02057nas a2200301   4500008004100000022001400041245007100055210006900126260009200195300001400287490000600301520105500307653003001362653001401392653001401406653001801420100002201438700001601460700002101476700002301497700001801520700001801538700002301556700001901579700002301598700002901621856010501650       2007                        eng d  a1533-488000aLow temperature synthesis of magnetite and maghemite nanoparticles0 aLow temperature synthesis of magnetite and maghemite nanoparticl  a26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USAbAMER SCIENTIFIC PUBLISHERScDEC  a4294-43020 v73 a<p>We report on the synthesis of iron oxide nanoparticles below 100 degrees C by a simple chemical protocol. The uniqueness of the method lies in the use of Ferrous ammoniurn sulphate (in conjugation with FeCl3) which helps maintain the stability of Fe-2+ state in the reaction sequence thereby controlling the phase formation. Hexamine was added as the stabilizer. The nanoparticles synthesized at three different temperatures viz, 5 degrees, 27 degrees, and 95 degrees C are characterized by several techniques. Generally, when a mixture of Fe3+ and Fe2+ is added to sodium hydroxide, alpha-Fe2O3 (the anti-ferromagnetic phase) is formed after the dehydration process of the hydroxide. In our case however, the phases formed at all the three temperatures were found to be ferro (ferri) magnetic, implying modification of the formation chemistry due to the specifics of our method. The nanoparticles synthesized at the lowest temperature exhibit magnetite phase, while increase in growth temperature to 95 degrees C leads to the maghemite phase.</p>10alow temperature synthesis10amaghemite10amagnetite10aNanoparticles1 aBhagwat, Shrikant1 aSingh, Hema1 aAthawale, Anjali1 aHannoyer, Beatrice1 aJouen, Samuel1 aLefez, Benoit1 aKundaliya, Darshan1 aPasricha, Renu1 aKulkarni, Shailaja1 aOgale, Satishchandra, B.  uhttps://library.ncl.res.in/content/low-temperature-synthesis-magnetite-and-maghemite-nanoparticles-002462nas a2200253   4500008004100000022001400041245010400055210006900159260005700228300001200285490000600297520161200303653001801915653001501933653001001948653000901958653001801967653001101985100001901996700002002015700001902035700002402054856013002078       2009                        eng d  a1557-195500aSilver fused conducting fiber formation of Au-Ag core-shell nanoparticles mediated by ascorbic acid0 aSilver fused conducting fiber formation of AuAg coreshell nanopa  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcJUN  a161-1700 v43 a<p>In this paper, we report the spontaneous formation of fibrous structures consisting of assemblies of Au-Ag core-shell nanoparticles (NPs) from a solution consisting of Au-Ag core-shell NPs and l-ascorbic acid (AA). AA acted both as the reducing agent for the generation of NPs and also as the mediator for the formation of fibers. The process of fiber formation involved three steps-reduction of HAuCl(4) to Au NPs by AA, subsequent formation of Au-Ag core-shell NPs after addition of AgNO(3), and spontaneous formation of fibers from the mixtures in water. It took typically about 30 days to form complete fibers that are of lengths of several hundred micrometers to millimeters, although nanofibers started forming from the first day of solution preparation. The width of each of these fibers was typically about 1-4 A mu m with length of each segment of fiber bundle, on the order of 40 A mu m. Formation of fibers was also observed in absence of AgNO(3). These fibers consisted of Au NPs and polymer of AA degradation products and were not electrically conducting. Also, low concentrations of AgNO(3) produced fibers with low electrical conductivity. However, it was observed that increase in the amount of AgNO(3) leads to the formation of fibers that were electrically conducting with conductivity values in the range of metallic conductivity. Spectroscopic and electron microscopic investigations were carried out to establish the formation of fibers. The details of fiber formation mechanism under different conditions and electrical conductivities of the fibers are discussed in the article.</p>10aAscorbic acid10acore-shell10aFiber10aGold10aNanoparticles10aSilver1 aMurugadoss, A.1 aKar, Manoranjan1 aPasricha, Renu1 aChattopadhyay, Arun  uhttps://library.ncl.res.in/content/silver-fused-conducting-fiber-formation-au-ag-core-shell-nanoparticles-mediated-ascorbic-002305nas a2200277   4500008004100000022001400041245009800055210006900153260011100222300001200333490000700345520133600352653001701688653001201705653001001717653001801727653001801745100002501763700001501788700001701803700001901820700002601839700001701865700001701882856012801899       2014                        eng d  a1573-413700aExtracellular biosynthesis of metal sulfide nanoparticles using the fungus fusarium oxysporum0 aExtracellular biosynthesis of metal sulfide nanoparticles using   aEXECUTIVE STE Y-2, PO BOX 7917, SAIF ZONE, 1200 BR SHARJAH, U ARAB EMIRATESbBENTHAM SCIENCE PUBL LTDcJUL  a588-5950 v103 a<p>The development of reliable, eco-friendly processes for the synthesis of nanomaterials is an important aspect of nanotechnology. One approach that shows immense potential is based on the biosynthesis of nanoparticles using microorganisms such as bacteria. In this report, we demonstrate the extracellular biosynthesis and complete characterization of metal sulfide (PbS, ZnS, MnS and NiS) nanoparticles using fungus, Fusarium oxysporum. We observed that the exposure of aqueous solution of 1 mM metal sulfate to fungus Fusarium oxysporum resulted in the formation of highly stable technologically important metal sulfide semiconductor nanoparticles. Fusarium oxysporum synthesizes lead sulfide and zinc sulfide nanoparticles of fractal type structure whereas manganese sulfide and nickel sulfide nanoparticles are of variable polydispersed morphology. The variable morphology may be due to the dissimilar interaction of metal sulfide nanoparticles with capping proteins secreted by the fungus in solution. The nanoparticles solution is found to be extremely stable with little evidence of aggregation even after a month of storage. The long term stability of the nanoparticles is due to the proteins secreted by fungus in the nanoparticle solution which bind to the surface of the nanoparticles and thus prevent aggregation.</p>10aBiosynthesis10aenzymes10afungi10ametal sulfide10aNanoparticles1 aSenapati, Satyajyoti1 aSyed, Asad1 aKhan, Shadab1 aPasricha, Renu1 aKhan, Mohammad, Islam1 aKumar, Rajiv1 aAhmad, Absar  uhttps://library.ncl.res.in/content/extracellular-biosynthesis-metal-sulfide-nanoparticles-using-fungus-fusarium-oxysporum-0