Christine Aikens of Kansas State University is supported by the Macromolecular, Supramolecular and Nanochemistry program in employing a variety of theoretical methods in order to investigate fundamental questions related to the atomistic mechanisms of gold and silver nanoparticle growth, decomposition, catalysis, and ligand exchange. Density functional theory will be utilized throughout the project since it provides a good balance of accuracy with a reasonable computational cost. Continuum solvent models such as COSMO will be used to examine how solvent polarity affects reaction energetics. Coupled cluster calculations during the catalysis work will improve the accuracy of barrier heights and reaction energies. We will refine parameters for ReaxFF, a classical force field, in order to apply this method to molecular dynamics simulations of large gold nanoparticle systems.
Small gold and silver nanoparticles with diameters on the order of 1-2 nanometers have a wide array of applications such as selective catalysis. Previous theoretical studies on these nanoparticles have primarily focused on their structure and/or physical properties rather than reactivity. In this research, the PI will examine factors that affect nanoparticle reaction mechanisms. This research will lead to better control of size and monodispersity of gold and silver nanoparticles. In addition, it will identify factors leading to nanoparticle toxicity. Furthermore, this research will lead to better control of nanoparticle catalysis and assembly into arrays. In addition, this proposal will enable the PI to continue broadening participation through the inclusion of female and minority students in research. Funding from this proposal will be used to assist undergraduate and graduate students as they perform research and disseminate their results. These results will be broadly circulated through peer-reviewed papers and through presentations at a variety of institutions and conferences.
