Anodically grown TiO2 nanotubes have a double‐walled structure. The two shells can either be separated or fused together using different thermal annealing treatments. The morphology is determined by the heating rate. Highly regular and robust TiO2 membranes can be obtained with a crystal structure that can be adjusted to an anatase or an anatase/rutile mixture.

Exploiting the self‐assembling properties of liquid crystals, large‐scale spontaneous alignment of single‐ and multi‐walled carbon nanotubes induced by elastic interactions with the nematic LC matrix is demonstrated (see Figure). Collective reorientation processes of the liquid crystal are further used to reversibly manipulate the alignment direction of the dispersed nanotubes, as evidenced by conductivity measurements.

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Using a sputtering-deposited titanium substrate, incorporating six equally spaced nanolayers of Ti-W alloy, the volume and composition changes accompanying the formation of porous anodic films on titanium in 0.5 wt % NH 4 F in glycerol are investigated. The findings reveal amorphous films with nanotubes of TiO 2 , containing fluoride ions and possibly glycerol derivatives. Tungsten and titanium species are lost to the electrolyte at differing rates during anodizing, leading to an enrichment of tungsten in the film relative to the composition of the substrate. The spacing of tungsten-containing bands in the film is ϳ2.3 that of the original alloy layers during growth of the major pores. The generation of the nanotubes can be explained either by field-assisted flow of film material within the barrier layer to the pore walls, with cation and anion transport numbers of anodic titania in the barrier layer region similar to those of barrier films and with field-assisted ejection of Ti 4+ ions to the electrolyte, or by fieldassisted dissolution, but with a reduction in cation transport number.

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