Conductimetric pH sensor based on novel conducting polymer composite thick films

Conducting polymer based composite thick film devices were produced and showed good pH-sensitivity. The devices functioned in the pH range pH2-pH8 when the measurements were taken while in contact with the test solution and in the range pH2-pH10 when the measurements were taken after contact with the solution. It was found that the polyaniline particles were the dominant pH-sensitive material in the films, with added polypyrrole contributing to a decrease in sensitivity and a decrease in film conductance, however, the added polypyrrole adds to greater stability at higher voltages. The devices showed a response time of less than 200 seconds and demonstrated good repeatability.