Template anodizing aluminium oxide

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]. 

In a template synthesis, CP is polymerized within the pores or channels of a nanoporous template to obtain the controlled structure and morphology upon removal of the template. Templates can be either a masking of a confined area that CP can grow in or a structured surface that CP is deposited upon. Masking type templates, namely nanoporous anodic aluminium oxide (AAO also commonly known as AI2O3, alumina, or anodise ) [113-118], hydrogels [119,120] and latex particles [121-130], have been used to prepare nanoscale fibrils, particles, and tubules of CPs. 

Shi and co-workers prepared polythiophene films with different roughnesses by electrochemical polymerization of thiophene in boron trifluoride-diethyl etherate (BFEE) [42]. The highest WCA of 116° on polythiophene film was observed. To further increase the WCA, aligned polythiophene nano-tubes were synthesized using anodized aluminium oxide (AAO) as template. The WCA increased to 134° (Fig. 7). As a comparison, the WCA of polythiophene polymerized in acetonitrile solution was measured to be less than 75°. 

Most of the work that has been carried out using porous membranes as hard templates was done on porous alumina (anodic aluminium oxide, AAO) or track-etched polycarbonate membranes. The general principle of nanotube formation relies on a continuous polymer film being formed on the inside of the pores that remains as a tubular structure once the template is removed. There are several possibilities as to how this polymer film can be formed inside the pore. A film can be obtained by wetting the pore with a polymer melt or a polymer solution. Alternatively, the polymerization of monomers... 

Kordas K, T6th G, Levoska J, Huuhtanen M, Keiski R, Harkonen M, George T G, Vahakangas J (2006) Room temperature chemical deposition of palladium nanoparticles in anodic aluminium oxide templates. Nanotechnology, 17, 1459-1463. 

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