Electrogenerated chemiluminescence of soliton waves in conjugated polymers.
We report the discovery of soliton-like electrogenerated chemiluminescence (ECL) waves in the electrochemical oxidation of thin films (15-250 nm) of the semiconducting conjugated polymer poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT). The ECL "wave fronts" were visualized and imaged in space and time by optical emission microscopy and observed to freely propagate parallel to the plane of the electrode. The data reveal that the EC solitons are triggered by the flux of electrolytes into the polymer film at nanoscale "leaks" (or defects) and propagate by a highly nonlinear, positive-feedback kinetic mechanism involving EC oxidation, mass transport of electrolyte anions, and oxidation-induced swelling, all taking place within the conjugated polymer film. Several model systems with spatially distributed reaction "triggers" were studied to elucidate the mechanistic details of this complex oxidation process in polymer films.
Chang
Ya-Lan
YL
Department of Chemistry and Biochemistry, Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, Texas 78712, USA.
Palacios
Rodrigo E
RE
Chen
Jiun-Tai
JT
Stevenson
Keith J
KJ
Guo
Song
S
Lackowski
William M
WM
Barbara
Paul F
PF