Water reorientation and proton transport at the nanoconfined water/amorphous oxide interface

This project, funded by the Environmental Chemical Sciences Program in the Chemistry Division at the National Science Foundation, Professor Stephen H. Garofalini of Rutgers University addresses fundamental questions regarding proton transport at the environmentally-important hydrophilic interfaces such as between silica and nanoconfined water. There are many examples of these types of interactions in our everyday lives. These examples include: low cost water purification methods, batteries for energy storage, glasses used in touch-screen devices and solar panels, and cements and building materials. By participating in this research, graduate and undergraduate students are able to expand their education to applications in environmental chemistry using computational methods. Professor Garofalini currently works with undergraduates from underrepresented groups performing computational studies. Additional students from the University's Aresty Research Program, which provides support for undergraduates to perform research with faculty, are offered positions on this project.

The research seeks to determine the proton transfer mechanisms near interfaces as well as the structure and role of the first and second shell waters adjacent to the H3O+ ion. The roles of an amorphous silica surface structure and the higher density of water adjacent to the interface effects water reorientations and proton transfer. The as effect of nanopore size and water saturation on transport is also being studied. Using molecular dynamics computer simulations that employ reactive force fields combined with ab-initio calculations, this research provides an atomistic explanation of interactions between hydrophilic interfaces and nanoconfined water. In addition to environmental applications, the results provide a fundamental basis for further expansion into other nanoconfined solutions where the interface plays an important role. These include, enabling studies of ion transport for low cost water purification methods, ion transport in new aqueous electrolytes for energy storage, proton exchange in catalysts, stress corrosion cracking of glasses used in touch-screen devices and solar panels, and local pH on mineral growth or dissolution in cements and building materials.