Article

Synthesis of nanosized silver colloids by microwave dielectric heating

Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
Journal of Chemical Sciences (Impact Factor: 1.19). 01/2005; 117(1):53-60. DOI: 10.1007/BF02704361

ABSTRACT

Silver nanosized crystallites have been synthesized in aqueous and polyols viz., ethylene glycol and glycerol, using a microwave
technique. Dispersions of colloidal silver have been prepared by the reduction of silver nitrate both in the presence and
absence of stabilizer poly(vinylpyrolidone) (PVP). It was observed that PVP is capable of complexing and stabilizing Ag nanoparticles
formed through the reduction of Ag+ ions in water and ethylene glycol. In the case of ethylene glycol, it has been shown that the use of PVP leads to particles
with a high degree of stability. The colloids are stable in glycerol for months even in the absence of stabilizer.

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Available from: Tulsi Mukherjee
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    • "These particles are under active research because they posses interesting physical properties differing considerably from that of the bulk phase. It comes from small sizes and high surface/volume ratio [2].Silver nano particles have received considerable attention due to their attractive physical and chemical properties. Metallic silver colloids were first prepared more than a century ago. "
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    ABSTRACT: Silver nanoparticles were prepared by the reduction of silver salt (silver nitrate AgNO 3) solution using three different methods. The main differences between these methods is by belong to the reducing agent. It is found that the prepared silver nanoparticle was pure and stable for long time. UV-VIS spectrometry indicated formation of spherical silver nano particles. The surface plasmon resonance peaks in absorption spectra for silver colloidal solution showed that the absorption maximum range was at 380-420 nm. The structures are confirmed by X-ray diffraction (XRD) and the crystallite size was determined from X-ray line broadening using the Scherrer's equation and it was about 32 nm.AFM measurements show that silver nano particles have the average diameter of 69.39 nm and 81.91 nm. ‫اﻟﻔﻀﺔاﻟﻨﺎﻧﻮﯾﺔ‬ ‫ﻟﺪﻗﺎﺋﻖ‬ ‫اﻟﻄﯿﻔﯿﮫ‬ ‫اﻟﺪراﺳﺔ‬ ‫اﻟ‬ ‫اﻟﻜﯿﻤﯿﺎﺋﯿﺔ‬ ‫ﺑﺎﻟﻄﺮﯾﻘﺔ‬ ‫ﻤﺤﻀﺮه‬ ‫اﻟﺨﻼﺻﮫ‬ ‫ﺗﺤﻀﯿﺮ‬ ‫ﺗ++ﻢ‬ ++‫دﻗﺎﺋﻘﺎﻟﻔﻀ‬ ‫ﮫ‬ ‫ﺑﺎ‬ ‫++ﺔ‬ +‫اﻟﻨﺎﻧﻮﯾ‬ ‫++ﺔ‬ +‫ﺛﻼﺛ‬ ‫ﺳ++ﺘﺨﺪام‬ ‫ط++ﺮ‬ ‫++ﺎﺧﺘﺰال‬ +‫ﺑ‬ ‫وذﻟ++ﻚ‬ ‫++ﮫ‬ +‫ﻣﺨﺘﻠﻔ‬ ‫ق‬ ‫++ﺔ‬ +‫اﻟﻔﻀ‬ ‫ﻧﺘ++ﺮات‬) (AgNO 3 . ‫ان‬ ‫+ﯿﻦ‬ +‫ﺑ‬ ‫+ﻲ‬ +‫اﻟﺮﺋﯿﺴ‬ ‫+ﺘﻼف‬ +‫اﻻﺧ‬ ‫+ﺬه‬ +‫ھ‬ ‫+ﺮق‬ +‫اﻟﻄ‬ ‫اﻟ‬ ‫+ﺘﺨﺪام‬ +‫اﺳ‬ ‫+ﻮ‬ +‫ھ‬ ‫+ﻞ‬ +‫ﻌﺎﻣ‬ ‫اﻟﻤ‬ ‫+ﺰل‬ +‫ﺨﺘ‬ . ‫اﻟﻨﺎﻧﻮ‬ ‫+ﮫ‬ +‫اﻟﻔﻀ‬ ‫+ﺎﺋﻖ‬ +‫دﻗ‬ ‫+ﮫ‬ +‫ﯾ‬ ‫+ﺪ‬ +‫وﺟ‬ ‫+ﺮة‬ +‫اﻟﻤﺤﻀ‬ ‫ت‬ ‫+ﮫ‬ +‫ﻧﻘﯿ‬ ‫اﻟﻄﻮﯾﻞ‬ ‫ﻟﻮﻗﺖ‬ ‫ّة‬ ‫وﻣﺴﺘﻘﺮ‬ . ‫اﻟﻜﺮوﯾﮫ‬ ‫اﻟﻔﻀﯿﺔ‬ ‫اﻟﻨﺎﻧﻮﯾﺔ‬ ‫اﻟﺪﻗﺎﺋﻖ‬ ‫ﺗﺸﻜﯿﻞ‬ ‫اﺷﺎرإﻟﻰ‬ ‫اﻟﻄﯿﻒ‬ ‫ﻗﯿﺎس‬ ‫ﺟﮭﺎز‬ . ‫طﯿ+ﻒ‬ ‫ﻗﻤﻢ‬ ‫+ﻲ‬ ّ ‫اﻟﻔﻀ‬ ‫ﻟﻠﻤﺤﻠ+ﻮل‬ ‫اﻻﻣﺘﺼ+ﺎص‬ ‫ﻣﺪى‬ ‫ﻓﻲ‬ ‫ﻛﺎن‬ ‫اﻷﻋﻈﻢ‬ ‫اﻹﻣﺘﺼﺎص‬ ّ‫ﺑﺄن‬ ‫اظﮭﺮت‬) nm420 -380 .(‫ﻗﯿﺎس‬ ‫ﺑﻮﺳﻄﺔ‬ ‫ﺪة‬ ّ ‫ﻣﺆﻛ‬ ‫اﻟﺒﻠﻮري‬ ‫واﻟﺤﺠﻢ‬ ‫اﻟﻨﺎﻧﻮﯾﮫ‬ ‫اﻟﻔﻀﮫ‬ ‫ﻟﺪﻗﺎﺋﻖ‬ ‫اﻟﺘﺮﻛﯿﺐ‬ ‫ﺣﯿﻮد‬ ‫اﻟﺴﯿﻨﯿﺔ‬ ‫اﻻﺷﻌﺔ‬) XRD (‫ﺑﺈﺳ+ﺘﻌﻤﺎل‬ ‫و‬ ‫ﻣﻌﺎدﻟﺔ‬ Scherrer's ‫ﺣﻮاﻟﻲ‬ ‫ﻛﺎن‬ 32nm . INTRODUCTION* olloidal particles are increasingly receiving attention as important starting points for the generation of micro and nano structures [1]. These particles are under active research because they posses interesting physical properties differing considerably from that of the bulk phase. It comes from small sizes and high surface/volume ratio [2].Silver nano particles have received considerable attention due to their attractive physical and chemical properties. Metallic silver colloids were first prepared more than a century ago. Ag nanoparticles can be synthesized using various methods: chemical, electrochemical [3], γ-radiation [4] photochemical [5], laser ablation
    Full-text · Article · Dec 2014
