scholarly journals Light-induced synthesis of micron-sized metallic silver in aqueous extract of Rivina humilis L. fruits and its interaction with Corptotermes curvignathus

Molekul ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 170
Author(s):  
Salprima Yudha S ◽  
Aswin Falahudin ◽  
Morina Adfa ◽  
Irfan Gustian ◽  
Herlina Herlina
Keyword(s):  
Aqueous Extract ◽  
Colour Change ◽  
Reduction Process ◽  
Silver Ions ◽  
Spectrophotometric Analysis ◽  
Metallic Silver ◽  
Spherical Form ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Average Size

The aqueous extract of Rivina humilis was suitable to reduce silver ions (Ag+) to form micron-sized metallic silver at room temperature and without any addition of external reducing agent or stabilizer compounds. The reduction process was assisted by light, indicated by the colour change of the reaction mixture and supported by the appearance of peak at 455 nm in spectrophotometric analysis when the reaction was carried out under room light. Based on transmission electron microscopy (TEM) analysis, the as-prepared metallic silver was in spherical form. The analysis results using particles size analyzer (PSA) show their particles distribution from micro to nano size (average size was 199 nm). The interaction behaviour of micron-sized metallic silver/extract solution with Corptotermes curvignathus termites shows that the silver gives small additional effects along with the activity of the extract.

Influence of Zr Additive on the Chemical Reduction Behaviour of MoO3 in Carbon Monoxide Atmosphere

2021 ◽  
Vol 317 ◽  
pp. 173-179
Author(s):  
Alinda Samsuri ◽  
Mohd Nor Latif ◽  
Norliza Dzakaria ◽  
Fairous Salleh ◽  
Maratun Ajina Abu Tahari ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Molybdenum Trioxide ◽  
Chemical Reduction ◽  
Reduction Process ◽  
Chemical Effect ◽  
Physical Analysis ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Reduction Behaviour ◽  
Temperature Programmed

Temperature-programmed reduction (TPR) was used to observe the chemical reduction behaviour of molybdenum trioxide (MoO3) and zirconia (Zr)-doped MoO3 catalyst by using carbon monoxide (CO) as the reductant. The characterisation of catalysts was performed by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and transmission electron microscopy (TEM) analyses. The reduction performance were examined up to 700°C and reduction was continued for 60 min at 700°C in a stream of 20 vol. % CO in nitrogen. The TPR profile showed that the doped MoO­3 catalyst was slightly moved to a higher temperature (580°C) as compared to the undoped MoO3 catalyst, which began at around 550°C. The interaction between zirconia and molybdenum ions in doped MoO3 catalyst led to an increase in the reduction temperature. According to characterisation of the reduction products by using XRD, it revealed that the reduction behaviour of pure MoO3 to MoO2 by CO reductant involved two reduction stages with the formation of Mo4O11 as the intermediate product. Meanwhile, MoO3 catalyst doped with zirconia caused a delay in the reduction process and was proven by the presence of Mo4O11 species at the end of reactions. Physical analysis by using BET showed a slight increase in surface area of 3% Zr-MoO3 from 6.85 m2/g to 7.24 m2/g. As for TEM analysis, black tiny spots located around MoO3 particles revealed that the zirconia was successfully intercalated into MoO3 particles. This confirmed that formation of intermetallic between Zr-MoO3 catalyst will give new chemical and physical properties which has a remarkable chemical effect by disturbing the reduction progression of MoO3 catalyst.

scholarly journals Bioinspired Synthesis of Acacia senegal Leaf Extract Functionalized Silver Nanoparticles and Its Antimicrobial Evaluation

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Edwina Olohirere Uzunuigbe ◽  
Abidemi Paul Kappo ◽  
Sixberth Mlowe ◽  
Neerish Revaprasadu
Keyword(s):  
Silver Nanoparticles ◽  
Colour Change ◽  
Silver Ions ◽  
Antibacterial Activities ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Leaf Extracts ◽  
Acacia Senegal ◽  
Transmission Electron ◽  
Antimicrobial Evaluation

Synthesizing nanoparticles with the less environmentally malignant approach using plant extract is of great interest; this is because most of the chemical approaches can be very costly, toxic, and time-consuming. Herein, we report the use of Acacia senegal leaf extracts to synthesize silver nanoparticles (AgNPs) using an environmentally greener approach. Silver ions were reduced using the bioactive components of the plant extracts with observable colour change from faint colourless to a brownish solution as indication of AgNP formation. The structural properties of the as-synthesized AgNPs were characterized using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and UV-Vis absorption spectrum. Antimicrobial assessment of the as-synthesized AgNPs was explored on some strains of gram-positive and gram-negative bacteria. The obtained results indicate that the as-synthesized AgNPs are pure crystallite of cubic phase of AgNPs, fairly dispersed with a size range of 10–19 nm. The AgNPs were found to be small in size and exhibit significant antibacterial activities, suggesting that the as-synthesized AgNPs could be used in the pharmaceutical and food industries as bactericidal agents.

