02318nas a2200277 4500008004100000022001400041245015400055210006900209260007300278300001200351490000700363520129900370653001801669653002501687653000901712653001001721653001601731653003801747100002001785700002501805700002001830700002201850700002101872700002101893856012601914 2012 eng d a0927-776500aNovel route for rapid biosynthesis of copper nanoparticles using aqueous extract of Calotropis procera L. latex and their cytotoxicity on tumor cells0 aNovel route for rapid biosynthesis of copper nanoparticles using aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUN a284-2880 v953 a

This paper accounts for novel, low-cost, eco-friendly route for rapid biosynthesis of copper nanoparticles. Cysteine proteases present in the latex of Calotropis procera L. were used to fabricate copper nanoparticles from copper acetate. Copper nanoparticles were initially characterized by transmission electron microscopy (TEM) and X-ray diffraction technique (XRD). Transmission electron microscopy (TEM) was used to estimate the size and shape of nanoparticles. The average size of copper nanoparticles was found to be 15 +/- 1.7 nm. Energy dispersive analysis of X-rays (EDAX) showed distinct peaks of copper. Fourier transform infrared spectroscopy (FTIR) was performed to confirm capping behavior of the latex proteins that contributed to long term stability of copper nanoparticles (6 months) in aqueous medium. Copper nanoparticles synthesized by above method were monodisperse type. Cytotoxicity studies of latex stabilized copper nanoparticles were carried out on HeLa, A549 and BHK21 cell lines by MTT dye conversion assay. HeLa, A549 and BHK21 cells showed excellent viability even at 120 mu M concentration of copper nanoparticles. This shows that copper nanoparticles synthesized by above method hold excellent biocompatibility. (C) 2012 Elsevier B.V. All rights reserved.

10aBiocompatible10aCopper nanoparticles10aFTIR10aLatex10aTumor cells10aX-ray diffraction technique (XRD)1 aHarne, Shrikant1 aSharma, Ashwinikumar1 aDhaygude, Mayur1 aJoglekar, Shriram1 aKodam, Kisan, M.1 aHudlikar, Manish uhttps://library.ncl.res.in/content/novel-route-rapid-biosynthesis-copper-nanoparticles-using-aqueous-extract-calotropis-002000nas a2200241 4500008004100000022001400041245012900055210006900184260000800253300001200261490000600273520114800279653002301427653002501450653002001475653001501495653001501510100002501525700002401550700002201574700003001596856013201626 2017 eng d a2169-432X00aSynthesis of copper nanoparticles in presence of surfactants and evaluation of heat transfer performance of copper nanofluid0 aSynthesis of copper nanoparticles in presence of surfactants and cAPR a334-3420 v63 a

Copper nanoparticles were synthesized by reduction of copper nitrate hexahydrate using glucose as a green reducing agent. Effect of various synthesis parameters such as the amount of reducing agent, type of surfactant, the concentration of surfactant on particle size and morphology has been studied. Particles thus synthesized were characterized using analytical tools like X-ray Diffraction (XRD), Dynamic Light Scattering (DLS) and Scanning Electron Microscopy (SEM). XRD results show copper peaks at 2 angles 43.34, 50.48 and 74.19° corresponding to the planes (111), (200) and (220) respectively and possessing FCC (Face Centred Cubic) crystal lattice and polydispersed particles with crystallite size ranging from 43 to 103 nm. Further Cu nanoparticles were dispersed in water to prepare nanofluid and heat transfer properties such as heat transfer coefficient, viscosity and density were evaluated. Nanofluid models proposed elsewhere were also used for theoretical property evaluations. Nearly 100% increase in heat transfer coefficient was observed at 1% (by volume) particle concentration of copper nanoparticles in water.

10aChemical Reduction10aCopper nanoparticles10agreen synthesis10aNanofluids10asurfactant1 aKapadnis, Chetan, V.1 aGundeli, Kartik, P.1 aSaini, Daulat, R.1 aBhatkhande, Dhananjay, S. uhttps://library.ncl.res.in/content/synthesis-copper-nanoparticles-presence-surfactants-and-evaluation-heat-transfer-performance02868nas a2200265 4500008004100000022001400041245015400055210006900209260000900278300001600287490000700303520188300310653002502193653003102218653003002249653002802279653002502307100002602332700002202358700002102380700002102401700002802422700003002450856012202480 2019 eng d a1944-824400aCu/Cu2O nanoparticles supported on a phenol-pyridyl COF as a heterogeneous catalyst for the synthesis of unsymmetrical diynes via glaser-hay coupling0 aCuCu2O nanoparticles supported on a phenolpyridyl COF as a heter cMAY  a15670-156790 v113 a

Covalent organic frameworks (COFs) are a new class of porous crystalline polymers with a modular construct that favors fiinctionalization. COF pores can be used to grow nanoparticles (nPs) with dramatic size reduction, stabilize them as dispersions, and provide excellent nP access. Embedding substrate binding sites in COFs can generate host-guest synergy, leading to enhanced catalytic activity. In this report, Cu/Cu2O nPs (2-3 nm) are grown on a COF, which is built by linking a phenolic trialdehyde and a triamine through Schiff bonds. Their micropores restrict the nP to exceptionally small sizes (similar to 2-3 nm), and the pore walls decorated with strategically positioned hydrogen-bonding phenolic groups anchor the substrates via hydrogen-bonding, whereas the basic pyridyl sites serve as cationic species to stabilize the [CuclusterCl2](2-) type reactive intermediates. This composite catalyst shows high activity for Glaser-Hay heterocoupling reactions, an essential 1,3-diyne yielding reaction with widespread applicability in organic synthesis and material science. Despite their broad successes in homocoupled products, preparation of unsymmetrical 1,3-diynes is challenging due to poor selectivity. Here, our COF-based Cu catalyst shows elevated selectivity toward heterocoupling product(s) (Cu nP loading 0.0992 mol %; turn over frequency: similar to 4S-50; turn over number: similar to 17S-190). The reversible redox activity at the Cu centers has been demonstrated by carrying out X-ray photoelectron spectroscopy on the frozen reactions, whereas the crucial interactions between the substrates and the binding sites in their optimized configurations have been modeled using density functional theory methods. This report emphasizes the utility of COFs in developing a heterogeneous catalyst for a truly challenging organic heterocoupling reaction.

10aCopper nanoparticles10aCovalent organic framework10aGlaser-Hay heterocoupling10aheterogeneous catalysis10aunsymmetrical diynes1 aChakraborty, Debanjan1 aNandi, Shyamapada1 aMullangi, Dinesh1 aHaldar, Sattwick1 aVinod, Chathakudath, P.1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/cucu2o-nanoparticles-supported-phenol-pyridyl-cof-heterogeneous-catalyst-synthesis