A Suite of Undergraduate Laboratories Focused on Surface and Interface Science

现代跨学科科学中的许多突破都发生在物质的两个阶段之间的界面上。不幸的是，许多机构的本科生化学实验室课程在增强学生对界面的理解方面几乎没有提供什么。密歇根州立大学的本科课程在湿化学定量分析、仪器分析、各种光谱测量、色谱与分离科学和电化学等传统领域提供了坚实的基础。目前，本科生很少有机会在密歇根州立大学的实验室或课程序列中获得最先进的表面和界面科学经验。这些本科生实验使用了一个原型界面系统；金上的烷硫醇。这些化合物很容易形成重复性很高的界面。单分子膜的初始吸附过程是快速的，以Au-S相互作用为主，而较长时间的单分子膜结构的形成是由脂肪链退火所介导的。学生们进行了一系列实验，以了解这些单独的单层形成步骤以及单层的稳态性质。第一个实验使用石英晶体微天平实时监测单层的生长。这项技术还可以直接测量烷硫醇在黄金上的初始吸附的吉布斯能，并以图形显示这种吸附的可逆性质。第二个实验利用傅里叶变换红外光谱和光学椭偏仪测量了薄膜的厚度和组织程度。为了将这些实验与界面的物理性质联系起来，学生们使用循环伏安法和接触角测量的传统界面方法来表征单分子膜。这些实验为学生提供了从传统表征到最先进的单层光谱分析的体验，这些光谱是在单一的表征良好的化学体系上进行的。

Many of the breakthroughs in modern interdisciplinary science occur at interfaces between two phases of matter. Unfortunately, the undergraduate chemistry laboratory curriculum at many institutions offers little in the way of enhancing the student's understanding of interfaces. The MSU undergraduate curriculum offers a solid foundation in the traditional areas such as wet chemical quantitative analysis, instrumental analysis, a variety of spectroscopic measurements, chromatography and separations science and electrochemistry. At present, there is little opportunity for undergraduate students to gain experience in state of the art surface and interface science within the laboratory or course sequence at MSU. An archetypal interfacial system is used for these undergraduate experiments; alkanethiols on gold. These compounds easily form highly reproducible interfaces. The initial adsorption process for the monolayers is rapid and is dominated by Au-S interactions while longer term monolayer structural formation is mediated by aliphatic chain annealing. Students perform a suite of experiments to access these separate monolayer formation steps as well as the steady state properties of the monolayers. The first experiment monitors the growth of the monolayer in real time using a quartz crystal microbalance. This technique also allows for the direct measurement of the Gibbs energy of initial adsorption of alkanethiols onto gold and demonstrates graphically the reversible nature of this adsorption. The second experiment measures the layer thickness and extent of organization using FTIR and optical ellipsometry. To relate these experiments to physical properties of interfaces, students characterize the monolayers using the traditional interface methods of cyclic voltammetry and contact angle measurements. These experiments offer students an experience ranging from traditional characterization to state of the art monolayer spectroscopy on a single well-characterized chemical system.