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With an emphasis on the rectified device performance and related liquid-crystal (LC) properties, this paper presents a timely review of the literature on recent development and understanding of colloidal systems of carbon nanotubes (CNTs) in thermotropic nematic liquid crystals (NLCs). The dispersion and stability of CNTs in a LC hydrosol are discussed. The effect of CNT inclusion on the physical properties of NLCs is addressed. It is clear that the effect of adding nanotubes to the LC host and the extent of improvement in LC device performance by doping CNTs, if any, depend strongly on the details of the interaction between the nanotubes and the host molecules. It shows that the combination of CNTs and NLCs is not only of scientific interest but also of technical significance.

The blue phase liquid crystal (BPLC) is a highly ordered liquid crystal (LC) phase found very close to the LC–isotropic transition. The BPLC has demonstrated potential in next-generation display and photonic technology due to its exceptional properties such as sub-millisecond response time and wide viewing angle. However, BPLC is stable in a very small temperature range (0.5–1 °C) and its driving voltage is very high (∼100 V). To overcome these challenges recent research has focused on solutions which incorporate polymers or nanoparticles into the blue phase to widen the temperature range from around few °C to potentially more than 60 °C. In order to reduce the driving voltage, strategies have been attempted by modifying the device structure by introducing protrusion or corrugated electrodes and vertical field switching mechanism has been proposed. In this paper the effectiveness of the proposed solution will be discussed, in order to assess the potential of BPLC in display technology and beyond.

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Using the concept of the Preisach model for a ferroelectric capacitor, we have analyzed the behavior of frequency (f)-dependent polarization reversal in surface-stabilized ferroelectric liquid crystals (SSFLCs) under an external field. At a fixed temperature, the peak height of the capacitance-voltage hysteresis loop is found to be decreasing with an increasing number of polarization cycles up to a certain typical value of frequency (e.g., fc) being different for different ferroelectric liquid crystals (FLCs). We also observed an inversion (a well instead of a peak) in the hysteresis loops appearing above a typical higher frequency denoted fi. The values of capacitance of the FLC capacitors became almost independent of the voltage for the frequencies between fc and fi. The frequency dependence of dielectric biaxiality in the SSFLCs is directly attributed to the appearance of such behavior.

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