Control of molecular orientations by a pulsating electric field applied to a monolayer at the air-water interface

Langmuir ◽  
1993 ◽  
Vol 9 (4) ◽  
pp. 1028-1030 ◽  
Author(s):  
Shunichi Arisawa ◽  
Ryoichi Yamamoto
Keyword(s):  
Electric Field ◽  
Water Interface ◽  
Air Water Interface

Anomalously large electro-optic Pockels effect at the air-water interface with an electric field applied parallel to the interface

2016 ◽  
Vol 108 (19) ◽  
pp. 191103 ◽  
Author(s):  
Yuto Suzuki ◽  
Kengo Osawa ◽  
Shunpei Yukita ◽  
Takayoshi Kobayashi ◽  
Eiji Tokunaga
Keyword(s):  
Electric Field ◽  
Water Interface ◽  
Pockels Effect ◽  
Electro Optic ◽  
Air Water Interface

scholarly journals Specific Ion Effects of Dodecyl Sulfate Surfactants with Alkali Ions at the Air–Water Interface

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2911 ◽  
Author(s):  
Weißenborn ◽  
Braunschweig
Keyword(s):  
Electric Field ◽  
Resonance Frequency ◽  
Sodium Dodecyl ◽  
Head Group ◽  
Water Interface ◽  
Surface Excess ◽  
Layer Potential ◽  
Air Water Interface ◽  
Dodecyl Sulfate ◽  
Na Ions

The influence of Li+, Na+ and Cs+ cations on the surface excess and structure of dodecyl sulfate (DS−) anions at the air–water interface was investigated with the vibrational sum-frequency generation (SFG) and surface tensiometry. Particularly, we have addressed the change in amplitude and frequency of the symmetric S-O stretching vibrations as a function of electrolyte and DS− concentration in the presence of Li+, Na+ and Cs+ cations. For the Li+ and Na+ ions, we show that the resonance frequency is shifted noticeably from 1055 cm−1 to 1063 cm−1 as a function of the surfactants’ surfaces excess, which we attribute to the vibrational Stark effect within the static electric field at the air–water interface. For Cs+ ions the resonance frequency is independent of the surfactant concentration with the S-O stretching band centered at 1063 cm−1. This frequency is identical to the frequency at the maximum surface excess when Li+ and Na+ ions are present and points to the ion pair formation between the sulfate headgroup and Cs+ counterions, which reduces the local electric field. In addition, SFG experiments of the O-H stretching bands of interfacial H2O molecules are used in order to calculate the apparent double layer potential and the degree of dissociation between the surfactant head group and the investigated cations. The latter was found to be 12.0%, 10.4% and 7.7% for lithium dodecyl sulfate (LiDS), sodium dodecyl sulfate (SDS) and cesium dodecyl sulfate (CsDS) surfactants, which is in agreement with Collins ‘rule of matching water affinities’.

Controlling the Orientation of Purple Membrane Fragments on an Air/Water Interface by a New Method of Direct Electric Field Application during Purple Membrane Spreading

1997 ◽  
Vol 36 (Part 1, No. 9A) ◽  
pp. 5674-5679 ◽  
Author(s):  
Yukihiro Sugiyama ◽  
Takakazu Inoue ◽  
Mineo Ikematsu ◽  
Masahiro Iseki ◽  
Tatsuhiko Sekiguchi
Keyword(s):  
Electric Field ◽  
Purple Membrane ◽  
Field Application ◽  
New Method ◽  
Water Interface ◽  
Air Water Interface

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.

Temperature Dependence of the Air/Water Interface Revealed by Polarization Sensitive Sum-Frequency Generation Spectroscopy

2018 ◽  
Author(s):  
Daniel R. Moberg ◽  
Shelby C. Straight ◽  
Francesco Paesani
Keyword(s):  
Temperature Dependence ◽  
Low Frequency ◽  
Potential Energy Function ◽  
Md Simulations ◽  
Sum Frequency Generation ◽  
Water Molecules ◽  
Water Interface ◽  
Sum Frequency ◽  
Air Water Interface ◽  
Frequency Generation

<div> <div> <div> <p>The temperature dependence of the vibrational sum-frequency generation (vSFG) spectra of the the air/water interface is investigated using many-body molecular dynamics (MB-MD) simulations performed with the MB-pol potential energy function. The total vSFG spectra calculated for different polarization combinations are then analyzed in terms of molecular auto-correlation and cross-correlation contributions. To provide molecular-level insights into interfacial hydrogen-bonding topologies, which give rise to specific spectroscopic features, the vSFG spectra are further investigated by separating contributions associated with water molecules donating 0, 1, or 2 hydrogen bonds to neighboring water molecules. This analysis suggests that the low frequency shoulder of the free OH peak which appears at ∼3600 cm−1 is primarily due to intermolecular couplings between both singly and doubly hydrogen-bonded molecules. </p> </div> </div> </div>

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