Polyaniline-dodecylhydrogensulfate-acid salt: synthesis and characterization

Polyaniline salts such as polyaniline-dodecylhydrogensulfate-sulfuric acid (PANI-DHS-H2SO4), polyaniline-dodecylhydrogensulfate-nitric acid (PANI-DHS-HNO3) and polyaniline-dodecylhydrogensulfate-hydrochloric acid salt (PANI-DHS-HCl) in chloroform were synthesized by chemical oxidative polymerization of aniline using pyridinium chloro chromate (PCC) as an oxidizing agent in aqueous-organic medium in presence of mineral acid and sodiumdodecylsulfate (SDS) surfactant. This process is being reported for the first time. PANI-DHS-H2SO4 was also synthesized in different organic solvents such as benzene, xylene and toluene. This polymerization pathway leads to incorporation of both acid and surfactant groups into the polyaniline chain as dopants. Incorporation of SDS surfactant in to the polyaniline chain solubilizes the polyaniline salt in organic solvents. In this polymerization SDS plays a dual role as efficient surfactant and as dopant. Polyaniline in the powder form was recovered by adding acetone to the organic solvent containing polyaniline salt. The polyaniline samples were characterized by Fourier transform-infrared, electronic absorption, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and conductivity measurements. The yield of PANI-DHS-H2SO4, PANI-DHS-HNO3 and PANI-DHS-HCl in chloroform solvent was 1.25 g, 1.15 g and 1.20 g, respectively. However, the conductivity of PANI-DHS-H2SO4 was found to be high (0.1 S cm−1) when compared to PANI-DHS-HNO3 (0.07 S cm−1) and PANI-DHS-HCl (0.04 S cm−1). The conductivity (0.1-0.2 S cm−1) and yield (1.20-1.25 g) of PANI-DHS-H2SO4 salts prepared using different solvents were almost the same.