A Suite of Undergraduate Laboratories Focused on Surface and Interface Science

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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.