Ethylene Glycol-water Based Graphene Oxide Nanofluid as Corrosion Inhibitor in Automotive Radiator

¹ Department of Mechanical Engineering, Universitas Muhammadiyah Magelang Jl. Mayjend Bambang Soegeng KM 5 Mertoyudan, Magelang, Jawa Tengah, Indonesia
² Research Center for Metallurgy, BRIN Gd.720. KST B.J.Habibie, Puspiptek Area, Serpong, Tangerang Selatan, Banten, Indinesia

Abstract

A rapid cooling process is essential to maintain an optimal working temperature in a vehicle, which directly impacts its efficiency. Corrosion is a persistent and inevitable damage in cooling systems that use water-based fluids. The current challenge is to explore water-based fluids that not only exhibit excellent corrosion resistance but also possess superior heat conduction properties to improve vehicle efficiency. This study investigated the incorporation of Graphene Oxide, renowned for its corrosion inhibition properties, into ethylene glycol/water solution to assess its protective efficacy on Al6061 material. A series of analytical methods, including Optical Emission Spectroscopy (OES), pH, conductivity, Fourier-Transform Infrared Spectroscopy (FTIR), and polarization techniques, are used to evaluate the corrosion inhibition performance of graphene oxide at various concentrations and under different ambient temperatures. The results showed a decrease in pH value and conductivity with increasing concentration of graphene oxide. FTIR analysis confirmed the formation of a protective layer on the surface of Al6061. Corrosion rate assessment was performed on Al6061 samples immersed in ethylene glycol/water mixture with graphene oxide concentrations of 0, 0.03%, 0.05%, and 0.10%. There was a significant decrease in corrosion rate with the addition of graphene oxide to the cooling system: at 30°C, the rate decreased to 4.620, 3.308, 2.565, and 1.006 mpy; at 40°C, up to 4,728, 2,541, 1,503, and 1,270 mpy; and at 50°C, up to 5.629, 1.146, 2.947, and 1.441 mpy, corresponding graphene oxide concentrations of 0.03%, 0.05%, and 0.1%, respectively. Experimental data confirmed that graphene oxide effectively reduces the corrosion rate of Al6061 in ethylene glycol/water mixtures. The study concluded that the use of graphene oxide as a corrosion inhibitor markedly improved the resistance and performance of Al6061 in ethylene glycol/water, with graphene oxide contributing to this protective mechanism through the process of physisorption.