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| Dissipative Impedance in a Doped Liquid Crystal |
| 1st Spring Meeting of the International Society of Electrochemistry, Abstract P06, Spain 2003 |
| C. V. Krishnan, M. Garnett Garnett McKeen Lab, Inc. Liquid crystal materials form macro-molecular arrays which are altered by electric or magnetic fields (Freedericks transition)[1] This electronic reactivity makes them interesting substances for electrochemical study. The liquid crystal palladium-lipoic acid polymer complex (PLA)[2,3], an investigative chemotherapy agent, exhibits a novel distortional impedance. This plot is restricted to a narrow (10mv.) voltage range near the zero volts polarization threshold of the mercury electrode [figs1-3: Z plot, Bode, CV]. The initial capacitive arc rises to form a counter-clockwise curve which moves through zero DC impedance through the upper left quadrant of the complex plane. This is an example of an Hg+1 dopan effect on the liquid crystal. The negative DC resistances are interpreted as charge dissipation. The dissipation is consistent with charge transfer. PLA reduces DNA [2, 3] . The mechanism for the charge transfer is believed to derive from the liquid crystal structure. In solid state crystals there is a finite array of uniform unit cells with a common dimension [4, 5]. The array propagates a fundamental frequency by lattice reflections and conduction band state. The liquid crystal mimics the solid crystal. We attempt to define the differences by looking at the influences of solution conditions including pH and temperature, and also by response to magnetic fields. Liquid crystals are a novel way to catalyze charge transfer in biochemical systems. |
| References 1. Collings, PJ. Liquid Crystals, PrincetonUniv. Press, 1990 2. M.Garnett, U.S. Patent No 5, 436,093, 1995 3. M. Garnett, and J.L. Remo, Microfabricated Systems and Mems V. Proc. ECS.2000-19:185-190, 2000. 4. D.C. Wallace, Thermodynamics of Crystals, Dover Pub., 1997 5. Kittel, C., Introduction to SolidState Physics-6th ed., John Wiley, 1986. DOWNLOAD AS WORD DOCUMENT |