Adsorption and Self-Assembly of Surfactants on Metallic Surfaces

该研究项目将利用实验技术和计算机模拟来研究表面活性剂分子在金属-水界面上的吸附和自组装，以及它们对界面电化学性质的影响。石油和天然气管道的腐蚀失效是一个重大的健康、安全、经济和环境问题。含有咪唑啉、胺和氨基的极性基团和疏水烷基的表面活性剂分子在金属表面具有很强的吸附和自组装能力。这些分子在石油和天然气管道中用作腐蚀缓蚀剂。结果表明，这些分子的自组装吸附膜通过排斥金属-水界面上的腐蚀物种，使界面疏水，或通过改变界面的电化学性质来减轻腐蚀。电化学实验技术将被用来测量金属界面在吸附时电学性质的变化。实验结果与分子模拟相结合，将为这些现象提供全面的分子图景。这一水平的理解将是朝着改进设计更有效的缓蚀剂分子以满足各种应用的方法学迈出的重要一步。表面活性剂在金属表面的吸附和自组装现象对于许多催化和电化学应用是至关重要的。由于金属的高极化率，金属与极性分子之间的相互作用依赖于局部环境。虽然在提高我们对金属-水界面的了解方面有了令人振奋的新进展，但在我们对表面活性剂分子在金属表面吸附的分子水平细节的理解方面仍存在重大差距。对这一现象的许多方面的了解还很模糊，例如金属原子和表面活性剂分子之间的结合性质；分子在吸附薄膜中的取向和堆积；促进自组装的因素；以及界面的电化学性质。利用电化学石英晶体微天平(EQCM)、原子力显微镜(AFM)、和频率发生光谱(SFG)、电化学阻抗谱(EIS)和分子模拟等实验技术，研究人员试图在拟议的研究中解决这些未知因素。除了就跨学科研究项目对研究生和本科生进行培训外，研究人员还计划在俄亥俄州的阿巴拉契亚地区开展外联活动，为这个经济困难地区的公民提供一条通过教育进步的途径。

The research project will employ experimental techniques and computer simulations to study the adsorption and self-assembly of surfactant molecules on metal-water interfaces, and their effect on the electrochemical nature of the interfaces. Corrosion-related failure of oil and gas pipelines is a significant health, safety, financial, and environmental problem. Surfactant molecules with imidazoline, amine and amido-amine based polar groups and hydrophobic alkyl chains are known to strongly adsorb and self-assemble onto metallic surfaces. These molecules are useful as inhibitors of corrosion in oil and gas pipelines. It is suggested that the self-assembled adsorbed films of these molecules mitigate corrosion by either repelling the corrosive species from metal-water interfaces, by rendering the interface hydrophobic, or by changing the electrochemical nature of the interface. Electrochemical experimental techniques will be employed to measure changes in electrical properties of metallic interfaces upon adsorption. The experimental results, combined with molecular simulations, will provide a comprehensive molecular picture of the phenomena. This level of understanding will be a significant step towards improving the methodologies of designing more effective corrosion inhibitor molecules for various applications.The phenomenon of adsorption and self-assembly of surfactants on metallic surfaces is fundamentally important for many catalysis and electrochemical applications. Because of high polarizability of metals, interactions between metals and polar molecules depend on the local environment. While there have been exciting new developments in improving our knowledge of metal-water interfaces, there are significant gaps in our understanding of the molecular-level details of adsorption of surfactant molecules on metallic surfaces. Many aspects of the phenomenon are only vaguely understood, such as the nature of binding between metal atoms and surfactant molecules; molecular orientation and packing in adsorbed films; factors promoting self-assembly; and the electrochemical nature of the interface. Using experimental techniques, such as electrochemical quartz crystal microbalance (EQCM), atomic force microscopy (AFM), sum frequency generation spectroscopy (SFG), electrochemical impedance spectroscopy (EIS) and molecular simulations, the investigators seek to address each of these unknowns in the proposed research. In addition to training graduate and undergraduate students on interdisciplinary research projects, the investigators plan to pursue outreach activities in the Appalachian region of Ohio to provide an avenue for the citizens of this economically disadvantaged area to advance via education.