Control of free volume through size exclusion in the formation of smectic C phases for display applications

Abstract

Ferroelectric liquid crystals are of interest in display devices because of their bistable operation and fast response times. However, they have not reached their potential for a number of reasons, low tilt angle and high birefringence being two of them. Although low birefringence can be achieved by incorporation of carbocyclic rings into the molecular structures of the materials this often lowers the occurrence of tilted phases, and additionally a high tilt angle is often very difficult to engineer. In this article we attempt to resolve these issues and demonstrate that through the incorporation a bulky terminal group attached to an external aliphatic chain in the molecular design, it is possible via size exclusion to achieve high tilt angles. We explore the conformational landscape of these materials with a combination of molecular modelling and NOE enhancements in ¹H NMR.