I have used NMP to dissolve polyaniline for making the solution for electrospinning to draw nanofibers. But while dissolving in NMP, PANI changes its color dark green to dark blue. but according to literature survey, when PANI salt (ES) is converted to PANI base (EB) it changes color from green to blue, and PANI base shows very low conductivity as compared to PANI salt.
The PAni emeraldine form corresponds to a oxidation degree of 0.5. Pani can be easily doped by protonation. Its doped state is ES (green color - conductive) and the dedoped state is blue (EB-isolant). Well, you are changing the pH of the media dissolving Pani in NMP and, then, deprotonating Pani, lowering its conductivity.
Thanks Mr. Edson Fernades sir and Mr. Sunil Dutt sir, I just refered the paper which you have suggested me to read. This paper cleared may of my doubts about conductivity of PANI-NMP solution.
apart from the various comments about dedoping and colour (green --> blue = conductive --> less and in fact not conductive) which are correct, one aspect is not correct:
When putting PAni into NMP, and even if you get a nice transparent (strongly blue in colour, but transparent, if you do it well) liquid, you did not "dissolve" PAni but disperse. The smallest particle size you may get with neutral (blue) PAni in NMP is about 5 nm, never a true solution.
Please carefully read this article:
https://www.researchgate.net/publication/234015260_Can_Conductive_Polymers_be_truely_soluble_or_will_they_form_dispersions?ev=prf_pub
Data Can Conductive Polymers be truely soluble? or will they form...
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