Viviane Schwartz is a member of the R&D Staff in the Chemical Functionality Group at the Center for Nanophase Materials Science (CNMS), Oak Ridge National Laboratory. Her research encompasses a series of activities with the ultimate goal of creating and sharing innovative solutions for nanomaterials in the catalysis science. Schwartz's research has contributed important new insights into carbon-based catalytic materials for oxidation chemistry and sulfur clean-up; study of selective catalysts for ethanol production; study of highly active and selective gold nano-catalysts for CO oxidation of value for automotive fuel cell applications; utilization of synchrotron techniques as a tool for unraveling the structure of nanomaterials. Schwartz has made an impact on the next generation of researchers in catalysis, mentoring three postdoctoral fellows and a number of graduate-student users from the CNMS User Program.
I joined ORNL some years ago as a Research Staff member in the Chemical Separations Group in the Chemical Sciences Division (CSD). In the CSD I have primarily been involved in the development of novel complexants, extractants and separation methods for the removal of environmentally troublesome anions such as perchlorate and sulfate from selected waste streams, and also for the removal of radionuclides such as Cs-137 and Tc-99 from nuclear waste streams. In 2006, I took on a joint (50/50) appointment between the CSD and the Macromolecular Nanomaterials Group in the CNMS.
Most of the work I do at the CNMS involves small molecule synthesis, which includes a wide variety of deuterated molecules (including monomers), and molecules that can be used as molecular building blocks for nanomaterials. I also utilize the 500 MHz nuclear magnetic resonance (NMR) spectrometer at the CNMS for molecular characterization, and also for the study of reaction pathways and dynamic processes.
I enjoy synthesizing new molecules, both from the standpoint of the art of the synthesis, as well as seeing what the new molecules can do. In one user project for an ORNL colleague (Radu Custelcean), I synthesized a bis-bipyridyl urea ligand that can, when in the presence of certain transition metals and certain anions, in solution self-assemble into a tetrahedral metal-organic cage complex. In these cages, the bipyridyl ligands coordinate to the transition metals, with four transition metals (such as Zn2+) forming the four corners of the tetrahedron. Interestingly, one divalent tetrahedral oxoanion (such as sulfate) is trapped inside the cage and held by the urea moieties (three additional sulfate anions are outside the cage for charge balance.) We were able to utilize NMR to observe the formation of these cages, and also determine which anions where capable of inducing cage formation. In a current user project (for Ken Jacobson, NIH), we are preparing polyamido(amine) (PAMAM) dendrimers for investigation as potential carriers for bioactive molecules. We have made a number of molecules with various degrees of deuteration, among them the “molecular glass” compound Octa-O-tert-butyl-D72 carbonated C-methyl-calixresorcinarene for Vivek Prabhu (NIST), for SANS characterization of well-defined polymer ligand-functionalized nanoparticles.
Peter Maksymovych is a Research Staff Member at CNMS and obtained his B. S. degree in Physical Chemistry in June 2001 from the Kiev Taras Shevchenko University, Ukraine, and a Ph.D. in Surface Science from the University of Pittsburgh in May 2007. He then was awarded a two-year Eugene P. Wigner Fellowship from the ORNL, followed by a continuing Staff Member appointment since 2009. His current research interests include the electron transport properties of nanoscale multiferroic materials, the epitaxial interfaces of ferroic and correlated electron materials, electronic dynamics in molecular materials and the development of scanning probe microscopy methods which are used throughout his research. Maksymovych has about 40 publications, including recent topics on polarization controlled tunneling through ferroelectric thin films, electron transport through ferroelastic domain walls, intrinsic thermodynamics of local bias-induced phase transitions and size effects in multiferroic BiFeO3.