Inorganic dopants in polymer cholesteric liquid crystals

<p>A variety of dopants are used for different types of polymers to change their properties. Inorganic dopants are usually used to change the dielectric properties of the polymers. These compositions find different applications especially in electronic systems due to ease of polymer processing, increased functionality and low cost of novel materials that are with relatively high dielectric constant compared to the base polymer material.</p><p>In this study, polymer cholesteric liquid crystal (PCLC) is used as a host material that is doped by different inorganic dopants, BaTiO₃ and TiO₂, all of them affected the dielectric constant of the polymer matrix. This is important from the fact that doped PCLC can be used for a variety of electro-optical applications, e.g. display applications and low energy consuming e-book application. The behaviour of inorganic dopants in PCLC is calculated by various existing mixing models; the best fit is observed by use of logarithmic equation.</p>

The role of conductive dopants in polymer cholesteric liquid crystals

<p align="center"> </p><p><strong>Abstract</strong></p><p>Variety of conductive dopants were used to modify the electric properties of polymer cholesteric liquid crystals. Different types of carbon blacks, carbon nanotubes, as well as metallic particles were used as conductive dopants in this work. All of them affected the conductivity of the polymer matrix, but at different dopant concentrations. The percolation threshold behaviour of used dopants in the polymer host showed pronounced dependence on the dopants’ particle size and particle shape anisotropy. For instance, the higher the aspect ratio of carbon-based dopant particles (aspect ratio = length : diametar), the lower the percolation threshold; while increase in metallic dopants' diameter yielded higher percolation threshold of polymer composition.</p><p align="center"><strong><br /></strong></p>