Highly conducting 1-D polypyrrole prepared in the presence of safranin

Abstract

A facile preparation of a conducting one-dimensional polypyrrole nanostructure (1-D PPy) was achieved in the presence of safranin dye. The polymerization temperature has a significant effect on the conductivity, specific surface area and morphology of PPy. A decrease in the polymerization temperature leads to a significant increase in the conductivity. The highest conductivity was obtained by frozen polymerization (−24 °C) with a value of 175 ± 4 and 23.7 ± 2.9 S cm⁻¹ for 1-D PPy and globular PPy, respectively. The temperature dependence of the conductivity of 1-D PPy prepared at −24 °C revealed a semiconducting behaviour with a 3-D variable range hopping charge transfer mechanism. Raman spectroscopy results suggested that the high conductivity can be attributed to the high protonation level of 1-D PPy. Nuclear magnetic resonance spectroscopy has been used to study the chemical structure of 1-D PPy and the incorporation of safranin into the polymer matrix.