Fabrication of homogeneous titania/MWNT composite materials

MWNT/titania nanocomposites were prepared by an impregnation method and subsequent heat treatment at 400 degrees C. Precursor compounds such as titanium (IV) propoxide and titanium (IV) ethoxide were used to cover the surface of CNTs under solution conditions. Electron microscopy and X-ray diffraction techniques were carried out to characterize the as-prepared titania layers. (C) 2011 Elsevier Ltd. All rights reserved

Preparation and characterization of multiwalled carbon nanotube/In2O3 composites

We have prepared multiwalled carbon nanotube (MWCNT)/In2O3 composites using a simple impregnation method. The precursor compound indium(III) chloride (InCl3) was used to cover the surface of MWCNTs and distilled water was used as solvent. The applied mass ratio was 4:1 (In2O3/MWCNT), and during the calcination process different temperatures (300, 350 and 400 degrees C) were investigated. The produced materials were characterized by X-ray diffraction, energy-dispersive X-ray spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, transmission and scanning electron microscopy, and a thermogravimetric analysis was executed also. The average thickness of the produced surface layer and the average sizes of the In2O3 particles were calculated with the Scherrer formula and the ImageJ-program. The results show that the heat treatment temperature affected the characteristic morphology and the crystal structure of the as-prepared composite. These multiwalled carbon nanotube-based composites are promising candidates as gas sensors and catalyst. (c) 2013 Elsevier Ltd. All rights reserved

Chemical challenges during the synthesis of MWCNT-based inorganic nanocomposite materials

Multiwalled carbon nanotubes (MWCNTs) were successfully covered with metal oxides - such as TiO2, ZnO, Al2O3, SnO2, and In2O3 nanoparticles - with different preparation methods under solvent conditions. The applied synthesis techniques were impregnation, a hydrothermal process and a ball-milling method. As-prepared inorganic coverage layers were characterized by TEM, HRTEM, SEM, SEM-EDX, and X-ray diffraction techniques. Results revealed that the choice of synthesis technique affects the quality and the layer structure of the deposited inorganic particles on the surface of carbon nanotubes. These materials might be suitable for nanotechnology applications. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

Preparation of homogeneous titania coatings on the surface of MWNTs

status: publishe

Influence of TiO2 phase composition on the photocatalytic activity of TiO2/MWCNT composites prepared by combined sol-gel/hydrothermal method

Titanium dioxide/multiwall carbon nanotube (TiO2/MWCNT) composites were prepared by sol-gel method with hydrolysis of titanium alkoxide precursor followed by crystallization via hydrothermal treatment at different acid concentrations. Transmission electron microscopy (TEM) measurements revealed that the acid concentration has serious control over the morphology which is in good agreement with the change of specific surface area. According to the X-ray diffraction analysis of the samples the anatase/rutile ratio of the TiO2 in the composite can be tuned by the manipulation of acid concentration used for the hydrothermal crystallization. Samples were tested in aqueous-phase photocatalytic degradation reaction of salicylic acid in a batch-type foam reactor using relatively low power UV-A irradiation. The change in salicylic acid concentration was monitored by UV-vis spectroscopy technique. Anatase/rutile ratio decreased with increasing acid concentration and photocatalytic performance was decreased with increasing rutile content, however low rutile content (11 wt%) enhanced the photocatalytic efficiency above all prepared samples. (C) 2016 Elsevier B.V. All rights reserved

Preparation of homogeneous titania coatings on the surface of MWNTs

The aim of this work was to develop a controllable route to produce a stable and inorganic layer on the surface of multi-wall carbon nanotubes. Precursor compounds such as TiBr4, TiCl4, Ti(OiPr)(4), and Ti(OEt)(4) were used to cover the surface of carbon nanotubes (CNTs) under either solvent free or solution conditions. Various titania precursors were compared in the formation of homogeneous layers on the surface of CNTs. As-prepared titania coverages were characterized by transmission electron microscopy (TEM), high resolution TEM, scanning electron microscopy, electron energy loss spectroscopy, and Xray diffraction techniques. Results revealed that homogeneous coverage can be achieved in a controllable way. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

The effect of titania precursor on the morphology of prepared TiO2/MWCNT nanocomposite materials

Since materials science is of great importance, the application of composite materials based on carbon nanotubes (CNTs) is widely investigated. Current work is aimed at preparing nanocomposites of TiO2/MWCNT using an impregnation method combined with slow hydrolysis. Different titanium alkoxide compounds as Ti(OEt)(4), Ti(OiPr)(4), and Ti(OBu)(4), respectively, were used as precursor materials to cover the surface of CNTs in ethanolic medium. In our samples themass ratiowas 10:1 (TiO2:MWCNT). The produced composite materials were characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), Raman microscopy, transmission (TEM) and scanning electron microscopy (SEM) techniques; moreover, thermal analysis and the determination of the specific surface area (BET) were also carried out. These as-prepared TiO2/MWCNT composites were also tested as photocatalysts in degradation reaction of the model compound salicylic acid. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

Differential effects of polymorphic alleles of FGF receptor 4 on colon cancer growth and metastasis

A gly(388)arg polymorphism (rs351855) in the transmembrane domain of the fibroblast growth factor receptor (FGFR4) is associated with increased risk, staging, and metastasis in several different types of cancer. To specifically assess the impact of the polymorphic FGFR4 in colorectal cancer (CRC), we engineered CRC cell lines with distinct endogenous expression patterns to overexpress either the FGFR4(gly) or FGFR4(arg) alleles. The biologic analyses revealed an oncogenic importance for both polymorphic alleles, but FGFR4(gly) was the stronger inducer of tumor growth, whereas FGFR4(arg) was the stronger inducer of migration. An evaluation of clinical specimens revealed that FGFR4 was upregulated in 20/71 patients independent of gly(388)arg status. There was no correlation between the presence of an FGFR4(arg) allele and CRC or polyp risk in 3,471 participants of the CORSA study. However, among 182 patients with CRC, FGFR4(arg)-carriers had a fivefold higher risk of tumors that were stage II or greater. Together, our results established that both allelic forms of FGFR4 exert an oncogenic impact and may serve equally well as therapeutic targets in CRC. One important implication of our findings is that FGFR4(arg)-carriers are at a higher risk for more aggressive tumors and therefore may profit from early detection measures