CAREER: Characterizing Water's Response to Hydrophilic Surfaces

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

Adam Willard of the Massachusetts Institute of Technology is supported by an award from the Chemical Theory, Models and Computational Methods program in the Division of Chemistry to study hydrophilic (water-loving) interactions. Water is the most important liquid on our planet, yet there are many aspects of water that we still struggle to understand. This includes water's microscopic behavior when it is next to a surface, where water-surface interactions cause the microscopic properties of water to differ significantly from those of the bulk liquid. Understanding these differences is important to solving many scientific problems such as steel corrosion, fuel cell operation, and preventing the formation of protein aggregates that lead to neurodegenerative diseases. Professor Willard's research focuses on investigating how the microscopic properties of water interfaces depend on the details of the interfacial environment. The Willard Group uses theory and computational approaches to develop methods for quantifying water's collective response to different types of surfaces. Their goal is to develop a molecular theory to describe the thermodynamic forces that govern water's microscopic behavior at surfaces. With this theory Dr. Willard and his research group can begin to address some important unsolved scientific problems, such as unraveling water's role in controlling protein interactions in biology. Dr. Willard is developing an outreach and educational development program that harnesses the educational potential of modern computer simulation including user-friendly software that allows students to design and carry out virtual experiments on nanoscale systems. He also produces educational videos that use sound to reveal important concepts in molecular physics. This "molecular music" provides insight into molecular physics that is otherwise unapparent. Dr. Willard and his coworkers engage in the theoretical investigation of the microscopic physical principles that govern hydrophilic solvation. The research is motivated, in large part, by the large imbalance that currently exists between the theoretical understanding of hydrophobic and hydrophilic solvation. Hydrophobic solvation can be understood in terms of a unifying theoretical basis, the development of which has led to many important discoveries. However, no analogous theory exists to describe the general principles of hydrophilic solvation. This limits the ability to understand and control a wide range of fundamental processes, including protein-ligand binding, aqueous electro-catalysis, and protein aggregation. The microscopic physics that govern hydrophilic solvation emerge through a competition between solute-water and water-water interactions. Dr. Willard investigates this competition through the development of analytical theory and computational methods. His approach aims to: (1) include water's nonlinear dielectric response in implicit models of solvation, and (2) determine how solute-induced strain on the interfacial hydrogen bonding network can drive specificity in solute-solute interactions.