(15d) Elucidation of Atomic-Scale Structure/Function Relationships: Toward Predictive and Rational Design of Nanoscale Materials

Research Interests: Nanoscale materials, atomic-scale structure/function relationships, synchrotron radiation characterization methods, catalysis, biomimetics

Teaching Interests:  With a background in physics and chemistry, and well suited to teach a wide-range of class work. I would be interested in teaching materials related courses, thermodynamics, and/or transport courses.

Elucidation of Atomic-Scale Structure/Function Relationships: Toward Predictive and Rational Design of Nanoscale Materials

Nicholas M. Bedford, National Institute of Standards and Technology, Boulder, CO 80305

Postdoctoral Fellow

Research Interests: The emergence of nanotechnology has produced advances in various application areas of technological importance. Unfortunately, the creation of nanoscale materials is too often achieved serendipitously or via Edisonian approaches, impeding rapid technological development. As the arrangement of atoms within a nanoscale material directly influences the materials properties, it is imperative to have a complete atomic-scale structural understanding to elucidate, predict, and ultimately design/tune materials properties for a given material. As such, my research interests are centered on understanding synthesis-driven structure/function relationships using atomic-scale synchrotron radiation characterization methods. In-situ characterization methodologies are also of interest to understand atomic-scale structural changes during relevant chemical processes, e.g. charge/discharge cycles of a battery materials or during catalytic turnovers occurring at a catalysts surface.

Successful Proposals: NRC Research Associateship Program Postdoctoral Fellowship (AFRL); DAGSI Graduate Student Research Fellowship Program; 20+ successful synchrotron general user facility proposals

Additional Proposal Experience: Panel reviewer for the Catalysis and Biocatalysis program at CBET-NSF; reviewer for SSRL general user beam time requests; Submission of multiple peer-review proposals to DOE, AFOSR, and ARO.

Postdoctoral Projects: â??Development and Characterization of Peptide-Assembled Nanoparticlesâ?

Under supervision of Dr. Rajesh Naik, Air Force Research Laboratory

â??Elucidation of Structure/Function Relationships for Engineering Nanomaterialsâ?

Under supervision of Dr. Tim Quinn, National Institute of Standards and Technology

Ph.D. Dissertation: â??Electrospun Fibers for Energy, Electrical, and Environmental Applicationsâ?

Under the supervision of Prof. Andrew J. Steckl and Donglu Shi at the University of Cincinnati Department of Material Science and Engineering

Research Experience: My research experience is highly interdisciplinary in nature with a common underlying theme of understanding nano- and atomic-scale phenomena. My formal Ph.D. training was in synthesis and characterization of polymeric and inorganic nanomaterials, while during my postdoctoral appointments I was immersed into the area of synchrotron radiation characterization, including high-energy X-ray diffraction (HE-XRD) coupled to atomic pair distribution function (PDF) analysis, X-ray absorption spectroscopy (XAS), and small angle X-ray scattering (SAXS). Through intensive training at several national laboratories and DOE user facilities, I have become proficient in all aspects of the aforementioned structural characterization methods, which can yield nanomaterial structural models with atomic-scale precision. Using such models, structure/function relationships can be readily examined, providing the needed understanding to create new nanomaterials with improved properties.

Teaching Experience: During my career, I have been involved in various avenues of teaching and mentorship. While at AFRL, I held a dual appointment in the Department of Chemistry at the University of Miami, where I was an instructor for the summer section of Principles of Chemistry I. As the instructor, I was responsible for all aspects of the class. While in graduate school, I was a TA for many engineering courses, including Basic Heat Transfer and Intro to Thermodynamics. During my undergraduate studies, I was laboratory assistant for both organic and general chemistry labs. Additionally, I have mentored several graduate, undergraduate, and high school students during my postdoctoral tenures at both NIST and AFRL.

