The Preparation And Electrochemical Analysis Of Novel Graphene-based Anticorrosive Materials

Metals corrosion bring huge economic losses to all over the world every year.Therefore,the research of improving the corrosion resistance of metals has become one of the hotest topics of many researchers.Graphene,two-dimensional nanomaterials,has very important application in a lot of fields,such as electrochenmical sensors,capacitors and so on.In recent years,graphene also has broad application prospect in anticorrosive field due to its impermeability,barrier performance and flexibility.In this paper,two graphene-based nano-composites,3,4,9,10-perylene tetracarboxylic acid-graphene(PTCA-G)composite,reduced graphene oxide-sodium cholate(MRGO)composite,were prepared via two different methods.And these composites were added into epoxy resin,respectively to prepare anti-corrosive coatings.The effects of sole graphene,sole 3,4,9,10-perylene tetracarboxylic acid,sole reduced graphene oxide and their composites on the anticorrosive properties of epoxy resin were studied.The influence of volume ratio of PTCA-G composite and the mass ratio of MRGO composite on the anti-corrosion performance of epoxy resin were also investigated.The main tasks are as follows:(1)So far,the research of PTCA-G composite in the field of anti-corrosion has not been reported.In this chapter,PTCA-G composite was synthesized by simple preparation method and the effect of the composite on the corrosion protection property of epoxy resin coating was also studied.The structure and morphology of PTCA-G composite were characteried by Fourier transform infrared spectroscopy,scanning electron microscope,transmission electron microscope.The results showed that due to?-?interaction and hydrophobic force between 3,4,9,10-perylene tetracarboxylic acid and graphene,PTCA-G composite was successfully prepared.The results of scanning electron microscopy and transmission electron microscopy showed that 3,4,9,10-perylene tetracarboxylic acid stacked in graphene in the form of face-to-face because of the?-?interaction between the sp~2 plane of graphene and five-benzene core of 3,4,9,10-perylene tetracarboxylic acid.The consequences of electrochemical measurements indicated that compared with pure epoxy resin coating,epoxy resin containing 3,4,9,10-perylene tetracarboxylic acid and the epoxy resin coating with the addition of graphene,the corrosion resistance of eroxy resin with the addition of PTCA-G composite was significantly improved.This might be attributed to the good dispersion of PTCA-G in epoxy resins and the barrier property of PTCA-G composite.In addition,the effects of different volume ratios of PTCA-G composites on the corrosion protection property of epoxy resin were also investigated.The results manifested that the corrosion resistance of PTCA-G/epoxy resin with 10:4 volume ratio of the 3,4,9,10-perylene tetracarboxylic acid and graphene is the best.May it's just because when the volume ratio of 3,4,9,10-perylene tetracarboxylic acid and graphene is 10:4,the PTCA-G composite in epoxy resin showed the most admirable barrier property and the most excellent dispersion.(2)In recent years,the studies of sodium cholate modified graphene has been reported,but the application of sodium cholate modified graphene in marine anti-corrosion field has not been reported.In this section,graphene oxide was obtained by modified Hummers'method and reduced graphene oxide and MRGO composite were prepared by using reducing agent hydrazine hydrate.The MRGO composite,reduced graphene oxide was added to epoxy resin,respectively,to prepare MRGO/epoxy resin and reduced graphene oxide/epoxy resin coating.And the anti-corrosive properties of different coatings were also studied.By comparing the dispersion performance of reduced graphene oxide with that of MRGO composite,it is observed that the dispersion and stability of MRGO are obviously superior to that of reduced graphene oxide.The morphology and structural characteristic of graphene oxide and MRGO were studied by transmission electron microscopy,Fourier transform infrared spectroscopy and X-ray diffraction.The results showed that MRGO composite was successfully synthesized,sodium cholate was adsorbed on reduced graphene oxide via hydrogen bonding and strong van der Waals force.The anti-corrosive performance of the prepared coatings was tested through electrochemical measurements.The consequence showed that the addition of MRGO could clearly improve the corrosion protection performance of epoxy resin coating,and the corrosion inhibition efficiency is 99.87%.This may be due to the layer structure of MRGO composite,which blocking the micro-pores of epoxy resin and the good dispersion of MRGO in epoxy resin.