▎ 摘　　要

NOVELTY - Preparing a aqueous coating comprises (1) dispersing aqueous epoxy resin emulsion, filler, dispersant, defoaming agent, anti-settling agent, and leveling agent in a high-speed disperser, grinding to a fineness of 30 µm, and introducing porphyrin-modified graphene suspension and stirring evenly. The preparation of porphyrin-modified graphene suspension is as follows: (a) placing 1-5 g of graphene in a three-necked flask, and adding a mixed acid solution of sulfuric acid and nitric acid to it and then cooled naturally to room temperature. (b) taking acidified graphene suspension, introducing 3-4 g of DMAC dimethylacetamide, chiral Schiff base cobalt complex, 1.5-2 g of 5,10,15,20-tetra(4-aminophenyl)porphyrin, 1-2 g of tetraethylammonium iodide, 10-20 ml of triethylamine, and ethylene glycol in sequence, (2) mixing curing agent and deionized water to obtain component B; (3) mixing component A and B, and coating on the surface of the substrate for curing at room temperature. USE - The method is useful for preparing aqueous paint. ADVANTAGE - The method enhances the friction and abrasion performance of the aqueous epoxy resin coating, the coating composition is added with modified graphene material, the bonding force of the coating friction surface is reduced, so as to obviously improve the mechanical property of the annealed coating and coefficient of friction coating, and the coating has excellent mechanical property and wear-resistant property. The method provides the coating that has very high suspension stability, no delamination occurs in one week, sedimentation and aggregation, extremely high suspended stability, and is capable of highly dispersing in the coating. DETAILED DESCRIPTION - Preparing an aqueous coating, comprises (1) preparing component A: uniformly dispersing aqueous epoxy resin emulsion, filler, dispersant, defoaming agent, anti-settling agent, and leveling agent in a high-speed disperser, then grinding to a fineness of 30 µm or fewer, and then adding a porphyrin-modified graphene suspension and stirring evenly to obtain component A. The preparation method for the porphyrin-modified graphene suspension is as follows: (a) placing 1-5 g of graphene in a three-necked flask, and adding a mixed acid solution of sulfuric acid and nitric acid to it. One neck of the three-necked flask is sealed, one neck is stirred, and one neck is refluxed. The three-necked flask is refluxed at 90-95℃ for 4-5 hours, and then cooled naturally to room temperature. The resulting solution is washed with a large amount of deionized water and filtered to obtain a pH=5-7, 60-70 wt.% acidified graphene suspension. The volume of the mixed acid solution is 500-700 ml, and the volume ratio of sulfuric acid to nitric acid is 1:1.5. The concentration of sulfuric acid is 70wt.%, and the concentration of nitric acid is 65 wt.%; (b) taking 2-4 g of 60-70 wt.% acidified graphene suspension, introducing 3-4 g of DMAC dimethylacetamide, 0.2-0.3mg of chiral schiff base cobalt complex, 1.5-2 g 5,10,15,20-tetra(4-aminophenyl)porphyrin, 1-2 g of tetraethylammonium iodide, 10-20 ml of triethylamine, and 5-15 ml of ethylene glycol in sequence, and fully mixing the raw materials under ultrasonic assistance. Using a carbon mesh glass body as the anode and a platinum sheet as the cathode, the electrochemical modification treatment is performed in an undivided electrolytic cell with the following electrolysis parameters: 150-200rpm stirring, argon protection, constant current electrolysis at 50-65℃, current density of 0.200.5 A/cm2, and electrolysis time of 2-3 hours. After the electrolysis is completed, the solution is vacuum distilled to remove part of the solvent, dried and dehydrated, and then re-suspended in deionized water to obtain a 20-30wt.% porphyrin-modified graphene suspension; (2) preparing component B: uniformly mixing curing agent and deionized water to obtain component B; (3) mixing: mixing component A and component B according to a mass ratio of 10:0.56, and coating on surface of substrate for curing at room temperature.