报 告 人：张栋茂 美国密西西比州立大学 教授
Dr. Dongmao Zhang is an Associate Professor of Chemistry in the Department of Chemistry at the Mississippi State University. He obtained B.S. in Chemistry from Wuhan University in 1987 and Ph.D. in Analytical/Physical Chemistry from Purdue University in 2002. He then worked three years in Purdue Discovery Park rising from research associate, assistant research scientist, to research scientist. He worked as an Analytical Chemist in GE for two years. He joined MSU in 2008 after a two-year stint as a research scientist at Rice University. His research interests include interfacial interactions of plasmonic nanoparticles, optical spectroscopy, and analytical method developments. His recent awards and recognitions: Chemist of the Year (2017) by the Mississippi State Chapter of American Chemical Society; Top ten most prolific authors in the world for the Journal of Physical Chemistry C for the most recent five year (2017); Dean’s Eminent Scholar (2015); NSF CAREER award (2013). He has published more than eighty articles in the Journal of Physical Chemistry, Analytical Chemistry, Nano Letters, and JACS. 张栋茂博士也将介绍如何申请全额奖学金去美国包括密西西比州立大学的化学系读博士及硕士研究生。
Photon/matter interactions are arguably the most exploited phenomena in both fundamental research and technological development. However, reliable quantification of the material optical activities remains difficult for optically complex materials that are often simultaneously photon absorbers, scatters, and emitters. Introduced in this talk is the polarized resonance synchronous spectroscopy (PRS2) recently invented by the Zhang group. When used in combination of UV-vis spectrophotometric measurements, this PRS2 technique enables quantification of a series of material optical parameters that are difficult or totally inaccessible before. This includes 1) the decomposition of the material extinction cross-section spectrum into its absorption and scattering cross-section component spectra, 2) the determination of material light scattering and fluorescence depolarization spectra, and 3) the quantification of the fluorescence cross-section, quantum yield, and depolarization at the wavelength region where the fluorophores both absorb and emit. This PRS2 method is broadly applicable for essentially all materials that can invariably be classified into the following five categories: i) approximately pure photon scatterers, (ii) pure absorbers, (iii) simultaneous photon absorbers and scatterers, (iv) simultaneous pure absorbers and emitters, and (v) all the way to simultaneous photon absorbers, scatterers, and emitters. The theoretical background, experimental and data analysis procedures, and a few example applications of this PRS2 technique will be discussed in this talk.