Based On Self-assembly And Coaxial Electrospinning To Construct A Metal Copper Corrosion Inhibitor And Its Spectral And Electrochemical Studies

Copper is a kind of metal,which has good conductivity of heat and electricity,and excellent mechanical properties.Copper is widely used in industry,such as the production of wire,sheet,pipe,alloy,etc.In general,copper has good corrosion resistance,however,if exposed to aggressive media,such as CN^–?Cl^–,nitric acid,it is susceptible to corrosion.The corrosion of copper will bring huge economic losses to the production and application.Therefore the corrosion protection of copper has attracted many researchers.So far there are a lot of efforts put on corrosion inhibition of copper,one of the economical and effective method is to modify copper surface with corrosion inhibitor agent.In this paper,three different corrosion inhibitors,single inhibitor,micelles-based self-healing film and coaxial electrospinning membrane were used as protection for metal copper surface to carry on a comparative research.Surface Enhanced Raman Scattering?SERS?can provide rich molecular vibration information,therefore,it can elucidate the inhibition mechanism.The corrosion inhibition behavior and inhibition efficiency of different inhibitors was explored using electrochemical impedance spectroscopy,electrochemical polarization curve,whilst Raman spectroscopy was used to study the mechanism of the corrosion inhibitors.1.4,5-diamino-2-mercaptopyrimidine?MPD?,pharmaceutical intermediate,has been widely used in medicine,biology and others fields due to its high biological activity..Besides,MPD molecule can adsorb on the metal surface easily since it contains-S-H and-N-H groups.In this work,4,5-diamino-2-mercaptopyrimidine was used as copper corrosion inhibitor.Different assembling time and different inhibitor concentration were investigated..The results showed that under optimal assembly condition?assembling concentration is 5×10^-44 M and the assembling time is 8 h?,the inhibition efficiency could reach up to 98.1%.2.Single inhibitor modified copper surface shown excellent corrosion inhibition effect,yet the metal surface would still be severely corroded once the inhibitor surface is damaged.So the self-healing performance of the corrosion inhibitor has gained more and more attention.4-methyl-4H-1,2,4-triazole-3-thiol?4-MTTL?,used in drugs,medicine and pesticide,can form stable chemical bond with d orbital of the metal surface through the lone pair electrons and heterocyclic?electrons via thethree N atoms in its heterocyclic ring,.Phytic acid?PA?as a kind of eco-friendly chemical additive widely exists in beans,rice and other plants.Phytic acid molecule,containing six phosphate bonds,is easy to combine with Cu²⁺metal ions.In this experiment,self-healing microcapsules were formed through 4-methyl-4H-1,2,4-triazole-3-thiol embedded phytic acid micelles under heating condition.,The corrosion inhibition performance was then carefully investigated.Experimental results showed that the optimal condition of micelles-based self-healing film is PA₁@4-MTTL₁₀0 under 5 h assembly time,the corrosion efficiency of which can reach 94.5%.Open circuit potential curves can prove that this film has the function of self-healing.3.Although the micelles-based self-healing method could provide a good corrosion inhibition efficiency with self-healing property,the main disadvantage of such coating is that the inhibitor assembly time is relatively long.Therefore,coaxial electrospinning is an alternative way to prepare corrosion resistance films with self repairing properties of copper.Polyvinylpyrrolidone?PVP?,with high stability,cohesiveness and film forming ability,is widely used in medicine,food and cosmetics due to its excellent solubility and biocompatibility.Polymethyl methacrylate?PMMA?is a non-toxic and eco-friendly that can be used in the production of tableware,sanitary ware,etc.It has good chemical stability,and has strong corrosion resistance in acid,alkali and salt media.The experiment results showed that the coaxial electrostatic spinning film are hydrophobic even under strong acid and alkali conditions?contact angle more than 110 degree?,and the inhibition efficiency can reach 94.1%and it has self-healing capabilities.