Use of linear salvation energy relationships for modeling responses from polymer-coated acoustic-wave vapor sensors

The applicability and performance of linear solvation energy relationships (LSERs) as models of responses from polymer-coated acoustic-wave vapor sens ors are critically examined. Criteria for the use of these thermodynamic mo dels with thickness-shear-mode resonator (TSMR) and surface-acoustic-wave ( SAW) vapor sensors are clarified. Published partition coefficient values de rived from gas-liquid chromatography (GLC) are found to be consistently low er than those obtained gravimetrically, in accordance with previous reports , suggesting that LSERs based on GLC-derived partition coefficients will no t provide accurate estimates of acoustic-wave sensor responses. The develop ment of LSER models directly from polymer-coated TSMR vapor sensor response data is demonstrated and a revised model developed from SAW vapor sensor r esponse data, which takes account of viscoelastic changes in polymeric coat ing films, is presented and compared to those developed by other methods.