Hexagonal nanowire

Figure 7.2 Scanning electron microscope images of ZnO nanowire arrays grown on sapphire substrates (a-e). A top view of the well-faceted hexagonal nanowire tips is shown in (e).

Nanowires of hexagonal cobalt can be grown by the selective adsorption of ligands on all crystal faces except the faces that become the sides of the wires. 

Fig. 10 Schematic representation of the nanoreplication processes from block copolymers, a Growth of high-density nanowires from a nanoporous block copolymer thin film. An asymmetric PS-fc-PMMA diblock copolymer was aligned to form vertical PMMA cylinders under an electric field. After removal of the PMMA minor component, a nanoporous film is formed. By electrodeposition, an array of nanowires can be replicated in the porous template (adapted from [43]). b Hexagonally packed array of aluminum caps generated from rod-coil microporous structures. Deposition of aluminum was achieved on the photooxidized area of the rod-coil honeycomb structure (Taken from [35])...

Et-HMM (HMM-1) and Ph-HMM (or HMM-p), respectively, have a highly ordered 2D-hexagonal structure that exhibits more hydrophobic properties than the sihca FSM-16. They may work as attractive templates for metal nanowires and nanopar-tides by the hydrophobic surface-mediated reaction. 

A number of other porous materials may be used as the host matrices for nanowire fabrication. A mesoporous molecular sieve termed MCM-41 (Beck et al., 1992) possesses hexagonally packed pores with very small... 

Bicrystalline nanowires of hematite (a-Fe,03) have been synthesized by the oxidation of pure Fe.207 Single-crystalline hexagonal u-Fe20, nanorods and nanobeits can be prepared by a simple iron-water reaction at 673 K.20 Mesoporous quasi-single crystalline... 

Han, Y.-X, Kim, X M.,andStucky, G. D., Preparation of noble metal nanowires using hexagonal mesoporous silica SBA-15. Chem. Mater. 12, 2068 (2000). 

Figure 2. Different shapes of PLD grown ZnO micro- and nanocrystals, (a) Hexagonal microcrystals with diameters of about 2 pm. (b) ZnO nanowires with diameters around 100 nm. (c) Needle like nanostructures, (d) Microcrystals exhibiting a dodecagonal cross section.

Besides, it has been shown that palladium is promising for direct alcohol fuel cells applications as it is very active for ethanol electro-oxidation in basic media and that its electroactivity is even higher than that of platinum. Recently, Pd nanoballs and nanowires synthesized by radiolysis in hexagonal mesophases have shown an important elec-trocatalytic activity for ethanol electro-oxidation. ... 

Mesoporous alumina membranes ( anodic aluminium oxide , or AAO) are prepared by anodic oxidation of aluminium metal [1,2]. The cylindrical pores, perpendicular to the membrane surface, form hexagonal arrays of straight non-intersecting channels with pore densities up to lO Vcm. Their diameters are controllable within the range 5 - 100 nm as a linear function of anodisation voltage. These membranes are used as molecular sieves, and have also found application as templates for metallic nanowires [3,4,5,6], metal elusters and colloids [7,8], and carbon nanotubes [9,10]. 

By y-ray irradiation at room temperature, ZnS nanowires were grown, in which the crystal growth was in situ templated by an inverted hexagonal liquid crystal formed from oligo(ethylene oxide)oleyl ether amphiphiles, n-hexane, n-hexanol/ isopropanol (2/1) and water [151]. Nanocrystalline jS-ZnS (sphalerite) was prepared in aqueous isopropanol solution [152]. The TEM images (Figure 7.36) indicate that the product from mercaptoethanol is most well dispersed, and that from thiourea... 

---