Green Synthesis of Silver Nanoparticles Using a Vitamin C Rich Phyllanthus emblica Extract

2012 ◽  
Vol 622-623 ◽  
pp. 864-868
Author(s):  
Sirirat Mookriang ◽  
Ampa Jimtaisong ◽  
Nisakorn Saewan ◽  
Krisada Kittigowittana ◽  
Pornchai Rachtanapun ◽  
...  
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Heating Temperature ◽  
Average Diameter ◽  
Reducing Agent ◽  
Deionized Water ◽  
Phyllanthus Emblica ◽  
High Concentration ◽  
Shape And Size

Silver nanoparticles were prepared by treating a solution of AgNO3 dissolved in deionized water with Emblica (Phyllanthus emblica) extract as reducing agent. The factors that affect the synthesis of silver nanoparticles (time, temperature and concentration of silver nitrate and reducing agent) were investigated. The high concentration of silver nitrate and reducing agent showed the higher in concentration of silver nanoparticles. The heating temperature help increase the yield of silver nanoparticles at shorter reaction time. Their structure, shape and size distribution were characterized by UV-vis spectrophotometer, SEM and TEM technique. The UV-vis spectrophotometer show peaks located of silver-Emblica nanoparticle at 430 nm and the particle size of silver-Emblica is 41.2 nm in average diameter determined by TEM.

Synthesis of Silver Nanoparticles Using o-Hydroxybenzoic, p-Hydroxybenzoic, and o,p-Dihydroxybenzoic Acids as Reducing Agents

2017 ◽  
Vol 901 ◽  
pp. 26-31 ◽  
Author(s):  
Dian Susanthy ◽  
Fadliah ◽  
Endang Tri Wahyuni ◽  
Sri Juari Santosa
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Reducing Agents ◽  
Reducing Agent ◽  
Para Position ◽  
Hydroxyl Groups ◽  
Hydroxybenzoic Acid ◽  
Dihydroxybenzoic Acid ◽  
Transmission Electron ◽  
Shape And Size

Synthesis of silver nanoparticles (AgNPs) by reduction of AgNO3 with o-hydroxybenzoic, p-hydroxybenzoic and o,p-dihydroxybenzoic acids as reducing agents was investigated. This research was conducted to determine the effect of the position and number of hydroxyl groups towards the size, shape and stability of the resulted AgNPs. Surface Plasmon Resonance (SPR) of AgNPs was characterized by UV/Vis spectrophotometer, the shape and size of AgNPs was determined by Transmission Electron Microscope (TEM). The results showed that the reducing agent that has substituents in the para position (p-hydroxybenzoic acid) has the higher reduction ability than the others. AgNPs were yielded by all types of reducing agents in alkaline system. Reducing agents which have greater number of substituents (o,p-dihydroxybenzoic acid) could produce AgNPs with smaller concentration of AgNO3 than the others. AgNPs that was produced by reducing agent having substituents on the para position (p-hydroxybenzoic acid) was more stable and smaller particle size, i.e. 34 ± 1.78 nm than reducing agent that has substituent on the ortho para positions (with particle size 45 + 3.67 nm) and ortho positions (with particle size 70 ± 4.96 nm).

Study on the Production of Silver/Modified Clay Nanocomposites

2013 ◽  
Vol 1547 ◽  
pp. 167-172
Author(s):  
Natália F. N. Pessanha ◽  
Gerson L. V. Coelho
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Sodium Borohydride ◽  
Particle Diameter ◽  
Reducing Agent ◽  
Clay Nanocomposites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Modified Clay

ABSTRACTThe aim of this study was to investigate the application of modified clay as a support in the synthesis of silver nanoparticles. Silver nitrate (AgNO3) was used as the silver precursor in several concentrations (0.005 M, 0.01 M, 0.02 M, 0.05 M, and 0.1 M) to obtain Ag-MMT purified and modified clay nanocomposites. The properties of nanocomposites were also studied as a function of the concentration of the reducing agent, sodium borohydride (NaBH4). It was observed through X-ray Diffraction that the MMT purified structure was gradually exfoliated with increased concentrations of AgNO3, while the modified clay structure remained intact. As observed through UV-vis spectra, samples of Ag+-MMT were reduced with NaBH4 to produce Ago and its particle diameter is dependent on the concentration of NaBH4.

