3,5-二溴水杨醛-2-噻吩甲酰肼席夫碱缓蚀剂在油田水中对碳钢的缓蚀性能及分子动力学模拟

合成了一种新的席夫碱缓蚀剂3,5-二溴水杨醛-2-噻吩甲酰肼(L2),通过Tefel极化曲线、电化学阻抗、扫描电镜和分子动力学模拟方法研究了该缓蚀剂在模拟油田水中对碳钢的缓蚀效果,并探讨了其缓蚀机理和吸附行为。结果表明,L2在不同温度、H2S浓度、pH值和Cl-浓度条件下的模拟油田水中对碳钢均具有良好的缓蚀性能。分子动力学模拟结果表明,在水溶液中缓蚀剂L2分子可以稳定地平行吸附在金属表面,有效地将金属表面和水分子隔开,从而起到缓蚀作用,吸附方式为多位点化学吸附;同时L2形成的分子吸附膜可有效地抑制腐蚀离子(Cl-和H3O+)在吸附膜中的扩散,避免了金属表面与腐蚀介质接触而发生腐蚀,从而表现出良好的缓蚀性能。

Inhibition Performance of a New 3,5-dibromosalicylaldehyde-2-thenoyl Hydrazine Schiff Base for Carbon Steel in Oilfield Water and Relevant Molecular Dynamics Simulation

A new 3,5-dibromosalicylaldehyde-2-thenoyl hydrazine Schiff base compounds (L2) was synthesized. Its inhibition performance and adsorption behavior for carbon steel in a simulated oilfield water were investigated by electrochemical methods, scanning electron microscopy and molecular dynamics simulation respectively. The results indicated that L2 exhibits excellent corrosion inhibition performance for carbon steel in the simulated oilfield water, and also that in simulated oilfield waters with various pH values at different temperatures. The molecular dynamics simulation results proved that L2 molecules may parallel be adsorbed on the steel surface firmly via several reactive sites and packed together to form a dense monolayer to prevent the metal surface from water and corrosive medium in the liquid. In addition, L2 molecule monolayer can suppress the inwards migration of corrosive species. That is why L2 exhibits excellent corrosion inhibition performance.