(389e) Screening of Polymeric Materials for Tritiated Water Separation By Molecular Simulations
Separation of tritiated water (HTO) from nuclear power plants is extremely challenging because the thermophysical properties of HTO and H2O are so similar. Hence, there is a critical need for developing new separations technologies that are energetically and economically efficient. It has been experimentally observed that some polymers can be effective at separating water isotopologues but the mechanism is not completely understood. Our hypothesis is that the difference in the strength of hydrogen bonds between the water isotoplogues and polar groups on the polymer is responsible for the observed separation. We use molecular simulations employing path integral molecular dynamics (PIMD) to investigate the effectiveness of different candidate polymers for isotope separation. The lifetime of hydrogen bonds between water isotopologues and the polymers is used as a metric for the efficiency of a given candidate polymer towards better materials. Effects of temperature and concentration of tritiated water towards the separation will be discussed. Machine-learning is used to study the hydrogen-bonding network in bulk water and water within the polymer.