Aluminum oxide template

Routkevitch D, Bigioni T, Moskovits M, Xu JM (1996) Electrochemical fabrication of CdS nanowire arrays in porous anodic aluminum oxide templates. J Phys Chem 100 14037-14047... 

Xu D, Chen D, Xu Y, Shi X, Guo G, Gui L, Tang Y (2000) Preparation of II-VI group semiconductor nanowire arrays by dc electrochemical deposition in porous aluminum oxide templates. Pure Appl Chem 72 127-135... 

Porous aluminum oxide can be used as a template for the production of nanowires and nanotubes. For example, metals can be deposited on the pore walls by the following procedures deposition from the gas phase, precipitation from solution by electrochemical reduction or with chemical reducing agents, or by pyrolysis of substances that have previously been introduced into the pores. Wires are obtained when the pore diameters are 25 nm, and tubes from larger pores the walls of the tubes can be as thin as 3 nm. For example, nanowires and nanotubes of nickel, cobalt, copper or silver can be made by electrochemical deposition. Finally, the aluminum oxide template can be removed by dissolution with a base. 

Che et al. recently demonstrated that not only propylene but also ethylene and pyrene can be used for the production of carbon tubes (25). They subjected anodic aluminum oxide template (channel diameter 200 nm) to either ethylene or pyrene gas stream at 900°C for 10 min and then the resultant carbon tubes were removed... 

Davydov, D. N., Sattari, P. A., AlMawlawi, D., Osika, A., and Haslett, T. L., Field emitters based on porous aluminum oxide templates. J. Appl. Phys 86, 3983 (1999). 

G. Zangari and D. N. Lambeth, Porous Aluminum Oxide Templates for Nanometer-Size Cobalt Arrays", IEEE Trans. Magn. 33, 3010 (1997). 

Figure 7.8. Comparison of the resolution for (a) low-resolution SEMJ 5] with (b) high-resolution FESEMJI Both images are of a nanoporous anodized aluminum oxide template at identical magnification.

Recently, Sun et al. [60] proposed to fabricate Ag nanostructures by electrochemical deposition of Ag in anodic aluminum oxide templates with each pore diameter of 100 nm. The morphology of Ag substrates was characterized by EESEM. The length of the Ag nanowires is estimated to be about 2 pm from the EESEM images. In addition, the SERS enhancement factor calculated for Ag nano wires SERS substrates is approximately 10 in magnitude. The Ag nano wire arrays are expected to have important applications in the development of high sensitivity SERS-based substrates. 

Pan S, Rothberg LJ (2003) Interferometric sensing of biomolecular binding using nanoporous aluminum oxide templates. Nano Lett 3 811-814... 

Gapin Al et al (2006) CoPt patterned media in anodized aluminum oxide templates. J Appl Phys 99 08G902... 

A two-dimensional cylindrical confinement of spherical micelles formed by a copolymer inside a porous anodic aluminum oxide template leads to the formation of mesoporous Si02 nanorods. About 0.1 g of a block copolymer, polyethylene-co-butylene-block-polyethylene oxide (PHB-PEO), is dissolved in about 1 mL of ethanol with mild heating. The copolymer forms spherical micelles under this condition. To this about 0.5 g of tetraethyl orthosilicate (TEOS) and 0.25 g of HCl is added and the solution is stirred for 2 h. The porous anodic aluminum oxide templates are loaded now with a drop of the above precursor solution. After filling the template, the excess precursor solution containing the polymer and silica is wiped out. The template is aged at 25°C for about 24 h followed by calcination at 550°C. Finally, the template is removed with 5% H3PO4 at... 

Figure P-8 TEM images of mesoporous silica nanorods synthesized by the 2D confinement of spherical micelles using different sizes of the porous aluminum oxide template (a) 25 nm, (b) 60 nm, and (c) 90 nm. (From A. Thomas et al. J. Mater. Chem. 2007, 17, 4558. Reproduced by permission of the Royal Society of Chemistry.)...

Z. Wang, M. Chen, and H.-L. Li, Preparation and characterization of uniform polyaniline nano-fibrils using the anodic aluminum oxide template. Mater. Sci. Eng. A., 328, 33-38 (2002). 

