Morphological and Dimensional Properties of Colloidal Silver Nanoparticles Prepared under Microwave Irradiation

2015 ◽  
Vol 1101 ◽  
pp. 138-143 ◽  
Author(s):  
Harjono ◽  
Yoki Yulizar

In this paper we report the effect of irradiation time on the morphological and dimensional properties of colloidal silver nanoparticles (AgNPs) using sodium citrate and silver nitrate as reductant and oxidant, respectively under microwave irradiation. The prepared NPs were characterized by UV–vis spectroscopy, Particle size analyzer (PSA), transmission electron microscopy (TEM) and selected areas electron diffraction (SAED). The formation of Ag NPs was confirmed by the appearance of a surface plasmon absorption between 411-425 nm. PSA showed that the colloidal nanoparticles had a diameters ranging from 25.5-41.2 nm. TEM images showed that the diameter of the silver nanoparticles in accordance with the results obtained using PSA. The rings patterns are in good agreement with the standard values of the facecentered-cubic form of silver nanocrystals.

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2326
Author(s):  
Entesar Ali Ganash ◽  
Reem Mohammad Altuwirqi

In this work, silver nanoparticles (Ag NPs) were synthesized using a chemical reduction approach and a pulsed laser fragmentation in liquid (PLFL) technique, simultaneously. A laser wavelength of 532 nm was focused on the as produced Ag NPs, suspended in an Origanum majorana extract solution, with the aim of controlling their size. The effect of liquid medium concentration and irradiation time on the properties of the fabricated NPs was studied. While the X-ray diffraction (XRD) pattern confirmed the existence of Ag NPs, the UV–Vis spectrophotometry showed a significant absorption peak at about 420 nm, which is attributed to the characteristic surface plasmon resonance (SPR) peak of the obtained Ag NPs. By increasing the irradiation time and the Origanum majora extract concentration, the SPR peak shifted toward a shorter wavelength. This shift indicates a reduction in the NPs’ size. The effect of PLFL on size reduction was clearly revealed from the transmission electron microscopy images. The PLFL technique, depending on experimental parameters, reduced the size of the obtained Ag NPs to less than 10 nm. The mean zeta potential of the fabricated Ag NPs was found to be greater than −30 mV, signifying their stability. The Ag NPs were also found to effectively inhibit bacterial activity. The PLFL technique has proved to be a powerful method for controlling the size of NPs when it is simultaneously associated with a chemical reduction process.


Antibiotics ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 68 ◽  
Author(s):  
Mahsa Eshghi ◽  
Hamideh Vaghari ◽  
Yahya Najian ◽  
Mohammad Najian ◽  
Hoda Jafarizadeh-Malmiri ◽  
...  

Silver nanoparticles (Ag NPs) were synthesized using Juglans regia (J. regia) leaf extract, as both reducing and stabilizing agents through microwave irradiation method. The effects of a 1% (w/v) amount of leaf extract (0.1–0.9 mL) and an amount of 1 mM AgNO3 solution (15–25 mL) on the broad emission peak (λmax) and concentration of the synthesized Ag NPs solution were investigated using response surface methodology (RSM). Fourier transform infrared analysis indicated the main functional groups existing in the J. regia leaf extract. Dynamic light scattering, UV-Vis spectroscopy and transmission electron microscopy were used to characterize the synthesized Ag NPs. Fabricated Ag NPs with the mean particle size and polydispersity index and maximum concentration and zeta potential of 168 nm, 0.419, 135.16 ppm and −15.6 mV, respectively, were obtained using 0.1 mL of J. regia leaf extract and 15 mL of AgNO3. The antibacterial activity of the fabricated Ag NPs was assessed against both Gram negative (Escherichia coli) and positive (Staphylococcus aureus) bacteria and was found to possess high bactericidal effects.


