scholarly journals Effect of Chloride Ions on the Bacterial Leaching of Sulfide Minerals with the Addition of Silver Ions.

1995 ◽  
Vol 111 (5) ◽  
pp. 317-321 ◽  
Author(s):  
Hiroshi NAKAZAWA ◽  
Hayato SATO ◽  
Ryouichi HOSHINO ◽  
Noritake OKAMOTO
Keyword(s):  
Silver Ions ◽  
Sulfide Minerals ◽  
Chloride Ions ◽  
Bacterial Leaching

Decomposition of hydrogen peroxide on nickel-silver two-component catalyst

1984 ◽  
Vol 49 (10) ◽  
pp. 2222-2230 ◽  
Author(s):  
Viliam Múčka ◽  
Rostislav Silber
Keyword(s):  
Hydrogen Peroxide ◽  
Chemical Properties ◽  
Silver Ions ◽  
Surface Concentration ◽  
Chloride Ions ◽  
Nickel Silver ◽  
Silver Catalysts ◽  
Physico Chemical ◽  
Low Degree ◽  
Defective Crystal

The catalytic and physico-chemical properties of low-temperature nickel-silver catalysts with nickel oxide concentrations up to 43.8% (m/m) are examined via decomposition of hydrogen peroxide in aqueous solution. The mixed catalysts prepared at 250°C are composed of partly decomposed silver carbonate or oxide and nickel carbonate or hydroxide decomposed to a low degree only and exhibiting a very defective crystal structure. The activity of these catalysts is determined by the surface concentration of silver ions, which is affected by the nickel component present. The latter also contributes to the thermal stability of the catalytic centres of the silver component, viz. the Ag+ ions. The concentration of these ions varies with the temperature of the catalyst treatment, the activity varies qualitatively in the same manner, and the system approaches the Ag-NiO composition. The catalytic centres are very susceptible to poisoning by chloride ions. A previous exposition of the catalyst to a gamma dose of 10 kGy from a 60Co source has no measurable effect on the physico-chemical properties of the system.

scholarly journals Antibacterial Effect of Amino Acid–Silver Complex Loaded Montmorillonite Incorporated in Dental Acrylic Resin

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1442
Author(s):  
Kumiko Yoshihara ◽  
Noriyuki Nagaoka ◽  
Aya Umeno ◽  
Akinari Sonoda ◽  
Hideki Obika ◽  
...  
Keyword(s):  
Amino Acid ◽  
Antibacterial Agents ◽  
Antibacterial Effect ◽  
Dental Materials ◽  
Silver Ions ◽  
Acrylic Resin ◽  
Chloride Ions ◽  
Antibacterial Efficacy ◽  
Growth Measurement ◽  
Dental Acrylic

Several dental materials contain silver for antibacterial effect, however the effect is relatively low. The reason for the lower antibacterial efficacy of silver is considered to be the fact that silver ions bind to chloride ions in saliva. To develop new effective silver antibacterial agents that can be useful in the mouth, we synthesized two novel amino acid (methionine or histidine)–silver complexes (Met or His–Ag) loaded with montmorillonite (Mont) and analyzed their antibacterial efficacy. At first the complexes were characterized using nuclear magnetic resonance (NMR), and amino acid–Ag complex-loaded Mont (amino acid–Ag–Mont) were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The antibacterial efficacy of these materials in dental acrylic resin was then investigated by bacterial growth measurement using a spectrophotometer. As controls, commercially available silver-loaded zeolite and silver-zirconium phosphate were also tested. Dental acrylic resin incorporating His–Ag–Mont strongly inhibited Streptococcus mutans growth. This was explained by the fact that His-Ag complex revealed the highest amounts of silver ions in the presence of chloride. The structure of the amino acid–Ag complexes affected the silver ion presence in chloride and the antibacterial efficacy. His–Ag–Mont might be used as antibacterial agents for dental materials.

scholarly journals Antifungal Activity of Silver Ions and Nanoparticles on Phytopathogenic Fungi

Plant Disease ◽  
2009 ◽  
Vol 93 (10) ◽  
pp. 1037-1043 ◽  
Author(s):  
Young-Ki Jo ◽  
Byung H. Kim ◽  
Geunhwa Jung
Keyword(s):  
Antifungal Activity ◽  
Colony Formation ◽  
Magnaporthe Grisea ◽  
Silver Ions ◽  
Pathogenic Fungi ◽  
Chloride Ions ◽  
Plant Diseases ◽  
Plant Pathogenic Fungi ◽  
In Planta

