LDRD seminar: June 26
Three Argonne researchers will discuss their Laboratory-Directed Research and Development (LDRD) sponsored work at the LDRD Seminar Series presentation Tuesday, June 26, 2018, at 12:30 p.m. in the Building 203 Auditorium. All are welcome to attend.
Visit the LDRD website to view upcoming seminars.
“Interface Engineering for Applications in Water Systems”
By Director of the Institute for Molecular Engineering Seth Darling (STPO)
Energy and water intersect in many ways, and our society is facing daunting challenges with both. Innovations in materials are a critical tool in addressing these challenges, and interfaces between materials and aqueous solutions, in particular, are at the forefront. In this project, our team is tailoring interfacial properties to explore new concepts in sorbents, membranes, catalysts and other classes of materials directly relevant to water treatment.
Seth B. Darling is the director of the Institute for Molecular Engineering at Argonne, which is a joint institute with the University of Chicago. After receiving his Ph.D. from the University of Chicago in physical chemistry, he joined Argonne as the Glenn Seaborg Fellow in the Materials Science Division. Following his postdoc, Darling became a staff scientist in the Center for Nanoscale Materials. His group’s research centers around molecular engineering with a particular emphasis on advanced materials for water treatment and renewable energy. He has published over 100 scientific articles, holds several patents, is a co-author of popular books on water and on debunking climate skeptic myths, and lectures widely on topics related to energy, water and climate
“Irradiation Effects on High Entropy Alloys”
By Postdoctoral Appointee Wei-Ying Chen (AMD)
High entropy alloys (HEAs) have attracted great interests in the field of nuclear materials because of its potential irradiation resistance from its high entropy effect, distortion lattice and sluggish diffusion kinetics. In order to evaluate HEAs for nuclear applications, this study compared HEAs with 316 stainless steels and pure nickel under consistent irradiation conditions. Two HEAs, Al0.3CoCrFeNi and CoCrFeMnNi, and 316H, a high carbon version of 316 stainless steel, were irradiated with 1 MeV Kr at 300°C, 500°C and 600°C to 1 dpa. Irradiation experiments at 400-500°C were also performed in a high-energy electron microscope (HVEM). The evolution of irradiation-induced dislocation loops and voids were observed with in-situ TEM. The results of this study indicate that the effect of HEAs characteristics on the irradiation process were more important at higher irradiation temperature. The dependence of the defect evolution under irradiation on the composition, impurity, stacking fault energy and defect mobility of HEAs and 316H will be discussed.
Wei-Ying Chen is a postdoctoral researcher in Applied Materials Division. He obtained his Ph.D. from the University of Illinois, Urbana-Champaign in 2014. His field of expertise is microstructure characterization using electron microscopy to investigate material phenomenon related to nuclear power applications. Chen’s current research focus on establishing long-term microstructural evolution, and the corresponding mechanical property of creep-resistant steels for use in sodium fast reactors. He also has broad experience in characterization of irradiation effects in materials and has particular interests in the development of radiation resistant alloys.
“High-Valent States in Molecular and Heterogeneous Oxygen-Evolving Catalysts and their role in O–O Bond Formation”
By Argonne Scholar Ryan Hadt (CSE)
The solar-to-fuels conversion is a promising alternative to traditional energy sources such as fossil fuels, and the overall efficiency relies heavily on catalysts of the oxygen evolution half-reaction (i.e., 2H2O → O2 + 4H+ + 4e–). This four-electron, four-proton coupled reaction provides the reducing equivalents for solar fuels synthesis. Earth-abundant first-row transition metal oxides of cobalt, nickel and their mixed-metal forms can drive this half-reaction at relatively low overpotentials. This presentation will discuss recent studies utilizing a combination of in situ and ex situ optical absorption and X-ray absorption and emission spectroscopies on oxygen-evolving thin films and their molecular and heterogeneous inorganic analogs. Experiment coupled with theory has provided insights into the electronic structures of the high-valent states involved in the mechanism of O–O bond formation.
Ryan Hadt received his B.S. and M.S. degrees in chemistry from the University of Minnesota Duluth in 2007 and 2008, respectively, and completed his Ph.D. at Stanford University in 2014. He was a visiting postdoctoral fellow at Harvard University before joining the Chemical Sciences and Engineering Division at Argonne, where he is currently an Enrico Fermi Fellow. Hadt will begin a faculty position in the Division of Chemistry and Chemical Engineering at the California Institute of Technology (Caltech) this fall.