On the Influence of Silver Nanoparticles Size in the Electrical Conductivity of PEDOT: PSS

2010 ◽  
Vol 644 ◽  
pp. 85-90 ◽  
Author(s):  
Rebeca G. Melendez ◽  
Karla J. Moreno ◽  
Ivana Moggio ◽  
Eduardo Arias ◽  
Arturo Ponce ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Reducing Agent ◽  
Molar Ratio ◽  
Plasmon Band ◽  
Vis Spectroscopy

In this paper, we studied the influence of the silver nanoparticles size on the electrical conductivity of PEDOT:PSS in Ag(PEDOT:PSS) films. The silver nanoparticles were synthesized in presence of PEDOT:PSS by varying the molar ratio between AgNO3 and the reducing agent (NaBH4). Both the particle size determined by TEM and the plasmon band obtained by UV-Vis spectroscopy were found to be strongly dependent on the reducing agent concentration. The electrical conductivity increases inversely with the concentration of reducing agent from 5.24 x 10-4 up to 1.63 S/cm; three orders of magnitude higher than pristine PEDOT:PSS.

scholarly journals Antioxidant and Antibacterial Activities of Biosynthesized Silver Nanoparticles using Aqueous Terminalia catappa Leaf Extracts as Novel Reducing Agent

2020 ◽  
Vol 32 (8) ◽  
pp. 2079-2083
Author(s):  
Paweena Porrawatkul ◽  
Rungnapa Pimsen ◽  
Saksit Chanthai ◽  
Prawit Nuengmatcha
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Particle Size Analysis ◽  
Reducing Agent ◽  
Size Analysis ◽  
Main Peak ◽  
Leaf Extracts ◽  
Characteristic Functional ◽  
Terminalia Catappa

In this study, silver nanoparticles (AgNPs) were successfully synthesized from aqueous Terminalia catappa leaf extract that acts as a novel reducing agent. Various parameters, including pH, temperature and reaction time, were determined. The UV-visible spectra showed the main peak at 416 nm, which was the characteristic surface plasmon resonance of AgNPs. The spherical shape and particle size of 49 ± 0.01 nm were observed from SEM, TEM and laser particle size analysis (LPSA). FTIR spectra of the leaf extract exhibited the characteristic functional groups that should be responsible for Ag+ ion reduction. The EDX spectrum proved that the obtained sample is silver. The antioxidant activity of AgNPs treated with the leaf extract as determined by the DPPH assay was higher compared to that of Terminalia catappa leaf extract, and the treated AgNP sample exhibited high antibacterial potential against both Gram-positive and Gram-negative bacteria.

scholarly journals Nanostructural Features of Silver Nanoparticles Powder Synthesized through Concurrent Formation of the Nanosized Particles of Both Starch and Silver

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
A. Hebeish ◽  
M. H. El-Rafie ◽  
M. A. El-Sheikh ◽  
Mehrez E. El-Naggar
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Zeta Potential ◽  
High Speed ◽  
Chemical Reduction ◽  
Reduction Process ◽  
Nanosized Particles ◽  
High Concentration ◽  
Particle Size Analyzer ◽  
Vis Spectroscopy

