scispace - formally typeset
Search or ask a question
Author

David M. Bartels

Other affiliations: Argonne National Laboratory
Bio: David M. Bartels is an academic researcher from University of Notre Dame. The author has contributed to research in topics: Radiolysis & Solvated electron. The author has an hindex of 24, co-authored 74 publications receiving 1969 citations. Previous affiliations of David M. Bartels include Argonne National Laboratory.


Papers
More filters
Journal ArticleDOI
TL;DR: Chemical Science Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352; Department of Chemistry, ShelbyHall, University of Alabama, Box 870336, Tuscaloosa, Alabama 35487-0336; Notre Dame Radiation Laboratory, Universityof Notre Dame,Notre Dame, Indiana 46556.
Abstract: Chemical Science Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352; Department of Chemistry, ShelbyHall, University of Alabama, Box 870336, Tuscaloosa, Alabama 35487-0336; Notre Dame Radiation Laboratory, University of Notre Dame,Notre Dame, Indiana 46556; Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 0520-8107; Argonne NationalLaboratory, 9700 South Cass Avenue, Argonne, Illinois 60439; Department of Computer Science and Department of Physics, 2710 University Drive,Washington State University, Richland, Washington 99352-1671; Lawrence Berkeley National Laboratory, 1 Cyclotron Road Mailstop 1-0472,Berkeley, California 94720; Department of Chemistry and Biochemistry, University of Texas at Austin, 1 University Station A5300,Austin, Texas 78712; Office of Basic Energy Sciences, U.S. Department of Energy, SC-141/Germantown Building, 1000 Independence Avenue,S.W., Washington, D.C. 20585-1290; Department of Physics and Engineering Physics, Stevens Institute of Technology, Castle Point on Hudson,Hoboken, New Jersey 07030; Department of Chemistry, Johns Hopkins University, 34th and Charles Streets, Baltimore, Maryland 21218;Department of Chemistry, University of Southern California, Los Angeles, California 90089-1062; Department of Chemistry, The Ohio StateUniversity, 100 West 18th Avenue, Columbus, Ohio 43210-1185; Department of Chemistry, Columbia University, Box 3107, Havemeyer Hall,New York, New York 10027; Department of Chemistry, University of Pittsburgh, Parkman Avenue and University Drive,Pittsburgh, Pennsylvania 15260; Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000; Department of Physics andAstronomy, Rutgers, The State University of New Jersey, 136 Frelinghuysen Road, Piscataway, New Jersey 08854-8019; Department of Chemistry,516 Rowland Hall, University of California, Irvine, Irvine, California 92697-2025; Stanford Synchrotron Radiation Laboratory, Stanford LinearAccelerator Center, 2575 Sand Hill Road, Mail Stop 69, Menlo Park, California 94025; School of Chemistry and Biochemistry, Georgia Institute ofTechnology, 770 State Street, Atlanta, Georgia 30332-0400; Geology Department, University of California, Davis, One Shields Avenue,Davis, California 95616-8605; Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue,Cambridge, Massachusetts 02139-4307; Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084Received July 23, 2004

534 citations

Journal ArticleDOI
TL;DR: Reactions with various electron scavengers including H+, NO2−, NO3− and H2O2 show that the kinetics are similar, but not identical, to those for solvated electrons formed in bulk water by radiolysis.
Abstract: Free, or solvated, electrons in a solution are known to form at the interface between a liquid and a gas. Here, the authors use absorption spectroscopy in a total internal reflection geometry to probe solvated electrons generated at a plasma in contact with the surface of an aqueous solution

242 citations

Journal ArticleDOI
TL;DR: The enthalpy and free energy of electron hydration are derived as a function of temperature on the basis of existing equilibrium data and absolute proton hydration energies derived from the cluster-based common point method and compares the effective "size" of the hydrated electron derived from both methods.
Abstract: Spectra of the hydrated electron in pressurized light and heavy water at temperatures up to and beyond the critical temperature are reported, for wavelengths between 0.4 and 1.7 μm. In agreement with previous work, spectra can be approximately represented by a Gaussian function on the low-energy side, and a Lorentzian function on the high-energy side in subcritical water, but deviations from this form are very clear above 200 °C. The spectrum shifts strongly to the red as temperature rises. At supercritical temperatures, the spectrum shifts slightly to the red as density decreases, and the Gaussian−Lorentzian form is a very poor description. Application of spectral moment theory allows one to make an estimate of the average size of the electron wave function and of its kinetic energy. It appears that for water densities below about 0.6 g/cc, and down to below 0.1 g/cc, the average radius of gyration for the electron remains constant at around 3.4 A, and its absorption maximum is near 0.9 eV. For higher de...

