Nanostructured Al₂O₃ has been applied as a protective coating against corrosion of the carbon steel (C.S) in seawater environment (3.5% NaCl) at temperatures range (298-328)K. Alumina nanoparticles were deposited on carbon steel substrates by cathodic electrophoretic deposition (EPD) with ethanol as suspension medium and poly (acrylic acid) (PAA) as polymeric charging agent.

Meanwhile, the surface morphology was examined using Atomic-force microscopy (AFM). The cross-section AFM showed that the particles sizes for the Al₂O₃ NPs is around 60-80 nm.

The anticorrosion behaviour of coated C.S was investigated in 3.5% NaCl at temperature range 298-328 K by potentiodynamic polarization measurements. Results show that using PAA in suspension coat increased PE% when compared with PE% in absence of PAA and gaves resistance in above temperature range. Kinetic parameters (activation energy and pre-exponential factor) were calculated and discussed. Also, thermodynamic Values ΔG and ΔH were calculated and it shows that corrosion reaction was spontaneous and exothermic in nature