This is a fundamental study into the radiolytic synthesis of nanoparticles that is more flexible and versatile than existing electrochemical, surfactant and pyrolytic methods. Radiolysis presents an entirely new area of basic research into alloy and superalloy nanoparticle synthesis that holds the promise for a universal method of nanoparticle formation. Our main focus of the project is to develop a fundamental understanding of the materials science behind these nanoparticle formations and expand it to the field of Ni-based superalloys. The program focuses on the basic research associated with both the nanoparticle formation (through the chemistry of the radiolysis of water and its effect on metal solution salts) and nanoparticle size retention (through interfacial chemistry of metal/alloys and organic capping agents).

We utilize an entirely new approach for the novel synthesis of superalloy nanoparticles, using gamma-irradiation for the radiolysis of solvating water from SNL's uniform Co-60 source and pulsed proton irradiation using the directional external beam end-station of SNL's Tandem Van de Graff accelerator. Our team focuses on the structure/property relationship between nanoscale materials and bulk scale effects. This involves DFT modeling, inorganic synthesis, radiation testing, and characterization to develop a fundamental understanding of "how" and "why" nanoparticles form by radiolysis and maintain their size and integrity.

For alloys, we are studying the chemistry needed for the radiolysis of solutions containing several types of reducible metal ions. We are also focusing on the materials science behind (1) alloy composition variation, (2) anisotropic nanoparticle formation, and (3) preservation of nano-dimensioned particles. We are also studying the interfacial science of interactions between nanoparticles and organic ligands (ie., functional groups, concentrations). In particular, we study the effects of different ligands on nanoparticle size stabilization.