Abstract
We report self-assembly and electronic conductivity transitions in
polyaniline (PANI) where the iminic nitrogens are protonated by sulfonic
acid-terminated low molecular weight poly(ethylene oxide) CH3−(O−C2H4−)46−CH2−SO3H (PEOSA), i.e., which contains 46 ethylene oxide repeat units. The complex PANI(PEOSA)0.5
self-assembles due to the comb-shaped architecture consisting of the
PANI backbone and the supramolecular PEO side chains, as characterized
using small- and wide-angle X-ray scattering (SAXS and WAXS) and
transmission electron microscopy (TEM). PEO in the complex PANI(PEOSA)0.5
is crystalline near room temperature; TEM and SAXS indicate lamellar
self-assembly with a long period of ca. 150 Å, and the conductivity is
of the order 10-4 S/cm. A collapse of the self-assembly
periodicity to 115 Å is observed at ca. 55 °C during a slow heating at 1
°C/min, and the conductivity drops stepwise to ca. half of the value as
the PEO chains melt. Even if the observed conductivity transition is
still relatively small, it is reproducible and reversible upon heating
and cooling, with some hysteresis. We expect that the concept can be
developed to open new possibilities for responsive conjugated polymers.
Original language | English |
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Pages (from-to) | 7793 - 7797 |
Number of pages | 5 |
Journal | Macromolecules |
Volume | 38 |
Issue number | 18 |
DOIs | |
Publication status | Published - 2005 |
MoE publication type | A1 Journal article-refereed |