scholarly journals GREEN TECHNOLOGY MEDIATED SYNTHESIS OF SILVER NANOPARTICLES FROM MOMORDICA CHARANTIA FRUIT EXTRACT AND ITS BACTERICIDAL ACTIVITY

2017 ◽  
Vol 10 (3) ◽  
pp. 196 ◽  
Author(s):  
S C Joshi ◽  
Utkarsh Kaushik ◽  
Aproova Upadhyaya ◽  
Priyanka Sharma
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silver Nanoparticles ◽  
Atomic Force Microscope ◽  
Momordica Charantia ◽  
Diffusion Method ◽  
Fruit Extract ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Scanning Electron

ABSTRACTObjective: The synthesis of nanoparticles from biological processes is evolving a new era of research interests in nanotechnology. Silver nanoparticlesare usually synthesized by chemicals and physical method, which are quite toxic and flammable in nature. This study deals with an environmentfriendly biosynthesis process of antibacterial silver nanoparticles using Momordica charantia fruit.Methods: AgNO3 (5 mM) was allowed to react with fruit extract of M. charantia. Biosynthesis of AgNPs was optimized by changing temperature,pH, and solvent. The silver nanoparticles so formed were characterized using ultraviolet-visible (UV-VIS) spectroscopy, Fourier transform infraredspectroscopy (FTIR), dynamic light scattering (DLS), atomic force microscope (AFM), and scanning electron microscopy (SEM).Results: UV-VIS spectra show absorption peak between 420 and 430 nm. The FTIR analysis showed the alcoholic, lactam, and nitro group presentin the plant extract, which were responsible for the reduction in AgNPs. The SEM images showed the size distribution of the nanoparticles and theaverage size was found to be 50-100 nm. By DLS analysis and AFM analysis, average sizes of the silver nanoparticles were of 150 nm. The results ofthese analyses confirmed the formation of silver nanoparticles. Silver nanoparticles were tested against Bacillus cereus and Staphylococcus epidermidisstrains using disc diffusion method and were found to be effective.Conclusion: Silver nanoparticles so synthesized in this study using fruit extract of M. charantia are simple, easy, and effective technique of nanoparticlesproduction.Keywords: Silver nanoparticles, Momordica charantia, Optimization, Antibacterial, Atomic force microscope, Scanning electron microscopy.

FACET PREPARATION OF SILICON NANO-WAVEGUIDES BY CLEAVING THE SOI CHIP

2011 ◽  
Vol 20 (04) ◽  
pp. 509-523 ◽  
Author(s):  
SHAIMAA MAHDI ◽  
MORITZ GREHN ◽  
AWS AL-SAADI ◽  
MICHAEL HÖFNER ◽  
STEFAN MEISTER ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Atomic Force Microscope ◽  
Optical Transmission ◽  
Silicon On Insulator ◽  
Atomic Force ◽  
Telecommunication Wavelength ◽  
Facet Surface ◽  
Fs Laser ◽  
Scanning Electron

Optical facet preparation of silicon-on-insulator (SOI) waveguides was done by polishing after saw dicing or cleaving after two different techniques of scoring by a mechanical saw and fs-laser. Cleaving after fs-laser scoring leads to smooth facet surface of air covered SOI waveguides; polishing after dicing is more efficient with SiO2covered waveguides. The prepared end facets were investigated using an atomic force microscope (AFM) and scanning electron microscopy (SEM). The SOI waveguides were characterized by optical transmission of telecommunication wavelength (1.5 μm).

scholarly journals Antibacterial ativity of biosynthesized silver nanoparticles against Pseudomonas aeruginosa in vitro

2017 ◽  
Vol 41 (1) ◽  
pp. 60-65
Author(s):  
Ahmad N. A. Salih ◽  
Mohammad J. Eesa
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pseudomonas Aeruginosa ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Silver Sulfadiazine ◽  
Diffusion Method ◽  
Olive Leaves ◽  
Scanning Electron

     This study was conducted for the synthesis of silver nanoparticles by using olive leaves aqueous extract and evaluate its antibacterial activity against Pseudomonas aeruginosa in vitro. The synthesis and characterization of silver nanoparticles was confirmed by Ultra Violet Visible – spectrophotometer and Scanning Electron Microscopy. Well diffusion method was used to show the antibacterial action of silver nanoparticles against Pseudomonas aeruginosa in vitro in comparison with standard antibacterial silver sulfadiazine by using different concentrations of each agent ranged from 12.5-200 μg/ml. The results of this study showed it possible to produce silver nanoparticles in eco-friendly and easy process and UV-Visible absorption spectra of the silver nanoparticles revealed maximum absorbance at 420 and 430 nm. The Scanning Electron Microscopy analysis demonstrated the mean of the silver particles diameter was 26 nm. The antibacterial findings of the synthesized silver nanoparticles against Pseudomonas aeruginosa in vitro showed that the silver nanoparticles were more effective than silver sulfadiazine against Pseudomonas aeruginosa. It could be concluded that olive leaves extract can be used effectively in the production of silver nanoparticles and these synthesized nanoparticles had considerable antibacterial activity against Pseudomonas aeruginosa in vitro.                                                        

scholarly journals Enhancement of Photoconductive Detector Based on Carbon Nanotubes Decorated with Silver Nanoparticles by Adding Conductive Polymer