115 citations

Journal ArticleDOI
TL;DR: A minimal model for the aqueous electron, consisting of a small water anion cluster embedded in a polarized continuum, conforms very well to experiment, suggesting it does in fact represent the dominant structural motif of the hydrated electron.
Abstract: Since its discovery over 50 years ago, the “structure” and properties of the hydrated electron have been a subject for wonderment and also fierce debate. In the present work we seriously explore a minimal model for the aqueous electron, consisting of a small water anion cluster embedded in a polarized continuum, using several levels of ab initio calculation and basis set. The minimum energy “zero Kelvin” structure found for any 4-water (or larger) anion cluster, at any post-Hartree–Fock theory level, is very similar to a recently reported embedded-DFT-in-classical-water-MD simulation (Uhlig, Marsalek, and Jungwirth, J. Phys. Chem. Lett. 2012, 3, 3071−3075), with four OH bonds oriented toward the maximum charge density in a small central “void”. The minimum calculation with just four water molecules does a remarkably good job of reproducing the resonance Raman properties, the radius of gyration derived from the optical spectrum, the vertical detachment energy, and the hydration free energy. For the first t...

82 citations

Journal ArticleDOI
TL;DR: The rate constant for the self-recombination of hydroxyl radicals in aqueous solution giving H2O2 product has been measured by direct measurement of the •OH radical transient optical absorption at 250 nm and the non-Arrhenius behavior can be well described in terms of the Noyes equation.
Abstract: The rate constant for the self-recombination of hydroxyl radicals (*OH) in aqueous solution giving H2O2 product has been measured from 150 to 350 degrees C by direct measurement of the *OH radical transient optical absorption at 250 nm. The values of the rate constant are smaller than previously predicted by extrapolation to the 200-350 degrees C range and show virtually no change in this range. In combining these measurements with previous results, the non-Arrhenius behavior can be well described in terms of the Noyes equation kobs-1 = kact-1+ kdiff-1, using the diffusion-limited rate constant kdiff estimated from the Smoluchowski equation and an activated barrier rate kact nearly equal to the gas-phase high-pressure limiting rate constant for this reaction. The aqueous *OH radical spectrum between 230 and 320 nm is reported up to 350 degrees C. A weak band at 310 nm grows in at higher temperature, while the stronger band at 230 nm decreases. An isosbestic point appears near 305 nm. We assign the 230 nm band to hydrogen-bonded *OH radical, and the 310 nm band is assigned to "free" *OH. On the basis of the spectrum change relative to room temperature, over half of the *OH radicals are in the latter form at 350 degrees C.

74 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: In this article, the working mechanisms of femtosecond laser nanoprocessing in biomaterials with oscillator pulses of 80-MHz repetition rate and with amplified pulses of 1-kHz repetition rate were investigated.
Abstract: We review recent advances in laser cell surgery, and investigate the working mechanisms of femtosecond laser nanoprocessing in biomaterials with oscillator pulses of 80-MHz repetition rate and with amplified pulses of 1-kHz repetition rate. Plasma formation in water, the evolution of the temperature distribution, thermoelastic stress generation, and stress-induced bubble formation are numerically simulated for NA=1.3, and the outcome is compared to experimental results. Mechanisms and the spatial resolution of femtosecond laser surgery are then compared to the features of continuous-wave (cw) microbeams. We find that free electrons are produced in a fairly large irradiance range below the optical breakdown threshold, with a deterministic relationship between free-electron density and irradiance. This provides a large ‘tuning range’ for the creation of spatially extremely confined chemical, thermal, and mechanical effects via free-electron generation. Dissection at 80-MHz repetition rate is performed in the low-density plasma regime at pulse energies well below the optical breakdown threshold and only slightly higher than used for nonlinear imaging. It is mediated by free-electron-induced chemical decomposition (bond breaking) in conjunction with multiphoton-induced chemistry, and hardly related to heating or thermoelastic stresses. When the energy is raised, accumulative heating occurs and long-lasting bubbles are produced by tissue dissociation into volatile fragments, which is usually unwanted. By contrast, dissection at 1-kHz repetition rate is performed using more than 10-fold larger pulse energies and relies on thermoelastically induced formation of minute transient cavities with lifetimes <100 ns. Both modes of femtosecond laser nanoprocessing can achieve a 2–3 fold better precision than cell surgery using cw irradiation, and enable manipulation at arbitrary locations.

