A5053650344- Ionic liquids properties and applications
- Advanced NMR Techniques and Applications
- Chemical and Physical Properties in Aqueous Solutions
- NMR spectroscopy and applications
- Spectroscopy and Quantum Chemical Studies
- Thermodynamic properties of mixtures
- Solid-state spectroscopy and crystallography
- Electrochemical Analysis and Applications
- Surfactants and Colloidal Systems
- Advanced ceramic materials synthesis
- Phase Equilibria and Thermodynamics
- Multicomponent Synthesis of Heterocycles
- Iron oxide chemistry and applications
- Microstructure and Mechanical Properties of Steels
- Metal and Thin Film Mechanics
- Microstructure and mechanical properties
- Various Chemistry Research Topics
- Zeolite Catalysis and Synthesis
- Molecular spectroscopy and chirality
- High Temperature Alloys and Creep
- Electron Spin Resonance Studies
- Advanced MRI Techniques and Applications
- Fatigue and fracture mechanics
- Subcritical and Supercritical Water Processes
- Mesoporous Materials and Catalysis
SUNY Brockport
2015-2025
State University of New York
2013-2024
York University
2003-2023
Max Planck Institute for Solar System Research
2017-2018
TU Bergakademie Freiberg
2012-2017
IMA Materialforschung und Anwendungstechnik
2016
Leibniz Institute for Solid State and Materials Research
2012-2014
Friedrich Schiller University Jena
2008
Architecture, Territoire, Environnement
2007
Université de Montpellier
2007
The proton NMR chemical shift has been measured for water from 25 to 600 °C and 1 400 bar, conditions extending well beyond the critical point. Dilute solutes were employed as references avoid effect of varying magnetic susceptibility. large changes in (4.1 ppm) are interpreted hydrogen bond network, because all other intermolecular interactions known result much smaller effects. Using a linear relation between mean number bonds, results show there still 29% many bonds at bar (ρ = 0.52 g/cm3...
We report chemical shift measurements of the hydroxyl protons in methanol and ethanol up to 450 °C over a wide range pressures. The extent hydrogen bonding compared room temperature conditions is obtained for alcohols. results are with our previously reported ones water. Surprisingly, all three substances show very similar behavior when on basis reduced thermodynamic variables. Compared room-temperature situation, an η about 30% prevails at near-critical conditions. density-reduced η/ρ*...
Molecular dynamics (MD) simulations are reported for [polyethylene glycol (PEG)200], a polydisperse mixture of ethylene oligomers with an average molar weight 200 g·mol-1. As first step, available force fields describing were tested on how accurately they reproduced experimental properties. They found to all fall short either reproducing density, static property, or the self-diffusion coefficient, dynamic property. Discrepancies data increased increasing size oligomer. From fields, optimized...
X-ray absorption fine structure (XAFS) spectroscopy was used to measure the coordination about Cu2+, Cu1+, and Br- in water at temperatures up 325 °C. The hexaaqua Cu2+ species maintains its distorted octahedral °C, whereas higher temperatures, dehydration reactions occur producing CuO. Under reducing conditions, dibromo Cu1+ species, [CuBr2]-, is predominant 200 °C above for systems having excess Br-. Even a very high salt concentration of 2.0 m NaBr, only observed with no evidence...
The mechanochemical reaction of malononitrile with various aldehydes was studied the goal to achieve quantitative stoichiometric conversion reactants their corresponding benzylidene-malononitriles in absence any solvents and catalysts. Besides already known reactions solid state, liquid were also attempted. These carried out vibration planetary ball mills as well as, for comparison, a melt under microwave irradiation. A successful depended strongly on choice aldehyde, precluding...
The coordination structure about Ni2+ in water at temperatures up to 525 °C was measured by the X-ray absorption fine (XAFS) technique. Solutions containing 0.2 m NiBr2 and NiBr2/0.8 NaBr were explored pressures 720 bar. For certain systems, both Ni Br XAFS data acquired a global model used fit two independent sets of data. These measurements gave excellent agreement on Ni2+/Br- contact-ion pairing. result is complete picture pairing including numbers, distances for water−ion ion−ion...
