In the present study, a complex between 8-hydroxyquinoline and cerium (III) (CeHQ) was synthesized in the presence of triethylamine. Afterwards, the complex was characterized by Field Emission Scanning Electron Microscopy (FESEM), Fourier-transform infrared spectroscopy (FTIR) and Thermo-Gravimetric Analysis (TGA). The inhibition efficiency of the Ce-HQ complex for the corrosion of carbon steel, evaluated by both Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Polarization (PP) plots, reached 90 % after 2 h of immersion in a M NaCl solution. | Vietnam Journal of Science and Technology 62 2 2024 299-311 doi 2525-2518 19391 Assessing the corrosion protection of 8-hydroxyquinoline-cerium III complex for carbon steel in a NaCl solution Anh Son Nguyen1 2 Thuy Duong Nguyen1 2 To Thi Xuan Hang1 2 Thi Vy Anh Vuong1 Thu Thuy Pham1 Thu Thuy Thai1 2 Anh Truc Trinh1 2 Nadine Pébère3 1 Institute for Tropical Technology Vietnam Academy of Science and Technology 18 Hoang Quoc Viet Cau Giay Ha Noi Viet Nam 2 Graduate University of Science and Technology Vietnam Academy of Science and Technology 18 Hoang Quoc Viet Cau Giay Ha Noi Viet Nam 3 Université de Toulouse CIRIMAT UPS INPT CNRS ENSIACET 4 allée Emile Monso BP 44362 Toulouse 31432 Cedex 4 France Email nason@ Received 10 November 2023 Accepted for publication 3 February 2024 Abstract. In the present study a complex between 8-hydroxyquinoline and cerium III Ce- HQ was synthesized in the presence of triethylamine. Afterwards the complex was characterized by Field Emission Scanning Electron Microscopy FESEM Fourier-transform infrared spectroscopy FTIR and Thermo-Gravimetric Analysis TGA . The inhibition efficiency of the Ce-HQ complex for the corrosion of carbon steel evaluated by both Electrochemical Impedance Spectroscopy EIS and Potentiodynamic Polarization PP plots reached 90 after 2 h of immersion in a M NaCl solution. Then EIS measurements were carried out to evaluate the effect of the Ce-HQ complex as inhibitive pigment after incorporation in a waterborne epoxy coating applied over carbon steel plate. The total resistance Rtotal of the coated sample containing the Ce-HQ complex was higher 107 Ω cm2 after 35 days of exposure in a M NaCl solution than the values obtained for the coating without Ce-HQ. The results showed that the EP Ce-HQ coating provided not only corrosion protection by the Ce III ions and 8HQ release at the metal coating interface but also improved the barrier properties. This work proposed a new type of .
