Templating porous alumina membrane

Figure 1.8 SEM image of porous alumina membrane, used in templating. (Reproduced by permission of The Royal Society of Chemistry from [36].)...

Imai H, Takei Y, Shimizu K, Matsuda M, Hirashima H (1999) Direct preparation of anatase Ti02 nanotubes in porous alumina membranes. J Mater Chem 9 2971-2972 Michailowski A, A1 Mawlawi D, Cheng GS, Moskovits M (2001) Highly regular anatase nanotubule arrays fabricated in porous anodic templates. Chem Phys Lett 349 1-5 Jung JH, Kobayashi H, van Bommel KJC, Shinkai S, Shimizu T (2002) Creation of novel helical ribbon and double-layered nanotube Ti02 structures using an... 

It should be mentioned that alternative possibilities to prepare similar membranes include the use of a porous alumina membrane as matrix, with the titania nanotubes grown in the channels. Nanoporous alumina membranes are commercial products, also synthesized by anodic oxidation. The commercial Whatman Corporation anodic membrane has holes of about 20-nm diameter at the top of the membrane and about 200-nm diameter at the bottom of membrane. Within these pores Ti02 nanotubes fabricated by template synthesis and water vapour hydrolysis could be grown, but non-uniform membrane characteristics are obtained due to the non-uniform pores of the commercial alumina... 

In this context, a novel and interesting method for the preparation of such systems has recently been reported. The pyrolysis of a nickel naphthalocyanine (Nc), a homolog of Pc with a larger tt system, previously organized in the nanoscale channels of a porous alumina membrane that acts as a template, leads to the formation of... 

Fig. 19.2.1. shows the procedure for the fabrication of nano-porous diamond films (diamond nanohoneycomb) by template synthesis with porous alumina membranes. Ordered thorough-hole anodic porous alumina membranes were laid on the top of the synthetic diamond films, and then deep holes were etched into the film by use of an oxygen plasma treatment. 

The silicalite-alumina membrane was prepared after adding a solution containing the silicalite precursor (i e silica + template) to the above-mentioned porous tube (hereafter called support) and a specific hydrothermal treatment performed [8], under the chosen conditions no material is formed in the absence of the porous support. The tube is then calcined at 673 K for removing the template. 

Space available in porous glass [487], ultrafine Nafion [488, 489], and metallic membranes [490, 491] has also been utilized for the development of smal particles. Cylindrical micropores in alumina membranes have been used, for example, as templates for the electrodeposition of parallel arrays of gold particles (0.26 pm in diameter, 0.3 pm to 3 pm in length) which were infrared transparent [491] and could be used as chemical sensors [490],... 

OMCs have been synthesized using various templates, including porous zeolites, and anodic alumina membranes, porous silica materials and sdica nanoparticles [51, 52], as weU as different carbon precursor phenoUc resins, furfuryl alcohol, mesophase pitch, sucrose, etc. In Table 7.2 are summarized the characteristic of OMC reported in the literature. 

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