1,226 citations

Journal ArticleDOI
TL;DR: In this article, the authors presented the hydrogen-based energy system as four corners (stages) of a square shaped integrated whole to demonstrate the interconnection and interdependency of these main stages.
Abstract: Power to hydrogen is a promising solution for storing variable Renewable Energy (RE) to achieve a 100% renewable and sustainable hydrogen economy. The hydrogen-based energy system (energy to hydrogen to energy) comprises four main stages; production, storage, safety and utilisation. The hydrogen-based energy system is presented as four corners (stages) of a square shaped integrated whole to demonstrate the interconnection and interdependency of these main stages. The hydrogen production pathway and specific technology selection are dependent on the type of energy and feedstock available as well as the end-use purity required. Hence, purification technologies are included in the production pathways for system integration, energy storage, utilisation or RE export. Hydrogen production pathways and associated technologies are reviewed in this paper for their interconnection and interdependence on the other corners of the hydrogen square. Despite hydrogen being zero-carbon-emission energy at the end-use point, it depends on the cleanness of the production pathway and the energy used to produce it. Thus, the guarantee of hydrogen origin is essential to consider hydrogen as clean energy. An innovative model is introduced as a hydrogen cleanness index coding for further investigation and development.

1,090 citations

Journal ArticleDOI
TL;DR: A review of the state-of-the-art of this multidisciplinary area and identifying the key research challenges is provided in this paper, where the developments in diagnostics, modeling and further extensions of cross section and reaction rate databases are discussed.
Abstract: Plasma–liquid interactions represent a growing interdisciplinary area of research involving plasma science, fluid dynamics, heat and mass transfer, photolysis, multiphase chemistry and aerosol science. This review provides an assessment of the state-of-the-art of this multidisciplinary area and identifies the key research challenges. The developments in diagnostics, modeling and further extensions of cross section and reaction rate databases that are necessary to address these challenges are discussed. The review focusses on non-equilibrium plasmas.

1,078 citations

Journal ArticleDOI
TL;DR: Using the same set of ions that was recently used to develop the SM6 continuum solvation model, SM6 retains its previously determined high accuracy; indeed, in most cases the mean unsigned error improves when it is tested against the more accurate reference data.
Abstract: Thermochemical cycles that involve pKa, gas-phase acidities, aqueous solvation free energies of neutral species, and gas-phase clustering free energies have been used with the cluster pair approximation to determine the absolute aqueous solvation free energy of the proton. The best value obtained in this work is in good agreement with the value reported by Tissandier et al. (Tissandier, M. D.; Cowen, K. A.; Feng, W. Y.; Gundlach, E.; Cohen, M. J.; Earhart, A. D.; Coe, J. V. J. Phys. Chem. A 1998, 102, 7787), who applied the cluster pair approximation to a less diverse and smaller data set of ions. We agree with previous workers who advocated the value of −265.9 kcal/mol for the absolute aqueous solvation free energy of the proton. Considering the uncertainties associated with the experimental gas-phase free energies of ions that are required to use the cluster pair approximation as well as analyses of various subsets of data, we estimate an uncertainty for the absolute aqueous solvation free energy of the...

846 citations

Journal ArticleDOI
TL;DR: Assessment of the potential role that electron microscopy of liquid samples can play in areas such as energy storage and bioimaging is assessed.
Abstract: This article reviews the use of electron microscopy in liquids and its application in biology and materials science.

821 citations