- Green approach to synthesize multi-walled carbon nanotubes by using metal formate as catalyst precursors
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The multi-walled nanotubes (MWNTs) have been synthesized in large scale by using metal formate as catalyst precursors. The calcium carbonate is used as catalyst support, it is chosen because of its non toxic and easily soluble nature. The synthesis was ca
- Rajarao, Ravindra,Bhat, Badekai Ramachandra
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p. 2153 - 2158
(2013/05/22)
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- Synthesis and characterization of new metal(II) complexes with formates and some nitrogen donor ligands
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New mixed-ligands complexes with empirical formulae: M(2,4'-bpy) 2L2?H2O (M(II)Zn, Cd), Zn(2-bpy) 3L2?4H2O, Cd(2-bpy)2L 2?3H2O, M(phen)L2?2H
- Czakis-Sulikowska,Czylkowska,Radwanska-Doczekalska,Grodzki,Wojciechowska
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p. 557 - 564
(2008/10/09)
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- Novel in situ fabrication of chestnut-like carbon nanotube spheres from polypropylene and nickel formate
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A novel in situ approach to mass fabrication of carbon nanotubes was reported. Composites of polypropylene (PP)/organomontmorillonite (OMMT)/nickel formate (NF) were prepared by mixing these components in a Brabender mixer at an elevated temperature. Chestnut-like carbon nanotube (CNT) spheres were in situ fabricated in high yields by heating the PP/OMMT/NF composites at 900°C without adding any additional pre-synthesized nickel nanocatalysts. The products were studied by X-ray diffractometer (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy, and N2 adsorption-desorption measurements. The results showed that nickel nanoparticles were in situ produced, which catalyzed the formation of multiwalled carbon nanotubes (MWNTs) in an autoclave-like microreactor formed by OMMT. These in situ formed nickel nanoparticles were found to be more catalytically active than pre-synthesized nickel nanocatalysts, resulting in higher yields of CNTs. The obtained CNT spheres have a high surface area, which makes them a good catalyst support. Loading of metal nanoparticles was preliminarily tried, and Pt nanoparticles of ca. 2.65 nm in size were successfully deposited on CNTs. The applications of these nanocatalysts in chemical reactions are currently being studied in our laboratory.
- Chen, Xuecheng,He, Junhul,Yan, Chunxiao,Tang, Huamin
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p. 21684 - 21689
(2008/10/09)
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- New complexes of Mn(II), Co(II), Ni(II) and Cu(II) with 2,2'- or 2,4'-bipyridine and formates (Synthesis, thermal and other properties)
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New mixed-ligand complexes with empirical formulae: Mn(2-bpy) 1.5L2?2H2O, M(2-bpy)2L 2?3H2O (M(II)=Co, Cu), Ni(2-bpy)3L 2?4H2O and M(2,4'-bpy)2L 2?2H2O (where 2-bpy=2,2'-bipyridine, 2,4'-bpy=2,4'-bipyridine; L=HCOO- ) have been obtained in pure solid-state. The complexes were characterized by chemical and elemental analysis, IR and VIS spectroscopy, conductivity (in methanol and dimethylsulfoxide). The way of metal-ligand coordination discussed. The formate and 2,4'-bpy act as monodentate ligands and 2-bpy as chelate ligand. The new complexes with ligand isomerism were identified. During heating the complexes lose water molecules in one or two steps. Thermal decomposition after dehydration is multistage and yields corresponding metal oxides as final products. A coupled TG-MS system was used to analysis principal volatile thermal decomposition (or fragmentation) products of Ni(2,4'-bpy)2(HCOO) 2?2H2O under dynamic air or argon atmosphere.
- Czakis-Sulikowska,Radwanska-Doczekalska,Czylkowska,Markiewicz,Broniarczyk
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p. 327 - 335
(2008/10/09)
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- Decomposition of organic salts of some d and f metals: Non-isothermal kinetics and FT-IR studies
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The thermal decomposition in non-isothermal conditions of formates, acetates, propionates and butyrates of Mn, Co, Zn, Cd, Eu, Sm and Ni was studied. The observed compensation effect allows us to calculate the isokinetic temperature. A selective activation mechanism was suggested. This leads to a good agreement between kinetic and spectroscopic data.
- Vlase,Vlase,Chiriac,Doca
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p. 839 - 845
(2008/10/08)
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- Measurement of equilibrium water vapor pressures for the thermal dehydrations of some formate dihydrates by means of the transpiration method
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The equilibrium water vapor pressures, PH2O for the thermal dehydrations of some formate dihydrates, M(HCO2)2·2H2O, where M is Mg, Mn, Co, Ni and Zn, were measured by means of the transpiration method using a laboratory-made apparatus. These hydrates have a monoclinic isomorphous crystal structure with a space group, P21/C. The thermodynamic data such as ΔG, ΔH and ΔS for the dehydration were derived from the PH2O and correlated to the crystal structures of these hydrates. Although the values of ΔH were expected to increase in the order of the hydrates of Mn2+-OH2 bond, they increased in the order of Mn2)2·2H2O and Zn(HCO2)2·2H2O seemed to be due to the relatively strong hydrogen bond between the water molecules and the formate ions. The values of ΔG obtained at 373 K, ΔG(373) showed a good correlation with the beginning temperatures of the dehydrations, Ti.
- Masuda, Yoshio,Hatakeyama, Makiko
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p. 165 - 170
(2008/10/09)
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