The effect of needle diameter on the resulting electrospun poly(methyl methacrylate) (PMMA) average nanofiber diameter has been evaluated for three different needle gauges. The resulting nanofibers were observed and analyzed by scanning electron microscopy (SEM), suggesting a lack of correlation between the needle diameter used and the resulting average nanofiber diameter. Thermogravimetric analysis (TGA) indicated an increase in the thermal stability of PMMA nanofibers when compared to powdered PMMA, while differential scanning calorimetry (DSC) studies evidenced lower glass transition temperatures (Tg) for PMMA nanofibers in the first heating cycle. Copyright © 2007 John Wiley & Sons, Ltd.

Cu-Pt bimetal and Pt-skin structured Cu-Pt catalysts supported on nanocrystalline CeO2 are synthesized via the low-cost sol-gel approach followed by impregnation processing. Crystal structure, particle size, bulk and surface compositions of the catalyst are systematically characterized. The average particle size of the catalytic composites is 63 nm. The ceria supporter has a fluorite structure, while Cu and Pt contents, not detected by XRD, may exist in amorphous phases. The Pt-skin structured nanocomposite is analyzed based on the surface elemental and bulk compositional analyses. No Cu is detected on the surface based on XPS analyses, however, EDX bulk compositional analyses confirm the co-existence of Cu and Pt. These two kinds of catalytic composites may have potentials to serve as sulfur-resistant anode in solid oxide fuel cells.

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