基于分子模拟的苯并三氮唑与Irgamet39缓蚀性能研究

Comparative research of corrosion performance between benzotriazole and Irgamet39 based on molecular simulation

苯并三氮唑(BTA)及其衍生物Irgamet39都能在铜绕组表面形成保护膜抑制硫腐蚀,但缓蚀性能却有差异.为探究两者缓蚀性能的差异性,采用分子模拟方法从微观层面对2种缓蚀剂的缓蚀性能进行对比研究.通过计算比较Cu(100),Cu(110)和Cu(111)晶面功函数的大小,选取Cu(110)晶面为研究表面.分析了在2种缓蚀剂吸附情况下Cu(110)表面的态密度变化,发现在费米能级附近,Irgamet39吸附时Cu表面的电子密度较BTA吸附时大,说明此时Cu表面的活性更大.同时比较和计算了2种缓蚀剂分子前线轨道分布以及最高占据轨道和最低空轨道能量差,并且分析了BTA与Irgamet39的电负性.结果表明,Iragmet39分子有多重吸附中心且前线轨道能量差更小,更容易与铜表面发生反应;Irgamet39分子的电负性小于BTA分子,电子易流向铜,更容易与铜形成配位键.以上模拟结果说明在清洁Cu表面,Irgamet39的缓蚀效果更好.

Benzotrizole and its derivative Irgamet39 can form protective films on the surface of copper winding to inhibit sulfur corrosion,but their corrosion inhibition properties are different.In order to explore the difference of corrosion inhibition performance,a molecular simulation method was used to compare the corrosion inhibition performance of BTA and Irgamet39 from micro view.By calculating and comparing the size of Cu(100),Cu(110),Cu(111)crystal surface work function,Cu(110)crystal surface was selected as the study surface.Moreover,the change of density of state of Cu(110) surface under two inhibitors was analyzed.It is found that the electron density at Fermi level of Cu surface is larger than that of BTA when Irgamet39 adsorbed,Indicating that the Cu surface is more active at this moment.Meanwhile,the molecular front-line orbital distribution of two inhibitors and the energy difference between the HOMO orbital and the LUMO orbital are compared and calculated.The result shows that the Iragmet39 molecule has multiple adsorption centers and the front orbital energy difference is smaller than that of BTA,it is easier to react with copper surface.Furthermore,the electronegativity of Irgamet39 molecule is smaller than that of BTA molecule,so electrons tend to flow to copper and combine with copper surface more closely.The above simulation results illustrate that the corrosion inhibition effect of Irgamet39 is better on the surface of clean Cu.