Nanofiber oxide

Figure 2.9 High-resolution XPS spectra of carbon nanofiber oxidized in stagnant air at 773 K for 2 hours and fitting curves (a) Cls peak (b) Ols peak. (From ref. 244, with permission from Elsevier.)...

Z. Zhang, J. Deng, and M. Wan, Highly crystalUne and thin polyaniline nanofibers oxidized by ferric chloride. Mater. Chem. Phys., 115, 275-279 (2009). 

The mechanical properties of these carbon nanofibers neither exceed nor even approximated the properties of microfibers. Although the strength of the classical microsized PAN precursors is one order of magnitude larger than that of PAN nanofibers, oxidation and carbonization can reduce this difference significantly. 

Surface Oxidation of Carbon Nanofibers Prior to Functionalization... 

Effect of oxidative treatments on catalytic property of carbon nanofiber composite... 

Dehydrogenation of ethylbenzene with carbon nanofiber supported iron oxide... 

Fig. 1(b) represents the selectivity to styrene as a ftmcfion of time fijr the above catal ts. It is observed that the selectivity to styrene is more than 95% over carbon nauofiber supported iron oxide catalyst compared with about 90% for the oxidized carbon nanofiber. It can be observed that there is an increase in selectivity to styrene and a decrease in selectivity to benzene with time on stream until 40 min. In particrdar, when the carbon nanofiber which has been treated in 4M HCl solution for three days is directly us as support to deposit the iron-precursor, the resulting catalyst shows a significantly lows selectivity to styrene, about 70%, in contrast to more than 95% on the similar catalyst using oxidized carbon nanofiber. The doping of the alkali or alkali metal on Fe/CNF did not improve the steady-state selectivity to styrene, but shortened the time to reach the steady-state selectivity. 

Oxidative dehydrogenation of propane over carbon nanofibers... 

Sonoelectrochemistry has also been used for the efficient employment of porous electrodes, such as carbon nanofiber-ceramic composites electrodes in the reduction of colloidal hydrous iron oxide [59], In this kind of systems, the electrode reactions proceed with slow rate or require several collisions between reactant and electrode surface. Mass transport to and into the porous electrode is enhanced and extremely fast at only modest ultrasound intensity. This same approach was checked in the hydrogen peroxide sonoelectrosynthesis using RVC three-dimensional electrodes [58]. 

Hu, B., Chen, C., Frueh, S.J., Jin, L., Joesten, R. and Suib, S.L. (2010) Removal of aqueous phenol by adsorption and oxidation with doped hydrophobic cryptomelane-type manganese oxide (K-OMS-2) nanofibers. Journal of Physical Chemistry C, 114, 9835-9844. 

Normal transmission IRLD can also be used to characterize polymeric fibers, although scattering can induce sloping baselines. Raman spectroscopy then becomes a convenient alternative. Rutledge et al. have recently probed the orientation in electrospun nanofibers composed of a core of Bombyx mori fibroin and an outer shell of poly (ethylene oxide) [24], The orientation values were low, less than 0.1, as is often the case in electrospun fibers. 

Bezemer, G. L., Radstake, P. B., Falke, U., Oosterbeek, H., Kuipers, H. P. C. E., van Dillen, A., and de Jong, K. P. 2006. Investigation of promoter effects of manganese oxide on carbon nanofiber-supported cobalt catalysts for Fischer-Tropsch synthesis. Journal of Catalysis 237 152-61. 

In addition to the more extensively investigated nanofibers (-rod, -wires, etc.) and nanotubes, other titanium oxide ID nanostructures have attracted the interest of researchers and are of potential interest for catalytic and photocatalytic applications. 

Application of transmission electron microscopy (TEM) techniques on heterogeneous catalysis covers a wide range of solid catalysts, including supported metal particles, transition metal oxides, zeolites and carbon nanotubes and nanofibers etc. 

The polymer resulting from oxidation of 3,5-dimethyl aniline with palladium was also studied by transmission electron microscopy (Mallick et al. 2005). As it turned out, the polymer was formed in nanofibers. During oxidative polymerization, palladium ions were reduced and formed palladium metal. The generated metal was uniformly dispersed between the polymer nanofibers as nanoparticles of 2 mm size. So, Mallick et al. (2005) achieved a polymer- metal intimate composite material. This work should be juxtaposed to an observation by Newman and Blanchard (2006) that reaction between 4-aminophenol and hydrogen tetrachloroaurate leads to polyaniline (bearing hydroxyl groups) and metallic gold as nanoparticles. Such metal nanoparticles can well be of importance in the field of sensors, catalysis, and electronics with improved performance. 

The advantage of template synthesis is that organo or hydrogelator templates can direct the shape-controlled synthesis of oxide nanotubes. Recent reports describe the use of carbon nanofibers as a template for the shape-controlled synthesis of zirconia, alumina and silica nanotubes [78]. The shape of vapor grown carbon nanofiber... 

Yuan ZY, Zhou W, Su BL (2002) Hierarchical interlinked structure of titanium oxide nanofibers. Chem Commun 1202-1203... 

The aim of this review paper is to give an extensive overview of the different promoters used to develop new or improved Co-based F-T catalysts. Special attention is directed towards a more fundamental understanding of the effect of the different promoter elements on the catalytically active Co particles. Due to the extensive open and patent literature, we have mainly included research publications of the last two decades in our review paper.In addition, we will limit ourselves to catalyst formulations composed of oxide supports, excluding the use of other interesting and promising support materials, such as, e.g., carbon nanofibers studied by the group of de Jong. ... 

A variety of nanomaterials have been synthesized by many researchers using anodic aluminum oxide film as either a template or a host material e.g., magnetic recording media (13,14), optical devices (15-18), metal nanohole arrays (19), and nanotubes or nanofibers of polymer, metal and metal oxide (20-24). No one, however, had tried to use anodic aluminum oxide film to produce carbon nanotubes before Kyotani et al. (9,12), Parthasarathy et al. (10) and Che et al. (25) prepared carbon tubes by either the pyrolytic carbon deposition on the film or the carbonization of organic polymer in the pore of the film. The following section describes the details of the template method for carbon nanotube production. 

Polymer nanofiber networks consisting of achiral polyaniline were prepared by Epstein et al. (3) by oxidizing aniline with ammonium peroxydisulfate and then doping with methanesulfonic acid. 

For the observation of the fibers intrinsic properties, nanofibers obtained from MONHP4 and MOCLP4 have been transferred from mica to glass (silicon oxide) using a standard procedure [17, 18] in order to avoid second-harmonic generation from the underlying substrate and a wetting layer. 

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