A Master of Science thesis in Mechanical Engineering by Khalil Mohammed Abed entitled, "Magnetic Fe3O4 Nano-Structured Coatings for Corrosion Protection of Mild Steel," submitted in July 2014. Thesis advisor is Dr. Taleb Ibrahim and thesis co-advisor is Dr. Shivakumar Ranganathan. Soft and hard copy available.
The use of coatings is a prime method in corrosion control of mild steel in the industry. Inorganic coatings have proven potency in corrosion control over organic ones; however, they have always been associated with a negative impact on the environment. Therefore, scientists and engineers have always been working toward improving the corrosion resistance of environmentally friendly organic coatings by different methods. This work looked into the effect of the addition of fig leaves extract, micro Fe3O4 pigments and Fe3O4 nano-particles to water-based acrylic coating in an attempt to enhance its corrosion protection properties. Both fig leaves extract and micro iron oxide powder demonstrated a corrosion-inhibitive effect when added to the coating. Upon confirming the positive impact of micro iron oxide, the effect of incorporating magnetic nano-particles Fe3O4 into alkyd-based enamel and water-based coatings was examined using Electrochemical Impedance Spectroscopy (EIS). For alkyd-based coating, Fe3O4 nano-particles were used in powder form and added during the grinding phase of preparing the coat. In addition, the effect of using glass beads during the grinding was also examined. In the case of water-based acrylic coating, Fe3O4 dispersion was prepared using a dispersant agent, a mechanical stirrer, and a snoicator. The dispersion was then added at the last stage of the grinding phase of the water-based acrylic coating. EIS measurements indicated an improvement on the corrosion protection properties of the alkyd-based coating. They also confirmed a positive effect for using glass beads as a grinding medium during the preparation of the alkyd-based coating. However, EIS technique exhibited a limitation in detecting the impact of incorporating Fe3O4 nano-particles into the water-based acrylic coating, due to the nature of its intrinsic low performance in immersion applications. Finally, an attempt was made to look inot the effect of exposing the nano-structured water-based coating to a magnetic field during the curing time of the coating. Nevertheless, It has also been difficult to infer the effect of exposing the nano-modified acrylic coating to a magnetic field due to the same reason.