The use of a phenylpyrazine liquid crystalline material with a liquid crystalline solvent mediator as an ion-selective electrode

Pulsed NMR analysis of ion-selective electrode membranes

“…2 Recently, the mesomorphic effects of ionophoric liquidcrystalline compounds on ISEs were studied by using non-ionophoric liquid-crystalline membrane solvents. 4,5 The properties of not only the individual components but also the whole membrane matrix appear to be quite critical to the ion-sensing behavior of ISEs. Properties of the whole membrane matrix such as impedance, membrane resistance, dielectric constant, ionic conductivity, chronoamperometric and chronopotentiometric method, and second-harmonic generation (SHG) have been well documented.…”

Dependence of Ion Selectivity on Ordered Orientation of Neutral Carriers in Ion-Sensing Membranes Based on Thermotropic Liquid Crystals

“…Liquid-crystalline compounds possess ordered molecular orientation, which is able to affect molecular orientation of other organic components existing in small quantities in the liquid-crystal phase. For instance, in ion-conducting composites containing liquid-crystalline crown ethers, their ion conductivity can be altered by the phase transition induced by external stimuli such as heat and light. − Liquid-crystalline compounds are also candidates for functional membrane solvents for ISEs, as far as they keep fluidity that guarantees the mobility of a neutral carrier enough for quick ion exchange in the membrane . In that case, it may be possible to know how the ordered orientation of neutral carriers modifies the ion sensor property.…”

“…[3][4][5][6] Liquid-crystalline compounds are also candidates for functional membrane solvents for ISEs, as far as they keep fluidity that guarantees the mobility of a neutral carrier enough for quick ion exchange in the membrane. 7 In that case, it may be possible to know how the ordered orientation of neutral carriers modifies the ion sensor property. The ordered orientation of neutral carriers by thermotropic liquid crystals might improve ion sensor properties such as selectivity, which might be switched by the measurement temperatures.…”

“…The ordered orientation of neutral carriers by thermotropic liquid crystals might improve ion sensor properties such as selectivity, which might be switched by the measurement temperatures. Liquid-crystalline compounds can be incorporated into poly(vinyl chloride)(PVC)-based ionsensing membranes, 7 but the liquid-crystal effect in that case does not seem to be very significant due to their compatibility with the polymer support. We have therefore attempted to use pure liquid membranes consisting of a liquid-crystalline membrane solvent and a neutral carrier for ion sensors, without using any polymer support.…”

Liquid crystal effect on neutral-carrier-type ion-sensing membranes

“…Since liquid crystals possess some molecular orientation as well as mobility, they may be a useful material for PVC-based ion-sensing membranes. 4 We have therefore attempted to use a liquid-crystalline membrane solvent and a neutral carrier as the membrane components for ISEs, expecting some improvement of ion sensor property. Here we report a remarkable liquid crystal effect of membrane solvent and neutral carrier on the resulting membrane electrodes.…”