Effects of Dopant Ions on the Properties of Polyaniline Conducting Polymer

Abstract

This work will show, for the first time, the effect of nicotinic acid (NA) and 2-methylnicotinic acid (MNA)on the synthesis and properties of conducting polyaniline (PANI). The work investigates the effects of sulphuric acid (H2SO4), nicotinic acid (NA), and 2-methylnicotinic acid (MNA) on the synthesis and properties of polyaniline. The results show that the preparation of polyaniline from a sulphuric acid electrolyte is faster than the preparation from nicotinic acid and 2- methylnicotinic acid electrolytes. Moreover, the electrical conductivity and thermal stability of PANI/H2SO4 were greater than PANI/NA and PANI/MNA. All the polymers prepared in this study were identified using FT-IR. Scanning electron microscopy (SEM) was used to examine the morphologies of the PANI samples, from which it was determined that PANI/H2SO4 has a fibrous and open structure with a higher porosity morphology compared to PANI/NA and PANI/MNA. The electrical conductivities of the PANI samples were measured as 1.09 S cm-1, 0.65 S cm-1 and 0.089 S cm-1 for PANI/H2SO4, PANI/NA and PANI/MNA, respectively. The thermal stability of PANI was examined using the Thermogravimetric Analysis (TGA) technique. PANI/H2SO4 was found to degrade between 450-500°C, while PANI/NA and PANI/MNA decomposed at temperatures between 300-400°C.