Ultrafast Non-linear Spectroscopy, Interfacial Chemistry, Materials Science
Interfaces and surfaces where chemical processes starts play a very significant role in bio-interfaces, heterogeneous catalytic reactions, nanoscience and renewable energy. For the past few years, scientists have been keen in building and developing spectroscopic and microscopic instruments that elucidate the chemical nature of different surfaces and interfaces (i.e. gas-liquid, liquid-solid and gas-solid interfaces). Sum frequency generation (SFG) spectroscopy is a non-linear vibrational technique that has been around for more than two decades is a powerful technique that can probe structure, orientation and chemical fingerprint of molecules at the interface. As a second-order nonlinear technique, SFG has an inherent interfacial specificity because in some cases, any signal derived from the bulk that has inversion symmetry is symmetry forbidden in the dipole approximation.
In our group, pico- and broadband sum frequency generation spectroscopic technique will be built and its corresponding results will be supported by other techniques such as FTIR, Raman, AFM, SEM and TEM to study systems such as biocompatible polymers, lithium battery materials, electrical energy storage materials, nanoparticles and flat metallic and dielectric surfaces, and occurrences of corrosion on conducting and semiconducting materials and lastly, future studies will also be made by time-resolved SFG spectroscopy. The integration of these various techniques allows us to look at these interfacial systems with a unique perspective.
Research interests in our group are very interdisciplinary which include physical chemistry, interfacial chemistry, analytical chemistry, nonlinear pico- and femtosecond spectroscopy and microscopy, nanotechnology, polymer science, corrosion, and energy application studies.>\
Cimatu, Katherine A.
, Mahurin, Shannon M., Meyer, Kent A. and Shaw, Robert W., “Nanoscale Chemical Imaging of Zinc Oxide Nanowire Corrosion.” J. Phys. Chem. C
, 116, 10405–10414.
Sagle, Laura B., Cimatu, Katherine A.
, Litosh, Vladislav A., Liu, Yi, Flores, Sarah C., Chen, Xin, Yu, Bin, and Cremer, Paul S., “Methyl Groups of Trimethylamine N-Oxide Orient Away from Hydrophobic Interfaces.” J. Am. Chem. Soc. 2011
, 133, 18707–18712.
Cimatu, Katherine A.
and Baldelli, Steven ,“Chemical Microscopy of Surfaces by Sum Frequency Generation Imaging” J. Phys. Chem. C 2009
, 113, 16575-16588.
Hernandez, M., Chinwangso, P., Cimatu, K.
, Srisombat, L., Lee, T. R., and Baldelli, S.,"Chemical Imaging and Distribution Analysis of Mono-, Di- and Tri-chelating Alkanethiol Self-assembled Monolayers on Gold by Sum Frequency Generation Imaging Microscopy." J. Phys. Chem. C
, 115, 11, 4688–4695.
, Moore, Justin, Barriet, David, Chinwangso, Pawilai, Lee, T. Randall and Baldelli, Steven. , “Sum Frequency Generation Imaging of -OCH3, -CH3, -C=C, -phenyl, cyclopropyl and fluoro terminated μ-CP SAMS on Au.” J. Phys. Chem. C. 2008
, 112, 14529-14537.
and Baldelli, Steven ,“Chemical Imaging of Corrosion: Sum Frequency Generation Imaging Microscopy of Gold Surface in Cyanide.” J. Am. Chem. Soc. 2008
, 130, 8030-8037.
Hedberg, Jonas, Leygraf, Christofer, Cimatu, Katherine
, and Baldelli, Steven. “Adsorption and Structure of Octadecanethiol on Zinc Surfaces As Probed by Sum Frequency Generation Spectroscopy, Imaging, and Electrochemical Techniques.” J. Phys. Chem. C. 2007
, 111, 11751-11755.
Cannara, Rachel J., Brukman, Matthew J., Cimatu, Katherine
, Sumant, Anirudha V., Baldelli, Steven and Carpick, Robert W. “Nanoscale Friction Varied by Isotopic Shifting of Surface Vibrational Frequencies.” Science 2007
, 318, 780.
, Moore, Justin, Lee, T. Randall and Baldelli, Steven “Imaging of Microcontact Printed Monolayers Generated from Aliphatic Dithiocarboxylic Acids with Sum Frequency Generation Imaging Microscopy: Contrast Based on Terminal Group Orientation.” J. Phys. Chem. C. 2007
, 111, 11751-11755.
and Baldelli, Steven “Spatially Resolved Surface Analysis of Octadecanethiol Self-Assembled Monolayer on Mild Steel Using Sum Frequency Generation Imaging Microscopy.” J. Phys. Chem. C 2007
, 111, 7137-7143.