Quantum chemistry in arbitrary dielectric environments: Theory and implementation of nonequilibrium Poisson boundary conditions and application to compute vertical ionization energies at the air/water interface

2018 ◽  
Vol 148 (22) ◽  
pp. 222834 ◽  
Author(s):  
Marc P. Coons ◽  
John M. Herbert
Keyword(s):  
Quantum Chemistry ◽  
Boundary Conditions ◽  
Water Interface ◽  
Poisson Boundary ◽  
Ionization Energies ◽  
Air Water Interface ◽  
Vertical Ionization Energies

scholarly journals Probing Interfacial Effects on Ionization Energies: The Surprising Banality of Anion-Water Hydrogen Bonding at the Air/Water Interface

2021 ◽  
Author(s):  
Suranjan Paul ◽  
John Herbert
Keyword(s):  
Hydrogen Bonding ◽  
Photoelectron Spectroscopy ◽  
Solvation Shell ◽  
Bulk Liquid ◽  
Water Interface ◽  
Simulation Data ◽  
Ionization Energies ◽  
Air Water Interface ◽  
Dynamics Simulations ◽  
Water Hydrogen

Liquid microjet photoelectron spectroscopy is an increasingly common technique to measure vertical ionization energies (VIEs) of aqueous solutes, although the interpretation of these experiments is subject to questions regarding sensitivity to bulk versus interfacial solvation environments. Here, we compute aqueous-phase VIEs for a set of inorganic anions, some of which partition preferentially at the air/water interface, using a combination of molecular dynamics simulations and electronic structure calculations. The results are in excellent agreement with experiment, regardless of whether the simulation data are restricted to ions at the air/water interface or to those in bulk liquid water. Although the computed VIEs are sensitive to ion-water hydrogen bonding, we find that the short-range solvation structure is sufficiently similar in the bulk and interfacial environments that it proves impossible to discriminate between the two on the basis of the VIE, a conclusion that has important implications for the interpretation of liquid-phase photoelectron spectroscopy. More generally, analysis of the simulation data suggests that partitioning of soft anions at the air/water interface is largely a second (or third) solvation shell effect, arising from disruption of water-water hydrogen bonds and not from significant changes in first-shell anion-water hydrogen bonding. <br>

scholarly journals Probing Interfacial Effects on Ionization Energies: The Surprising Banality of Anion-Water Hydrogen Bonding at the Air/Water Interface

2021 ◽  
Author(s):  
Suranjan Paul ◽  
John Herbert
Keyword(s):  
Hydrogen Bonding ◽  
Photoelectron Spectroscopy ◽  
Solvation Shell ◽  
Bulk Liquid ◽  
Water Interface ◽  
Simulation Data ◽  
Ionization Energies ◽  
Air Water Interface ◽  
Dynamics Simulations ◽  
Water Hydrogen

Liquid microjet photoelectron spectroscopy is an increasingly common technique to measure vertical ionization energies (VIEs) of aqueous solutes, although the interpretation of these experiments is subject to questions regarding sensitivity to bulk versus interfacial solvation environments. Here, we compute aqueous-phase VIEs for a set of inorganic anions, some of which partition preferentially at the air/water interface, using a combination of molecular dynamics simulations and electronic structure calculations. The results are in excellent agreement with experiment, regardless of whether the simulation data are restricted to ions at the air/water interface or to those in bulk liquid water. Although the computed VIEs are sensitive to ion-water hydrogen bonding, we find that the short-range solvation structure is sufficiently similar in the bulk and interfacial environments that it proves impossible to discriminate between the two on the basis of the VIE, a conclusion that has important implications for the interpretation of liquid-phase photoelectron spectroscopy. More generally, analysis of the simulation data suggests that partitioning of soft anions at the air/water interface is largely a second (or third) solvation shell effect, arising from disruption of water-water hydrogen bonds and not from significant changes in first-shell anion-water hydrogen bonding. <br>

Investigation of adsorption of surfactant at the air-water interface with quantum chemistry method

2007 ◽  
Vol 52 (11) ◽  
pp. 1451-1455 ◽  
Author(s):  
MeiLing Chen ◽  
ZhengWu Wang ◽  
HaiJun Wang ◽  
GeXin Zhang ◽  
FuMing Tao
Keyword(s):  
Quantum Chemistry ◽  
Water Interface ◽  
Chemistry Method ◽  
Air Water Interface ◽  
Quantum Chemistry Method

Sampling and analysis of the air-water interface with SEM and EDS of microlayers

1989 ◽  
Vol 47 ◽  
pp. 1004-1005
Author(s):  
Randall W. Smith ◽  
John Dash
Keyword(s):  
Heavy Metals ◽  
Surface Microlayer ◽  
Surface Films ◽  
Water Interface ◽  
Physical Processes ◽  
Infrared Spectroscopic Analysis ◽  
Eds Analysis ◽  
Air Water Interface ◽  
Significant Area ◽  
Bulk Chemical

The structure of the air-water interface forms a boundary layer that involves biological ,chemical geological and physical processes in its formation. Freshwater and sea surface microlayers form at the air-water interface and include a diverse assemblage of organic matter, detritus, microorganisms, plankton and heavy metals. The sampling of microlayers and the examination of components is presently a significant area of study because of the input of anthropogenic materials and their accumulation at the air-water interface. The neustonic organisms present in this environment may be sensitive to the toxic components of these inputs. Hardy reports that over 20 different methods have been developed for sampling of microlayers, primarily for bulk chemical analysis. We report here the examination of microlayer films for the documentation of structure and composition.Baier and Gucinski reported the use of Langmuir-Blogett films obtained on germanium prisms for infrared spectroscopic analysis (IR-ATR) of components. The sampling of microlayers has been done by collecting fi1ms on glass plates and teflon drums, We found that microlayers could be collected on 11 mm glass cover slips by pulling a Langmuir-Blogett film from a surface microlayer. Comparative collections were made on methylcel1ulose filter pads. The films could be air-dried or preserved in Lugol's Iodine Several slicks or surface films were sampled in September, 1987 in Chesapeake Bay, Maryland and in August, 1988 in Sequim Bay, Washington, For glass coverslips the films were air-dried, mounted on SEM pegs, ringed with colloidal silver, and sputter coated with Au-Pd, The Langmuir-Blogett film technique maintained the structure of the microlayer intact for examination, SEM observation and EDS analysis were then used to determine organisms and relative concentrations of heavy metals, using a Link AN 10000 EDS system with an ISI SS40 SEM unit. Typical heavy microlayer films are shown in Figure 3.

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