The structure and equilibrium of chromate (CrO42-), bichromate (HCrO4-), dichromate (Cr2O72-) in ambient aqueous solutions was investigated by both IR X-ray absorption fine (XAFS) spectroscopy. individual bands for each these species have been identified, quantitative analysis the used to examine chemical equilibria. A dilution study at a constant, low solution pH revealed speciation change from dominance high total chrome concentration concentration, thereby unequivocally confirming...
A study of dynamic nuclear polarization (DNP) in polyethylene glycol and related nonionic surfactants is presented. In these experiments, we found the surprising result that DNP enhanced 13C magic angle spinning (MAS) spectra display two sets resonances, one with broad sharp spectral features are 180° opposite phase. These indicate presence a direct transfer channel as expected for MAS second unexpected indirect channel. Plots enhancements function applied magnetic field resonances show...
Synthesis of novel trityl-nitroxyl biradicals and their performance as polarization agents in DNP-enhanced solid-state MAS NMR spectroscopy is presented. Signal enhancements 1H, 1H → 13C CP MAS, experiments obtained with these radicals dissolved 1,1,2,2-tetrachloroethane (TCE) solution are compared the from TCE solutions binitroxyl radicals. The signal correlated distance between radical centers biradicals, determined by theoretical structure calculations. Some biradical display...
Polyethylene glycol (PEG) is gaining interest as an alternative green solvent in chemical synthesis and processing. This report presents density viscosity data from 293.15 K to 358.15 well self-diffusion coefficient 298.15 for oligomers of PEG di- nonaethylene glycol. The results were obtained by extrapolation measurement series where water, the most common impurity PEGs, was intentionally added several increments. are carefully compared literature data, which widely available only...
The Knoevenagel condensation of malononitrile with various arylaldehydes was studied as an uncatalyzed reaction at ambient temperature. This study prompted after discovering that a mixture left standing for extended times mechanochemical treatment would continue to react significantly higher yields. We report (solid/solid or solid/liquid) reactants converts in some cases quantitatively the target product absence any solvent room yields can be increased if is seeded product. It also possible...
Rare earth free alloys are in focus of permanent magnet research since the accessibility elements needed for nowadays conventional magnets is limited. Tetragonally strained iron-cobalt (Fe-Co) has attracted large interest as promising candidate due to theoretical calculations. In experiments, however, applied strain quickly relaxes with increasing film thickness and hampers stabilization a strong magnetocrystalline anisotropy. our study we show that already 2 at% carbon substantially reduce...
Polyethylene glycol (PEG) and three related surfactants were studied by dynamic nuclear polarization (DNP) enhanced solid state NMR spectroscopy differential scanning calorimetry (DSC). DNP surprisingly reveals the presence of local molecular motions that are normally understood to be inactive at temperatures ∼100 K. This surprising phenomenon could explained experimentally necessary rapid freezing samples. Specifically, DSC shows PEG 200 forms a glass upon PEG-related least partially in or...
This research explores the application of surfactants as green solvents for rapid microwave synthesis metal-organic framework (MOF) materials. Lead, copper, and iron materials were synthesized using surfactant-thermal synthesis. The MOF characterized by powder X-ray diffraction, infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis. With exception MOF, which was expected to be amorphous, are crystalline, though generally exhibiting smaller crystals than those...
The structural and dynamic behavior of the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([C(6)mim][NTf(2)]) in chloroform has been studied by experimental measurements (1)H (19)F self-diffusion coefficients, viscosity, excess molar volume concentration range 0.001-1.0 mol·kg(-1) temperatures ranging from 15 to 45 °C. Within measurement uncertainty, coefficients are identical at same conditions temperature, indicating that even lowest measured concentrations...