Silver in ionic or nanoparticle forms has a high antimicrobial activity and is therefore widely used for various sterilization purposes including materials of medical devices and water sanitization. There have been relatively few studies on the applicability of silver to control plant diseases. Various forms of silver ions and nanoparticles were tested in the current study to examine the antifungal activity on two plant-pathogenic fungi, Bipolaris sorokiniana and Magnaporthe grisea. In vitro petri dish assays indicated that silver ions and nanoparticles had a significant effect on the colony formation of these two pathogens. Effective concentrations of the silver compounds inhibiting colony formation by 50% (EC50) were higher for B. sorokiniana than for M. grisea. The inhibitory effect on colony formation significantly diminished after silver cations were neutralized with chloride ions. Growth chamber inoculation assays further confirmed that both ionic and nanoparticle silver significantly reduced these two fungal diseases on perennial ryegrass (Lolium perenne). Particularly, silver ions and nanoparticles effectively reduced disease severity with an application at 3 h before spore inoculation, but their efficacy significantly diminished when applied at 24 h after inoculation. The in vitro and in planta evaluations of silver indicated that both silver ions and nanoparticles influence colony formation of spores and disease progress of plant-pathogenic fungi. In planta efficacy of silver ions and nanoparticles is much greater with preventative application, which may promote the direct contact of silver with spores and germ tubes, and inhibit their viability.

scholarly journals Effect of Chloride Ions on the Point-of-Use Drinking Water Disinfection Performance of Porous Ceramic Media Embedded with Metallic Silver and Copper

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1625
Author(s):  
Rekha Singh ◽  
Woohang Kim ◽  
James A. Smith
Keyword(s):  
Drinking Water ◽  
Porous Ceramic ◽  
Chloride Ion ◽  
Silver Ions ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Metallic Silver ◽  
E Coli ◽  
Ion Concentrations ◽  
Copper Release

This study quantifies the effects of chloride ions on silver and copper release from porous ceramic cubes embedded with silver and copper and its effect on E. coli disinfection in drinking water. Log-reduction of E. coli by silver ions decreased after 4 h of contact time as the chloride ion concentration increased from 0 to 250 mg/L but, it was not changed by copper ions under the same conditions. For silver addition by silver-ceramic cubes, log reductions of E. coli decreased sharply from 7.2 to 1.6 after 12 h as the chloride concentration increased from 0 to 250 mg/L. For the silver-ceramic cube experiments, chloride ion also reduced the total silver concentration in solution. After 24 h, total silver concentrations in solution decreased from 61 µg/L to 20 µg/L for corresponding chloride ion concentrations. According to the MINTEQ equilibrium model analysis, the decrease in disinfection ability with silver embedded ceramic cubes could be the result of precipitation of silver ions as silver chloride. This suggests that AgCl was precipitating within the pore space of the ceramic. These results indicate that, although ionic silver is a highly effective disinfectant for E. coli, the presence of chloride ions can significantly reduce disinfection efficacy. For copper-ceramic cubes, log reductions of E. coli by copper embedded cubes increased from 1.2 to 1.5 when chloride ion concentration increased from 0 to 250 mg/L. Total copper concentrations in solution increased from 4 µg/L to 14 µg/L for corresponding chloride ion concentrations. These results point towards the synergistic effect of chloride ions on copper oxidation as an increased concentration of chloride enhances copper release.

Measurement of short-circuit current and ion transport across the ileum

1964 ◽  
Vol 206 (3) ◽  
pp. 658-668 ◽  
Author(s):  
T. W. Clarkson ◽  
S. R. Toole
Keyword(s):  
Ion Transport ◽  
Sodium Transport ◽  
Chemical Potential ◽  
Short Circuit ◽  
Silver Ions ◽  
Short Circuit Current ◽  
Chloride Ions ◽  
Salt Transport ◽  
Complexing Agents ◽  
Bathing Solution

An apparatus is described which allowed control over both the electrical and chemical potential gradients across the isolated ileum of the rat and at the same time permitted the measurement of the transport of ions and water. Silver ions, released from the electrodes, affected ion transport. In the absence of complexing agents, the short-circuit current ( SCC) fell during the 60-min measurement period and was equal to the net sodium transport. With 10–3 m reduced glutathione in the bathing solution, the SCC was constant and equal to 94% of the sodium transport. With 10–4 m cysteine, the SCC was greatly increased. Sodium transport, also increased, was equal to 75% and chloride secretion to 20% of the SCC. A mechanism by which silver ions stimulate sodium transport, is proposed. Comparison of water and salt transport between open- and short-circuited tissues indicated that chloride ions were more effective in producing water movement when transported from mucosal to serosal solutions directly through the tissue (open circuit) rather than via the Ag/AgCl electrode system (short-circuit experiments).

