School of Humanities and Sciences
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Senior Fellow at the Freeman Spogli Institute for International Studies and at the Stanford Institute for Economic Policy Research and Professor, by courtesy, of Economics
Current Research and Scholarly InterestsSee my personal website for all my recent working papers.
David Mulvane Ehrsam and Edward Curtis Franklin Professor in Chemistry
BioMy research group studies complex molecular systems by using ultrafast multi-dimensional infrared and non-linear UV/Vis methods. A basic theme is to understand the role of mesoscopic structure on the properties of molecular systems. Many systems have structure on length scales large compare to molecules but small compared to macroscopic dimensions. The mesoscopic structures occur on distance scales of a few nanometers to a few tens of nanometers. The properties of systems, such as water in nanoscopic environments, room temperature ionic liquids, functionalized surfaces, liquid crystals, metal organic frameworks, water and other liquids in nanoporous silica, polyelectrolyte fuel cell membranes, vesicles, and micelles depend on molecular level dynamics and intermolecular interactions. Our ultrafast measurements provide direct observables for understanding the relationships among dynamics, structure, and intermolecular interactions.
Bulk properties are frequently a very poor guide to understanding the molecular level details that determine the nature of a chemical process and its dynamics. Because molecules are small, molecular motions are inherently very fast. Recent advances in methodology developed in our labs make it possible for us to observe important processes as they occur. These measurements act like stop-action photography. To focus on a particular aspect of a time evolving system, we employ sequences of ultrashort pulses of light as the basis for non-linear methods such as ultrafast infrared two dimensional vibrational echoes, optical Kerr effect methods, and ultrafast IR transient absorption experiments.
We are using ultrafast 2D IR vibrational echo spectroscopy and other multi-dimensional IR methods, which we have pioneered, to study dynamics of molecular complexes, water confined on nm lengths scales with a variety of topographies, molecules bound to surfaces, ionic liquids, and materials such as metal organic frameworks and porous silica. We can probe the dynamic structures these systems. The methods are somewhat akin to multidimensional NMR, but they probe molecular structural evolution in real time on the relevant fast time scales, eight to ten orders of magnitude faster than NMR. We are obtaining direct information on how nanoscopic confinement of water changes its properties, a topic of great importance in chemistry, biology, geology, and materials. For the first time, we are observing the motions of molecular bound to surfaces. In biological membranes, we are using the vibrational echo methods to study dynamics and the relationship among dynamics, structure, and function. We are also developing and applying theory to these problems frequently in collaboration with top theoreticians.
We are studying dynamics in complex liquids, in particular room temperature ionic liquids, liquid crystals, supercooled liquids, as well as in influence of small quantities of water on liquid dynamics. Using ultrafast optical heterodyne detected optical Kerr effect methods, we can follow processes from tens of femtoseconds to ten microseconds. Our ability to look over such a wide range of time scales is unprecedented. The change in molecular dynamics when a system undergoes a phase change is of fundamental and practical importance. We are developing detailed theory as the companion to the experiments.
We are studying photo-induced proton transfer in nanoscopic water environments such as polyelectrolyte fuel cell membranes, using ultrafast UV/Vis fluorescence and multidimensional IR measurements to understand the proton transfer and other processes and how they are influenced by nanoscopic confinement. We want to understand the role of the solvent and the systems topology on proton transfer dynamics.
James D. Fearon
Theodore and Frances Geballe Professor in the School of Humanities and Sciences, Senior Fellow at the Freeman Spogli Institute for International Studies and Professor, by courtesy, of Economics
Current Research and Scholarly Interestspolitical violence
Burnet C. and Mildred Finley Wohlford Professor in the School of Humanities and Sciences
Current Research and Scholarly InterestsHuman genetic and cultural evolution, mathematical biology, demography of China
Lecturer, Art & Art History
BioLukas Felzmann was born and educated in Zürich Switzerland, and holds a MFA from the San Francisco Art Institute. He has taught photography at the California College of the Arts, the San Francisco Art Institute and at Stanford University since 1993. His photographs have been shown in Europe, Egypt, Columbia and the United States.
Lukas Felzmann’s early works were Installations with Sculptures and Photographs. More recently the work has focused on photography with a special interest in bookmaking and publishing. Lukas Felzmann’s first Monograph “Landfall” was published in 2004 by Lars Muller Publishers and was accompanied by a retrospective at the Fotostiftung Schweiz in Winterthur. Among recent work has been a photographic exploration of the Sacramento Valley as place and as metaphor by documenting a marsh altered through agriculture. In the work images and ideas about landscape, as well as natural and cultural conditions intersect. This work resulted in two large monographs both published by Lars Muller Publishers in 2009 and 2011. The two books form a conceptual pair with the first one “Waters in Between” with texts by John Berger looking down at the conditions on the ground. The second one “Swarm” with texts by Deborah Gorden and Wallace Stevens among others, looks up at the movements of flocks of birds. A fourth book “Helix” with a text by Edgar Allen Poe was published by Cavallo Point in 2009.
Lukas Felzmann is interested in all forms of cultural expressions, particularly music, the visual arts, architecture, bookmaking and how they intersect with the natural world. His teaching embraces both digital and analogue tools and is strongly influenced by his practice as an artist.