NSF Award
1900590
In this project funded by the Chemical Structure Dynamics and Mechanism (CSDM-A) program of the Chemistry Division, Professor Daniela Kohen of Carleton College, is using state of the art computational techniques to study behavior within zeolites (molecular sieves). The goal of these studies is to provide a basic understanding of the processes that underlie the use of molecular sieves as filters to remove carbon dioxide from the atmosphere. In some of these materials, cations (atoms that have lost electrons) act as selective trapdoors, allowing some, but not all, gases to diffuse through. Computer simulations allow gaining microscopic insight into this interesting behavior. These studies offer a singular opportunity to gain fundamental understanding that can assess and guide the design and identification of materials useful in a variety of industrial processes. At Carleton College, a predominantly undergraduate institution, Professor Kohen actively engages undergraduate students in chemistry research. The students involved in this research study chemistry through the lens of molecular simulations, which provides them with a powerful tool to give new meaning to familiar concepts, as well as training that allows them to become proficient with complicated computations, an important benefit given the ever-increasing needs of our technological society.<br/><br/>Zeolites are an attractive option for carbon dioxide capture in many industrial processes due to their variety and stability. However, some of their fundamental behaviors are not understood, which limits the ability to rationally design new materials or to improve existing ones. The shortage of experimental techniques that allow for the direct observation of cation motion, combined with the deficiency of appropriate computational models, has significantly limited understanding of cation motion at an atom by atom level. This understanding is not only of fundamental interest, but these motions can also be intimately related to behaviors that give zeolites useful properties in many practical applications. This project is an in-depth computational study of the motions of cations within zeolites. It aims to gain detailed microscopic understanding by a careful combination of well-established molecular dynamics simulation tools (where all atoms are treated as interacting objects) with recently developed ab initio molecular dynamics techniques (were atoms as treated as protons and electrons interacting with each other). Recent developments in computational techniques enable a systematic study of the dynamics of the cations and how they relate to zeolite geometry and chemical environment. This project characterizes and then compares cation dynamics within different zeolite families. These families are chosen to capitalize on existing experimental data and aim to contribute to fundamental understanding needed to develop critical applications. In addition to the research itself and its potential applications of our findings, a key component in the proposed activities is the training of undergraduates as active researchers that focus on fundamental understanding of behavior within thought-provoking and promising materials.<br/><br/>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.
