Collaborative Research: Unraveling Interactions that Drive Water-Osmolyte Interactions in Confinement and Impact Self-Assembly

Depauw University, Greencastle IN

Investigators

Abstract

In this collaborative project funded by the Chemical Structure, Dynamics, and Mechanisms A (CSDM-A) Program of the Chemistry Division, Professors Nancy Levinger (Colorado State University) and Bridget Gourley (DePauw University) along with their research groups are using a combination of magnetic and laser techniques to shed light on water's dynamical properties when confined in minuscule structures that are nanometers, or approximately 40 billionths of an inch, in size. In these minuscule environments, water's molecular behavior does not match what happens in a glass full of water. Additionally, other molecules such as sugars, which are often found with water in such tight spaces, radically influence water’s properties. By creating and characterizing a range of systems, this work advances the understanding of water's behavior in environments that are important to processes such as chemical synthesis, environmental remediation, cellular activity, and beyond. Students involved in this research program develop expertise at the molecular level while with learning effective project collaboration skills by working together on an inter-institutional team of scientists at multiple career stages, undergraduate, graduate, and post-graduate. To facilitate effective mentoring the project also creates and assesses a "mentor the mentor" program led by the PIs to guide graduate researchers as mentors of more novice researchers and thus nurture the development of the next generation of mentors and scientists. This program employs 1D and 2D NMR along with time-resolved and steady-state optical spectroscopies to characterize the confined environments created in reverse micelles and the interactions occurring within them. Combining data from these tools reveals the interplay of confinement and water-osmolyte interactions and feed predictive models. Having characterized the reverse micelle environments that encapsulate osmolytes, results reveal how these environments affect proton and electron transfer reactions. Additionally, the project investigates water-osmolyte interactions transitioning from bulk solution to nanoscopic contexts and explores the impact of osmolytes on reverse micelle structure, stability, and form. The project seeks to advance knowledge by developing predictive tools through direct correlation between observed behaviors and proposed mechanisms to uncover fundamental interactions that exist in confined aqueous environments. The broader impacts of this experimental program are two-fold. First, the program provides undergraduate and graduate students important training in NMR and time-resolved optical spectroscopies as well as experience working in a multi-institutional collaborative team. The science reveals details about crowded biological environments where osmolytes are active and provide predictive models that apply to big ideas like the food, energy, water nexus, and Rules of Life. 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.