Colloidal stability of polypyrrole-ITO conducting inks
Yukihiro Tsugita, Shuichi Maeda
Abstract
Abstract We have obtained conducting inks through the hybridization of indium tin oxide (ITO) and polypyrrole. Different conductive inks were obtained at different ITO loadings. The zeta potentials of the polypyrrole-ITO conductive inks were investigated as functions of the pH of the solution. The polypyrrole-ITO conductive inks exhibited zero zeta potential at approximately pH = 5, and the zeta potentials varied with the pH of the solution, which also significantly depended on the pH range. Thermogravimetric analysis was performed to investigate the thermal behavior of ITO and its conductive inks. Conductivities of the conductive inks were measured by the 4-point probe method and compared to those of the neat polymer. These polypyrrole-ITO conductive inks are surfactant-free; therefore, surfactant removal is not required. Even at low temperatures, the printed electronics exhibited excellent conductivity, enabling the lighting of LED devices.