L-蛋氨酸对预腐蚀Q235碳钢缓蚀性能的分子动力学研究  

Molecular dynamics simulation study on the corrosion inhibition performance of L-methionine for Q235 carbon steel

作　　者：孙海礁[1,2] 张江江 龙武[1,2] 郭玉洁[1,2] 赖南君[3] 朱元强 SUN Haijiao;ZHANG Jiang-jiang;LONG Wu;UO Yu-ji;LAI Nan-jun;ZHU Yuan-qiang(Northwest Oilfield Branch of China Petroleum and Chemical Corporation,Urumqi 830011,China;Key Laboratory of Enhanced Oil Recovery in Carbonate Fracture-hole Reservoirs of China Petroleum and Chemical Corporation,Urumqi 830011,China;School of Chemistry and Chemical Engineering,Southwest Petroleum University,Chengdu 610500,China)

机构地区：[1]中国石油化工股份有限公司西北油田分公司,新疆乌鲁木齐830011 [2]中国石油化工集团公司碳酸盐岩缝洞型油藏提高采收率重点实验室,新疆乌鲁木齐830011 [3]西南石油大学化学化工学院,四川成都610500

出　　处：《化学研究与应用》2023年第9期2063-2070,共8页Chemical Research and Application

摘　　要：采用失重法、密度泛函理论和分子动力学模拟研究了预腐蚀对L-蛋氨酸在60℃、1M的HCl溶液中对Q235碳钢的影响和缓蚀剂的缓蚀机理。结果表明:预腐蚀作用降低了L-蛋氨酸对Q235碳钢缓蚀作用,缓蚀率下降15%。密度泛函理论和分子动力学模拟结果表明,羧基上的氧原子带有明显的负电荷能够吸附到金属表面形成缓蚀剂膜,发挥缓蚀作用,为成膜缓蚀机理。L-蛋氨酸在没有预腐蚀的Q235碳钢表面吸附分子数为24时,缓蚀剂膜最致密。而L-蛋氨酸在预腐蚀后的Q235碳钢表面吸附时的吸附能显著降低,缓蚀剂在碳钢表面的分布密度也明显下降,这很好解释了预腐蚀作用降低了缓蚀剂缓蚀率的实验结果。本文的研究结果对缓蚀剂的研究和实际应用具有一定的指导意义。The effect of pre-corrosion of Q235 carbon steel and the corrosion inhibition mechanism of L-methionine in 1M HCl solu-tion at 60 C were studied using weight loss method,density functional theory,and molecular dynamics simulation.The results showed that the corrosion inhibition performance of L-methionine on Q235 carbon steel was reduced by pre-corrosion,and the corro-sion inhibition efficiency decreased by 15%.Density functional theory and molecular dynamics simulation results show that oxygen atoms on the carboxyl group with significant negative charges can be adsorbed onto the surface of Q235 forming a corrosion inhibitor film,which prevents the metal from corrosion.The corrosion inhibitor film is the densest when the number of L-methionine molecules adsorbed on the surface of Q235 carbon steel without pre-corrosion is 24.However,the adsorption energy of L-methionine on the surface of Q235 carbon steel after pre-corrosion significantly decreased,and the density distribution of the corrosion inhibitor mole-cules on the surface of carbon steel also significantly decreased,which well explains the results of the weight loss test.The results of this study have certain guiding significance for the research and practical application of corrosion inhibitors.

关 键 词：预腐蚀 分子动力学模拟 L-蛋氨酸 缓蚀性能 

分 类 号：O643.1[理学—物理化学]