The binary and ternary phase behavior of a series of di-n-alkyldimethylammonium bromide surfactants has been investigated. The formation of clear, isotropic microemulsion phases in ternary mixtures with oil and water has been mapped on composition diagrams and this has been correlated with their binary phase behavior in water and with conductivity measurements of the water connectivity in the system.

The synthesis and binding properties of new macrocyclic polyethers are described. These systems incorporate 2,2'bipyridyl functions in such a fashion that binding of metal nuclei can occur at either the macrocycle or the bipyridyl function. Evidence is presented that binding of alkali metals occurs at the crown ether cavity while binding of transition metals occurs at the bipyridyl function. Binding of two different metals is interpreted in terms of a simple model for allosteric effects.

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We describe herein a novel approach for visual indication of trace organic vapors. The sensor utilizes a microporous material within a visual thin film transducer to produce changes in color upon exposure to a very wide range of volatile organic compounds. Visual indication at 5 parts per million (ppm) is demonstrated, with optoelectronic detection achieved to below 50 parts per billion (ppb). Through a thoughtful design of the sensor, we are able to avoid interference from water vapor, a critical attribute needed for practical application.

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