title: QCM gas phase detection with ceramic materials--VOCs and oil vapors.
abstract: Titanate sol-gel layers imprinted with carbonic acids were used as sensitive layers on quartz crystal microbalance. These functionalized ceramics enable us detection of volatile organic compounds such as ethanol, n-propanol, n-butanol, n-hexane, n-heptane, n-/iso-octane, and n-decane. Variation of the precursors (i.e., tetrabutoxy titanium, tetrapropoxy titanium, tetraethoxy titanium) allows us to tune the sensitivity of the material by a factor of 7. Sensitivity as a function of precursors leads to selective inclusion of n-butanol vapors down to 1 ppm. The selectivity of materials is optimized to differentiate between isomers, e.g., n- and iso-octane. The results can be rationalized by correlating the sensor effects of hydrocarbons with the Wiener index. A mass-sensitive sensor based on titanate layer was also developed for monitoring emanation of degraded engine oil. Heating the sensor by a meander avoids vapor condensation. Thus, a continuously working oil quality sensor was designed.
authors.affiliation: Department of Analytical Chemistry, University of Vienna, Vienna, Austria.
authors.forename: Usman
authors.initials: U
authors.lastname: Latif
authors.forename: Andreas
authors.initials: A
authors.lastname: Rohrer
authors.forename: Peter A
authors.initials: PA
authors.lastname: Lieberzeit
authors.forename: Franz L
authors.initials: FL
authors.lastname: Dickert