Controlled electrochemical synthesis of conductive nanopolypyrrole and its application in the design of a solid-state ion sensor

A polypyrrole (PPy) conductive polymer was electrochemically synthesized from pyrrole-cupric chloride (CuCl2)-H2O (system A) and pyrrole-CuCl2-sodium dodecyl sulfate-H2O (system B). Their morphologies and growth behavior were studied, and their aggregates were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron spectroscopy, thermogravimetry, and Fourier transform infrared studies. The powder X-ray diffraction pattern showed only one peak characteristic of PPy. In system B, the dimensions of the fractal patterns were calculated and found to be very close to the theoretical value of diffusion-limited aggregation. Various morphological transitions were observed at different field intensities and CuCl2 concentrations. Transmission electron spectroscopy studies revealed the formation of nanosized spherical particles 5-10 nm in size. For system B, a potassium-ion-selective electrode was constructed on the basis of a dibenzo-18-crown-6 impregnated poly(vinyl chloride) matrix membrane over a synthesized polymer-modified electrode. The electrode showed Nernstian behavior with a slope of 57 mV; this revealed the potential application of the as-synthesized material in the design of a solid-state ion-selective electrode. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42729.