Synthesis of Ethylenediamine–Graphene Oxide Coating on Carbon Steel by Electrophoretic Deposition and Its Anticorrosion Properties

Abstract

Graphene oxide (GO) is widely used in carbon steel anticorrosion coatings due to its unique two-dimensional structure. However, pure GO is hydrophilic, and the GO coating is easily damaged and fails by the erosion of water molecules. In this paper, ethylenediamine (EDA) is used to reduce and modify GO, and a simple and environmentally friendly electrophoretic deposition (EPD) method is used to deposit EDA-GO coatings on carbon steel, which are then surface treated with stearic acid (SA) solution to form SA-EDA-GO coatings. A series of analyses show that ethylenediamine successfully functionalizes and partially reduces GO, forming coatings with higher crystallinity. The results of the pull-off test prove that ethylenediamine can act as a complexing agent to increase the bonding force between the coating and the metal. Electrochemical tests show that the EDA-GO coating structure is denser, the flakes are more organized, and the corrosion resistance of the coating is improved. The cobweb-like structure on the surface of the SA-EDA-GO coating can reduce the aggregation of water droplets on the surface of the coating and provide better corrosion resistance, which can be more widely used in the field of corrosion protection of carbon steel.