January 1, 1998
Journal Article

Comparisons of Polymer/Gas Partition Coefficients Calculated from Responses of Thickness Shear Mode and Surface Acoustic Wave Vapor Sensors

Abstract

Apparent partition coefficients, K, for the sorption of toluene by four different thin films on thickness shear mode (TSM) and surface acoustic wave (SAW) devices are compared. The polymers examined were poly(isobutylene) (PIB), poly(epichlorohydrin) (PECH), poly(butadiene) (PBD), and poly(dimethylsiloxane) (PDMS). Independent data on partition coefficients for toluene in these polymers were compiled for comparison, and TSM sensor measurements were made using both oscillator and impedance analysis methods. K values from SAW sensor measurements were about twice those calculated from TSM sensor measurements when the polymers were PIB and PECH, and they were also at least twice the values of the independent partition coefficient data, which is interpreted as indicating that the SAW sensor responds to polymer modulus changes as well as to mass changes. K values from SAW and TSM measurements were in agreement with each other and with independent data when the polymer was PBD. Similarly, K values from the PDMS-coated SAW sensor responses in the cases of PBD and PDMS. However, K values from the PDMS-coated TSM device or independent measurements, and the impedance anlayzer results indicated that this sensor using our sample of PDMS at the applied thickness did not behave among the test polymers on SAW devices are interpreted in terms of their differing viscoelastic properties.

Revised: May 14, 2019 | Published: January 1, 1998

Citation

Grate J.W., S.N. Kaganove, and V.R. Bhethanabotla. 1998. Comparisons of Polymer/Gas Partition Coefficients Calculated from Responses of Thickness Shear Mode and Surface Acoustic Wave Vapor Sensors. Analytical Chemistry 70, no. 1:199-203. PNNL-SA-28947. doi:10.1021/ac970608z