Polypyrrole microcontainers

Figure 11.6 SEM images of polypyrrole microcontainers synthesized electrochemical ly using a soap bubble -assisted soft-template method. (Reprinted with permission from Chemical Communications, Electrochemical synthesis of novel polypyrrole microstructures by L. T. Qu and G. Q. Shi, 2003, 2, 206-207. Copyright (2003) Royal Society of Chemistry)...

Figure 11.7 SEM images of polypyrrole microcontainers formed by soft-template polymerization under different electropolymerization conditions. (Reprinted with permission from Advanced Eunctional Materials, Conducting-polymer microcontainers Controlled syntheses and potential applications by V. Bajpai, P. G. He and L M. Dai, 14, 2, 145-151. Copyright (2004) Wiley-VCH)...

Figure 11.14 Schematic representation of the functioning of a polypyrrole microcontainer electrochemical system. (Reprinted with permission from Journal of the American Chemical Society, Microcontainers with Electrochemically Reversible Permeability by Dmitry G. Shchukin etai, 128, 14. Copyright (2006) American Chemical Society)...

Furthermore, porous CPs (e.g., polypyrrole, polyanUine) films have been used as host matrices for polyelectrolyte capsules developed from composite material, which can combine electric conductivity of the polymer with controlled permeability of polyelectrolyte shell to form controllable micro- and nanocontainers. A recent example was reported by D.G. Schchukin and his co-workers [21]. They introduced a novel application of polyelectrolyte microcapsules as microcontainers with a electrochemically reversible flux of redox-active materials into and out of the capsule volume. Incorporation of the capsules inside a polypyrrole (PPy) film resulted in a new composite electrode. This electrode combined the electrocatalytic and conducting properties of the PPy with the storage and release properties of the capsules, and if loaded with electrochemical fuels, this film possessed electrochemically controlled switching between open and closed states of the capsule shell. This approach could also be of practical interest for chemically rechargeable batteries or fuel cells operating on an absolutely new concept. However, in this case, PPy was just utilized as support for the polyelectrolyte microcapsules. 

Innovative microstructures have been produced by self-assembly during electropolymerization in the presence of surfactants. Dai and coworkers have recently shown that bowl-shaped microcontainers of polypyrrole can be produced by stabilizing H2 gas bubbles on the electrode surface [79]. Carboxylic acid dopants have also been used, resulting in hollow nanotubes of polyaniline [80]. 

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