Growth, nanofibers

Kai, K. and Karthaus, O. (2007) Growth of unidirectionally oriented pentacene nanofibers by a roller method . e-J. Surf. Sci. Nanotechnol, 5, 103-105. 

Atomic-scale Monitoring of Carbon Nanofiber Growth in Steam Reforming Catalysts... 

Fig. 7. Growth mechanism of graphitic carbon nanofibers. The illustration highlights the observation of spontaneous nickel step edge formation at the carbon-nickel interface. The observations in Reference (52) are consistent with a growth mechanism involving surface transport of carbon and nickel atoms along the graphene-nickel interface.

Examples of HRTEM movies of the carbon nanofiber growth from Reference (52) can be found at http //www.haldortopsoe.com/site.nsf/pages/nanotechnology. 

In some cases the initially precipitaed [Pt(NH3)4](HC03)2 nanofibers are slightly bended. The nanotubes, however, are exclusively straight. The preferred growth of SiC>2 as smooth layer material is a well known phenomenona [19]. This aspect will be discussed in more detail in a forthcoming paper [20]. 

As reported elsewhere [22], similar to those found on other catalysts, the forms of carbon materials deposited on Fe-loading zeolite molecular sieves are carbon nanotube, carbon nanofiber and amorphous carbon. One obvious phenomenon of the carbon nanotubes formed on Fe/NaY or Fe/SiHMS catalysts is that almost all tips of these tubes are open, indicating the interaction between catalyst particles and supports is strong [23]. On the other hand, the optimal formation time of carbon nanotubes on Fe/SiHMS is longer than that on Fe/NaY. However, the size of carbon nanotubes is easily adjusted and the growth direction of carbon nanotubes on the former is more oriented than on the latter. 

Synthetic nanofiber matrices can provide physically and chemically stable 3D surfaces for ex vivo growth of cells. Meiners and coworkers showed that fibroblasts or rat kidney cells that have been grown on electrospun polyamide nanofiber meshes displayed all the characteristics of their counterparts in vivo [205], In addition, breast epithelial cells underwent morphogenesis to form multicellular spheroids containing lumens. 

Critical size / density Needle growth by agglomeration Figure 8.3 Sketch of the growth model for nanofibers via sublimation in high vacuum. 

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