Polarization modulation-infrared reflection absorption spectroscopy (PM-IRRAS) was employed to analyze two unique samples: (1) an industrially prepared alkoxysilane-pretreated aluminum alloy (AA6111) in the absence and presence of a ~600-nm-thick lubricant coating and (2) a chemical warfare agent simulant, triethyl phosphate (TEP), on glass. For the pretreated aluminum samples, PM-IRRAS spectra were analyzed for three distinct regions; the SiO stretching vibration around 1120 cm(-1), the NH(2) bending mode at ~1600 cm(-1) and the CH stretching region around 2900 cm(-1). Our results showed that increasing the curing temperature (from 55 to 100 °C) improved the overall extent of cross-linking within the siloxane network.
View Article and Find Full Text PDFPolarization modulation-infrared reflection absorption spectroscopy (PM-IRRAS) was employed to detect the chemical warfare agent (CWA) simulant triethyl phosphate (TEP) on gold, as well as on US military paint, i.e., chemical agent resistant coating (CARC).
View Article and Find Full Text PDFA recognition layer formed by multiwalled carbon nanotubes (MWCNTs) covalently modified with a ferrocene-lysine conjugate deposited on the indium tin oxide (ITO) was investigated as a sensor for chemical warfare agent (CWA) mimics. Electrochemical impedance spectroscopy measurements showed that upon addition of CWA mimic dramatic changes occurred in the electrical properties of the recognition layer. These changes allowed the detection of nerve agent analogues at the micromolar level, and a limited sensitivity was observed toward a sulfur mustard mimic.
View Article and Find Full Text PDFThe electrochemistry of gas-generated naked Ag nanoparticles deposited on indium-tin oxide covered glass plates is compared to bulk polycrystalline Ag. The nano-specific electrochemistry has been identified and includes the preferential formation of beta-oxides. In 100 mM KOH supporting electrolyte, disruption of beta-oxide formation is exploited to test for the presence of diethyl cyanophosphonate.
View Article and Find Full Text PDFNeopentane and TMS are used as model M(CH(3))(4) systems to investigate intramolecular interactions. The nonbonded site-site potential between two proximal hydrogen atoms on different methyl groups, V(nb)(d(HH)), is not Lennard-Jones- or Morse-like but is found to be pseudolinear in hydrogen-hydrogen internuclear separation, d(HH), for both neopentane and TMS. The Morse potential is found to be a poor basis in which to expand V(nb)(d(HH)).
View Article and Find Full Text PDFLocal mode frequencies, omega, and anharmonicities, omegax, are obtained from the delta upsilon(CH) = 2-7 spectral regions of 1,3,5,7-cyclooctatetraene (COT) and 1,1,1-trichloroethane. In 1,1,1-trichloroethane omega and omega x are used in conjunction with ab initio potential energy surfaces to calculate local mode anharmonicity-torsion coupling terms, delta(omega x), and frequency-torsion coupling terms, delta(omega). Blue-shifting of sterically hindered CH oscillators in 1,1,1-trichloroethane indicates nonbonded, through-space intramolecular interactions with Cl.
View Article and Find Full Text PDFThe vapor phase CH stretching vibrational overtone spectra of tert-butylbenzene and tert-butyl chloride are measured in the Delta upsilon(CH) = 2-7 region, while the spectrum of tert-butyl iodide is recorded in the Delta upsilon(CH) = 2-6 region. The overtone spectrum of tert-butylbenzene is too complex to make detailed spectral assignments. Local mode frequencies, omega, and anharmonicities, omegax, are obtained for tert-butyl chloride and tert-butyl iodide.
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