Ionic and Molecular Materials of High Thermal Stability: Design, Structure, and Function

University Of South Alabama, Mobile AL

Investigators

Abstract

In this project, funded by the Chemical Structure, Dynamics and Mechanism B Program of the Chemistry Division, Professor James Davis and his students of the Department of Chemistry at the University of South Alabama are exploring the synthesis, characterization, and properties of a new type of ionic liquid salts. The salts being investigated are expected are highly resistant to heat and retain their liquid character, without evaporation, decomposition, or flammability, for long periods of time. Salts of this type can be used as substitutes for more traditional liquids in applications ranging from heat transfer fluids and high-performance lubricants to biomass processing and the synthesis of important electronic materials such as semiconductors. The project brings together elements of chemical synthesis as well as material science and engineering, and offers engaged students a broad opportunity for gaining experience from a spectrum of activities. Since the institution at which the research is taking place serves a high proportion of individuals from groups underrepresented in the sciences and engineering, the project provides important opportunities to engage in the professional training of individuals from these communities. Ionic liquid salts are materials of considerable fundamental interest and growing practical utility. Because of their non-volatility, ionic liquids can be used in applications requiring high temperatures, such as in heat transfer, lubrication, or high-temperature materials synthesis. Although typical ionic liquid salts have relatively high degrees of thermal stability, many of them are still incapable of being used for long durations at temperatures above 200 degrees Celsius. By exploiting tetraarylphosphonium and triarylsulfonium salts, ionic liquid salts capable of remaining stable at temperatures of 300 degrees Celsius for periods over three months have been achieved by Professor Davis' group. New strategies are being pursued to improve their thermal stability profile. These strategies include the use of thermally stable anions, cross-linking of the molecules, the incorporation of graphene, and blending with oligophenylene ethers. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.