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The optical transmittance and the electrical capacitance as a function of the externally applied dc voltage are obtained for a twisted nematic cell composed of inorganic clay; i.e., sodium montmorillonite, as an additive to the organic liquid crystal E7. Higher loaded nematic, with smectite clay content of over 3 wt%, exhibits wider voltage–transmittance and voltage–capacitance hystereses, indicating that such cells suffer from more serious ion-charge effects and the orientation barrier of the liquid crystal. Experimental evidence suggests that the addition of merely 0.5–1% by weight of clay substantially rectifies the electro-optical characteristics of the pristine nematic, leading to an apparent lowering of the dc threshold voltage. [ABSTRACT FROM AUTHOR]

Transient currents induced by the polarity reversal of an applied dc voltage in nematic liquid crystal hybridized with montmorillonite clay have been studied. Comparative values of the ion-charge concentrations deduced from the experimental data suggest that the clay hybridized into liquid crystal has a great impact on the ion-charge concentration, which can be dramatically reduced to as low as to [inline image] for a nematic cell containing merely 0.5 wt% clay. Such hybridization suppresses the formation of electric bilayers and the charge-screening effect. Due to the clay and liquid-crystal molecules being aligned to the direction of the field, a higher mobility is observed in hybridized cells. This study demonstrates that montmorillonite clay hybridized into liquid crystal yields many advantages to improve the electro-optical properties of the display device. [ABSTRACT FROM AUTHOR]