分子动力学模拟水溶液中席夫碱基表面活性剂在Zn表面的吸附行为

Molecular Dynamics Simulation of Adsorption Behavior of Schiff Base Surfactants on Zn Surface in Aqueous Solution

合成了3种聚乙二醇(400)月桂酸单酯席夫碱基表面活性剂(M1,M2和M3),并进行了结构表征。采用分子动力学模拟研究了M1,M2和M3在Zn表面的吸附行为和席夫碱基表面活性剂分子中基团对吸附性能的影响,探讨了其吸附机理。利用失重法、电化学阻抗谱和SEM研究了3种表面活性剂对碱性Zn电极的缓蚀性能。结果表明,M3的缓蚀性能最好,当其浓度达到1.0 mmol/L时,缓蚀率达92%。席夫碱基表面活性剂分子基本平行吸附在Zn表面,形成致密吸附分子膜。3种表面活性剂分子吸附能大小依次为:M3>M2>M1,吸附速率顺序为:M3>M2>M1;相比于M2和M1,M3对碱性Zn电极具有更好的缓蚀性能。

Three polyethylene glycol （400） lauric acid monoester Schiff base surfactants （M1, M2 and M3） were synthesized and characterized. The adsorption behavior and the effect of the group of surfactant molecules on the adsorption properties about M1, M2, M3 on the metal Zn surface were investi- gated by means of molecular dynamics simulation method. While the corrosion inhibition performance of the three surfactants on alkaline Zn-electrode was assessed by means of mass loss method, electro- chemical impedance spectroscopy and scanning electron microscopy. It showed that M3 exhibited the best corrosion inhibition, and the corrosion inhibition efficiency was 92% when the concentration reached 1.0 mmol/L. The Schiff base surfactant molecules adsorbed on Zn surface parallelly to form a dense molecular adsorption film. What＇s more, the ranking of the adsorption energy of the three surfactants was M3〉M2〉M1, and that of the adsorption rate was M3〉M2〉M1. M3 had better corrosion inhibition per- formance for alkaline zinc electrode, and had better inhibition effect on zinc dendrite.