scholarly journals One-Step Synthesis of Green Fluorescent Carbon Dots for Chloride Detecting and for Bioimaging

2021 ◽  
Vol 9 ◽  
Author(s):  
Juan Yue ◽  
Ling Yu ◽  
Li Li ◽  
Pai Liu ◽  
Qian Mei ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Limit Of Detection ◽  
Chloride Concentration ◽  
Chloride Ion ◽  
Silver Ions ◽  
Chloride Ions ◽  
Cell Functions ◽  
Green Fluorescent ◽  
Fluorescent Carbon

The chloride ion is an essential ion in organisms, which plays an important role in maintaining normal cell functions. It is involved in many cell activities, such as cell proliferation, cell excitability regulation, immune response, and volume regulation. Accurate detection of the chloride ion can balance its concentration in vivo, which is of great significance. In this study, we developed a green fluorescent carbon quantum dot to detect chloride concentration through the “off–on” mechanism. First, the fluorescence of carbon dots is quenched by the complex of sulfhydryl and silver ions on the surface of carbon dots. Then, the addition of chloride ions pulls away the silver ions and restores the fluorescence. The fluorescence recovery is linearly related to the concentration of chloride ions, and the limit of detection is 2.817 μM, which is much lower than those of other reported chloride probes. Besides, cell and zebrafish experiments confirmed the biosafety and biocompatibility of the carbon dots, which provided a possibility for further applications in bioimaging in vivo.

scholarly journals Use of silver–bentonite in sorption of chloride and iodide ions

2020 ◽  
Vol 326 (3) ◽  
pp. 1795-1804
Author(s):  
Dóra Buzetzky ◽  
Noémi M. Nagy ◽  
József Kónya
Keyword(s):  
Interlayer Space ◽  
Exchange Process ◽  
Silver Ions ◽  
Exchange Capacity ◽  
Chloride Ions ◽  
Precipitation Process ◽  
High Concentration ◽  
Iodide Ions ◽  
Ion Exchange Process ◽  
Increasing Temperature

AbstractAg–bentonite was prepared by ion exchange process to sorb iodide and chloride ions in batch experiments. The modified bentonite was examined with XRF and XRD. 75% of the cation exchange capacity was exchanged by silver ions. It was found that the sorption of chloride ions is an exothermic precipitation process because the solubility decreases with increasing temperature. In the case of iodide sorption, the dissolution of AgI was observed under high concentration of non-radioactive iodide ions, which is well known in analytical chemistry. The phenomenon occurs not only in the bulk aqueous phase but also in the interlayer space of montmorillonite.

Electrochemical Noise Analysis of Chalcopyrite Carbon Paste Electrodes by Acidithiobacillus ferrooxidans

2007 ◽  
Vol 20-21 ◽  
pp. 83-86 ◽  
Author(s):  
Daniela G. Horta ◽  
Denise Bevilaqua ◽  
Heloísa A. Acciari ◽  
Oswaldo Garcia Jr. ◽  
Assis Vicente Benedetti
Keyword(s):  
Electrochemical Noise ◽  
Noise Analysis ◽  
Silver Ions ◽  
Chloride Ions ◽  
Corrosion Process ◽  
Electrochemical Cells ◽  
Carbon Paste ◽  
Mineral Salts ◽  
Accelerated Corrosion ◽  
Carbon Paste Electrodes

The electrochemical response of chalcopyrite was studied using electrochemical noise analysis (ENA). The assay was carried out under constant aeration using 30 mL in two electrochemical cells containing iron-free mineral salts solution. These cells were initially monitored for 56 hours. After 72 hours, 7.25×1010 cells mL-1 of A. ferrooxidans strain LR were added in both cells and monitored until 128 h. Subsequent to this period, 0.927 mmol L-1 of silver ions and 400 mmol L-1 of chloride ions were added each one separately. Both conditions were monitored until 168 hours. According to results obtained, it was observed that Cl- ions addition induced an accelerated corrosion process. However, there is a tendency of the system to reach the stationary state due to repassivation of the electrodic surface. In the other side, the Ag+ addition contributed for the maintenance of the oxidant atmosphere, in spite of controversial effect caused by considerable variations in the Rn values, resulting in a instability in the chalcopyrite reactivity.

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