Preparation And Anti-corrosion Properties Of Graphene/Polyaniline Nanocomposites

In this paper,in-situ chemical oxidation polymerization method is used to prepare a series of graphene/doped polyaniline with different ratios under different inorganic and organic acid systems.By analyzed and compared the morphology structure and performance of product,the best ratio of graphene and aniline in different acid systems is screened out.According to unique doping-dedoping characteristic of polyaniline,the graphene/redoped polyaniline can be obtained by using the redoped method.The product was characterized by a four-probe conductivity tester,scanning electron microscope,Fourier transform infrared spectrometer,and ultraviolet spectrometer.The electrochemical test is performed by an electrochemical workstation,andthe test results and fitting datas have been analyzed.The main conclusions are as follows:(1)Graphene/doped polyaniline nanocomposites can be prepared in different acid systems by in-situ chemical oxidation polymerization method.In the same acid system,the graphene/doped polyaniline product is superior to the doped polyaniline in terms of morphology,yield,and conductivity.In the same acid system,the product morphology,yield and conductivity of graphene/doped polyaniline with different ratios are different.When the ratio of graphene and aniline is1:15 in periodic acid,sulfuric acid,phosphoric acid,and hydrochloric acid systems,and the ratio is 1:20 in perchloric acid,the product has excellent morphology,high yield,and a large degree of conductivity improvement.When the ratio of graphene and aniline is1:15 in oxalic acid,tartaric acid and citric acid,the ratio is 1:10 in acetic acid system,the product has excellent morphology,high yield,and a large degree of conductivity improvement.(2)Compared with graphene/doped polyaniline and redoped polyaniline under the same acid system,the graphene/redoped polyaniline product has better morphology and the yield and conductivity of graphene/redoped polyaniline have also been significantly improved,which shows that the redoping process coupled with the graphene material and polyaniline composite will play a synergistic effect and improve the morphology and property of the product.(3)In the same acid system,the anticorrosion performance of graphene/doped polyaniline is better than that of graphene and polyaniline.which shows that the corrosion inhibition rate of graphene/doped polyaniline is improved and the radius of impedance arc is increased compared with graphene and doped polyaniline.In thesame acid system,different ratios of graphene/doped polyaniline have different anticorrosive effects: When the ratio of graphene and aniline is1:15 in periodic acid,sulfuric acid,phosphoric acid,and hydrochloric acid systems,and the ratio is 1:20 in perchloric acid,the product has the best corrosion inhibition rate and the radius of impedance arc is increased.When the ratio of graphene and aniline is1:15 in oxalic acid,tartaric acid and citric acid,the ratio is 1:10 in acetic acid system,The product has the best corrosion inhibition rate and the radius of impedance arc is increased.This also confirms that the graphene/doped polyaniline products in different acid systems at the corresponding ratios have obtained the best morphology,yield,conductivity and other properties,and also obtained the best corrosion resistance.(4)In the same acid system,the anticorrosion effect of graphene/redoped polyaniline is better than that of redoped polyaniline and graphene/doped polyaniline,which shows the corrosion inhibition rate and the impedance arc radius increase.This indicates that the graphene in the composite plays a shielding role and provides better physical protection.At the same time,the redoping makes it easier to release the functional acid ions or functional groups contained in the composite,which is conducive to improvement of anticorrosion performance.The anticorrosion property of graphene/redoped polyaniline in different acid systems is also different.Among inorganic acids,graphene/redoped polyaniline in perchloric acid system has the best anticorrosive effect,and the corrosion inhibition rate is 84.53%.Among organic acids,graphene/redoped polyaniline has the best anticorrosion effect under the oxalic acid system,and the corrosion inhibition rate is 81.01%.