PHAS Colloquia

Optical Kerr Effect Spectroscopy of Liquids - Probing Liquid-State Dynamics from Simple Liquids to Complex Fluids

Tuesday, 29 November 2022 from to (America/Chicago)
at Texas Tech Physics Department ( 234 )
Dr. Edward L. Quitevis (Department of Chemistry Texas Tech University) 

Optical Kerr Effect Spectroscopy of Liquids - Probing Liquid-State Dynamics from Simple Liquids to Complex Fluids 

Abstract: One of the major areas of research in the Quitevis group is understanding the dynamics of liquids using optical Kerr effect spectroscopy.  The variant of OKE spectroscopy used in my labs is optical heterodyne-detected Raman induced Kerr spectroscopy (OHD-RIKES).  OHD-RIKES is a femtosecond nonlinear time-domain technique that measures the collective polarizability anisotropy correlation function of a liquid.  At timescales longer than a picosecond or so, the polarizability anisotropy is dominated by diffusive orientational motions, and at shorter timescales by intermolecular dynamics associated with frustrated inertial motion motions of the molecules. By use of a Fourier-transform deconvolution procedure, the OHD-RIKES transients can be converted to a spectral density which is directly related to the depolarized Raman spectrum of the liquid. To illustrate how OKE spectroscopy provides insights into the molecular motions in a liquid and the intermolecular forces that govern these motions, previous studies performed by the Quitevis group on various types of liquids, from simple molecular liquids to complex fluids, such as liquid crystals and ionic liquids, will be described.

Bio: Edward L. Quitevis is a Professor of Chemistry in the Department of Chemistry & Biochemistry at Texas Tech University.  He is a native Californian, born and raised in San Francisco. He received his B.S. degree in Chemistry from the University of California, Berkeley in 1974, his S.M. degree in Physics and his Ph.D. degree in Chemical Physics, respectively, in 1976 and 1981, from Harvard University under the direction of Professor Dudley R. Herschbach.  His doctoral research involved using molecular beams to study electron transfer to weakly bound complexes. Inspired by a talk on liquids by Victor Weisskoff that he attended at MIT, he decided to do his postdoctoral studies at the University of Toronto where he did research under the direction of Professor Geraldine Kenney-Wallace on the rotational diffusion of dyes in liquids using picosecond pump-probe spectroscopy. In 1984 he joined the faculty at Texas Tech University as an Assistant Professor and rose through the academic ranks, becoming Joint Professor of Physics in 1989, Associate Professor in 1990, and finally Professor in 1998. His current research interests include ultrafast nonlinear optical spectroscopy of liquids, dynamics of complex fluids, the physical chemistry of ionic liquids, and supercooled liquids and the glass transition.    

Face-to-Face colloquium. 

Location: Science 234
Date: TUESDAY Nov. 29st 
Time: 3:30-4:30 pm
Host: Ioannis Chatzakis
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Organised by I. Chatzakis