Metallic nanowires, alignment

Porous Membranes of Nanoparticies from Templating Against AAO Membranes Using LB Technique. AAO-porous substrate has broad applications in making metal and semiconductor nanowires, aligned mesostructured nanorods, inorganic nanotubes. 

A method to form metal-SAM-metal nanowires with a diameter < 40 nm was developed by Mallouk and coworkers [51, 76]. The nanowires were produced by electrodeposition of Au or Pd into the nanopores of a polycarbonate membrane. A SAM was formed at the end of the wire and a second metal contact (Au, Ag or Pd) was deposited on top of this. The polycarbonate was subsequently dissolved in dichloromethane, which released a large quantity (1011 cm-2) of nanowires that could be aligned individually between pairs of lithographically fabricated metal electrodes. A schematic illustration of the nanowire molecular junctions is shown in Fig. 10.14. 

Metallic nanowires with vertical alignment have been prepared on silicone substrates using a nanoporous alumina template. The fact that the substrate is flexible should be an advantage in a number of applications. 

Smith, P.A., Nordquist, C.D., Jackson, T.N., et al. Electric-field assisted assembly and alignment of metallic nanowires. Appl Phys. Lett. 77(9), 1399-1401 (2000)... 

Figure 23.9 Trace analysis of a metal (M) analyte in the presence of surfactants (S) using the vertically active and horizontally passive aligned nanowires. Such adaptive operation leads to opening and closing of the surface to allow measurement and protection of the transducer between measurements. Also shown are the optical images (top view) of the glassy-carbon disk electrode covered with the vertically (left) and horizontally (right) aligned nanowires.47 (Reprinted with permission from R. Laocharoensuk et al.,...

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