Thermoelectric Studies of Silver Nitrate in Sodium Nitrate – Potassium Nitrate Eutectic Melt

1971 ◽  
Vol 49 (12) ◽  
pp. 2044-2047
Author(s):  
L. G. Boxall ◽  
K. E. Johnson

The Seebeck coefficient, εT, of the thermocell Ag(T)/AgNO3 in NaNO3 − KNO3/Ag (T + ΔT) was measured as a function of silver nitrate concentration and temperature. Extrapolation of the results to unit mole fraction, N, of AgNO3 gave the value εT0 = − 277.5 − 0.136T °C (µV deg−1).For several mixed melts of AgNO3 and an alkali nitrate the function [Formula: see text] was calculated and shown to be linear in N. P was extrapolated to finite values for the pure alkali nitrates.

Author(s):  
N. I. Hulkoti ◽  
T. C. Taranath

In this study we describe the phytofabrication of AgNps through a green route as a cost-effective, instantaneous and an eco-friendly approach using Petrea volubilis L. stem broth. The influence of physico-chemical parameters - contact time, stem broth quantity, pH, temperature, and silver nitrate concentration were studied and optimised to engineer, nanoparticles of diverse sizes. Nanoparticles were characterized by UV-Vis spectroscopy, FTIR, XRD, Zeta potential, EDS, and HRTEM. The characterization using HRTEM showed that, the nanoparticles were spherical and with increase in contact time, stem broth quantity, pH, and temperature, the NPs size minimised whereas escalation in silver nitrate concentration, increased their size. Capping molecules were negatively charged and the NPs were passably stable according to zeta potential readings and they were crystalline as per XRD data. According to FTIR analysis, the bio reduction was attributed to alcohol, ethers, carboxylic acids, and esters. The highest anti-bacterial activity was observed against S. aureus and S. typhi whose ZOI diameter was 13 mm at 100?l in both bacteria. The highest anti-fungal activity of silver nanoparticles was observed against A. flavus whose ZOI diameter was 9 mm at 100?l compared to P. chrysogenum which is 3 mm at 100?l. The stem broth did not show any anti-microbial activity for the microbes. Anti-microbial activity of AgNPs is due to its small size and high surface area. Our findings clearly discloses that sizes of silver nanoparticles can be varied by varying the physico-chemical parameters and the small sized nanoparticles so formed are promising antimicrobial agents and has a great potential in various medical applications.


2019 ◽  
Vol 20 (1) ◽  
pp. 182
Author(s):  
Dian Susanthy ◽  
Sri Juari Santosa ◽  
Eko Sri Kunarti

This paper describes the antibacterial performance of silver nanoparticles (AgNPs) which have been synthesized by using p-aminobenzoic acid as reducing and stabilizing agent simultaneously. The silver nitrate with various concentrations was reacted with pH 11-adjusted p-aminobenzoic acid with a concentration of 5 × 10–3 mol L–1 for 30 min in a boiling water bath. The synthesized AgNPs were characterized by UV-Vis spectrophotometry, Transmission Electron Microscope (TEM), and Particle Size Analyzer (PSA). The antibacterial performance of the synthesized AgNPs was evaluated by agar well diffusion method on Escherichia coli and Staphylococcus aureus. The higher silver nitrate concentration, the bigger the nanoparticle size, the wider particle size distribution, and the higher number of AgNPs formed. AgNPs synthesized from higher silver nitrate concentration had higher antibacterial activity. It is an indication that the antibacterial activity of AgNPs is mainly controlled by the silver ion concentration which influences the AgNPs particle size and existence of silver ion in the AgNPs colloidal solution


2012 ◽  
Vol 506 ◽  
pp. 254-257
Author(s):  
Faungchat Thammarakcharoen ◽  
K. Wasoontararat ◽  
Jintamai Suwanprateeb

The preparation of nanosilver loaded calcium phosphate aiming to enhance the antimicrobial performance by converting calcium sulfate hemihydrate based materials to calcium phosphate in the presence of silver nitrate (ranging 0.001-0.1 M) using low temperature phosphorization technique at 80 °C for 24 hours was performed. Phase composition, mechanical properties and microstructure of the resulting structures were characterized by x-ray diffraction, three-point bending and transmission electron microscopy techniques. Hydroxyapatite and monetite were found to be the main phases in the converted samples with different amount of residual calcium sulfate depending on the initial silver nitrate concentration in the converting media. Spherical-shaped silver nanoparticles were observed to distribute within the cluster of calcium compound crystals having average particle size in the range of 3.1-11.6 nm. Flexural modulus and strength of converted samples were observed to decrease from 1991 to 860 MPa and from 4.1 to 1.9 MPa respectively with increasing silver nitrate concentration from 0.001 to 0.1 M.


2020 ◽  
pp. 2000150
Author(s):  
Sayedur Rahman ◽  
Ali Khoddami ◽  
Les Copeland ◽  
Brian J. Atwell ◽  
Thomas H. Roberts

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