Use of Linear Solvation 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 sensors are critically examined. Criteria for the use of these thermodynamic models with thickness-shear-mode resonator (TSMR) and surface-acoustic-wave (SAW) vapor sensors are clarified. Published partition coefficient values derived from gas-liquid chromatography (GLC) are found to be consistently lower than those obtained gravimetrically, in accordance with previous reports, suggesting that LSERs based on GLC-derived partition coefficients will not provide accurate estimates of acoustic-wave sensor responses. The development of LSER models directly from polymer-coated TSMR vapor sensor response data is demonstrated and a revised model developed from SAW vapor sensor response data, which takes account of viscoelastic changes in polymeric coating films, is presented and compared to those developed by other methods.