Mechanism of Silver Nanoparticles Deposition by Electrolysis and Electroless Methods on a Graphite Substrate

This study shows a silver electrodeposition model (EDM) on a graphite ‎substrate. The electrolyte was a 0.01 M solution of pure silver and chromium nitrate using an ‎electrolyzing cell. EDC with current density up to 20 mA/cm2 and 15 mV and pulse current were studied. Results revealed that silver deposited at a ‎rate of 0.515 mg/cm2/min with 12 mA /cm2 that decreases to 0.21 and 0.16 mg/cm2.min ‎with the decrease of current density to 6 and 5 mA/cm2 respectively. The model postulates that ‎silver ions (a) were first hydrated before diffusing (b) from the solution bulk to ‎the cathode vicinity, the next step (c) involved the chemical adsorption of these ions on certain ‎accessible sites of the graphite substrate (anode), the discharged entities (d) adhere to the graphite ‎surface by Van der Vales force. Silver ions are deposited because the ‎discharge potential of silver is low (0.38 mV) as compared to other metal ions like chromium (0.82 mV). Pulse ‎current controls silver deposition due to flexibility in controlling steps (a) - (c) of the ‎deposition mechanisms.

An Alternative Method to Develop Embroidery Textile Strain Sensors

In this paper, a method to develop embroidered textile strain resistive sensors is presented. The method is based on two overlapped zigzag conductive yarn patterns embroidered in an elastic textile. To demonstrate the functionality of the proposed configuration, a textile sensor embroidered with a conductor yarn composed of 99% pure silver-plated nylon yarn 140/17 dtex has been experimentally characterised for an elongation range from 0% to 65%. In order to show the sensor applicability, a second test with the sensor embroidered in a knee-pad has been done to evaluate the flexion knee angle from 180° to 300°. The experimental results show the usefulness of the proposed method to develop fabric strain sensors that can help to manufacture commercial applications on the healthcare sector.

Comparative evaluation of antibacterial activity of silver oxides with different oxygen content

Aim of the study. To study the presence of antibacterial properties in silver oxides with different oxygen content in relation to sensitive and methicillinresistant Staphylococcus aureus strains. Material and Methods. Films of silver and its oxides were coated on paper surface in vacuum via the method of ion-plasma arc sputtering of the metallic target. Antibacterial activity of the obtained samples of silver oxides and pure silver against Staphylococcus aureus АТСС 29213 and Staphylococcus aureus ATCC 43300 was studied applying the diff usion method as well as in liquid nutrient broth with consequent measuring of optical density. Results. As a result of antibacterial activity investigation of the samples obtained via the diff usion method and liquid nutrient broth, it was revealed that all samples possessed antibacterial activity in relation to type strains of S. aureus. Th erewith, the effi cacy of the samples with pure silver was signifi cantly lower than that of silver oxides (Ag0,2O, Ag0,4O, Ag1O, Ag1,5O, Ag2O). It was shown that the activity of silver oxides did not depend on the oxygen concentration in them. Thus, statistically signifi cant diff erences in optical density of the nutrient medium with bacteria and the medium with incubated S. aureus АТСС 29213 (MSSA) and AgxO (р<0.001). Analogical results were obtained aft er studying of infl uence exerted by silver on S. aureus АТСС 43300 (MRSA). Conclusion. All silver oxides samples created were characterised by antibacterial activity against S. aureus. The data obtained point at the prospects in application of silver oxide with low oxygen content for prevention and treatment of Staphylococcus aureus strains infection.

Recovery of Silver from Solar Panel Waste: An Experimental Study

The aim of this study was to develop a recycling process to recover silver metal from solar panel waste. Experimental procedure consisted of mechanical/physical separation, leaching of silver from silicon wafer and precipitation to retrieve silver chloride (AgCl) precipitate. The precipitated AgCl was reduced to silver precipitate form which was subsequently heated up to produce silver metal. The leaching process was first conducted by using 4 M of nitric acid for 24 hrs. The silver-containing leached solution would then be added by sodium chloride solution to precipitate AgCl. The precipitate was filtrated out from the solution and was rinsed with water ready for further step. The rinsed precipitate was dissolved in water, then sucrose and sodium hydroxide were added to achieve precipitated silver. Finally, the precipitated silver was burned with acetylene gas to finally obtain silver metal. Base on the experiment the purity of silver metal of 99.98% can be achieved and by considering recycling of solar panel of 1,000 kg the recycling product of pure silver of 0.23 kg could be acquired.

Soft chemistry of pure silver as unique plasmonic metal of the Periodic Table of Elements

The International Year of The Periodic Table of Chemical Elements revealed that the Table remains both a deeply fundamental paradigm for various branches of chemistry and a universal practical tool for predictable design of new materials. Silver is a notable “nanoelement” particularly known by its plasmonic properties. A key advantage of this metal is an easily achievable morphological variety of nanostructured materials. This element represents a research branch of precise engineering of shapes and sizes of nanoparticle ensembles and smart hierarchic nanostructures. In the review, unique features of silver are discussed with respect to the development of novel analytical methods for forthcoming applications of surface-enhanced Raman spectroscopy (SERS) in ecology, biology and medicine.