scholarly journals Formation of Eco-friendly Silver Nanoparticle Microalgae using Chlorella vulgaris

2019 ◽  
Vol 24 (1) ◽  
pp. 7
Author(s):  
Hermin Pancasakti Kusumaningrum ◽  
Muhammad Zainuri ◽  
Widianingsih Widianingsih ◽  
Wahyu Dewi Utari Haryanti ◽  
Indras Marhaendrajaya ◽  
...  
Keyword(s):  
Antimicrobial Agent ◽  
Silver Nanoparticle ◽  
Chemical Elements ◽  
Research Result ◽  
Sem Analysis ◽  
Spherical Form ◽  
Tem Analysis ◽  
Edx Analysis ◽  
Transmission Electron ◽  
Uv Visible

Biosynthesized silver nanoparticles (AgNPs) using organism have spurred great interest as a antimicrobial and biomedical agents. Green microalgae have advantages as they are easily available, grow rapidly and producing varieties metabolites. Synthesized of AgNPs from  microalgae C. vulgaris offer environmentally antimicrobial agent. The objectives of the study is producing AgNPs microalgae using C. vulgaris as eco-friendly antimicrobial agent. The research methods was conducted by synthesizing silver nanoparticle microalgae using C. vulgaris following by characterization under UV–visible spectroscopy,  transmission electron microscopy  (TEM), and scanning electron microscope (SEM) and Energy-dispersive X-ray spectroscopy (EDX). The research result showed AgNPs C. vulgaris microalgae were produced with and without agitation treatment under different condition. The synthesized AgNPs C. vulgaris exhibited a maximum absorption at 312 nm and 398 nm, and EDX analysis had determined that abundance chemical elements presented in a sample were carbon  and silver.  The TEM analysis revealed that they are spherical form. The spot of EDX analysis showed the presence of silver atoms. The SEM analysis shows the spherical shaped with some silver particle inside of the cell. These resut indicated that formation of silver nanoparticle microalgae using C. vulgaris has been succesfully obtained under the treatment. 

scholarly journals Optimization of biogenic synthesis of silver nanoparticles from flavonoid-rich Clinacanthus nutans leaf and stem aqueous extracts

2020 ◽  
Vol 7 (7) ◽  
pp. 200065 ◽  
Author(s):  
Siti Nur Aishah Mat Yusuf ◽  
Che Nurul Azieyan Che Mood ◽  
Nor Hazwani Ahmad ◽  
Doblin Sandai ◽  
Chee Keong Lee ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Functional Groups ◽  
Silver Ions ◽  
Cost Effective ◽  
Aqueous Extracts ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
The Face ◽  
Clinacanthus Nutans

Background : Silver nanoparticles (AgNPs) are widely used in food industries, biomedical, dentistry, catalysis, diagnostic biological probes and sensors. The use of plant extract for AgNPs synthesis eliminates the process of maintaining cell culture and the process could be scaled up under a non-aseptic environment. The purpose of this study is to determine the classes of phytochemicals, to biosynthesize and characterize the AgNPs using Clinacanthus nutans leaf and stem extracts. In this study, AgNPs were synthesized from the aqueous extracts of C. nutans leaves and stems through a non-toxic, cost-effective and eco-friendly method. Results : The formation of AgNPs was confirmed by UV-Vis spectroscopy, and the size of AgNP-L (leaf) and AgNP-S (stem) were 114.7 and 129.9 nm, respectively. Transmission electron microscopy (TEM) analysis showed spherical nanoparticles with AgNP-L and AgNP-S ranging from 10 to 300 nm and 10 to 180 nm, with average of 101.18 and 75.38 nm, respectively. The zeta potentials of AgNP-L and AgNP-S were recorded at −42.8 and −43.9 mV. X-ray diffraction analysis matched the face-centred cubic structure of silver and was capped with bioactive compounds. Fourier transform infrared spectrophotometer analysis revealed the presence of few functional groups of phenolic and flavonoid compounds. These functional groups act as reducing agents in AgNPs synthesis. Conclusion : These results showed that the biogenically synthesized nanoparticles reduced silver ions to silver nanoparticles in aqueous condition and the AgNPs formed were stable and less toxic.

