Nanofiber structure

Pt (5 wt%) supported on platelet and ribbon graphite nanofibers exhibited similar activities to those observed by Pt (25 wt°/o) on carbon black [138], This phenomenon was attributed to the crystallographic orientations adopted by the catalyst particles dispersed on graphitic nanofiber structures [139]. Also, the electrocatalysts supported on CNFs were less susceptible to CO poisoning than Pt supported on carbon black. 

If cellulosics such as BC are composed of nanosized fibers and the nanofiber structuring determines the product properties, these polymers are described as nanocelluloses. 

The second chapter by Dieter Klemm, Dieter Schumann, Hans-Peter Schmauder, and coworkers focuses on the recent knowledge of cellulosics characterized by a property-determining supramolecular nanofiber structure. Topics in this interdisciplinary contribution are the types of nanocelluloses and their use in technical membranes and composites as well as in the development of medical devices, in veterinary medicine, and in cosmetics. 

Fig. 2 Scaffold architecture affects cell binding and spreading. The examples were obtained by (a) phase separation/leaching combination and (b-d) electrospinning. Porosity data was roughly estimated note that classic nanofiber structure is <100 nm, but here is <1000 nm, as found commonly in biomedicine. Scale bars (a) 500 pm, (b-d) 10 pm. Top row. adapted from [12] bottom row. reprinted, with permission, from [47] copyright (2004) Elsevier [48] copyright (2010) Wiley-VCH...

Nanofiber structures, which appear to grow spontaneously from carbon vapor under the appropriate experimental conditions, have also been identified (Figure 9(b)).They consist of concentric cylinders which are closed at the ends by capping groups similar in structure to one half of the onion structures described previously. Under specific experimental conditions (02/molten Pb) some endcaps appear to open, and the lead atoms flow inside the tubes. ... 

Highly Aligned Polymer Nanofiber Structures Fabrication and Applications in Tissue Engineering... 

Despite a general agreement for some trends related to mandrel effects on fiber microstructure, it is difficult to precisely predict how a rotating mandrel will affect nanofiber structure for a specific system due to the amount of variables involved. 

Fig. 3 shows the TEM micrographs of the carbon nanofibers as a function of the synthesis temperature at 600 and 700 °C. At low synthesis temperature the carbon nanofiber structure was more disordered, with a non-regular diameter (Fig. 3a). The structure became more ordered when the synthesis temperature was increased to 700 °C (Fig. 3b). High-resolution TEM micrographs (not shown) also revealed the presence of a nickel particle at some fiber tips which indicated that during the synthesis both tip and base growth mechanisms occurred.

Fig. 3. TEM images of the carbon nanofibers structure as a function of the synthesis temperatures (a) 600 °C, (A) 700 °C.

Ma X. F., Zhu T., Xu H. Z., et ah. Rapid response behavior, at room temperature, of a nanofiber-structured TiOj sensor to selected simulant chemical-warfare agents, Anal. Bioanal. Chem., 390(4), 1133-1137, 2008. 

M. Numata, T. Hasegawa, T. Eujisawa, K. Sakurai, S. Shinkai, /3-1,3-Glucan (schizophyllan) can act as a one-dimensional host for creation of novel poly(aniline) nanofiber structures, Org. Lett, 2004, 6, 4447 450. 

The electrical conductivity of these nanofiber structures can be varied by controlling the ratio of PPy/PEO. As illustrated in Figure 4.11, the conductivity through the thickness of the electrospun PPy/PEO nanofibers increased by two orders of magnitude from the lowest to the highest concentration of PPy and ranged from about 4.9 x 10 to 1.2 x 10 S cm [38]. 

It is well-known that a catalytic amount of benzylamine or HCl allows the sol-gel polycondensation to proceed. In the present system, however, we could not find any fibrous structure from such reaction conditions. The result indicates that the very slow condensation reaction is favorable for onedimensional growth of sihca nanofibers. In fact, it took more than two weeks to create the complete nanofiber structure. Thus, to elucidate the reaction... 

The average diameter of electrospun fibers of individual fibers with and without potyp3nrole are shown in SEM images (Fig. 8.5). Mole percent of the initially added Py concentration varies from 0.035-0.070%. The average diameters of the nanofibers are reduced from 200 to 120 nm. In this stucty, elimination of surface roughness on nanofibers structure was due to the well interaction of PPy with matrix and well dispersion of latex particles in the DBSA medium resulting in an improvement in the solubility of PPy. 

Thus, the titanium nitride powder in the halide-sodium azide system is synthesized in the form of nanostructured particles. They can have a nanofiber structure with fibers 50-100 nm in diameter and a nanocrystalline structure with an average crystallite size of 100-200 nm. 

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