An analysis of adsorption and kinetic effects in cesium salt solutions on the mercury-water interface within the framework of new electrostatic models

It has been shown by Evans (1937) that the effects of the alkali metal chlorides at a hexane-water interface are markedly similar to the effects of the same salts on the surface tension of water as determined by Heydweiller (1910) and Schwenker (1931), i.e. the tension apparently increases steadily with concentration. Hence, from the Gibbs adsorption principle, the salt is negatively adsorbed throughout. The recent work of Jones and Ray (1937) has, however, demonstrated that the surface tension of the salt solutions examined by them first decreases with increase of concentration, passes through a minimum and subsequently increases beyond the value possessed by pure water. On general grounds it would be expected that phenomena similar to those observed by Jones and Ray at the free surface should likewise be exhibited at an interface. In an attempt to investigate this point interfacial tension data have been obtained for the interface dekalin ( trans -decahydro- naphthalene)/water, using salts of various valence type.

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Specific Ion Effects of Salt Solutions at the CaF2/Water Interface

Langmuir ◽

10.1021/la100607b ◽

2010 ◽

Vol 26 (13) ◽

pp. 10784-10790 ◽

Cited By ~ 29

Author(s):

Adam J. Hopkins ◽

Simon Schrödle ◽

Geraldine L. Richmond

Keyword(s):

Water Interface ◽

Salt Solutions ◽

Specific Ion Effects ◽

Ion Effects

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Isomorphous replacement in electron diffraction of wet crystals of rat hemoglobin

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100075968 ◽

1983 ◽

Vol 41 ◽

pp. 446-447

Author(s):

William F. Tivol ◽

Murray Vernon King ◽

D. F. Parsons

Keyword(s):

Electron Diffraction ◽

Heavy Atom ◽

Isomorphous Substitution ◽

X Ray Diffraction ◽

Salt Solutions ◽

X Ray ◽

Isomorphous Replacement ◽

Structure Factors ◽

Diffraction Structure ◽

The Mean

Feasibility of isomorphous substitution in electron diffraction is supported by a calculation of the mean alteration of the electron-diffraction structure factors for hemoglobin crystals caused by substituting two mercury atoms per molecule, following Green, Ingram & Perutz, but with allowance for the proportionality of f to Z3/4 for electron diffraction. This yields a mean net change in F of 12.5%, as contrasted with 22.8% for x-ray diffraction.Use of the hydration chamber in electron diffraction opens prospects for examining many proteins that yield only very thin crystals not suitable for x-ray diffraction. Examination in the wet state avoids treatments that could cause translocation of the heavy-atom labels or distortion of the crystal. Combined with low-fluence techniques, it enables study of the protein in a state as close to native as possible.We have undertaken a study of crystals of rat hemoglobin by electron diffraction in the wet state. Rat hemoglobin offers a certain advantage for hydration-chamber work over other hemoglobins in that it can be crystallized from distilled water instead of salt solutions.

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Bulk standards for low-temperature biological x-ray microanalysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100111525 ◽

1984 ◽

Vol 42 ◽

pp. 282-283

Author(s):

P. Echlin ◽

M. McKoon ◽

E.S. Taylor ◽

C.E. Thomas ◽

K.L. Maloney ◽

...

Keyword(s):

Phase Separation ◽

Low Temperature ◽

Analytical Method ◽

Salt Solutions ◽

Absolute Concentration ◽

Cooling Process ◽

X Ray ◽

The Absolute ◽

Analytical Procedures ◽

Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100157000 ◽

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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