Author/Authors :
Gutacker، نويسنده , , Andrea and Koenen، نويسنده , , Nils and Scherf، نويسنده , , Ullrich and Adamczyk، نويسنده , , Sylwia and Pina، نويسنده , , Joمo and Fonseca، نويسنده , , Sofia M. and Valente، نويسنده , , Artur J.M. and Evans، نويسنده , , Rachel C. and Seixas de Melo، نويسنده , , J. and Burrows، نويسنده , , Hugh D. and Knaapila، نويسنده , , Matti، نويسنده ,
Abstract :
Optical spectroscopy and photophysical measurements on cationic fluorene-thiophene diblock copolymers in solution show distinct properties for the two blocks, with clear indications of singlet exciton migration from the polyfluorene to polythiophene blocks. Electrical conductivity measurements and small angle X-ray scattering studies show that different aggregates are formed in water and methanol. This may be associated both with different solubilities of the two blocks and with the effect of solvent on the degree of dissociation of the ionic part. Atomic force microscopy (AFM) shows that different nanostructures are deposited from the two solvents, with large, vesicular structures deposited on mica from methanolic solution. Aggregation behavior is also found to be modulated, and to lead to more rigid thiophene blocks, by addition of the oppositely charged surfactant sodium dodecylsulfate.
