Preparation Of Graphene Based Corrosion Inhibitor Container And Its Anticorrosion Performance

Graphene has high aspect ratio,impermeability and mechanical properties,which can be used as filler to enhance the penetration inhibition performance of the coating.However,the pure graphene with perfect aromatic system is difficult to disperse and may even degrade the performance of coating.Graphene oxide is a derivative of graphene,which greatly improves the dispersibility of graphene.Nevertheless,with the rich oxygen-containing groups on its surface,graphene oxide has high hydrophilicity.Thegraphene oxide / coating interface will be conduits for faster water penetration.How to improve the dispersion of graphene and keep its high barrier behavior are the hotspots in the graphene modified coating development.In this paper,graphene oxide was used as the precursor.The vertical growth of covalent organic frameworks(COF-1)nanosheets on r GO(v-COF-r GO)was synthesized via two-steps solvothermal reaction.During the solvothermal reaction,both of the growth of COF-1nanocrystalline and reduction of graphene oxide were achieved.The reduced graphene oxide substrate exhibited lower defects and more hydrophobic than graphene oxide.The aromatic system on reduced graphene oxide and COF-1 were used as the adsorption sites of benzotriazole(BTA),which inhibited the corrosion of the defects in the coating and further improved the corrosion resistance of the coating.The impedance of v-COF-r GO-BTA composite epoxy coating is increased by 1.3 orders of magnitude than that of pure epoxy coating;corrosion rate of the Q235 mild steel treated by v-COF-r GO-BTA is 1/2 lower than that of blank sample;the impedance of v-COF-r GO-BTA composite epoxy coating with artificial defects is increased by 0.4 orders of magnitude than that of pure epoxy coating.On the basis of ensuring the high dispersion of graphene,we futher developes graphene as a inhibitor container.Porous organosilica intercalated graphene oxide(p-GA)was synthesized via the two-step polymerization method using 1-(2-aminoethyl)-3-aminopropyltrimethoxysilane as monomer.The controlled release of inhibitor ions from the molybdate loading p-GA(p-GAMo)occurred during the hydrophilic transformation process of the organosilica pores.The p-GAMo was embedded in polyvinyl butyral(PVB)coating and applied on mild steel.The results show that p-GAMo/PVB coating has high dispersion and permeation-inhibition performance.Its impedance is 0.5 order of magnitude higher than that of pure PVB coating;the corrosion rate of mild steel treated by p-gamo is 1/20 lower than that of blank steel;the impedance of p-GAMo composite PVB coating with artificial defects is 0.4 order of magnitude higher than that of pure PVB coating.In order to further improve the long-term self-healing performance of graphene based inhibitor container,the one-step method was adopted to:(1)graft PVA and citric acid onto graphene;(2)embed green corrosion inhibitor cerium hydroxide in the container.Artificial defects in the modified PVB coatings were produced.The controlled release of inhibitor was realized by controlling the ratio of PVA / r GO in the synthesis process.The results show that r GPC(0.01)has not only high inhibitor capacity,but also moderate inhibitor release rate.It is an inhibitor container with long-term self-healing performance.The impedance of r GPC composite PVB coating is 3 orders of magnitude higher than that of pure PVB coating;the corrosion rate of steel treated by r GPC is 1/4 lower than that of blank steel;the impedance of r GPC composite PVB coating with artificial defects is 0.6 orders of magnitude higher than that of pure PVB coating.