A systematic study of LiFePO 4 with cyclic voltammetry ͑CV͒ was conducted using thin electrodes with a loading of 4 mg/cm 2 . Peak current of the CV profile was proportional to the square root of scan rate under 0.2 mV/s. Results were analyzed using a reversible reaction model with a resistive behavior. This resistance was consistent with other resistances obtained from electrochemical impedance spectroscopy and charge-discharge curves. Apparent Li diffusion constants of 2.2 ϫ 10 −14 and 1.4 ϫ 10 −14 cm 2 /s were obtained at 25°C for charging and discharging LiFePO 4 electrodes in 1 M LiPF 6 ethylene carbonate/diethyl carbonateϭ3:7 by volume, respectively. Activation energies of the apparent diffusion constants and electrode resistance are about 0.4 eV. These parameters are good indicators for assessing the effectiveness of material modifications such as surface coating and doping.

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The enantiomeric composition of the chiral flavoring agent limonene was analyzed by means of a quartz-crystal microbalance (QCM) sensor. As chiral selectors three different modified beta-cyclodextrins were investigated. The selector molecules were applied as mixtures in different polysiloxane matrices. The chiral separation factors alpha for limonene obtained at 30 degrees C by gas chromatography and by use of the QCM sensor were comparable. Evaluation of sensor data was performed by use of an artificial neuronal network (ANN); this enabled prediction of the enantiomeric composition of the gas mixtures.

In an alkaline rebreathing circuit, the inhalation anesthetic sevoflurane degrades into at least two products, one of them being the chiral halodiether 1,1,1,3,3-pentafluoro-2-(fluoromethoxy)-3-methoxypropane (halodiether B). Using octakis(3-O-butanoyl-2,6-di-O-n-pentyl)-y-cyclodextrin (Lipodex E) as chiral host diluted in the polysiloxane PS255, an exceptional large chiral separation factor alpha of 9.7 at 30 degrees C was found for halodiether B by capillary gas chromatography (cGC). Hence, the interaction of the single enantiomers and the racemic mixture of the halodiether B with Lipodex E was selected as a model system to study the enantioselective recognition by thickness shear mode resonators (TSMR), surface acoustic wave sensors, surface plasmon resonance (SPR), and reflectometric interference spectroscopy. Further investigations of the recognition process by using chemical sensors confirmed the preferential enrichment of the S-enantiomer resulting in 9-fold higher signals. Based on the distinction between enantioselective and nonenantioselective sorption, thermodynamic complexation constants of the single enantiomers with Lipodex E could be determined. The difference in Gibbs free energy -deltaE2,E1(deltaG) of the complexation of the enantiomers of halodiether B with pure Lipodex E was determined at 30 degrees C by TSMR and SPR to be 5.7 or 5.9 kJ/mol, respectively, agreeing well with that determined by cGC, i.e., 5.7 kJ/mol at 30 degrees C.