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    • "The size-induced properties of nanoparticles enable the development of new applications or the addition of flexibility to existing systems, in many areas, such as catalysis, optics, microelectronics, and textiles. Antimicrobial effect of sliver nanoparticles on textiles has already been shown by various researchers [1] [2] [3]. Wool fiber, known for its lightness, softness, warmness, and smoothness, is known as a natural clothing material. "
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    ABSTRACT: Sliver nanocolloids have been synthesized by chemical reduction of sliver salt solution, characterized by SEM usage of nanoparticles. Sliver nanocolloids are treated with wool fibres and dyed wool fibres (direct and acid dyes). The physical properties, colour strength, and fastness properties have been studied for dyed wool fibres and ordinary wool fibres. It is observed that the fibres with nanotreated fibres have better strength than untreated wool fibres. It is also observed that there is considerable improvement in colour strength and colour fastness of silver nanocolloids-treated wool fibres (dyed).
    Full-text · Article · Dec 2012
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    • "Nanomaterials due to their small size show unique and considerably changed physical, chemical, and biological properties compared to their macro scale counterparts [1] . AgNPs have been produced using different methods: electrochemical method, laser ablation, microwave irradiation, thermal decomposition and sono-chemical synthesis [2] [3] . Although chemical and physical methods may successfully produce pure, well-defined nanoparticles, these methods are quite expensive and potentially dangerous to the environment. "
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    ABSTRACT: Objective: To synthesize the silver nanoparticles (AgNPs) using Hypnea sp. and to investigate the antibacterial activity against Eshcherichia coli, Staphylococcus aureus and invitro cytotoxic activity on HT-29. Methods: In the present study, AgNPs were synthesized using the aqueous extract of marine macro-algae, and were characterized using UV-visible spectroscopy, Fourrier Transform Infra red (FT-IR) spectroscopy, X-ray diffraction (XRD) analysis and Transmission Electron Microscopy (TEM) analysis. Further these synthesized AgNPs were evaluated for their antibacterial activity with the clinical isolates from wound specimens. The isolates were characterized by different tests viz., microscopical observation, colony morphology, biochemical & sugar fermentation tests. The synthesized AgNPs were tested for its antibacterial activity against the isolates by agar well diffussion method. The AgNPs were assessesd for its cytotoxic activity on Human Caucasian colon adenocarcinoma (HT-29) cell lines. Results: In this study, it is clear that the synthesized AgNPs were spherical measuring 10-20nm and was found to be more bactericidal against Gram-negative bacteria (E. coli) than Gram-positive bacteria (Staphylococcus aureus) isolated from wound specimen. The invitro screening of the AgNPs showed potential cytotoxic activity against the colon cancer cell lines. At a concentration 1.25 mg/ml, 57.69% of cytotoxicity and at a concentration 2.5 mg/ml, 42.30% cytotoxicity was recorded. Conclusion: Proteins can bind to nanoparticles either through the electrostatic attraction of negatively charged carboxylate groups in Hypnea sp. and stabilization of the AgNPs by protein occurs. The antimicrobial activities of AgNPs are influenced by the dimensions of the particles the smaller the particles, the greater antimicrobial effect. The cytotoxic activity may be due to the presence of alkaloids present in the Hypnea sp.
    Full-text · Article · Oct 2012
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