POLYMERIZATION OF ANILINE IN AQUEOUS SULFURIC-ACID STUDY BY ELECTROCHEMICAL THERMOSPRAY MASS-SPECTROMETRY

Electrochemical thermospray Mass Spectrometry (ETMS) has proved to be a suitable method for the investigation of electrode processes. The me chanisms for the anodic oxidation of N,N-dialkylanilines in neutral aq ueous solution and of phenothiazine in non-aqueous methanol/ammonium a cetate electrolyte solution were elucidated. These reactions showed fo rmation of higher oligomers. First experiments were done on the electr ochemical polymerization of aniline at a Pt-electrode in sulfuric acid . ETMS allows the detection of soluble products. Experiments with the rotating disc electrode indicate that the polymerization of aniline pr oceeds via soluble oligomers. Thermospray mass spectra are presented o f the aniline/sulfuric acid electrolyte and of the electrochemically g enerated oligomers. Mass spectrometric cyclic voltamograms of aniline and the oxidation of isotope labeled aniline give information about th e structure of dimers and trimers and a first insight in the mechanism of the aniline polymerization process.