Fabrication of cm scale buckypapers of horizontally aligned multiwalled carbon nanotubes highly filled with Fe3C: the key roles of Cl and Ar-flow rates

A key challenge in the fabrication of ferromagnetically filled carbon-nanotube buckypapers in the presence of Cl-radicals is the achievement of a preferential horizontal nanotube-alignment.</p

Synthesis and structure of free-standing germanium quantum dots and their application in live cell imaging

Free-standing Ge quantum dots around 3 nm in size were synthesized using a bench-top colloidal method and suspended in water and ethanol. In the ethanol solution, the photoluminescence of the Ge quantum dots was observed between 650 and 800 nm. Structural and optical properties of these colloidal Ge quantum dots were investigated by utilizing X-ray diffraction, X-ray absorption spectroscopy, Raman spectroscopy, and photoluminescence spectroscopy and transmission electron microscopy. The structure of the as-prepared Ge quantum dots that were found is best described by a core-shell model with a small crystalline core and an amorphous outer shell with a surface that was terminated by hydrogen-related species. As-prepared Ge quantum dots were suspended in cell growth medium, and then loaded into cervical carcinoma (HeLa) cells. The fluorescent microscopy images were then collected using 405 nm, 488 nm, 561 nm and 647 nm wavelengths. We observed that, based on fluorescence measurements, as-prepared Ge quantum dots can remain stable for up to 4 weeks in water. Investigation of toxicity, based on a viability test, of as-prepared uncoated Ge quantum dots in HeLa cells was carried out and compared with the commercial carboxyl coated CdSe/ZnSe quantum dots. The viability tests show that Ge quantum dots are less toxic when compared to commercial carboxyl coated CdSe/ZnS quantum dots. This journal i

Room temperature synthesis of ReS2 through aqueous perrhenate sulfidation.

In this study, a direct sulfidation reaction of ammonium perrhenate (NH4ReO4) leading to a synthesis of rhenium disulfide (ReS2) is demonstrated. These findings reveal the first example of a simplistic bottom-up approach to the chemical synthesis of crystalline ReS2. The reaction presented here takes place at room temperature, in an ambient and solvent-free environment and without the necessity of a catalyst. The atomic composition and structure of the as-synthesized product were characterized using several analysis techniques including energy dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy, x-ray diffraction, transmission electron microscopy, Raman spectroscopy, thermogravimetric analysis and differential scanning calorimetry. The results indicated the formation of a lower symmetry (1T') ReS2 with a low degree of layer stacking

Bimetallic Fe/Mo–SiO2 aerogel catalysts for catalytic carbon vapour deposition production of carbon nanotubes

Abstract Highly porous nanocomposite aerogels based on bimetallic Fe and Mo nanoparticles with a variable Fe:Mo weight ratio ranging from 5:1; 3:1; and 0.7:1 dispersed on amorphous silica were obtained. N2 physisorption, X-ray diffraction, and transmission electron microscopy indicate that the Fe/Mo–SiO2 nanocomposite aerogels as obtained by a co-gelation sol–gel route followed by supercritical drying and reduction treatment under H2 exhibit Fe and Mo nanocrystals with size in the range 4–10 and 15 nm, respectively, supported on highly porous silica. The catalytic performance of the Fe/Mo–SiO2 aerogels for the synthesis of multi wall carbon nanotubes (MWCNT) by catalytic chemical vapour deposition (CCVD) was evaluated in terms of amount and quality of the produced CNTs as assessed by gravimetric results, thermal analysis, and TEM. The effect of catalyst composition and CCVD temperature was investigated, pointing out that high reaction temperatures (800 ?C) favor the formation of MWCNTs with high quality in elevated yield, the highest C uptake value being[400 %. Catalyst composition and CCVD temperature were also found to affect the homogeneity of CNT morphology, the best MWCNT quality (with outer diameter 23–25 nm) being achieved at 800 ?C with the catalyst having the largest Mo content

Tumor Necrosis Factor Gene Polymorphisms in Turkish Patients with Sarcoidosis

Background As reported recently, some gene polymorphisms are suspected to determine susceptibility to sarcoidosis and are held responsible for the extent and progression of the disease. Polymorphism at -857 locus of tumor necrosis factor (TNF)-alpha gene is considered to be a predisposition factor in sarcoidosis and held responsible for pathogenesis of the disease. We compared these polymorphisms in healthy Turkish control subjects and Turkish patients with sarcoidosis