Electrochemomechanical and photoluminescent properties of aryl amine polymers

L LIZARRAGA; P. S ANTONEL; WALTER ARMADA; E M ANDRADE; F. V. MOLINA

Polonia

Workshop; WEEM 2009; 2009

ISE

Aryl amine conducting polymers, mainly the poly(aniline) family, arouse a sustained interest in the scientific community both for its interesting behavior from an academic point of view as their attractive properties in applied fields. Here we present research conducted in recent years on these compounds. One major area is the mechanical behavior of these polymers arising from redox changes, or electrochemomechanical properties. The aryl amine polymers suffer expansions and contractions when switching between leucoemeraldine and emeraldine forms. The analysis of these processes to establish the influence of the external medium and the polymer composition has shown that the structural changes due to amine-imine rearrangement of the N atoms are the main contribution to those properties. Recent studies with copolymers confirm these findings, and allows us to advance the theoretical model. Finally, another point of interest was the  poly(aniline) photoluminescence. While the fluorescent emission has very low intensity, it is interesting from the standpoint of fundamental knowledge. The analysis of fluorescence as a function of the oxidation state of polymeric aryl amine films can be rationalized in terms of the structure composed of quasicrystalline domains, which quench emission, separated by amorphous regions where emission persists. The study of the film thickness dependence of the emission intensity on metal electrodes, on the other hand, shows a complex behavior due to the interference of the electric field of the emitting dipole with that reflected by the metal surface.