writer：J. Sun, G. Wu,* J. Geng,*
keywords：Fractal-like structures, Polythiophene, Solvent vapor annealing
source：期刊
specific source：Polym. J. 2013, 45, 813-818
Issue time：2013年

Polymer films with holes or fractal-like structures whose size is on the micron scale are of great interest. In this study, fractallike structures of insoluble polythiophene were prepared via CS2 vapor annealing of solid thermocleavable polythiophene films in the presence of high humidity and subsequent thermal curing. Atomic force microscope and transmission electron microscopy observations demonstrate that holes form during the initial stage of solvent vapor annealing (SVA), further developing into fractal-like structures with the coalescence of the individual holes. Meanwhile, the crystallinity of the films can also be improved. A mechanism that involves solvent-covered water droplets has been proposed to explain the formation of the holes and the fractal-like structures. This is the first report of the formation of holes and fractal-like structures from solid films of conjugated polymers via SVA. The fractal-like structures can be preserved during the conversion from thermocleavable polythiophene to insoluble polythiophene by thermal curing.