B. Wessling, R. Hiesgen, D. Meissner

STM investigation on primary particle morphology of polyaniline

Acta Polymer., 44, 132 - 134 (1993)

The primary particle morphology of PAni was confirmed to consist of about 10 nm particles using scanning tunneling microscopy. Earlier investigations*, ** had lead to this hypothesis. The object of the STM study was a transparent thin layer prepared from a pure PAni dispersion** on a PET film and gold substrates.

Cross section through a transparent PAni layer on PET (300 nm).
Globules of about 50-100 nm diameter are visible as constructive units (SEM)

The examination of the layer of the previous figure after strectching under
liquid N2 leads to the assumption of electo-static attractive forces
between the globules in the PAni layer / PET interface (SEM)

Area of about 40 nm x 40 nm of STM images exhibiting
spherical primary particles of 5-10 nm diameter

Higher magnification as in the previous figure; chain elements and chain
folding can be detected locally. The more protuding areas are probably
representing the benzenoid/quinoid rings of the PAni chain

Click on figures above for more details

* B. Wessling, Makromol. Chem. 185 (1984), 1265 - 1275

**B. Wessling, Synth. Met. 41 - 43 (1991), 907 - 910