| Zirconium dioxide(ZrO2)shows excellent properties such as high strength,high fracture toughness,excellent wear resistance,high hardness and excellent chemical resistance.It plays an important role in effectively improving the mechanical properties,high temperature resistance and corrosion resistance of the coating when ZrO2 as a filler adding to an anti-corrosion coating.However,in the curing process,the corrosion of the solvent is likely to cause corrosion channels due to the evaporation of the solvent,and the addition of the nanoparticles is difficult to reduce the influence of the corrosion channel.The two-dimensional filler has a large area,which can block the penetration of corrosive medium inside the coating,prolong the corrosion passage and improve the corrosion resistance of the coating.This paper designs two kinds of two-dimensional nanofillers,inert ZrO2 nanoparticles were used to encapsulate the surface of graphene(rGO),and the role of zirconium dioxide/graphene(ZrO2/rGO)nanocomposites in anti-corrosion coatings was studied in detail.Additionally,ZrO2 nanosheets were prepared using graphene as template,and the anti-corrosion performance of OD and 2D ZrO2 nanofillers were compared.The specific details are as follows:(1)ZrO2/rGO nanocomposite was prepared and used as filler in epoxy anti-corrosion coatings.ZrO2/rGO nanocomposite was prepared by electrostatic adsorption and hydrothermal method,and then used as a filler in epoxy resin to prepare anti-corrosion coatings.The structure and morphology of ZrO2/rGO were analyzed by X-ray diffraction,infrared spectroscopy,transmission electron microscopy and scanning electron microscope.The anti-corrosion performance of ZrO2/rGO/epoxy composite coating was analyzed by electrochemical impedance spectroscopy.It can be found that rGO was successfully encapsulated by ZrO2 and still maintained a sheet structure.ZrO2/rGO/epoxy composite coating showed superior anti-corrosion performance to pure epoxy coating and rGO epoxy coating,with its resistance value of 81.80 G?·cm2.When the coating was damaged,rGO promoted the corrosion reaction at the coating damage,however,ZrO2/rGO could effectively inhibit this effect.(2)2D ZrO2 nanosheets were prepared and used as filler in epoxy anti-corrosion coatings.Using GO sheets as sacrificing templates,ZrO2 nanosheets were obtained through adjusting the pH value and nucleation rate,followed by heating treatment.ZrO2 nanosheets were then used as a filler in epoxy resin to prepare anti-corrosion coatings.The results showed that the prepared ZrO2 was flake structure in shape,analogous to the wrinkled structure of graphene.Compared with pure epoxy coating and zero-dimensional ZrO2/epoxy composite coating,the anti-corrosion performance of two-dimensional coating was greatly improved,with its resistance value of 89.09 G?·cm2.After the coating was immersed in the electrolyte solution for 60 days,the metal substrate with ZrO2/epoxy composite coating remained non-corrosive.Such an anti-corrosion performance of two-dimensional ZrO2/epoxy composite coating is comparable to that of ZrO2/rGO/epoxy composite coating,and more importantly,avoiding the disadvantages of rGO in anti-corrosion coatings. |
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