Electrochemical synthesis and properties of poly(azure B)

A blue poly(azure B) film has been synthesized using repeated potential cyc ling between -0.25 and 1.10 V (versus SCE). The electrolytic solution consi sted of 2.5 mmol dm(-3) azure B, 0.5 mol dm(-3) NaCl and 0.2 mol dm(-3) NaH 2PO4 at the pH range of 2.0 to 11.0. The in situ visible spectrum during el ectrolysis of azure B shows that the intensity at 740 nm peak increases wit h increasing numbers of potential cycles, which is attributable to the form ation of poly(azure B). The wavelength of its corresponding absorption peak is 98 nm longer than that of azure B. The polymerization rate is strongly affected by pH values. The anodic peak potential and cathodic peak potentia l of the poly(azure B) in a solution of pH 3.0 are not affected by increasi ng the scan rate from 25 to 600 mV s(-1). Poly(azure B) has good electroche mical reversibility and fast charge transfer characteristic in the pH range of 2.0 and 11.0. The conductivity of poly(azure B) is 1.5 x 10(-4) S cm(-1 ) According to the differences between FTIR spectra of poly(azure B) and az ure B, an electrochemical polymerization mechanism of azure B is proposed i n this paper.