Synthesis of Copper Nanoparticles at Room Temperature Using Hydrazine in Glycerol

2013 ◽  
Vol 481 ◽  
pp. 21-26 ◽  
Author(s):  
Huei Ruey Ong ◽  
Maksudur Rahman Khan ◽  
Ridzuan Ramli ◽  
Rosli Mohd Yunus
Keyword(s):  
Copper Nanoparticles ◽  
Room Temperature ◽  
Red Wine ◽  
Copper Chloride ◽  
Reduction Process ◽  
Stability Study ◽  
Ambient Conditions ◽  
Transmission Electron ◽  
Average Size ◽  
Hydrazine Solution

Copper nanoparticles (CuNPs) have been prepared by the reduction of copper chloride in glycerol using hydrazine at ambient conditions. The reduction process takes place under vigorous stirring for 8 h. The formation of CuNPs and size were confirmed by UV/Vis analysis and TEM imaging respectively. The experiment result showed that, 7.062 mM of hydrazine solution and 0.0147 mM of Cu2+ solution were needed to synthesize narrow size monodisperseCuNPs.The presence of nanoparticle was found after an induction period of 4 h and further reaction time, complete Cu0 state nanoparticle was obtained as deep red wine colour was observed. Stability study of CuNPs showed that the nanoparticles were stable up to 4 days. The particle size of the nanoparticles have been analysed by transmission electron microscopy (TEM) and the average size of CuNPs was in the range 2 to 10 nm.

scholarly journals Zirconium Carboxyaminophosphonate Nanosheets as Support for Ag Nanoparticles

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3185
Author(s):  
Morena Nocchetti ◽  
Anna Donnadio ◽  
Eleonora Vischini ◽  
Tamara Posati ◽  
Stefano Ravaioli ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Ag Nanoparticles ◽  
Silver Ions ◽  
Colloidal Dispersion ◽  
Metallic Silver ◽  
Transmission Electron ◽  
Organic Solid ◽  
Bactericidal Properties ◽  
Zinc Cations ◽  
Layered Matrix

A layered insoluble inorganic-organic solid, namely zirconium phosphate glycine-N,N-bismethylphosphonate, was used to prepare dispersions of nanosheets to support active metals such as metallic silver nanoparticles and zinc ions. Zr phosphate-phosphonate microcrystals were first exfoliated with methylamine to produce a stable colloidal dispersion and then the methylamine was removed by treatment with hydrochloric acid. The obtained colloidal dispersion of Zr phosphate-phosphonate nanosheets was used to immobilize silver or zinc cations, via ion exchange, with the acidic protons of the sheets. The layered matrix showed a great affinity for the metal cations up taking all the added cations. The treatment of the dispersions containing silver ions with ethanol yielded metal silver nanoparticles grafted on the surface of the layered host. The samples were characterized by X-ray powder diffraction, elemental analysis transmission electron microscopy, and selected samples were submitted to antimicrobial tests. The nanocomposites based on Ag nanoparticles showed good bactericidal properties against the bacterial reference strain Staphylococcus epidermidis (S. epidermidis).

scholarly journals Synthesis and Characterization of Cysteine-Capped CdSe Nanoparticles Using an Alternative of Selenium

2019 ◽  
Vol 31 (11) ◽  
pp. 2457-2460
Author(s):  
K.E. Mokubung ◽  
M.J. Moloto ◽  
K.P. Mubiayi ◽  
N. Moloto
Keyword(s):  
Cdse Nanoparticles ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Visible Absorption ◽  
Prepared Nanoparticles ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Xrd Patterns ◽  
Average Size

Present work reports synthesis of L-cysteine capped CdSe nanoparticles at different temperatures via an aqueous medium, non-toxic and green colloidal route. Cadmium chloride (CdCl2·5H2O) and sodium selenite (Na2SeO3) were used as cadmium and selenium sources respectively. The prepared nanoparticles are characterized by UV-visible absorption and photoluminescence spectroscopy, Fourier transform infrared, X-ray diffraction and transmission electron microscopy. The XRD patterns confirm a cubic phase structure of the prepared nanoparticles at 55, 75 and 95 ºC, respectively. The TEM analysis, optical absorption and photoluminescence spectra shows epitaxial growth of CdSe nanoparticles as the temperature increases with average size diameter of 4.12 ± 0.32, 5.02 ± 0.234 and 5.53 ± 0.321 nm for 55, 75 and 95 ºC, respectively.

