自组装新型席夫碱膜钢片在饱和CO_2油田水中的缓蚀性能及吸附机理  

Corrosion Inhibition and Adsorption Mechanism of Carbon Steel Self-Assembled Schiff Bases Monolayer in CO_2-Saturated Oilfield Water

作　　者：陈世亮[1,2] 刘峥[1] 何育梅[1] 刘洁[1] 

机构地区：[1]桂林理工大学化学与生物工程学院,广西桂林541004 [2]陕西咸阳化学工业有限公司,陕西咸阳712000

出　　处：《油田化学》2012年第4期486-492,共7页Oilfield Chemistry

基　　金：广西高校优秀人才资助计划项目"迁移性混泥土钢筋阻锈剂的制备及阻锈性能的QSAR和QCAR研究"(项目编号RC2007021);广西研究生教育创新计划项目"取代吡啶甲酰腙席夫碱的合成;表征及其缓蚀行为研究"(项目编号2009105960817M22)

摘　　要：利用邻氧乙酸苯甲醛缩间氨基苯甲酸钾席夫碱(K2L2)缓蚀剂在20号碳钢表面制备了自组装膜(SAMs),用电化学方法研究缓蚀剂合成原料摩尔比、自组装时间、温度对成膜缓蚀率的影响。结果表明,KOH与邻氧乙酸苯甲醛按摩尔比2:1反应得到的K2L2缓蚀剂,在碳钢表面自组装1 h后,形成稳定、致密的缓蚀膜,缓蚀率为94.24%。随温度升高,缓蚀膜在模拟油田水中的缓蚀率先降低后升高。在模拟油田水中浸泡48 h后,由扫描电镜照片发现,组装缓蚀膜钢片表面较光滑,而空白样表面腐蚀严重,有较多晶体颗粒产生。K2L2 SAMs抑制了碳钢的阴极还原过程,改变了电极表面双电层结构,使零电荷电位负移,固/液界面双电层电容明显降低,缓蚀效果良好。K2L2的吸附行为符合Langmuir吸附等温式,吸附机理是典型的化学吸附,吸附平衡常数为7.496×104L/mol。By using 2-[ （3-carboxyl） phenyl imin omethylene ] phenoxyacetic acid （K2 L2） as corrosion inhibitor, the self-assembled monolayers （SAMs） were prepared on the surface of carbon steel. And the effects of mole ratio of raw material for synthesis of the corrosion inhihitors, self-assembly time and temperature on inhibition efficiency of the film were investigated by electrochemical method. The results showed that K212 inhibitor synthesized by KOH and O-formylphenoxyacetic acid in molar ratio 2：1 could take shape fairly dense stable corrosion SAM on carbon steel surface after 1 h assambling, and the inhibition efficiency was of 94.24%. With increasing temperature, the inhibition efficiency of inhibitory film on carbon steel in simulated oilfield water decreased first and increased subsequently. The scanning electron microscope research showed that the surface of carbon steel with inhibitory film immersed in simulated oilfield water 48 hrs was glazed. However, that of blank sample corroded seriously and some crystalline particles were produced. The structure of double-electric layer on carbon steel electrode surface was changed by K2 I2 SAMs and the potential of zero charge （PZC） shifted along a negative direction. In addition, the SAMs restrained the process of cathodic reduction and had well anticorrosion effect. The adsorption behavior of K2L2 SAMs followed Langmuir＇s adsorption isotherm formula, and the adsorption mechanism was typical chemisorptions with adsorption equilibrium constant 7. 496 × 10^4 L/mol.

关 键 词：碳钢 自组装膜 席夫碱 CO2腐蚀 电化学 缓蚀机理 

分 类 号：O646.6[理学—物理化学] TG174.42[理学—化学]