Future Directions: As faculty I plan to continue applying my expertise in nanomaterials synthesis and synchrotron radiation characterization to establish synthesis-based nanomaterials design rules for a variety of materials systems. My initial focus will involve nanomaterials with emergent catalytic, electrocatalytic, photocatalytic, energy harvesting and/or energy storage properties. Using XAS, HE-XRD coupled to atomic PDF, and SAXS, structural information can be accessed over various length scales, providing the needed data to build full nanomaterial structural models with atom-scale resolution. These models will then be used to assess synthesis-driven structure/function relationships to be implemented in future nanomaterial design. In-situ methodologies will be explored as well, wherein structural transitions occurring during relevant chemical events can provide additional insights in assessing and predicting materials properties.

Synthetically, I plan to explore multiple avenues for the creation of nanomaterials synthesis, where the initial focus will be on biomimetic approaches. Using the specificity of biological molecules, nanomaterials can be synthesized and assembled with unpredicted precision. Additionally, the complexity and modularity of chemical functional groups within biomolecules provide a large basis set of possible biotic/abiotic interactions to manipulate materials properties. In tandem with the aforementioned synchrotron radiation characterization expertise, I fully expect the capability to use biomimetic approaches to achieve nanomaterials with enhanced properties through the development of structure/function relationships.

Selected Publications (*denotes corresponding author), current H-index=11 (Google Scholar):

N. M. Bedford,* Z. Hughes, Z. Tang, B. D. Briggs, Y. Ren, V. G. Petkov, R. R. Naik,* M. R. Knecht,* T. R. Walsh,* â??Probing the Sequence-Dependent Structure/Function Relationships of Catalytic Peptide-Enabled Au Nanoparticlesâ?, J. Amer. Chem. Soc. 2016, 138, 540.

N. A. Merrill, E. M. McKee, K. C. Merino, L. F. Drummy, S. Lee, B. Reinhart, Y. Ren, A. I. Frenkel, R. R. Naik, N. M. Bedford,* M. R. Knecht* â??Identifying the Effects of Metal Composition on the Structure and Catalytic Activity of Peptide-Templated Materialsâ?, ACS Nano, 2015, 9, 11968.

B. D. Briggsâ? , N. M. Bedfordâ? , S. Seifert, H. Koerner, H. Ramezani-Dakhel, H. Heinz, A. I. Frenkel, R. R. Naik,* M. R. Knecht,* â??C-C Coupling of Peptide-Capped Pd Nanoparticle Progresses Through an Atom Leeching Mechanismâ?, Chem. Sci. 2015, 6, 6413. â? Equal author contribution

N. M. Bedford,* H. Ramezani-Dakhel, J. M. Slocik, B. D. Briggs, Y. Ren, A. I. Frenkel, V. G. Petkov, H. Heinz,* R. R. Naik,* M. R. Knecht,* â??Elucidation of Biologically Programmed Atomic-Scale Structure of Nanoparticle Interfaces that Modulates Catalytic Activityâ?, ACS Nano 2015, 9, 5082. Featured on the front coverN. M. Bedford, R. Bhandari, J. M. Slocik, S. Seifert, R. R. Naik, M. R. Knecht,* â??Peptide-Modified Dendrimers as Templates for the Production of Highly Reactive Catalytic Nanomaterialsâ?, Chem. Mater. 2014, 26, 4082.

N. M. Bedford, M. Pelaez, C. Han, D. D. Dionysiou, A. J. Steckl,* â??Photocatalytic cellulosic electrospun fibers for the degradation of potent cyanobacteria toxin microcystin-LRâ?, J. Mater. Chem. 2012, 22, 12666. Published as HOT Article by RSC

N. M. Bedford, M. B. Dickerson, L. F. Drummy, H. Koerner, K. M. Singh, M. C. Vasudev, M. F. Durstock, R. R. Naik,* A. J. Steckl,* â??Nanofiber-Based Bulk-Heterojunction Organic Solar Cells Using Coaxial Electrospinningâ?, Adv. Ener. Mater. 2012, 2, 1136.