scholarly journals Hydrogen-Bond Dynamics in the Air−Water Interface

2005 ◽  
Vol 109 (7) ◽  
pp. 2949-2955 ◽  
Author(s):  
Pu Liu ◽  
Edward Harder ◽  
B. J. Berne
Keyword(s):  
Hydrogen Bond ◽  
Water Interface ◽  
Air Water Interface ◽  
Hydrogen Bond Dynamics

Cooperative Hydrogen-Bond Dynamics at a Zwitterionic Lipid/Water Interface Revealed by 2D HD-VSFG Spectroscopy

2017 ◽  
Vol 8 (20) ◽  
pp. 5160-5165 ◽  
Author(s):  
Ken-ichi Inoue ◽  
Prashant C. Singh ◽  
Satoshi Nihonyanagi ◽  
Shoichi Yamaguchi ◽  
Tahei Tahara
Keyword(s):  
Hydrogen Bond ◽  
Water Interface ◽  
Hydrogen Bond Dynamics

scholarly journals Reorientation-induced relaxation of free OH at the air/water interface revealed by ultrafast heterodyne-detected nonlinear spectroscopy

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Ken-ichi Inoue ◽  
Mohammed Ahmed ◽  
Satoshi Nihonyanagi ◽  
Tahei Tahara
Keyword(s):  
Hydrogen Bond ◽  
Vibrational Relaxation ◽  
Three Dimensional ◽  
Technical Difficulty ◽  
Nonlinear Spectroscopy ◽  
Water Interface ◽  
Hydrogen Bond Network ◽  
Relaxation Dynamics ◽  
Air Water Interface ◽  
Bond Network

Abstract The uniqueness of water originates from its three-dimensional hydrogen-bond network, but this hydrogen-bond network is suddenly truncated at the interface and non-hydrogen-bonded OH (free OH) appears. Although this free OH is the most characteristic feature of interfacial water, the molecular-level understanding of its dynamic property is still limited due to the technical difficulty. We study ultrafast vibrational relaxation dynamics of the free OH at the air/water interface using time-resolved heterodyne-detected vibrational sum frequency generation (TR-HD-VSFG) spectroscopy. With the use of singular value decomposition (SVD) analysis, the vibrational relaxation (T1) times of the free OH at the neat H2O and isotopically-diluted water interfaces are determined to be 0.87 ± 0.06 ps (neat H2O), 0.84 ± 0.09 ps (H2O/HOD/D2O = 1/2/1), and 0.88 ± 0.16 ps (H2O/HOD/D2O = 1/8/16). The absence of the isotope effect on the T1 time indicates that the main mechanism of the vibrational relaxation of the free OH is reorientation of the topmost water molecules. The determined sub-picosecond T1 time also suggests that the free OH reorients diffusively without the switching of the hydrogen-bond partner by the topmost water molecule.

Hydrogen-bond dynamics at the bio–water interface in hydrated proteins: a molecular-dynamics study

2017 ◽  
Vol 19 (1) ◽  
pp. 318-329 ◽  
Author(s):  
Prithwish K. Nandi ◽  
Niall J. English ◽  
Zdenek Futera ◽  
Antonio Benedetto
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Bond ◽  
Water Interface ◽  
Protein Residues ◽  
Hydrated Proteins ◽  
Hydrogen Bond Dynamics ◽  
Dynamical Crossover

Hydration water's dynamical-crossover lies not at the origin of the protein residues' larger-amplitude motions, but rather arises as a consequence thereof.

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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