Green innovative strategy was developed to accomplish silver nanoparticles formation of starch-silver nanoparticles (St-AgNPs) in the powder form. Thus, St-AgNPs were synthesized through concurrent formation of the nanosized particles of both starch and silver. The alkali dissolved starch acts as reducing agent for silver ions and as stabilizing agent for the formed AgNPs. The chemical reduction process occurred in water bath under high-speed homogenizer. After completion of the reaction, the colloidal solution of AgNPs coated with alkali dissolved starch was cooled and precipitated using ethanol. The powder precipitate was collected by centrifugation, then washed, and dried; St-AgNPs powder was characterized using state-of-the-art facilities including UV-vis spectroscopy, Transmission Electron Microscopy (TEM), particle size analyzer (PS), Polydispersity index (PdI), Zeta potential (ZP), XRD, FT-IR, EDX, and TGA. TEM and XRD indicate that the average size of pure AgNPs does not exceed 20 nm with spherical shape and high concentration of AgNPs (30000 ppm). The results obtained from TGA indicates that the higher thermal stability of starch coated AgNPS than that of starch nanoparticles alone. In addition to the data obtained from EDX which reveals the presence of AgNPs and the data obtained from particle size analyzer and zeta potential determination indicate that the good uniformity and the highly stability of St-AgNPs).

scholarly journals Efficient synthesis of plant-mediated silver nanoparticles and their screening for antimicrobial activity

2017 ◽  
Vol 4 (3) ◽  
pp. 143-150 ◽  
Author(s):  
Kamlesh Shukla ◽  
Bhoopander Giri ◽  
Rashmi Dwivede
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Color Change ◽  
Bacterial Species ◽  
Nitrate Solution ◽  
Reducing Agent ◽  
Curvularia Lunata ◽  
Synthesis Of Nanoparticles ◽  
Vis Spectroscopy

Now days, the development of safe, cost effective, reliable and eco-friendly processes for the synthesis of nanoparticles is an important aspect of nanotechnology. Among the various agents, plants show immense potential for the synthesis of nanoparticles. The bio-molecules found in plants induce reduction of Ag+ ions from silver nitrate to silver nanoparticles (AgNPs); therefore, in the present work, the aqueous leaves extract of the plant was used as reducing agent for the synthesis of silver nanoparticles. We synthesized extracellular silver nanoparticles using extract of the leaves of four different medicinal plants which act as a reducing agent at room temperature. The characteristic color change was observed on addition of plant extract to the silver nitrate solution due to their specific properties (Surface Plasmon Resonance). UV-Vis spectroscopy was used for the characterization of the silver nanoparticles. Green synthesized nanoparticles are evaluated for their antimicrobial activity against the Gram-positive and Gram-negative bacteria as well as two pathogenic fungi Aspergillus fumigatus and Curvularia lunata. The silver nanoparticles (SNPs) of selected plant parts have shown more toxicity towards bacterial species than that of the fungal species. Comparing with simple plant extracts, the SNPs exhibited greater antimicrobial efficacy and advantage over conventional antibiotics to which these microorganisms usually impart resistance.

scholarly journals Antibacterial Activity of Silver Nanoparticles Capped by p-Aminobenzoic Acid on Escherichia coli and Staphylococcus aureus

2019 ◽  
Vol 20 (1) ◽  
pp. 182
Author(s):  
Dian Susanthy ◽  
Sri Juari Santosa ◽  
Eko Sri Kunarti
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Silver Nitrate ◽  
Nitrate Concentration ◽  
Aminobenzoic Acid ◽  
Antibacterial Performance ◽  
Silver Nitrate Concentration

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

scholarly journals GREEN SYNTHESIS OF SILVER NANOPARTICLES USING SAGO (METROXYLON SAGU) VIA AUTOCLAVING METHOD

2018 ◽  
Vol 19 (1) ◽  
pp. 178-184
Author(s):  
Aliyah Jamaludin ◽  
Che Ku Mohammad Faizal
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Silver Nitrate ◽  
Large Scale ◽  
Reducing Agent ◽  
Average Particle ◽  
Particle Sizes ◽  
Green Method ◽  
Metroxylon Sagu

