Characterization of polymeric surface acoustic wave sensor coatings and semiempirical models of sensor responses to organic vapors.
Anal Chem 1993 Aug; 65(15):2055-2066
The ability of models developed for describing partitioning of organic vapors into polymeric materials in gas liquid chromatography (GLC) to model the responses of polymer coated surface acoustic wave (SAW) vapor sensors was evaluated. SAW vapor sensors operating at 158 megahertz were coated with OV-275, OV-25, poly(phenyl)ether, or poly(isobutylene) (PIB). Arrays of these sensors were exposed to a series of 39 organic solvent vapors. During a typical experimental run, the sensors were exposed to each test vapor over a three to ten fold concentration range twice for 40 seconds at each concentration. The responses of the sensors (frequency shifts and the coating/vapor partition coefficient (logK)) were tested against three models derived from GLC: the boiling point (BP), solubility parameter (SP), and the linear solvation free energy relationship (LSER) model. The logK values could be fit to all three models. In the case of the BP and SP models, the best correlations were obtained for the PIB coating, which was nonpolar, and the poorest for the OV-275 coating, which was the most polar. The best overall correlation for all four sensors was obtained with the LSER model. All sensor responses came within a factor of 2 of those predicted by this model and 83% of the responses came within 25% of those predicted. The authors conclude that models developed for describing partitioning of organic vapors into polymeric materials can be successfully adapted for modeling the responses of polymer coated SAW vapor sensors.
NIOSH-Publication; NIOSH-Grant; Grants-other; Organic-vapors; Surface-properties; Adsorbents; Chemical-analysis; Mathematical-models
Environmental & Indust Health U of Michigan Sch of Public Hl 109 South Observatory Ann Arbor, MI 48109-2029
Other Occupational Concerns; Grants-other
University of Michigan at Ann Arbor, Ann Arbor, Michigan