Polymeric films in optical gas sensors

Polymeric films of silicone rubber and PVC containing organoruthenium compl exes and films of Nafion(R) containing crystal violet have been investigate d in the development of optical gas and moisture sensors. The gases include d in these studies are chlorine, nitrogen dioxide, and oxygen. The film thi ckness determines the speed of response to gases and their reversal. The no ise in the measured signal in silicone rubber films, to some extent, is det ermined by their surface topography. While the Ruthenium trisbipyridyl comp lex (Ru-bipy)/silicone rubber films showed high sensitivity to chlorine, th e Ru-dpp/PVC films showed poor response to chlorine but good responses to b oth nitrogen dioxide and oxygen. Nafion films containing crystal violet sho wed rapid and reversible response to humidity. This polymer film showed red uced memory effects. All the films studied are simple to construct and exhi bited long shelf lifetimes. (C) 1998 Elsevier Science S.A. All rights reser ved.