Influence of pH on poly-(N-methylpyrrole) electrochemically synthesized inaqueous solution: an infrared study

Structural changes induced by pH variations or by oxidation state in electr ochemically synthesized poly-N-methylpyrrole have been studied by FTIR spec troscopy. With this aim, two different ways have been followed, in the firs t, polymer synthesis has been carried out in NaNO3 aqueous solutions at dif ferent pH values from acidic to neutral; in a second way a polymer film has been synthesized in a solution at pH = 4 and after, introduced in solution s of increasing pH and its infrared spectra analyzed. Evidence of protonati on of already synthesized polymer is obtained although no new functional gr oup is formed and only structural changes related with oxidation state are observed. (C) 2001 Elsevier Science B.V. All rights reserved.