Nanofiber Arrays

Fig. 14.6). A key is that in many cases solution processing can lead to new structures that are difficult or impossible to attain by other means. This can include, for example, nanofiber arrays, core-shell structures, nanopods, and nanoribbons.30 32 These structures can lead to a variety of new functionalities—from 3D prototyping, to third-generation PV structures, to electronic paper, to a new class of non linear optics, to the ability to order nanostructures at very small length scales and maybe even to the holy grail of the energy field, artificial photosynthesis. Below we briefly discuss how some of these concepts are beginning to be realized.

Liu, J. Kuo, Y.-T. Klabunde, K.). Rochford, C. Wu, J. Li,)., Novel dye-sensitized solar cell architecture using Tio2-coated vertically aligned carbon nanofiber arrays. Acs. Appl. Mater. Interfaces 2009,1,1645-1649. 

Under normal electrospinning conditions, the deposition area of an electrospinning jet can be undesirably large and difficult to predict. This can lead to difficulties in precise and repeatable fabrication of uniform nanofiber arrays, and materials may be wasted. It is desirable to explore methods to control the deposition of an electrospinning jet in terms of both focused fiber deposition area and controlled placement of the fiber deposition area. The range of fiber deposition is usually decreased as the needle-to-collector distance is decreased however, this alone may... 

Sun QH et al (2009) Fabrication of aligned polyaniline nanofiber array via a facile wet chemical process. Macromol Rapid Commun 30(12) 1027-1032... 

Li M, Wei ZX, Jiang L (2008) Polypyrrole nanofiber arrays synthesized by a biphasic electrochemical strategy. J Mater Chem 18(19) 2276-2280... 

Chen F et al (2010) Hydroxyapatite nanorods/poly(vinyl pyrolidone) composite nanofibers, arrays and three-dimensional fabrics electrospun preparation and transformation to hydroxyapatite nanostructures. Acta Biomater 6(8) 3013-3020... 

Another strategy for synthesizing conducting-polymer nanofiber arrays based on a two-phase system has also been reported by Li et al [165]. This system ensures a very low concentration of monomer, for instance pyrrole, in the polymerization process (Figure 16.17). 

Figure 16.17 Schematic illustration of two-phase electropolymerization (a) Pyrrole diffuses from the organic phase into the aqueous phase slowly (indirect diffusion). Then polypyrrole is deposited by the diffusion of pyrrole to the electrode (direct diffusion), (b) Aligned polypyrrole nanofibers are produced by successive CV electropolymerizations. (Reprinted with permission from Journal of Materials Chemistry, Polypyrrole nanofiber arrays synthetized by a biphasic electrochemical strategy by M. Li, Z. Wei and L. Jiang, 18, 2276-2280. Copyright (2008) Royal Society of Chemistry)...

Fig. 7 PS-1)-PMMA nanofibers prepared by capillary wetting into AAO hard templates, a Tips with menisci b section through a PS-fi-PMMA nanofiber array, evidencing the solid rod-like nature of the nanofibers. The SEM images are a courtesy Dr. Olaf Kriha...

Grimm, S., Giesa, R., Sklarek, K. et al. 2008. Nondestructive replication of self-ordered nano-porous alumina membranes via cross-finked polyacrylate nanofiber arrays,... 

Li J, Andrews RJ (2007) Trimodal nanoelectrode array for precise deep brain stimulation prospects of a new technology based on carbon nanofibers arrays. Acta Neurochir Suppl 97 537-545... 

Liu, H.-X, Wang, X.-M., Cui, W.-X, Dou, Y.-Q., Zhao, D.-Y. Xia, Y.-Y Highly ordered mesoporous carbon nanofiber arrays from a crab shell biological template and its application in supercapacitors and fuel-cells. J. Mater Chem. 20 (2010), pp. 4223 230. 

Kim, S., Sitti, M., Jang, J.-H., and Thomas, E.L. (2008) Fabrication of bio-inspired elastomer nanofiber arrays with spatulate tips using notching effect Presented at 2008 8th IEEE Conference on Nanotechnology, Arlington, Texas, USA. 

Fig. 12 (a, b) An 80 jjim carbon nanotobe island grown on a 100 xm conductive titanium nitride pad scale bar is 10 p.m [91]. These entwined nanotubes give a matted surface scale bar is 100 p.m. Reproduced with permission (c) Vertically aligned multiwalled carbon nanofiber array after elec-trodepositing a 40-nm-thick conformal polypyrrole film scale bar is 500 nm [92]. Reproduced with permission, (d) PEDOT nanotubes formed using PLLA templates [93]... 

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