2018 ◽  
Vol 7 (4) ◽  
pp. 1 ◽  
Author(s):  
F. Aldosari ◽  
A. M. Azzeer ◽  
A. M. Hassib

The study has aimed to investigate optical and photoacoustic properties of some colloidal silver nanoparticles at different concentration over the time. The phase purity with crystal structure of silver nanoparticles were studied using X-ray diffraction (XRD) and was confirmed by Transmission Electron Microscopy (TEM). Optical property was changed during the variable concentration of nanoparticles and duration time of sample. The absorbance of silver colloidal solutions is increased, when concentration increases but decreased with respective to the longer period of sample. Absorption peaks and stability of particles in solutions is influenced by the duration time of solution and its concentration. The low concentration-based solutions fall in the absorbance over the times. The observed PA signal is subjected by the factor of parameters; such as, pump wavelengths, energy, repetition rate, concentrations, and temperature. Stability of fluorescence and absorption peaks are influenced by the concentration of particles and time period of colloidal solution. Effects on PA signal with fluorescent and absorption peaks upon the concentration was also significant.


2011 ◽  
Vol 9 (6) ◽  
pp. 982-989 ◽  
Author(s):  
Agnieszka Król-Gracz ◽  
Ewa Michalak ◽  
Piotr Nowak ◽  
Agnieszka Dyonizy

AbstractThis paper discusses the experimental results of the production of nanocolloidal silver using photoreduction method. Ultrafine crystalline gelatine-stabilised aqueous suspensions of silver bromide were used as a substrate for the synthesis of silver nanoparticles (Ag NPs). The influences of the reductant to substrate molar ratio, the medium’s pH, the type of the source of actinic radiation and the time of exposure to the efficient production of the Ag NPs were studied. A typical reaction was suggested, which involves the photo-induced reduction of silver bromide nanocrystals in the presence of ascorbic acid under specified physicochemical conditions. The properties of resultant silver particles were examined using UV-Vis spectroscopy and Dynamic Light Scattering (DLS). In addition, Transmission Electron Microscopy (TEM) was used for imaging the silver nanoparticle suspensions.


2012 ◽  
Vol 488-489 ◽  
pp. 1409-1413
Author(s):  
Adeleh Granmayeh Rad ◽  
Hamed Abbasi

In this work we report the preparation of colloidal silver nanoparticles. In order to prepare the silver nanoparticles laser ablation method has been used.A silver coin as a target (purity 99.9 %) was ablated by a Q-Switched Nd:YAG laser with a fluence of about 91 mJ/cm2 at a repetition rate of 10 Hz at room temperature. In order to evaluate these particles transmission electron microscopy (TEM) and spectrophotometry (from UV to NIR) have been used. The average size of prepared nanoparticles is ~ 20 nm. The importance of morphology of nanoparticles has been investigated. Developed applications of silver nanoparticles have been studied,silver nanoparticles are considered as biocompatible and low in toxicity and have good potential for biological applications. Lately silver nanoparticles have found a novel approach in different fields of medicine, biology and industry.


2014 ◽  
Vol 4 (3) ◽  
pp. 43-46
Author(s):  
Tan Man Nguyen ◽  
Hai Le ◽  
Huu Tu Le ◽  
Thu Hong Tran ◽  
Duy Hang Nguyen ◽  
...  

Silver nanoparticles were prepared from (Ag+) aqueous solution by the method of γ-ray irradiation using chitosan as stabilizer. The saturated conversion dose (Ag+ à Ago) determined by UV-Vis spectroscopy was found to be about 16 kGy. The UV-Vis spectrum showed that an absorption peak at λmax = 400 nm due to surface plasma resonance. The image of transmission electron microscopy (TEM) showed that the silver nanoparticles were mostly spherical in shape and the average diameter was of about ~ 12 nm. The prepared colloidal silver nanoparticles solution was in good stability during storage time.


