Ammonia sensitivity of polyaniline films via emulsion polymerization

The sensitivity of polyaniline (PANI) films to ammonia has been investigate d. The PANI, soluble in several organic solvents, was prepared by emulsion polymerization. These PANI films display high sensitivity, wide range of me asured concentrations and high stability. The concentration, response and t emperature characteristics of the samples were also studied. It is found th at the resistance of the sample increases with the increasing ammonia conce ntration, but decreases with the increasing temperature; the relative resis tance of the film varies from 1.28 to 23.6 for ammonia concentration rangin g from 10 to 1000 ppm; the sensitivity of the PANI films remains constant f or a period of SO days in ambient environment; and the response time of the film is less than 2 min. (C) 2000 Elsevier Science Ltd. All rights reserve d.