| The construction of hydrogen transmission pipelines that can effectively reduce the cost of hydrogen transportation is an important part of achieving the promotion of hydrogen energy applications and ultimately achieving the dual carbon goals.However,hydrogen embrittlement has always been a major challenge threatening the long-term service life of steel materials.When steel is exposed to a hydrogen environment for a long time,hydrogen will penetrate into the interior of the steel,accumulate at high-energy sites,and combine into hydrogen molecules,which will cause hydrogen bubbles to appear inside the steel.This becomes a crack source under fatigue load,leading to a decrease in the fatigue strength of the steel and posing a serious threat to the long-term safe operation of pipelines.Therefore,it is necessary to design a cheap and easy-to-construct organic anti-hydrogen coating for hydrogen transmission pipelines to ensure their long-term reliable operation.However,general organic coatings have a loose large molecule chain structure,and there are certain pores between large molecules that can be permeated by hydrogen atoms/molecules,requiring the addition of fillers for anti-hydrogen modification to achieve anti-hydrogen function.Based on the phenomenon that nano-scale hydrogen traps can enhance the antihydrogen performance of materials,this paper selected graphene oxide(GO)with strong hydrogen absorption ability and anti-hydrogen effect based on DFT theoretical calculation results to modify organic coatings and prepared a series of GO-modified organic antihydrogen coatings.The anti-hydrogen mechanism of GO in them was explored,and the formula of the organic anti-hydrogen coatings was optimized.The main contents are as follows:(1)GO-modified epoxy resin coatings were prepared,and the electrochemical hydrogen permeation testing method combined with scanning electron microscopy morphology analysis was used to verify the anti-hydrogen effect of GO as a hydrogen trap in the coatings.Furthermore,APTES was used to silanize GO,and APTES-GO,which had better dispersion in the rich zinc epoxy resin coating and retained the graphene layer anti-hydrogen structure,was prepared.The optimization of the APTES silanization process parameters for GO was carried out using Raman spectroscopy,and the optimal proportion of APTES to GO was determined to be 5 mL/g.When X80 steel was protected by APTES-GO-modified epoxy resin coatings,its anti-hydrogen performance in electrochemical hydrogen permeation testing was twice as high as that of X80 steel protected by epoxy resin coatings with the same amount of GO modification.(2)APTES-GO was used to modify PVDF coatings,exploring the relationship between the dispersion of enhanced particles and the electrochemical hydrogen permeation performance of the coatings,as well as their anti-hydrogen mechanism in the coatings,and optimizing the formulation of the coatings.The anti-hydrogen performance of the coatings increased as the APTES-GO content in the PVDF coatings increased from 0.1 wt%to 1 wt%,but when the APTES-GO content in the PVDF coatings exceeded 1 wt%up to 10 wt%,APTES-GO aggregated beyond the solubility of the coating,and the higher the content,the more serious the aggregation phenomenon,resulting in a decrease in the anti-hydrogen performance of the coatings.Infrared spectroscopy analysis found that APTES-GO could also increase the crystallinity and chain regularity of PVDF,thereby increasing the structural density and improving the structural anti-hydrogen performance of the coatings.(3)When the amount of APTES-GO added was 1 wt%,the maximum anti-hydrogen performance of APTES-GO-PVDF coatings was 112 times that of X80 steel,and it could guarantee that the fatigue life of the matrix would not decrease under a stress amplitude of 510 MPa after 5 hours of electrochemical hydrogen permeation.In contrast,the fatigue life of the unprotected samples decreased by 50%. |
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