ELECTROCHEMICAL SYNTHESES OF POLYPYRROLES IN NATURAL AMINO ACID AQUEOUS SOLUTIONS AND THEIR CHARACTERIZATION
天然氨基酸水溶液中聚吡咯的电化学合成及其表征

Amino-acid-doped polypyrroles obtained by electrochemical polymerization of pyrrole in various natural α-amino acid aqueous solutions under the nitrogen atmosphere have been studied in this paper.The experiments show that the oxidation potential is relatively low and the polymerization rate is relatively high in acidic amino acid solutions,but the electrochemical polymerization barely occurs in alkaline solutions.In the electrolytic polymerization process,the amino acids act both as supporting electrolytes,and as dopant ions doped into the polymer,which can be proved by Raman,FTIR,and UV-Vis spectra.The electronic conductivity of polypyrrole is measured in the range of 0.3 and 1.0 S/cm,and the conductivity of the products obtained in strong amino acid is obviously higher than that obtained in weak amino acid.The polymers exhibit good electrochemical activity and stability,the cyclic voltammograms of these polymers have a pair of oxidation-reduction peaks between -0.5 V and 0.5 V,and their shape and trait of the polymers can stay stable after 100 electrochemical cycles.Different amino acids have different effects on the shape of the polypyrrole,polypyrrole with nano-fiber structure forms in some of the amino acid solutions due to the soft template effect,which can be seen from the SEM and TEM images.