, S), π-electrons, and polar functional groups, which bind with the unoccupied orbitals of iron atoms of steel surface [ 15 ]. The reactions covering the mechanisms of corrosion attack in the Cl − containing medium and adsorption of inhibitor onto the steel surface are described below in equations (1) , (2) , (3) , (4) , (5) , (6) , (7) , (8) , (9) .…”