Synthesis and Investigation of the Linear and Nonlinear Optical Properties of Alloyed CdSe0.3Te0.7Nanocrystals

2014 ◽  
Vol 13 (01) ◽  
pp. 1450007
Author(s):  
H. S. Bahari ◽  
Z. Dehghani ◽  
E. Saievar-Iranizad ◽  
M. Molaei ◽  
M. H. Majles Ara
Keyword(s):  
Nonlinear Optical ◽  
Hexagonal Phase ◽  
Nonlinear Refraction ◽  
Refraction Index ◽  
Tem Analysis ◽  
Nlo Properties ◽  
Band Emission ◽  
Transmission Electron ◽  
Thermochemical Method ◽  
Average Size

Alloyed CdSe 0.3 Te 0.7nanocrystals (NCs) were prepared by a thermochemical method using Thioglycolic acid (TGA) as a capping agent molecule. X-ray diffraction (XRD) and Transmission electron microscopy (TEM) analysis demonstrated hexagonal phase NCs with an average size of around 2.5 nm. Synthesized NCs indicated a narrow band emission with a peak located at 561 nm. Nonlinear optical (NLO) properties of the CdSe 0.3 Te 0.7NCs have been investigated by z-scan technique using Continuum Wave H e– Ne laser. The nonlinear absorption coefficient and nonlinear refraction index were obtained in the order of 10-2 and 10-8, respectively. The results revealed that these NCs exhibit strong NLO properties effects such as self-defocusing and two photons absorption.

scholarly journals MAGNETIC AND THERMAL PROPERTIES OF NANOMATERIALS BASED ON HIGHLY BRANCHED FERROCENE-CONTAINING POLYMERS

2018 ◽  
Vol 13 (5) ◽  
pp. 49-57 ◽  
Author(s):  
R. A. Dvorikov ◽  
V. A. Vasnev ◽  
А. А. Korlukov ◽  
М. I. Buzin
Keyword(s):  
Ir Spectroscopy ◽  
Magnetic Particles ◽  
Heating Temperature ◽  
Treatment Temperature ◽  
Magnetic Nanomaterials ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Average Size ◽  
Principal Possibility

New magnetic nanomaterials with magnetization up to 32 Gs·cm3/g were synthesized from highly branched ferrocene-containing polymers by thermal structural transformations in a field of 2.5 kOe. The structure and properties of the prepared polymers were studied by IR spectroscopy, transmission electron microscopy (TEM) and thermogravimetric analyses. According to IR spectroscopy the content of 1,3,5-substituted benzene rings in the ferrocene-containing polymer increases at 500°C. X-ray diffraction study showed that iron in such a sample is present exclusively in the form of Fe3O4 magnetite. As the heating temperature increased to 600°C, the composition of the samples became more complex: along with magnetite they contain cementite Fe3C and wustite FeO.97O. The magnetization of the ferrocene-containing polymer depends on the synthesis and heat treatment temperature. For a sample synthesized at 140°C the formation of a magnetically ordered phase begins at 500°C, and at 800°C the magnetization reaches a maximum value of 32 Gs·cm3/g. The average size of magnetic particles according to TEM analysis was 8-26 nm. The principal possibility of controlling the size and composition of the nanoparticles, as well as their magnetization depending on the conditions of production and the temperature of polymer structuring is shown. The obtained results provide a good basis for the directed synthesis of magnetic ferrocene-containing polymers with preset characteristics.

SYNTHESIS OF SILVER NANOPARTICLES USING AQUEOUS EXTRACT OF PERGULARIA DAEMIA AND ANALYSIS OF ANTIMICROBIAL ACTIVITY

INDIAN DRUGS ◽  
2020 ◽  
Vol 57 (08) ◽  
pp. 25-29
Author(s):  
Jambuwant A. Kadam ◽  
Mahesh A Karale ◽  
Pushpa Karale
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Aqueous Extract ◽  
Visual Observation ◽  
Leaf Extracts ◽  
Tem Analysis ◽  
E Coli ◽  
Antimicrobial Potential ◽  
Transmission Electron ◽  
Research Findings

The present work deals with the green synthesis of silver nanoparticle from aqueous extract of Pergularia daemia as reducing agent and evaluation of the antimicrobial potential of synthesized green nanoparticles (GNPs). The synthesized silver nanoparticles (SNPs) were characterized by UltravioletVisible absorption spectroscopy (UV-Vis) and high-resonance transmission electron microscopy (TEM) analysis. Visual observation showed that the color of the fresh leaf extracts of P. daemia turned into dark brown after incubation of 24 h with Ag precursors. The TEM analysis showed that nanoparticles were spherical in shape and the size was found to be in the range of 7-22 nm. The green synthesized nanoparticles showed concentration dependent (25 µg/mL, 50 µg/mL and 100 µg/mL) noteworthy antimicrobial activity against E. coli, S. aureus and B. subtilis with ciprofloxacin as a standard. Research findings conclude that GNPs possess superior antimicrobial potential and it is a new option to combat antibiotic resistance.

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