2021 ◽  
Vol 19 (50) ◽  
pp. 84-93
Author(s):  
Taqwa Yousif ◽  
Asama Naje
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Silver Nanoparticles ◽  
Forward Bias ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Scanning Electron

In this work, wide band range photo detector operating in UV, Visible and IR was fabricated using carbon nanotubes (MWCNTs, SWCNTs) decorated with silver nanoparticles (Ag NPs). Silicon was used as a substrate to deposited CNTs/Ag NPs by the drop casting technique. Polyamide nylon polymer was used to coat CNTs/Ag NPs to enhance the photo-response of the detector. The electro-exploding wire technology was used to synthesize Ag NPs. Good dispersion of silver NPs achieved by a simple chemistry process on the surface of CNTs. The optical, structure and electrical characteristic of CNTs decorated with Ag NPs were characterized by X-Ray diffraction and Field Emission Scanning Electron Microscopy.  X-ray diffraction patterns of Ag NPs exhibited 2θ values (38.1°,44.3°) corresponding to the Ag nanocrystal, while the XRD pattern of MWCNTs and SWCNTs /Ag NPs peaks appeared at 2θ = 26.2° corresponding to the (002) and at 2theta=44° which corresponds with miller indices (100) for CNTs and (200) for Ag NPs. The optical properties measured by UV-Vis. Spectroscopy. Broad and strong surface plasmon resonance (SPR) peak was detected at 420 nm, for Ag NPs. The absorption of CNTs/Ag NPs increased significantly from UV to near IR region (300-1000 nm).  Ag NPs decorated CNTs without any impurities, according to field mission scanning electron microscopy examination, with typical particle sizes of (50-80nm) for Ag-NPs, 44nm for MWCNTs/Ag-NPs, and 30nm for SWCNTs/Ag NPs. ֹThe I-V characteristics at forward bias voltage (0.5-10) volt were studied. The figure of merits (responsivity, photocurrent gain, NEP and detectivity) after coating with polymer of the detector were measured in the dark and after illumination with UV LED (365 nm), Tungsten lamp (500-800 nm) and Laser diode (808 nm).

Green Synthesis of Silver Nanoparticles for Control of Biodeterioration

2014 ◽  
Vol 1618 ◽  
pp. 241-246 ◽  
Author(s):  
M.A. Martínez Gómez ◽  
M.C. González Chávez ◽  
J.C. Mendoza Hernández ◽  
R. Carrillo González
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silver Nanoparticles ◽  
Cultural Heritage ◽  
Green Synthesis ◽  
Biological Synthesis ◽  
Vis Spectroscopy ◽  
Heritage Buildings ◽  
Biofilm Development ◽  
Scanning Electron

ABSTRACTChemical and biological deterioration of surfaces of historic constructions is one of the main causes of destruction of cultural heritage buildings. Effective techniques are searched in order to control the biofilm development of cultural heritage without damaging the environment. Nanotechnology is an emerging option with several applications, including those for improving stability and corrosion resistance in surfaces. Production of nanomaterials from organic nature or green synthesis offers ecological advantages such as low environmental impact. This paper proposes the use of silver nanoparticles of biological synthesis as an alternative for control of microorganisms that cause biodeterioration. The present study highlights the effect of these nanoparticles in the inhibition of bacterial growth. These particles were produced by biological synthesis with Tecoma stans L. extracts. Their characterization included analysis UV / Vis spectroscopy, scanning electron microscopy (SEM) and particle size distribution.

scholarly journals Corrosion Behavior and Mechanical Properties of a Nanocomposite Superhydrophobic Coating

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 652
Author(s):  
Divine Sebastian ◽  
Chun-Wei Yao ◽  
Lutfun Nipa ◽  
Ian Lian ◽  
Gary Twu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Nanocomposite Coating ◽  
Superhydrophobic Coating ◽  
Force Microscopy ◽  
Atomic Force ◽  
Microscopy Images ◽  
Scanning Electron

In this work, a mechanically durable anticorrosion superhydrophobic coating is developed using a nanocomposite coating solution composed of silica nanoparticles and epoxy resin. The nanocomposite coating developed was tested for its superhydrophobic behavior using goniometry; surface morphology using scanning electron microscopy and atomic force microscopy; elemental composition using energy dispersive X-ray spectroscopy; corrosion resistance using atomic force microscopy; and potentiodynamic polarization measurements. The nanocomposite coating possesses hierarchical micro/nanostructures, according to the scanning electron microscopy images, and the presence of such structures was further confirmed by the atomic force microscopy images. The developed nanocomposite coating was found to be highly superhydrophobic as well as corrosion resistant, according to the results from static contact angle measurement and potentiodynamic polarization measurement, respectively. The abrasion resistance and mechanical durability of the nanocomposite coating were studied by abrasion tests, and the mechanical properties such as reduced modulus and Berkovich hardness were evaluated with the aid of nanoindentation tests.

Sign in / Sign up

Export Citation Format

Share Document