Abstract
The composite protective coating is the most widespread technology among various methods used in corrosion protection for the marine industry. Carbon-based materials are the most promising as anticorrosion pigments due to its mechanical strength, chemical inertness, non-cytotoxicity, and very strong absorption of ultraviolet (UV) and visible light. In present study graphene oxide (GO) and multiwalled carbon nanotubes (MWCNT) were investigated as addictive and also, they were modified by nitrogen-doping. The samples of stainless steel (316L) coated by epoxy resin with carbon-based pigments were exposed to UV irradiation (340nm) for 1000h and corrosion behavior in 3.5 wt% sodium chloride (NaCl) solution was investigated before and after UV degradation. Experimental results showed that corrosion current significantly decreased in presence of carbon-based materials, especially nitrogen-doped ones, in the composite coating. The degradation of the epoxy coating after UV exposure was retarded by the presence of the GO, MWCNT and the nitrogen-doped pigments, suggested that carbon-based nanomaterials may enhance the lifetime of composite coating. Finally, a protection mechanism was built to explain the carbon-based nanomaterials improved corrosion resistance and effect of nitrogen-doping on the corrosion behavior.
