Lectures and Events - Department of Materials and Interfaces

Upcoming Lectures

  • October29

    11:00 AM

    "New Directions for Electricity and Fuels from Sunlight

    Prof. Harry Atwater

    The recent rapid, global growth of photovoltaics has moved scientific research frontiers for solar energy conversion...

    The recent rapid, global growth of photovoltaics has moved scientific research frontiers for solar energy conversion towards new opportunities including i) ultrahigh efficiency photovoltaics (η > 30%) and ii) direct synthesis of energy-dense chemical fuels from sunlight, including hydrogen and products from reduction of carbon dioxide. I will illustrate several examples of how design of materials for light harvesting, charge transport and catalytic selectivity can enable advances in electricity and fuel synthesis. Photonic design has opened new directions for high efficiency photovoltaics and luminescent solar concentrators. Semiconductors coupled to water oxidation and reduction catalysts have enabled approaches to photoelectrochemical solar-to-hydrogen generation with >19% efficiency using artificial photosynthetic structures. Solar-driven reduction of carbon dioxide presents both an enormous opportunity and challenge because of the need for selectivity in generating useful multi-carbon products by multiple electron and multi-proton transfer steps. Present work and future directions in selective photocatalytic and photo-electrocatalytic materials for artificial photosynthesis aimed at catalytic reduction of carbon dioxide will be discussed.

  • October31

    09:30 AM

    Gerhard M.J. Schmidt Lecture Hall

    The Helen and Martin Kimmel Institute for Magnetic Resonance

    Characterization of Biomolecule and Structure Changes using Polarization Transfer from Hyperpolarized Water

    Jihyun Kim

    Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical tool for the characterization of protein...

    Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical tool for the characterization of protein structure and intermolecular interactions. However, NMR is not readily applicable to determine fast structural changes and weak interactions between molecules because of low signal sensitivity and time requirements to record multi-dimensional NMR spectra. To overcome these limits, the hyperpolarization technique of dissolution dynamic nuclear polarization (D-DNP) is combined with NMR. Not all molecules can be directly hyperpolarized. Instead, polarization transfer from hyperpolarized small molecules to a target of interest can be utilized as a means of obtaining polarization, as well as for detecting intermolecular interactions between these molecules Here, hyperpolarized water-assisted NMR spectroscopy was developed to measure intermolecular interactions with water. Firstly, the use of DNP hyperpolarization was demonstrated for the accurate determination of intermolecular cross-relaxation rates between hyperpolarized water and fluorinated target molecules.[1] Because hyperpolarized water acts as a source spin with a large deviation of the population from the equilibrium, the 19F signal on the target molecules is enhanced through NOE, allowing obtain an entire NOE buildup curve in a single, rapid measurement. When the hyperpolarized water-assisted NMR experiment is applied to a protein, water hyperpolarization can be transferred to amide protons on the protein through proton exchange. Further, this polarization spreads within the protein through intramolecular NOE to nearby protons including aliphatic groups.[2] By utilizing this polarization transfer, this method extends to measure enhanced 2D NMR spectra of the protein under folded and refolding conditions.[3] With the ability to rapidly measure protein signals that were enhanced through transferred polarization from hyperpolarized water, NMR spectra can be acquired within the timescale of the protein folding. Compared to the folded protein experiment, signals attributed to exchange-relayed NOEs are not observable in the refolding experiment (Figure 1b). These differences are explained by the absence of long-range contacts with nearby exchangeable protons such as OH protons

  • November03

    11:00 AM

    Gerhard M.J. Schmidt Lecture Hall

    Transmission Electron Microscopy in Motion

    Prof. Frances M. Ross

    We can watch crystals grow in the electron microscope by adding atoms one at a time onto a clean surface. The movies...

    We can watch crystals grow in the electron microscope by adding atoms one at a time onto a clean surface. The movies tell us about kinetics and thermodynamics but can also be entertaining, frustrating, or both at the same time. I will attempt to share the joy of this type of “in situ” microscopy as we aim to understand how atoms assemble into nanowires or nanocrystals and use the information to control the formation of more complicated nanostructures with new properties

  • November06

    11:00 AM

    Gerhard M.J. Schmidt Lecture Hall

    TBA

    Prof. Tim Bender

    TBA

    TBA

  • November13

    11:00 AM

    Perlman Chemical Sciences Building

    Room 404

    Application of Electron Crystallography Methods in Metallurgy

    Prof. Louisa Meshi

    Due to the direct correlation among the physical properties and crystal structure of materials, study of the latter is...

    Due to the direct correlation among the physical properties and crystal structure of materials, study of the latter is crucial for fundamental understanding of the properties. In the era of nano-science, objects of interest are getting smaller and traditional single-crystal and powder X-ray diffraction methods cannot be applied for characterization of their atomic structures due to the unavailability of single crystals and/or small quantity and size of these crystals in the multiphase specimens. Thus, electron crystallography (EC) (which is defined as a combination of electron diffraction and imaging methods) is sometimes the only viable tool for the analysis of their structure. In the previous century, electron diffraction (ED) was considered to be unsuitable for structure determination due to the problems of data quality arising from dynamical effects. At the last decades, researchers have shown that influence of dynamical effects can be substantially reduced if beam precession (PED) is used and/or data collection is performed in the off-axis conditions - enabling solution of atomic structures with various complexity (from inorganics to proteins). Our group focuses on development and application of EC methods for structure solution of nano-sized precipitates and characterization of structural defects in steels and light alloys. This study is technologically essential since precipitates and defects dictate physical properties of these structural materials. It must be noted that, atomic structures of intermetallics were not solved previously using solely ED methods. Reason for that is in the nature of intermetallic compound's structures. Contrarily to other complex materials, the atomic distances and angles of intermetallics are not fixed and coordination polyhedra are usually unknown. Thus, structure solution of these compounds is harder to validate. In the present seminar, contribution of our group in the development of routine structure solution path for aluminides (as an example of intermetallics) will be presented. In addition, characterization of structural defects, influencing the performance of the studied materials, will be shown.

  • November27

    11:00 AM

    Gerhard M.J. Schmidt Lecture Hall

    TBA

    Prof. Jennifer Elisseeff

  • December11

    11:00 AM

    Perlman Chemical Sciences Building

    Room 404

    TBA

    Prof. Meital Reches

Upcoming Events

  • April05

    08:00 AM

    David Lopatie Conference Centre

    Kimmel Auditorium

    A Random Walk in Soft Matter- in honor of Jacob Klein