Preparation of Propiolic Acid Doped Polyaniline and Investigation of Opto-Electronic Properties

Abstract

Among the conducting polymers, polyaniline is of vital importance as an electronicmaterial [1{4] because of its easy synthesis, environmental stability, reversible proton dopabil-ity, redox recyclability, cost-e ectiveness, and reasonable electrical conductivity. Electrical andoptoelectronic applications of conducting polymers often require high current densities thatcan be achieved by either heavy doping or a high-level carrier injection. Polyaniline occurs infour oxidation states (i.e., leucoemeraldine, emeraldine base, emeraldine salt, and pernigrani-line), out of which only emeraldine salt is conductive in nature (the others are insulating innature). Polyaniline (PANI) exists in a variety of forms that di er in chemical and physicalproperties [5{9].Polyaniline is one of the most promising conducting materials for applications in optoelec-tronics and microelectronics devices.The doping of polyaniline can be accomplished through protonic acid and oxidative doping.Protonic acid doping of emeraldine base units results in complete protonation of imine nitrogenatoms to give the fully protonated emeraldine salt [10, 11].The AC (alternative current) conductivity properties of Polyaniline (PANI) and doped PANIparallel plate materials were investigated by impedance spectroscopy. The real part of conduc-tivity (0), and the real part of impedance (Z0p) were measured in the logarithmic frequencyrange of 100 to 1.5x107 Hz at 25, 40, 50 and 100 C temperatures. The AC conductivity value ofthe undoped PANI is high values for polymeric materals to ionic conduction and electrode po-larization in low frequency. The alternative current (AC) conductivity increases with increasingMB concentration and the frequency.