THE METAL–SOLUTION SILVER ION EXCHANGE

1956 ◽  
Vol 34 (1) ◽  
pp. 14-40 ◽  
Author(s):  
I. I. Tingley ◽  
I. H. S. Henderson ◽  
C. C. Coffin

The exchange of silver ions between silver nitrate solutions and surfaces of metallic silver was studied, using radioactive silver (Ag110, 270 day half-life) as a tracer. Marked differences in behavior of surfaces prepared in different ways were observed. Crystalline (annealed and etched) surfaces exchanged rapidly to a depth of a few atomic layers, and about 80% of the acquired radioactivity was removed as quickly by exchange with inactive silver nitrate solution. Highly polished surfaces exchanged up to ten times as great an extent as the etched annealed surfaces, but required 40 hours' immersion to attain their maximum activity. The deactivation of polished surfaces by inactive solutions was inversely proportional to the period of immersion in active solution, with surfaces immersed for 17 hr. or more retaining all but 30% of their acquired activity. Abraded surfaces exchanged quickly and retained most of their activity, the extent of the exchange depending upon the ratio of “worked” to “unworked” material on the surface. Some evidence of comparatively rapid diffusion in the polish layers was obtained. The interior of cold-worked silver when exposed to the nitrate solution behaved similarly to abraded surfaces. Mechanisms for the behavior of these different types of surface are offered, and the data of other workers discussed.

1950 ◽  
Vol 28b (2) ◽  
pp. 43-55 ◽  
Author(s):  
Alan N. Campbell ◽  
Elinor M. Kartzmark

The conductances, densities, and viscosities of solutions of silver nitrate and of ammonium nitrate, at 25 °C., have been determined at concentrations ranging from 0.1 N to saturation (about 9 and 11 N respectively). By way of comparison, the same data have been obtained for the weak electrolyte acetic acid, up to 99.7% by weight concentration. It is shown that the weak electrolyte, at these concentrations, deviates even more from the Ostwald dilution law than do the strong electrolytes. Various attempts have been made to correct the conductance for viscosity. In addition to the older methods, two new attempts have been made, viz.; sugar was added to N/10 silver nitrate (used as the basis for these calculations) until its viscosity became equal to each of the silver nitrate solutions in turn. The conductance of a N/10 silver nitrate solution containing enough sugar to make its viscosity exactly equal to that of any given silver nitrate solution was used in the evaluation of the conductance ratio. Again, the viscosities of silver nitrate solutions at different temperatures were determined and the conductance found at the temperature at which the viscosity had become equal to that of N/10 silver nitrate at 25 °C. This conductance was used as the numerator in the conductance ratio. All attempts, however, resulted in "overcorrection", that is, in an apparently increasing equivalent conductance, with increasing concentration, after a certain concentration is reached. It is shown that a remarkable agreement exists, in the case of ammonium nitrate, with the Walden modification of the Ostwald formula.


2016 ◽  
Vol 15 (05n06) ◽  
pp. 1660001 ◽  
Author(s):  
V. P. Manjamadha ◽  
Karuppan Muthukumar

The current work elucidates the utilization of biowaste as a valuable reducing agent for the synthesis of silver nanoparticles. In this study, the wastewater generated during the alkaline pretreatment of lignocellulosic wastes (APLW) was used as a bioreductant to reduce silver nitrate under room temperature. Synthesis of stable silver nanoparticles (AgNPs) was achieved rapidly on addition of APLW into the silver nitrate solution (1[Formula: see text]mM). The morphological characterization of AgNPs was performed using field emission scanning electron microscopy (FESEM). The micrograph clearly depicted the presence of spherical AgNPs. The presence of elemental silver along with biomoilties was determined using energy dispersive X-ray spectroscopy (EDAX) analysis. The X-ray diffraction (XRD) study proved the crystalline form of stable AgNPs. The AgNPs exhibited excellent antibacterial performance against Gram negative organism. The immediate bioreduction of silver ions using APLW was well illustrated in the present study. Thus, APLW serve as an alternative source for reducing agents instead of utilizing valuable medicinal plants for nanoparticles synthesis.


1953 ◽  
Vol 31 (4) ◽  
pp. 319-327 ◽  
Author(s):  
A. Baerg ◽  
C. A. Winkler

The extent of the exchange between silver foils and silver ions in nitrate solution was compared with surface area measurements made by the Bowden-Rideal method. No quantitative correspondence between the two measurements was observed. During one hour the exchange with mechanically abraded surfaces affected about 30 apparent atomic layers of the metal, but this was reduced to about one-half this value when the surfaces were equilibrated for several days in inactive silver nitrate. Etched foils exchanged during one hour to a.depth of only about 2 apparent atomic layers and this was not affected by equilibration. Bowden-Rideal area measurements gave values of roughly 7 and 15 times the planar area for etched and abraded specimens respectively. These values were not altered by equilibration of the surfaces. Only about 50% of the acquired radioactivity was subsequently removable in inactive silver nitrate solution. Part of the measured radioactivity was present on the surface in adsorbed ionic form and was not removable by a simple water wash. The magnitude of this adsorbed activity was found to be measurable electrometrically.


