ISSN:
0025-116X
Schlagwort(e):
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
It was found that oxidized polypyrrole (PPy) film, electrochemically polymerized from aqueous H2SO4 solutions, shows correct stoichiometry in the mole ratio C : H : N, although still containing a large amount of oxygen. The apparent density of the film obtained was close to its flotation density of 1,514 g/cm3. Morphology studies by SEM showed an aggregation of ca. 1 μm properties into hollow bowls of 30 μm diameter in the case of PPy-BF4, PPy-PF6 and PPy-CIO4 films, electrochemically prepared from CH3CN (1% H2O) solutions, while a PPy-HSO4 film from aqueous solution gave a much smoother film surface and no hollow bowls. Interesting morphology was observed for the growth of electrochemically oxidized PPy in CH3CN solution on a wire net anode of 27 × 27 μm2 holes. The nucleation of the oxidized PPy growth was found to be always initiated at the mid-points of the four sides of the square holes so that regular arrays of hollow bowls resulted. In aqueous H2SO4 solution the oxidized PPy grew on the surface of the net wires. Besides particles of ca. 0,3 μm diameter numerous solid blocks of 5 μm size with sharp edges were observed. The metallic temperature dependence of the conductivity of various oxidized PPy films was demonstrated by voltage shorted compaction (VSC) measurements, while a partially electrochemically reduced PPy-BF4 film showed a broad maximum in VSC conductivity around 100 K.
Zusätzliches Material:
9 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/macp.1985.021860520
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