Molecular orbital computation of the electrical properties of doped polyaniline
Abstract
Molecular orbital properties, namely internal energy, HOMO–LUMO gap, bandwidth, and dipole moment, of doped and undoped polyaniline were computed using HyperChem® 7.0/7.5. These properties were correlated to the electrical conductivity of the polymer. Results show that the addition of dopants ions decreases the total energy, thus increases the stability of the polymers. The metallic dopants have lower energy gaps and have smaller HOMO–LUMO gaps compared to organic dopants, suggesting an increased conductivity. Consequently, the thicker bandwidths resulting from the metallic dopants indicate a higher number of energy states enhancing the conductivity of the polymer. The dipole moment of the organic compounds like H2SO4 and CSA are high since they are bulky in structure suggesting high conductivity.