when Polyaniline is synthesized, first, extremely small nanoparticles are created (10 nm small). Anyway, PAni has a very high surface tension (in the range of several 100 dyn/cm = Nm), 10 nm small particles even higher.
Therefore, in order to reduce interfacial tension, they deposit on anything they can find, not only on glas, also on plastic stirrers etc.
regarding surface tension, page 538 ff, but the whole subchapter from 525 ff will help you to understand PAni better than before, together with this article: