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Since liquid crystals have found wide use in liquid crystal displays, we try to apply liquid crystals to biotechnology. The purpose of this study is to describe the physical properties of the biopolymer DNA in regard to electrooptics. Synthetic oligonucleotide molecules were dispersed in a nematic liquid crystal (NLC). The ICP analyses showed that all of the oligonuleotide molecules added dispersed in the NLC. This sample was injected into the twisted nematic liquid crystal display cells, and then we measured its dielectric properties. The NLC doped with oligonucleotide molecules exhibited dielectric relaxation characteristics, depending on the concentration of oligonucleotide molecules. After analyzing this effect by using the equivalent circuit model, we found a difference in electrical conductivity between Watson--Crick base pairs (AT and GC). This result suggests that the difference might have contributed to the existence of a functional group involved in the hydrogen-bond interaction.

We investigated the formation of a high-viscosity wormlike-micelle solution consisting of a mixed aqueous solution containing the cationic surfactant cetyltrimethylammonium bromide (CTAB) and sodium cinnamate (NaCin) and control of the solution viscosity by photoisomerization of the NaCin. The aqueous CTAB/NaCin solution exhibited higher zero-shear viscosity than a classic wormlike micelle-forming system CTAB/sodium salicylate of the same concentration. UV irradiation of the aqueous CTAB/NaCin wormlike-micelle solution resulted in a remarkable decrease in its viscosity, from 6.6 × 10 to 2.1 × 10−3Pa s.