Acquisition of a Nanosecond Laser Flash Photolysis Spectrometer to Enhance Understanding of Photochemistry and Reaction Kinetics in Undergraduate Research/Curriculum
Abstract
The National Defense Authorization Act for Fiscal Year (FY) 2014 and the Department of Defense (DoD) Appropriations Act for 2014 allocated $10.7M to assist Historically Black Colleges and Universities and Minority-Serving Institutions (HBCU/MI) and to enhance their research and education capabilities in scientific areas relevant to the defense mission. The FY 2014 program supports the acquisition of research equipment and instrumentation to augment existing capabilities and to develop new capabilities that will facilitate greater participation in DoD research programs and encourage more students to pursue careers in science, technology, engineering, and mathematics (STEM) disciplines. This proposal from Principal Investigator, Dr. Yassin Jeiliani, requests support for the acquisition of a nanosecond laser flash photolysis spectrometer to enhance research training and student classroom experience at Spelman College. The spectrometer system includes a pulsed Nd:YAG laser with 2nd and 4rd harmonic generators (for 532 nm and 266 nm output). The 266 nm wavelength was selected for the excitation of munitions waste compounds. The spectrometer incorporates stopped-flow spectroscopic techniques. It also includes dedicated photomultiplier detectors for both fluorescence and absorbance kinetics. The spectrometer has capabilities for studying by direct measurement the reactions of transient species such as excited states, ions, and radicals in both chemical and biological systems. Sample excitation is performed with lasers, therefore the technique has the specificity of single wavelength excitation and nanosecond time resolution. Fast kinetics measurements can be performed on either nanosecond or microsecond timescales. The spectrometer will broaden the scope on current research that focus on structure and remediation of explosive compounds by initiating new studies in kinetics of photodegration of explosives including RDX, HMX, and TNT. The spectrometer will support research in areas that are important to the chemical and biological defense innovation including: (a) kinetics of protontransfer reactions of explosive compounds including trinitroluene (TNT) and dinitrotoluenes (DNTs), (b) stopped-flow experiments will be used to study effect of parameters including pH, temperature, and reagent concentrations on the reaction kinetics of munitions waste, naphthalenes, phthalates, etc., and (c) kinetics of laser-induced fluorescence of contaminants including DNTs, naphthalenes, and polyaromatic hydrocarbons. Understanding the reactions and the transient species in laser-induced pathways together with fluorescence emission studies of explosives can lead to the direct fluorescent detection of these compounds. The spectrometer will complement existing instrumentation in science, technology, engineering, and mathematics (STEM) labs used for teaching and research. Teaching modules based on the spectrometer will be gradually integrated into existing lab courses including: inorganic chemistry, physical chemistry, biochemistry and analytical chemistry. Students will learn multi-wavelength kinetic data analysis, time-resolved spectral reconstitution, and reaction modeling and simulation as well as photochemistry and kinetics of munitions waste and organometallics. The spectrometer will be used for faculty development activities as well across the Chemistry and Physics Departments.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1510032
Entities
People
- Yassin Jeiliani
Organizations
- Army Contracting Command
- Office of the Secretary of Defense
- Spelman College