2007 ◽  
Vol 334-335 ◽  
pp. 813-816
Author(s):  
Yan Yang ◽  
Hai Tao Huang

A simple method is described for preparing silver nanoparticles via photoreduction in layered laponite suspensions without any additional reduction agent or heat treatment. The properties of silver nanoparticles were studied as a function of the UV irradiation time. Transmission electron microscopy (TEM) was employed to study the variation of particle shape, size and size distribution. The crystal structure of silver nanoparticles was characterized powder Xray diffractometry (XRD). The optical absorption spectra of silver nanoparticles were obtained by ultraviolet-visible (UV-Vis) spectroscopy.


2021 ◽  
Vol 2 (1) ◽  
pp. 42-50
Author(s):  
Mohd Shahrul Nizam Salleh ◽  
Sangetha Cheladorai ◽  
Roshafima Rasit Ali ◽  
Kamyar Shameli ◽  
Zatil Izzah Tarmizi ◽  
...  

In this studies, synthesis of silver nanoparticles (Ag-NPs) on pullulan-based biofilm was achieved by microwave irradiation technique. Synthesis of Ag-NPs was achieved using pullulan as both a reducing and stabilizing agent. The effect of different microwave irradiation duration on pullulan and silver nitrate in synthesis of silver nanoparticles (Ag-NPs) was investigated. The synthesized Ag-NPs/PL were first screened and identified using surface plasmon peaks of UV–Vis spectroscopy. The research results indicated that the surface plasmon resonance peaks were observed between 400–414 nm wavelengths in UV-VIS spectroscopy studies. From Fourier-transform infrared spectroscopy (FTIR) spectra, stretching vibrations of hydroxyl (OH), carbonyl (C=O) and C=C stretches exhibits the reduction and stabilization of Ag-NPs. Further, five characteristic peaks Ag(111), Ag(200), Ag(210), Ag(220) and Ag(311) confirmed the presence of elemental silver and the crystalline structure of silver nanoparticles from X-ray Diffraction analysis. Biofilms were produced by mixing the synthesized Pulullan-Ag-NPs with polyvinyl alcohol. The AgNP/PL were applied for the antimicrobial activity against Bacillus subtilis and found to have high antibacterial activity. In addition, the clear zones of inhibition was found at 11 mm to 16 mm against Bacillus Subtillis. The experimental results demonstrated that pullulan could be used as reducing and stabilizing agent for formation of Ag-NPs.


2021 ◽  
Vol 3 (1) ◽  
pp. 76-81
Author(s):  
Siti Husnaa Mohd Taib ◽  
Kamyar Shameli ◽  
Roshafima Rasit Ali ◽  
Zahra Izadiyan ◽  
Zatil Izzah Ahmad Tarmizi

The present paper reports the synthesis of silver nanoparticles (Ag-NPs) by a green method using Hibiscus sabdariffa (H. sabdariffa) leaves extract as reductant and stabilizer. The synthesized Ag-NPs were characterized by ultraviolet-visible (UV-vis) spectroscopy, transmission electron microscopy (TEM), atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR). UV-vis spectrum of synthesized Ag-NPs showed a peak at 378 nm. TEM analysis revealed that the particles were spherical and irregular in shape and has average size around 56.52 nm. This structure and size of particles were confirmed by AFM analysis. The UV-vis and FTIR spectrum provides evidence of the presence of caffeic acid component as a representative biomolecule in stabilising the nanoparticles based on previous studies. Hence, this study advocates that H. sabdariffa have potential for synthesizing nanoparticles.


RSC Advances ◽  
2016 ◽  
Vol 6 (100) ◽  
pp. 98325-98336 ◽  
Author(s):  
O. Pandoli ◽  
R. D. S. Martins ◽  
E. C. Romani ◽  
S. Paciornik ◽  
M. H. D. P. Maurício ◽  
...  

Silver nanoparticles (Ag-NPs) are effective nano-filler agents with antifungal activity able to improve bamboo's durability against fungus. Ag-NPs were used to fill up the bamboo biological matrix to obtain an engineered biocomposite material.


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