Drop-Coated Polyaniline Composite Conductimetric pH Sensors

This work describes the fabrication and development of a polyaniline based conductimetric pH sensor. Two types of drop coated polyaniline films were investigated and it was found that the undoped emeraldine base polyaniline produces the best electrical response to pH. The results obtained show that the lowest conductance of these films occurs at the lowest pH value (pH2), with the conductance increasing with increasing pH. It is thought that this response is due to effects from the polymer binder, which is used to increase adhesion between the pH-sensitive film and the substrate.