Figure 11. Transmission electron micrograph of aggregated polypyrrole tiron colloid particles (x150 K). Reprinted with permission from [4], G. G. Wallace and P. C. Innis, J. Nanosci. Nanotech. 2, 441 (2002). © 2002, American Scientific Publishers.

the preparation of these sub-5 nm particles were quaternary ammonium based cations such as octyltrimethylam-monium bromide, decyltrimethylammonium bromide, and dodecyltrimethylammonium bromide. At room temperature these surfactants produced nanoparticles larger than 10 nm while at 70 °C ca. 50 nm particles were observed.

Nanoscale patterning of polypyrrole dot structures of 80 to 180 nm diameter in self-organized arrays has also been achieved via a block copolymer surface-micelle tem-plated approach [95]. Using this approach, micelle templates were prepared using the Langmuir-Blodgett (LB) technique to deposit an AB diblock copolymer onto a mica substrate followed by the selective chemical deposition of polypyrrole onto these templating structures. Selective deposition is achieved by exploiting the preference of polypyrrole to deposit onto hydrophobic surfaces rather than hydrophilic substrates. An advantage of this approach is that lithographic patterning techniques can be avoided due to the self-assembly of the micelle via the LB technique. Inverse structures of these PPy dots have also been prepared

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