2021 ◽  
Vol 24 (2) ◽  
pp. 103-110
Author(s):  
Umair Yaqub Qazi

The effect of different additives on the AgNPs formation process was explored in this study. AgNPs were synthesized in an aqueous solution of silver nitrate-containing surfactants by photoreduction of silver ions. The concentration dependency of AgNPs formation suggested that stability was induced by the equilibrium of AgNPs adsorbed by surfactants with higher carbon chain molecules such as SDS and AOT. These results open up a new window both for structural control and the development process. It also indicated that different additives had an impact on the morphology of NPs. The hydrocarbon chain influenced the growth process and demonstrated that <10 carbon chain surfactants such as SMS, SOS, did not constitute the CGC and had a minor effect on the mechanism of growth. However, the NPs formation begun at a lower limit indicated as CGC. It was observed only with hydrocarbon chains of > 10 carbon atoms such as AOT, SDS. Fluorescence results confirmed that after laser irradiation, hemi-micelle formation after the development of AgNPs.


MRS Advances ◽  
2016 ◽  
Vol 2 (24) ◽  
pp. 1285-1290
Author(s):  
Hiroaki Igashira ◽  
Michimasa Kamo ◽  
Masayuki Kyomoto ◽  
Toshiyuki Ikoma

ABSTRACTThe antibacterial properties are useful to restrain inflammatory response caused by bacterial infection after implantation. The composites of hydroxyapatite (HAp) and silver nano-dots, silver oxide or silver phosphate have been investigated; however there are still some disadvantage in sintering; 1) silver nano-dots grow large, and are not homogenously distributed, 2) silver nano-dots melt and remove, and 3) silver phosphate and silver oxide formed exhibit higher solubility than metal silver. In this study, the distribution of silver nano-dots in HAp microparticles sintered was controlled at grain boundary with a modified silver mirror reaction as a novel route. HAp microparticles adsorbed formaldehyde by a vapor deposition method were soaked in an ammoniacal silver nitrate solution and were then sintered. There was a single phase of HAp including metal silver at 6.4 wt% even after sintering. The silver nano-dots were homogeneously distributed inside the microparticles. The release profiles of silver ions in phosphate buffer saline were compared with a reference; the HAp microparticles were soaked into silver nitrate solution and were then sintered. The distribution of silver in the reference was not homogeneous and large silver microparticles were grown outside the particles at 6.3wt%. The elution amount of silver ions from the microparticles at 12 hours was one-eighteenth of that from the reference. These results suggest that the HAp microparticles including silver nano-dots at grain boundary will be suitable for a long-term antibacterial material.


1991 ◽  
Vol 56 (10) ◽  
pp. 2142-2147
Author(s):  
Ivo Sláma

The dependence of the induction period of crystallization on supercooling was examined for the silver nitrate-ethylene glycol system over the concentration region of silver nitrate lome fraction of 0 to 0.12. Addition of AgNO3 to ethylene glycol was found to increase considerably the critical induction period of crystallization, although to a lesser extent than Ca(NO3)2, CaCl2, ZnCl2, LiCl and LiNO3 do. The effect of these salts on the critical induction period of crystallization in dimethylsulfoxide, dimethylformamide, dimethylacetamide and methanol was compared in terms of the solvent-rich composition limit of the glass-forming ability. By using the TTT(Time-Temperature-Transformation) theory, it has been deduced that the effect of the salts on the critical induction period of crystallization of ethylene glycol is probably due to the different dependences of viscosity on their concentration in ethylene glyco in the supercooling region.


2008 ◽  
Vol 37 (8) ◽  
pp. 818-819 ◽  
Author(s):  
Yoshiko Miura ◽  
Kazuko Yui ◽  
Hiroshi Uchida ◽  
Kiyoshi Itatani ◽  
Seiichiro Koda

2018 ◽  
Vol 772 ◽  
pp. 73-77
Author(s):  
Ruelson S. Solidum ◽  
Arnold C. Alguno ◽  
Rey Capangpangan

We report on the green synthesis of silver nanoparticles utilizing theP.purpureumleaf extract. Controlling the surface plasmon absorption of silver nanoparticles was achieved by regulating the amount of extract concentration and the molarity of silver nitrate solution. The surface plasmon absorption peak is found at around 430nm. The surface plasmon absorption peak have shifted to lower wavelength as the amount of extract is increased, while plasmon absorption peak shifts on a higher wavelength as the concentration of silver nitrate is increased before it stabilized at 430nm. This can be explained in terms of the available nucleation sites promoted by the plant extract as well as the available silver ions present in silver nitrate solution.


1902 ◽  
Vol 23 ◽  
pp. 163-168 ◽  
Author(s):  
Hugh Marshall

Although the action of potassium persulphate on silver nitrate solution was one of the first persulphate reactions observed (vol. xviii. p. 64), I had not until lately paid any special attention to the behaviour of the ammonium salt in this respect. It appears, however, that in the latter case there are additional actions of great interest, not possible with the potassium salt. A general description of these will be given now, but there are still some points deserving of further investigation.


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