一种曼尼希碱和钨酸钠复配缓蚀剂的新机理

摘要

Applying molecular dynamics to investigate inhibition mechanism of Mannich base and Na2WO4on Fe(001)surface in HCl solution was implemented.The results show that,Mannich base and Na2WO4can be preferentially adsorbed on the Fe(001)surface compared with corrosive particles such as Cl-,H3O+,H2O and OH-,and the adsorption energies are-7.31eV and-1.59eV,respectively.When the two corrosion in-hibitors are mixed,compared to the single absorption,the adsorption energy of Mannich base can be enhanced by 0.45eV and they form into a co-adsorbed state.In this case,compared to one kind of corrosion inhibitor, the surface coverage of metal film is increased and corrosive particles are more difficult to contact metal sur-face.In addition,when the system is equilibrated,the oxygen atoms of the hydronium ion mainly distributed in the vicinity of 3.43?of the tungsten atoms can be found and co-movement can happen to them.The H-bond groups generated by tungstate and hydrogen ions can restrain the movement of hydrogen ions and prevent them from passing through the protective film so as to achieve a better corrosion-inhibition effect.%应用分子动力学研究了曼尼希碱与钨酸钠在Fe(001)表面上的缓蚀机理.研究表明:相比Cl-、H3O+、H2O、OH-等腐蚀性粒子,曼尼希碱和钨酸根可优先吸附在Fe(001)表面,吸附能分别为-7.31、-1.59eV.当两种缓蚀剂复配时,曼尼希碱的吸附能比单独吸附时增强0.45eV,两者会形成共吸附态.此时复配缓蚀剂与单种缓蚀剂相比,金属表面膜的表面覆盖度增高,阻碍了腐蚀性粒子接触金属表面.除此之外,还发现当系统平衡时水合氢离子的氧原子主要分布在钨原子的3.43?附近,两者会发生共运动,钨酸根与氢离子形成的氢键基团限制了氢离子的移动使它难以通过保护膜,以此达到更好的缓蚀效果.