S. Xiong, Q. Wang, and H. Xia, Preparation of polyaniUne nanotubes array based on anodic aluminum oxide template. Mater. Res. Bull, 39, 1569 1580 (2004). 

Yada. M. Ohya, M. Ohe, K. Machida. M. Kijima, T. Porous yttrium aluminum oxide templated by alkyl sulfate assemblies. Langmuir 2000, 16. 1535. 

S. -H. Yoo, L. Liu, S. Park, Nanoparticle Films as a Conducting Layer for Anodic Aluminum Oxide Template-Assisted Nanorod Synthesis. Journal of Colloid and Interface Science 2009, 339, 183-186. 

Routkevitch, D., Bigioni, T., Moskovits, M, and Xu, J. M. Electrochemical Fabrication of CdS Nanrrowite Aays in Porous Anodic Aluminum Oxide Templates. The Journal of PItysical Chemistry, 100(33), 14037-14047(1996). 

A copolymer of pyrrole and thiophene nano-fibrUs was electrochemically polymerized within the pores of microporous, anodic, aluminum oxide template membranes [105]. The copolymer nucleated and grew on the pore wall of the membrane since the polymers were cationic and the membrane had anionic sites on the pore wall. The length, thickness, and diameter of the copolymer nanofibrils could be controlled and with higher applied potential, more thiophene units were incorporated into the copolymer nanofibrUs [105]. Copolymer nanofibrils of pyrrole and aniline were also electrochemically polymerized within the pores of microporous, anodic, aluminum oxide template membranes [106]. Copolymer nanofibrils of PPy and poly(3-methylthiophene) prepared chemically in the microporous aluminum oxide template showed higher conductivity than the homopolymers did [107]. 

Shimizu. T, Xie, T., Nishikawa, J., Shingubara, S., Senz, S., and Gosele, U. (2007) Synthesis of vertical high-density epitaxial Si(lOO) nanowire arrays on a Si (100) substrate using an anodic aluminum oxide template. Adv, Mater, 19, 917-920. 

Other Electrochemical Approaches CdS has also been prepared from aqueous solutions by other methods, with electrodeposition as an important step. CdS nanotubes have been formed by the self-assembly of CdS nanowires that were prepared by electrode-positing Cd into an AAO (anodic aluminum oxide) template followed by sulfurization [25]. A hybrid electrochemical/chemical (E/C) method was employed to synthesize epitaxially oriented CdS on graphite surfaces [26], which involves the electrodeposition of Cd, the conversion of Cd to Cd(OH)2, and the formation of CdS via the displacement of OH by S . Another E/C method in which H2S was used as the sulfur source and reacted with electrodeposited Cd at 300 °C was reported in the preparation of CdS/S core-shell nanoparticles [27]. 

Shen CM, Zhang XG, Li HL (2001) DC electrochemical deposition of CdSe nanorods array using porous anodic aluminum oxide template. Mater Sci Eng A303 19... 

Recently, electrodeposition has been proved to provide a versatile method for producing metal nanoparticles and nanowires in the pores of polycarbonate, mica, and aluminum oxide templates [33-36]. In this case, the template imparts size control. Behm et al. obtained... 

Robinson, A.P, Burnell, G., Hu, M. MacManus-Diiscoll, J.L. (2007). Controlled, perfect ordering in ultrathin anodic aluminum oxide templates on silicon. Applied Physics Letters Vol.91, pp.l43123(3). 

FESEM. Both images are of a nanoporous anodized aluminum oxide template at identical magnification. 

It should be noted that anodic aluminum oxide templates are also frequently used to produce nanomaterials by sol-gel, by PVD or CVD techniques. Most straightforward is, however, electrodeposition for pore filling. 

GiaUongo, G. Durante, C. Pilot, R. GaroU, D. Bozio, R. Romanato, F. Gennaro, A. Rizzi, G. A. Granozzi, G. Growth and optical properties of silver nanostructures obtained on connected anodic aluminum oxide templates. Nanotechnology 2012, 23, 325604. 

Al-Kaysi RO, Ghaddar TH, Guirado G (2009) Fabrication of one-dimensional organic nanostructures using anodic aluminum oxide templates. J Nanomater 2009 1-4... 

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