| Corrosion phenomenon reached throughout all areas of national economy and national defense construction.Graphene,which is an ideal two-dimensional sheet-like nano-materials,has a very attractive potential prospects in the anti-corrosion functional coatings.Coatings are the most commonly used and the most direct protection.This paper was based on the graphene oxide and combined with the advantages of nano-materials and epoxy resin.Meanwhile,two kinds of inorganic nano-particles?ZrO2 and TiO2?were respectively grafted onto GO surface by silane coupling agent to prepare GO-Zr O2 and GO-Ti O2 composites with different mass ratio.Then,the prepared composite materials were added into epoxy resin to prepare epoxy resin coatings and the mechanical properties and corrosion resistance of the coatings were studied.In addition,the anti-corrosion mechanism of coatings was discussed.Conclusions are as follows:?1?GO was prepared by modified Hummer method and was characterized by FTIR,XRD and SEM.The results showed that the prepared graphene oxide lamellar layer was very thin and had a large amount of oxygen-containing functional groups on the surface of GO.GO-ZrO2?2:1?,GO-ZrO2?3:1?GO-ZrO2?4:1?composites were prepared by grafting nano-zirconia?ZrO2?onto GO surface with 3-aminopropyltriethoxysilane?APTS?and were characterized by FT-IR,XRD and SEM.Then the results showed that the ZrO2 was successfully grafted onto the GO surface and the dispersibility and compatibility of GO in the epoxy resin were greatly improved.Moreover,the dispersion of GO-ZrO2?3:1?in the epoxy resin was the best.The mechanical properties of the coating showed that the adhesion of GO-ZrO2?3:1?/ EP can reached 0 grade and the hardness was 3H.The results of electrochemical impedance spectroscopy?EIS?showed that the epoxy resin coatings with 2wt.% GOZr O2?3:1?had the best corrosion resistance and the impedance value of the coating was about 109? · cm2 after soaking in 3.5% NaCl electrolyte for 20 days.The Tafel curves showed that the corrosion potential of GO-ZrO2?3:1?/ EP was the highest,at-0.210 V,and the corrosion current was the lowest,at 1.97 × 10-7A.The influence of different filler on the lowest frequency impedance of the coatings showed that the coatings resistance of GO-ZrO2 composites decreased slowly with time.After 25 days of soaking,the impedance value of GO-ZrO2?3:1?/ EP was the largest and stabilized at about 1.0 × 109? · cm2.The neutral salt spray test results showed that the corrosion resistance of GO-ZrO2?3:1?/ EP was the best after soaking in 5% NaCl electrolyte for 360 h.?2?The composite materials of GO-TiO2?2:1?,GO-TiO2?3:1?and GO-Ti O2?4:1?were prepared by grafting TiO2 onto GO surface with APTS according to different mass ratio?MGO:Mf-TiO2?and were characterized by FT-IR,XRD and SEM.Then the results showed that the TiO2 was successfully grafted onto the GO surface,and the dispersibility and compatibility of GO in the epoxy resin were greatly improved.The mechanical properties of the coatings showed that the adhesion of GO-TiO2?2:1?/EP can reached 1 grade and the hardness was 2H.The results of EIS showed that the epoxy resin coatings with 2wt.% GO-TiO2?2:1?had the best corrosion resistance,and the impedance value of the coating was about 109? · cm2 after soaking in 3.5% NaCl electrolyte for 20 days.The Tafel curves showed that the corrosion potential of GOTiO2?2:1?/ EP was the highest,at-0.439 V,and the corrosion current was the lowest,at 7.94 × 10-9A.The influence of different filler on the lowest frequency impedance of the coatings showed that the coatings resistance of GO-TiO2 composites decreased slowly with time.After 25 days of soaking,the impedance value of GO-TiO2?3:1?/ EP was the largest and stabilized at about 1.1 × 109? · cm2.The neutral salt spray test results showed that the corrosion resistance of GO-TiO2?3:1?/ EP composite coatings was the best after soaking in 5% NaCl electrolyte for 360 h.?3?dGO-ZrO2?2:1?,dGO-ZrO2?3:1?,dGO-ZrO2?4:1?composites were prepared by grafting nano-ZrO2 onto GO surface with APTS and GPTS according to different mass ratio?Mf-GO: Mf-ZrO2?and were characterized by FT-IR,XRD and SEM.The results showed that the ZrO2 was successfully grafted onto the GO surface,and the dispersibility and compatibility of GO in the epoxy resin were greatly improved.Meanwhile,the dispersion of dGO-ZrO2?3:1?in the epoxy resinwas the best.The mechanical properties of the coatings showed that the adhesion of d GO-ZrO2?3:1?/ EP can reached 1 grade and the hardness was 3H.The results of EIS showed that the epoxy resin coatings with 2wt.% dGO-ZrO2?3:1?had the best corrosion resistance and the impedance value of the coating was about 109? · cm2 after soaking in 3.5% NaCl electrolyte for 20 days.The Tafel curves showed that the corrosion potential of dGO-ZrO2?3:1?/ EP was the highest,at-0.163 V,and the corrosion current was the lowest,at 8.71 × 10-9A.The influence of different filler on the lowest frequency impedance of the coatings showed that the resistance of dGO-Zr O2/EP decreased slowly with time.After 25 days of soaking,the impedance value of d GO-ZrO2?3:1?/ EP was the largest and stabilized at about 2.3 × 109? · cm2.The neutral salt spray test results showed that the corrosion resistance of dGO-ZrO2?3:1?/ EP was the best after soaking in 5% NaCl electrolyte for 480 h. |
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