Ballistic energy transport in molecules

Tulane University, New Orleans LA

Investigators

Abstract

With this award, the Chemical Structure, Dynamics and Mechanisms (CSDM-A) Program in the Division of Chemistry is funding Professors Igor Rubtsov and Alexander Burin of Tulane University to investigate unusually rapid movement of energy in molecules, so-called "ballistic energy transport." Most often energy (as heat) is transported slowly through materials as thermal diffusion. Professor Rubtsov's research group has discovered systems where energy deposited in long molecules is rapidly transferred to distant locations. This anomalous transfer of energy may help scientists discover new materials with improved thermal properties. The graduate and undergraduate students working on this project will receive training in laser and optical science. The PI and co-PI participate in a number of educational activities on their campus, including the Tulane LSAMP Summer Undergraduate Research Training Program, which provides undergraduates students from groups underrepresented in science with authentic research experiences. Professors Igor Rubtsov and Alexander Burin and their respective research groups will combine ultrafast laser spectroscopy (relaxation-assisted two-dimensional infrared spectroscopy) combined with theoretical modeling to develop a better understanding of how the very rapid energy transport over molecularly-significant distances occurs. Some of the questions that these scientists hope to answer include: (1) What are the main factors determining the speed and efficiency of ballistic transport? How does temperature effect the speed of ballistic transport? How does the three dimensional structure of a material effect the speed of ballistic transport? Among the factors affecting transport to be examined are the primary and secondary chain structure, chain architecture, the nature and energy of the source vibrational mode, and the temperature. These studies will help to establish the most likely transport mechanisms and,as such, will likely suggest ways of reducing losses for ballistic energy transport. The ballistic transport mechanism may have to be considered as a principal component of energy transport in molecules, especially for molecules featuring functional groups with repeating units, which are very common. Thus, this study has the potential of developing new ways of understanding vibrational energy transport in molecules at a very fundamental level and may have a broad impact on physical and materials science and engineering.