[Limhes]

Hi, I am currently having a question I cannot answer myself and cannot find in books/on the web.

I am making polyaniline through electrochemical polymerization, but don't know the mechanism of the reaction. There's an aniline in sulfuric acid solution (PhNH₃⁺/HSO₄^-), an iron electrode (negative potential, cathode) and a stainless steel electrode (positive potential, anode). After applying approx. 1.5V over the electrodes, hydrogen gas evolves at the cathode. At the same time, a polyaniline film is deposited on the anode.
Now, polyaniline is something of this: -[-Ph-.NH⁺-]_n-. So, inbetween the aromatic rings, there is a radical, positive nitrogen atom with ONE hydrogen attached. Thus, in polymerization, 3 hydrogen radicals have to be removed (and 1.5 H₂ molecules evolve per molecule of aniline).

My question is now: since H₂ evolves at the cathode, and polymerization is at the anode, in what state are the aniline molecules when they travel from cathode to anode??? And how do they polymerize?

Thanks in advance! It would be great if someone could shed a light on this