Calculated Properties of Ag Clusters on Silver Halide Cubic Surface Sites

Silver halide grains (AgX, X=Cl,Br,I) are commonly recognized as important entities in photographic applications. Depending on the preparation specifications one can grow cubic, octahedral, tabular a.o. morphologies, each with its own physical and chemical characteristics. In the present study crystallographic defects introduced by the mixing of 5-20% iodide in a growing AgBr tabular grain are investigated. X-ray diffractometry reveals the existence of a homogeneous Ag(Br1-xIx) region, expected to be formed around the AgBr kernel. In fig. 1 a two-beam BF image, taken at T≈100 K to diminish radiation damage, of a triangular tabular grain is presented, clearly showing defect contrast fringes along four of the six directions; the remaining two sides show similar contrast under relevant diffraction conditions. The width of the central defect free region corresponds with the pure AgBr kernel grown before the mixing with I. The thickness of a given grain lies between 0.15 and 0.3 μm: as indicated in fig. 2 triangular (resp. hexagonal) grains exhibit an uneven (resp. even) number of twin interfaces (i.e., between + and - twin variants) parallel with the (111) surfaces. The thickness of the grains and the existence of the twin variants was confirmed from CTEM images of perpendicular cuts.

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Enthalpies of mixing in the liquid silver halide-alkali halide mixtures

Journal de Chimie Physique ◽

10.1051/jcp/1974710216 ◽

1974 ◽

Vol 71 ◽

pp. 216-222 ◽

Cited By ~ 4

Author(s):

Pierre Dantzer ◽

Ole Jakob Kleppa

Keyword(s):

Alkali Halide ◽

Silver Halide ◽

Liquid Silver ◽

Enthalpies Of Mixing

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Special issue Visual system and image technology. 7. Image quality of hard copies. 4. Image quality evaluation in silver halide photography.

The Journal of the Institute of Television Engineers of Japan ◽

10.3169/itej1978.40.328 ◽

1986 ◽

Vol 40 (4) ◽

pp. 328-332

Author(s):

Satoru Honjo

Keyword(s):

Image Quality ◽

Visual System ◽

Quality Evaluation ◽

Silver Halide ◽

Special Issue ◽

Image Quality Evaluation

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Mercury Removal from Wastewater by Steamed Hoof Powder

Water Science & Technology ◽

10.2166/wst.1999.0340 ◽

1999 ◽

Vol 40 (7) ◽

pp. 109-116 ◽

Cited By ~ 4

Author(s):

M. H. Ansari ◽

A. M. Deshkar ◽

P. S. Kelkar ◽

D. M. Dharmadhikari ◽

M. Z. Hasan ◽

...

Keyword(s):

Heavy Metals ◽

Adsorption Capacity ◽

Adsorption Process ◽

Adsorption Equilibrium ◽

Light Metal ◽

Mercury Removal ◽

High Adsorption ◽

Surface Sites ◽

Ph Values ◽

High Adsorption Capacity

Steamed Hoof Powder (SHP), size < 53μ, was observed to have high adsorption capacity for Hg(II) with >95% removal from a solution containing 100 mg/L of Hg(II) with only 0.1% (W/V) concentration of SHP. The SHP has good settling properties and gives clear and odour free effluent. Studies indicate that pH values between 2 and 10 have no effect on the adsorption of Hg(II) on SHP. Light metal ions like Na+, K+, Ca2+ and Mg2+ up to concentrations of 500 mg/L and heavy metals like Cu2+, Zn2+, Cd2+, Co2+, Pb2+, Ni2+, Mn2+, Cr3+, Cr6+, Fe2+ and Fe3+ up to concentrations of 100 mg/L do not interfere with the adsorption process. Anions like sulphate, acetate and phosphate up to concentrations of 200 mg/L do not interfere. Chloride interferes in the adsorption process when Hg(II) concentration is above 9.7 mg/L. The adsorption equilibrium was established within two hours. Studies indicate that adsorption occurs on the surface sites of the adsorbent.

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Work function studies of propylene, acetylene, hydrogen and nitrogen chemisorption on molybdenum

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19822996 ◽

1982 ◽

Vol 47 (11) ◽

pp. 2996-3003

Author(s):

Zdeněk Bastl

Keyword(s):

Work Function ◽

Surface Topography ◽

Surface Coverage ◽

Dissociative Chemisorption ◽

Complete Coverage ◽

Surface Sites ◽

Function Change ◽

Work Function Change

The work function changes of vacuum deposited molybdenum films caused by the chemisorption of propylene, acetylene, hydrogen and nitrogen were measured using the Kelvin vibrating capacitor method. During the hydrocarbon chemisorption, the work function increased in a low surface coverage region but decreased at the higher surface coverages. The saturation values of the work function changes corresponding to complete coverage of the surface by chemisorbed propylene and acetylene equal -0.08 eV and -0.42 eV, respectively. The observed dependences of the work function change on surface coverage are interpreted by the dissociative chemisorption of hydrocarbons on a limited number of surface sites which are simultaneously the sites of preferred adsorption. The extent of dissociation decreases in the adsorption with the increasing surface coverage. The results of the study of the work function changes induced by the hydrogen and nitrogen chemisorption enabled to draw several conclusions on the surface topography of the used films.

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A topological quantum-chemical study of the chemisorption of carbon monoxide on the fcc (112) surfaces of Ni, Pt, Pd, Rh, and Ir

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19901907 ◽

1990 ◽

Vol 55 (8) ◽

pp. 1907-1919

Author(s):

Jiří Pancíř ◽

Ivana Haslingerová

Keyword(s):

Carbon Monoxide ◽

Quantum Chemical ◽

Co Adsorption ◽

Quantum Chemical Study ◽

Chemical Study ◽

Dissociative Chemisorption ◽

Frontier Orbitals ◽

Surface Sites ◽

Charged Surfaces ◽

Topological Quantum

A semiempirical quantum-chemical topological method is applied to the study of the fcc (112) surfaces of Ni, Pt, Pd, Rh, and Ir and the nondissociative as well as dissociative chemisorption of carbon monoxide on them. On Ni, dissociative chemisorption is preferred to linear capture, whereas on Pd and Pt, linear capture is preferred although dissociative chemisorption is also feasible. On Rh and, in particular, on Ir, dissociative chemisorption is energetically prohibited. The high dissociative ability of the Ni surface can be ascribed to a rather unusual charge alteration and to the degeneracy of the frontier orbitals. Negative charges at the surface level are only found on the Ni and Pt surfaces whereas concentration of positive charges is established on the Rh and Ir surfaces; the Pd surface is nearly uncharged. Metals with negatively charged surfaces seem to be able to dissociate molecules of carbon monoxide. It is demonstrated that CO adsorption can take place on all metal surface sites, most effectively in the valley of the step. In all the cases studied, the attachment to the surface is found to be energetically more favourable for the carbon than for the oxygen.

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Oxonol dyes

Physical Sciences Reviews ◽

10.1515/psr-2020-0189 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Heinz Mustroph

Keyword(s):

Silver Halide ◽

Medical Diagnostics ◽

Water Soluble ◽

Eukaryotic Cells ◽

Polymethine Dyes ◽

Technical Application ◽

Structural Types ◽

Oxonol Dyes ◽

Oxygen Atoms

Abstract Oxonol dyes are classified as anionic polymethine dyes, which cover a wide variety of structural types. The name of the class originates from the oxygen atoms which terminate each end of the polymethine chains that form the backbone of their structure. In technically useful dyes, these oxygen atoms tend to be substituents of heterocycles. The main technical application of water soluble oxonol dyes was in silver halide photography as filter dyes and antihalation dyes. Lipophilic oxonol dyes are used in bio-analysis and medical diagnostics to stain cells, bacteria or liposomes for example. Their main bioanalytical usage is in the determination of membrane potentials in eukaryotic cells and prokaryotic bacteria.

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