Sago (metroxylon sagu) is a polysaccharide bio resource, which is biodegradable and low in toxicity that can be found in large scale in Mukah, Sarawak.  A simple green method of synthesizing silver nanoparticles (AgNPs) has been developed using sago dissolved in water as the reducing agent. The mixture of dissolved sago and silver nitrate (AgNO3) were autoclaved at 121 °C for 20 minutes. The size, morphology and structures of the AgNPs formed in the sago solution were investigated through UV-Vis spectrophotemeter, XRD and FESEM analysis. The synthesized AgNPs were spherical in shape and well distributed with average particle sizes of 19.3 ± 2.7 nm.ABSTRAK: Sago (Pokok Rumbia) adalah sumber bio polisakarida yang bioterurai dan rendah ketoksikan yang boleh didapati dalam skala yang besar di Mukah, Sarawak. Satu kaedah hijau yang mudah untuk mensintesis nanopartikel perak telah dihasilkan dengan menggunakan sagu yang larut dalam air sebagai ejen penurunan. Campuran sagu yang dilarutkan dan perak nitrat (AgNO3) telah autoklaf pada suhu 121°C selama 20 minit. Saiz, morfologi dan struktur nanopartikel perak yang terhasil di dalam larutan sago telah disiasat melalui analisis spektrofotometer UV-Vis, XRD dan FESEM. Nanopartikel perak yang dihasilkan adalah berbentuk bulat dengan purata saiz partikel 19.3 ± 2.7 nm.

Synthesis of Silver Nanoparticles at the Liquid–Liquid Using Ultrasonic Wave

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
Seong-Ik Hong ◽  
Alma Duarte ◽  
Gabriel A. Gonzalez ◽  
Nam-Soo Kim
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Silver Nanoparticle ◽  
New Technologies ◽  
Ultrasonic Waves ◽  
Reducing Agent ◽  
Liquid Interface ◽  
Silver Ion ◽  
Nanoparticle Size ◽  
Ion Movement

The high demand of flexible electronics and the miniaturization of electronic components have been increasing very rapidly. Nanotechnology and in particular nanoparticles have become very important for the development of new technologies and applications which depend on the synthesis and characterization of nanoparticles with specific properties. Significant attention has been focused on the characteristics of the nanoparticles since their properties, particle size and shape are very different when compared to those of the bulk materials. In order to produce nanoparticles with more efficient structures and electronic properties for nano ink, it is necessary to control the particle size to avoid agglomeration. Currently, the nanoparticle size and its agglomeration is controlled by surfactants, but some studies have shown that adding surfactants have negative effects on the conductivity of the nanoparticles along with the high curing temperatures of nano-ink. In this study, silver nanoparticles were synthesized by adding methanol to water instead of surfactants in order to control the silver nanoparticle size. The water and methanol solution was prepared by using different ratios v/v of water/methanol obtaining a liquid–liquid interface and forming a molecular–molecular interface restricting the silver ion movement in the solution. In addition to the liquid–liquid interface, the ion concentration and movement were also restricted through a spraying mist by using ultrasonic waves. The silver ion and the reducing agent were found to have a difference in concentration by the spraying mist method. The movement of the silver ions and the reducing agents were controlled by the difference in concentration. It was observed that the control of the nanoparticles and ion movement was more efficient by spraying silver ion solution than using a reducing agent solution. We confirmed that by increasing the volumetric ratios of methanol the silver nanoparticle size also increased. The mist particle size and the concentration were also calculated at different volumetric ratios of methanol.

Synthesis of Silver Nanoparticles by Sonochemical Induced Reduction Application in SERS

2010 ◽  
Vol 9 ◽  
pp. 77-81 ◽  
Author(s):  
Esaú Solano-Ruiz ◽  
Roberto Sato Berrú ◽  
J. Ocotlán-Flores ◽  
José M. Saniger
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Ultrasonic Irradiation ◽  
Sodium Citrate ◽  
Reducing Agent ◽  
Visible Spectroscopy ◽  
Transmission Electron

In this work, we present the synthesis of silver nanoparticles by ultrasonic irradiation of a solution containing silver nitrate as precursor and sodium citrate as reducing agent. These nanoparticles were characterized by ultraviolet-visible spectroscopy and transmission electron microscopy (TEM) and then were tested as SERS-active colloids.

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