Selective measurement of organic vapors using SAW sensors with reactive or sorptive coatings: steric, electronic, and solubility factors

Models for predicting vapor/coating sorption based on the physical and chemical properties of the coatings and vapors have been investigated in an effort to establish selection criteria for sorptive SAW sensor array coatings for organic vapors. Sensor response data for two coatings exposed to over 30 organic vapors have been used to examine four predictive models. These preliminary results show that semiquantitative prediction of SAW sensor responses is possible. In an alternative approach, SAW sensor coatings containing reactive trapping agents have been used to selectively detect various olefin vapors. Advantage is taken of the ability of certain olefins to replace ethylene in reagents of the general formula PtCl/sub 2/(ethylene)(substituted-pyridine). Subtle differences in the steric properties of the olefin vapors, and the steric and electronic properties of the pyridine ligand in the trapping reagent lead to significant changes in sensor response.<>