Career: Connecting Structural Order to Thermodynamic and Kinetic Properties Of Aqueous Solutions: A Research and Education Program

Jeffrey R. Errington SUNY Buffalo "Connecting Structural Order to Thermodynamic and Kinetic Properties of Aqueous Solutions: A Research and Education Program." A research project dedicated to gaining a fundamental understanding of the relationship between the macroscopic thermodynamic and kinetic properties of aqueous solutions and their underlying microscopic structure is described. In addition, several initiatives to enhance undergraduate and graduate education in the field of molecular modeling as well as programs to promote science and engineering in the local and global community are presented. The behavior of water and aqueous mixtures plays a key role in biology, chemistry, physics, and the design of many chemical and biological processes. In aqueous systems, directional interactions (hydrogen bonds) combine with short-range repulsions to determine the relative orientation of neighboring molecules as well as their instantaneous separation. These seemingly simple underlying interactions result in macroscopic behavior that is complex and poorly understood. The objective of this investigation is to provide a deeper understanding of the connection between the macroscopic behavior and microscopic interactions in aqueous systems. A further understanding of this connection will be beneficial from both a scientific and industrial standpoint. Within this proposal, a novel formalism for interrogating the behavior of aqueous systems is introduced. The new approach addresses two limitations of previous studies. First, the concept of quantifying structural order is utilized to bring quantitative rigor to the characterization of structural properties. This route is opposed to the examination of mainly phenomenological indicators of solution structure that has been employed in earlier studies. Second, a novel technique for calculating thermodynamic properties of solvation, based on transition matrix Monte Carlo concepts, is presented. The new method addresses many of the deficiencies of existing methods and provides a means for calculating thermodynamic properties that were previously intractable. The goal of the proposed study is to obtain a more complete understanding of three classes of solutes in water: ions, carbohydrates, and amino acids. Each of the selected systems exhibits unique behavior and presents distinct challenges for investigation. The proposal calls for the examination of individual solutes as well as mixtures of solutes in aqueous solution. The three systems selected enjoy both scientific and industrial relevance. Ionic solutions play a key role in geology and their role in corrosion is important to the auto industry. Carbohydrates are an important energy source for plants and animals and are used extensively in the development of pharmaceuticals. Amino acids are the subunits of proteins, and as such are of fundamental importance to metabolic processes as well as to the development of biotechnologies. On the education front, recognizing that nanotechnologies and other applications where a molecular-level approach is employed are emerging fields for employment of chemical engineers, a proposal for curriculum development, which features courses on molecular modeling at both the undergraduate and graduate level, is presented. In addition, an outreach program for the PI and a plan for the PI to organize of an outreach program for undergraduate students is described. The goals of these initiatives are to promote science in the local community, excite students about science and mathematics at a young age, and to improve the retention rate of sophomore and junior undergraduates. Finally, a plan to develop a web-based microscopic learning center is presented. The objective of this initiative is to provide the global community with modules that describe scientific phenomena from a microscopic perspective. From the proposed web site, teachers from all over the world will be able to download material for use in their courses.