Oxide nanofibers

A wide range of oxide nanofibers have been reported in the literature prepared using either a procedure based on sol-gel chemistry or via calcination of a polymer nanofiber carrying a salt of the metal of interest, such as the acetates 

Oxide Precursor Alcohol Acid/Catalyst Polymer Reference 

PbTiOa Lead acetate/Ti(OCH4)4 Ethanol Acetic acid PVP Lu et al. (2006) 

V2O5 Vanadium oxide isopropoxide Ethanol — PVAc Viswanathamurthi et al. (2003a) 

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

Vondran JL, Sun W, Schauer CL (2008) Crosslinked, electrospun chitosan-poly(ethylene oxide) nanofiber mats. J Appl Polym Sci 109(2) 968-975... 

FIGURE 8.7 Transmission emission microscope (TEM) image of a single polyethylene oxide nanofiber embedded with nano MgO at regular intervals. (Hussain, M.M. and Ramkumar, S.S., 2006, Functionalized nanofibers for advanced applications, Indian J. Fiber Text. Res.. 31, 41-51.)... 

N. J. Pinto, A. T. Johnson, Jr., A. G. MacDiarmid, C. H. MueUer, N. Theofylaktos, D. C. Robinson, and F. A. Miranda, Electrospun polyaniline/polyethylene oxide nanofiber field-effect transistor, Appl. Phys. Lett., 83, 4244—4246 (2003). 

Poly-3-hexylthiophene is also a polymer of great interest, widely used in organic electronics, especially in photovoltaic devices. Fabrication of poly-3-hexylthiophene/ polyethylene oxide nanofibers (P3HT-PEO) with diameters down to 500 nm using... 

A. Laforgue and L. Robitaille, Fabrication of poly-3-hexylthiophene/polyethylene oxide nanofibers using electrospinning, Synth. Metals, 158, 577-584 (2008). 

As compared to mesoporous oxide nanofibers, much lesser attention has been paid to their mesoporous amorphous carbon analogues. However, mesoporous carbon exhibits superior resistance to acids and bases, excellent heat resistance, as well as high intrinsic electric conductivity. Potential applications for hybrid membranes consisting of mesoporous carbon within hard templates include size-selective electrosorption, electrosynthesis of nanostructures, catalysis, separation and storage. The first reported procedure for the synthesis of mesoporous carbon nanofibers involved the preparation of... 

Pinto, N.J., et al. 2003. Electrospun polyaniline/polyethylene oxide nanofiber field-effect transistor. 

In another study, the so-called sohd-liquid-solid (SLS) technique was used to prepare a silicon oxide nanofiber surface [64]. The amorphous sihcon oxide nanofibers shown in Fig. 10b were made by heating a silicon substrate coated with a thin gold layer at 1100°C for 3 h in a lutrogen atmosphere in contrast to the previous example, no additional source of silicon materials was used in this case. As before, the nanofiber growth starts at the interface of the Au/Si alloy droplet and the Si substrate and is maintained by the diffusion of the Si atoms from the substrate to the interface [65]. The surface was then UV/ozone-treated to generate surface hydroxyl groups that were subsequently reacted with perfluorodecyltrichlorosilane. The chemically modified nanofiber surface exhibited a WCA of 152°. 

Faridi-Majidi R, Sharifi-Sanjani N (2007) In situ synthesis of iron oxide nanoparticles on poly (ethylene oxide) nanofibers through an electrospinning process. J Appl Polym Sci... 

Table 2.3 Characteristics of several metal oxide nanofiber-based conductometric gas sensors...

Fouda MMG, El-Aassar MR, Al-Deyab SS. Antimicrobitd activity of ctuboxymethyl chito-san/polyethylene oxide nanofibers embedded silver nanoparticles. Carbohydr Polym. 

Nuansing et al. [36] investigated the formation of hybrid nanofibers by electro-spinning polymer/ceramic in the form of a network. Through electrospinning of an ethanol solution containing both polyvinylpyrrolidone (PVP) and titanium (diiso-proproxide) bis (2,4-pentanedionate) nanofibers were formed. After heat treatment of these fibers in air at 300-700 °C, the authors obtained titanium oxide nanofibers with diameters between 85 and 132 mn. 

The approach is illustrated hy nanocomposite fibers of nanoparticle-Fe/ carbon. Nanofihers of PAN were electrospun from DMF (6.7 wt%) solutions containing 3.3 wt% of dissolved ferric acetylacetanoate. Subsequent carbonization of the nanofihers in an inert (Ar and H2) atmosphere (Hou and Reneker 2004) at high temperatures yielded carbonized nanofihers with nanoparticles of elemental iron. These were in the size range of 10-20 nm for the most part and were embedded on the surface of the fibers. Essentially, the same approach was also used with polycarbonate (PC)-palladium acetate solutions, but on calcination of the electrospun polymer nanofihers yielded inorganic palladium oxide nanofibers (Viswanathamurthi et al. 2004a) rather than Pd-nanoparticle/PC. The oxygen in keto groups of the PC was speculated to have reacted with the metal acetate to yield the oxide. Palladium nanoparticles are of particular interest in industry because of their potential use in catalysis (Briot and Primet 1991). 

TABLE 8.3 A selection of metal oxide nanofibers reported in the recent electrospinning literature ... 

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