Ferroelectric lyo-mesophase of banana-shaped molecules

Abstract

Preliminary results are reported on the first ferroelectric 'lyo-mesophases' of banana-shaped molecules. We studied the effect of the non-polar solvents p-xylene and m-xylene on the macroscopic properties of banana-shaped molecules having a B₇ phase. It was observed that by adding only 15% of solvent the isotropic-B₇ transition temperature was lowered from 130°C to 70°C and the ferroelectric electro-optical switching range was extended from 1-2°C to more than 50°C, thus maintaining the switching even at room temperature. The xylene molecules act as spacers, maintaining larger separations between the banana-molecules, thus reducing the polar packing order. These observations provide unique opportunities for tuning the intermolecular interactions of banana-shaped molecules and modifying their macroscopic properties.