▎ 摘　　要

NOVELTY - Saltwater corrosion resistant composite coating comprises chitosan, reduced graphene oxide (rGO) having a nanosheet morphology in which a multiple wrinkled nanosheets are turbostratically stacked on top of each other, a conductive polymer uniformly deposited on a surface of the nanosheet of the rGO, and a cured epoxy. The rGO and the chitosan are dispersed in particles of the conductive polymer to form a three-dimensional (3D) network. The 3D network comprises 85-95 wt.% conductive polymer, 0.5-5 wt.% rGO, and 1-10 wt.% chitosan, based on a total weight of the conductive polymer, the rGO, and the chitosan. The at least a portion of the chitosan is covalently bound to the rGO. The at least a portion of the conductive polymer is covalently bound to the chitosan. USE - Saltwater corrosion resistant composite coating used in saltwater corrosion resistant surface (claimed). ADVANTAGE - The saltwater corrosion resistant composite coating has enhanced adhesion strength and anticorrosive behavior, improved penetration resistance which can be attributed to the physical shielding protective film to obstruct harsh species from electrolytes to the steel surface, improved effective physical barrier that causes the substantial enhancement in corrosion protective behavior of the epoxy coatings by homogeneous distribution and efficient compatibility of the PANI/chitosan (CS)/rGO in the epoxy matrix, and reduced the penetrability of the epoxy by zigzagging a dispersion path and making the dispersion pathway of the electrolyte more discursive by PANI/CS/rGO seals the micro defects and free volumes of the epoxy film. DETAILED DESCRIPTION - Saltwater corrosion resistant composite coating comprises chitosan, reduced graphene oxide (rGO) having a nanosheet morphology in which a multiple wrinkled nanosheets are turbostratically stacked on top of each other, a conductive polymer uniformly deposited on a surface of the nanosheet of the rGO, and a cured epoxy. The rGO and the chitosan are dispersed in particles of the conductive polymer to form a three-dimensional (3D) network. The 3D network comprises 85-95 wt.% conductive polymer, 0.5-5 wt.% rGO, and 1-10 wt.% chitosan, based on a total weight of the conductive polymer, the rGO, and the chitosan. The at least a portion of the chitosan is covalently bound to the rGO. The at least a portion of the conductive polymer is covalently bound to the chitosan. The 3D network is dispersed in the cured epoxy. The saltwater corrosion resistant composite coating comprises 1-10 wt.% conductive polymer, the rGO, and the chitosan in total, and 90-99 wt.% cured epoxy, based on a total weight of the conductive polymer, the rGO, the chitosan, and the cured epoxy. INDEPENDENT CLAIMS are included for: 1. a saltwater corrosion resistant surface, which comprises: a substrate, and a layer of the saltwater corrosion resistant composite coating partially coated on a surface of the substrate; and 2. a method of making the saltwater corrosion resistant composite coating, which involves: (a) mixing chitosan and rGO in an acid to form a dispersion; (b) adding a conductive polymer monomer to the dispersion to form a mixture; (c) adding an oxidizing agent into the mixture and stirring for at 15-25℃ least 2 hours to form a reaction mixture; (d) filtering and washing the reaction mixture with a polar protic solvent to form a wet powder; (e) drying the wet powder at a temperature 50-80℃ for at least 10 hours to form a dry powder; (f) sonicating the dry powder in an aprotic solvent for at least 5 minutes to form a suspension; (g) mixing the suspension with a hardener and sonicating for at least 5 minutes to form a uniform suspension;(h) evaporating the aprotic solvent from the uniform suspension to leave a paste; and (i) mixing the paste with an epoxy resin and degassing at a temperature greater than 25℃ for at least 10 minutes to form the saltwater corrosion resistant composite coating.