Thermochemistry and adsorption equilibria at hematite — water interface

2007 ◽  
pp. 108-112 ◽  
Author(s):  
N. Kallay ◽  
S. Žalac ◽  
J. Ćulin ◽  
U. Bieger ◽  
A. Pohlmeier ◽  
...  
Keyword(s):  
Water Interface ◽  
Adsorption Equilibria

Interaction of Prothrombin with Phospholipids Monolayers in Presence of Ca**.

1979 ◽  
Author(s):  
M.F. Lecompte ◽  
I.R. Miller
Keyword(s):  
Lipid Monolayer ◽  
Surface Measurement ◽  
Proteolytic Degradation ◽  
Water Interface ◽  
Lipid Layer ◽  
New Approach ◽  
Adsorption Equilibria ◽  
Activation Rate ◽  
Comparative Results ◽  
Structural Aspects

The activation rate of Prothrombin and its conversion into thrombin through a proteolytic degradation is enhanced by phospholipids in the presence of Ca++. In this work, we could elucidate stoechiomet rio and structural aspects of the interaction between prothrombin. phospholipids and Ca++. We studied the adsorption equilibria of Ca++ and of prothrombin un phospholipids monolayers by a new approach which comoines two complementary methods of surface measurement.Electrochemical investigations on lipid monolayer interacting with prothrombin showed penetration of prothrombin in presence or not of Ca++ (by increasing the lipid layer capacitance). with a preferential orientation. The adsorption of Ca++ and prothrombin to the lipid layer was measured by counting the surface radioactivity of 45Ca and 3H-prothrombin. Synergetic attachment of Ca++ and prothrombin to the phospholipid water interface was observed and the number of Ca++ per attached prothromoin was determinen. The two methods give comparative results for the proposed ionic-hydrophobic interaction.

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.

Porous materials from cellulose nanocrystal and mxene surfactants at the oil/water interface

2020 ◽  
Author(s):  
Bingqing qian ◽  
Haiqiao Wang ◽  
Dong Wang ◽  
Hao-Bin Zhang ◽  
Jessica Wu ◽  
...  
Keyword(s):  
Porous Materials ◽  
Cellulose Nanocrystal ◽  
Water Interface ◽  
Oil Water

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>

Sign in / Sign up

Export Citation Format

Share Document