Scanning tunneling microscopy of temperature dependent molecular processes at the solution-solid interface

Washington State University, Pullman WA

Investigators

Abstract

Professor Kerry W. Hipps of Washington State University is supported by the Chemical Measurement and Imaging (CMI) Program in the Division of Chemistry to conduct studies using scanning tunneling microscopy on several basic temperature-dependent surface problems of fundamental and technical importance at the solid-solution interface. A variable temperature scanning tunneling microscope (STM) will be customized and used to conduct the proposed research. Processes occurring at the solid solution interface can be dramatically affected by temperature, and understanding these temperature induced processes at the molecular level will facilitate advances in several science research fields including surface chemistry, catalysis, adhesion, corrosion, photophysics, and self-assembly in industrial and biological systems. The results from this research may lead to inexpensive and efficient manufacturing methods in areas such as opto-electronic devices, solar cells and sensors. The objective of the proposed research is to customize a variable temperature instrument to mitigate the problems associated with STM imaging at elevated temperatures, such as thermal drift, temperature differences between different parts of the instrument, and solvent evaporation and condensation on the STM head and other parts of the instrument. The newly customized instrument will be employed to study several basic temperature-dependent surface problems of fundamental as well as practical importance. These include: 1) structures, formation kinetics and thermodynamics of physical adsorbates at the solution solid interface; 2) chemical reactions at the solid-solution interface; 3) phase transformations in covalently attached monolayers; and mechanisms and kinetics of chemical transformations of preformed organic adlayers. Graduate and undergraduate students will be trained in chemistry and instrument construction, two areas for which cross-training is particularly valuable. The results of this study will be incorporated in higher level courses in Chemistry and Materials Science. During the course of conducting this research, the research team will perform outreach activities through the WSU "Imagine Tomorrow" high school energy program.