Thermotropic chiral nematic side-chain polymers and cyclic oligomers

For all the theoretical, experimental and computational research on chiral nematic systems over the last four decades, understanding of cholesteric mesomorphism from the molecular perspective is still rather limited at the present time. Nevertheless, the unique property of selective wavelength reflection accompanied by circular polarization has presented tremendous potential for various optical applications. Theories governing optical birefringence and selective reflection bandwidth are outlined to serve as a foundation for molecular design. Both polymeric and low molar mass glass-forming chiral nematics are surveyed in terms of chemical structure, thermotropic and optical properties. Characterized by relative ease of processing, the low molar mass approach is illustrated with our recent results in terms of design concept, materials synthesis and characterization. We also highlight outstanding issues that need to be addressed to help advance chiral nematics as a class of advanced optical materials. Copyright (C) 1996 Elsevier Science Ltd