Influence of silver nitrate concentration on the properties of silver nanoparticles

2011 ◽  
Vol 6 (8) ◽  
pp. 656 ◽  
Author(s):  
A. Sobczak-Kupiec ◽  
D. Malina ◽  
Z. Wzorek ◽  
M. Zimowska
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


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.


2020 ◽  
Vol 11 (3) ◽  
pp. 4726-4732
Author(s):  
Sharanappa A ◽  
Anil R. Shet ◽  
Laxmikant R. Patil ◽  
Veeresh S. Hombalimath ◽  
Santosh Kadapure

Silver nanoparticles (Ag-NPs) have attracted huge importance due to their distinctive chemical, biological and physical properties. Silver nanoparticles are widely synthesized by the chemical method, which involves the use of toxic chemicals which affects its applications. The bio-reduction method, in comparison with chemical method is more economic and eco-friendly. In the present work, the bio-based production of Ag-NPs was done by using peel extract of orange (citrus sinensis), which played a role of reducing and stabilizing agent. The biosynthesis of silver nanoparticles was optimized by one factor at a time (OFAT) with respect to peel extract concentration, silver nitrate concentration and reaction temperature. The green synthesized silver nanoparticles were characterized by UV-visible spectroscopy, Fourier transforms infrared (FT-IR) spectroscopy, Scanning electron microscopy (SEM) and X-ray diffraction (XRD). Disk diffusion method was used for the study of antibacterial activity of the bio-synthesized silver nanoparticles against the bacteria Escherichia coli and Staphylococcus aureus. The results showed that at a peel extract concentration of 6%, the temperature of 60oC and silver nitrate concentration of 0.1M, the synthesis of Ag-NPs was effective. The orange peel synthesized Ag-NPs showed effective antibacterial activity against both bacteria. However better activity was observed against bacterium Staphylococcus aureus. The results confirmed the synthesis of Ag-NPs using peel extract of citrus sinensis and its role as antibacterial agent.


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.


2015 ◽  
Vol 1119 ◽  
pp. 165-169
Author(s):  
S.K. Srikar ◽  
D.D. Giri ◽  
C. Upadhyay ◽  
P.K. Mishra ◽  
S.N. Upadhyay

Highly stable silver nanoparticles synthesized in single-step green method by mixing silver nitrate and aqueous extract of Almond (Prunus amygdalus). Experiments were conducted to influence the change in the silver nitrate concentration and time on the synthesis of silver nanoparticles at room temperature under dispersed sun light. The almond extract acted both as the reducing and stabilizing agent for the synthesis of silver nanoparticles. The change in the color of the reaction mixture was monitored using UV-Visible spectrometry whereas particles synthesized were characterized using Scanning Electron Microscopy, Dynamic Light Scattering and Fourier Transform Infrared Spectroscopy. The synthesized nanoparticles were almost spherical in shape with an average size about 20 nm and they exhibited bacteriostatic property against E. coli.


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