Investigations of Novel Liquid Crystals

点击翻译按钮获取中文摘要

This project entitled Investigations of Novel Liquid Crystals focuses on the investigation of novel liquid crystal structure types and design principles based upon complementary shapes and frustration. Two major new directions of research will be pursued. Bent-rod mesogens will be studied as a result of their potential to display ferroelectric and biaxial phases. Preliminary results suggest that achiral tetracatenar bent-rod liquid crystals may display biaxial nematic and ferroelectric (banana type) phases. Based on these results systematic studies of a large number of derivatives will be undertaken. Other systematic mesogen designs will focus on producing liquid crystal phases with greater thermodynamic stability and frustration. The former will be important for applications and the latter will be explored as a route to re-entrance behavior. In cases of re-entrant nematics, the high antiferroelectric correlations are proposed as a potential means to generate a biaxial nematic phase. Another initiative will focus on chiral columnar phases. This effort builds on key results demonstrating that fluxional octahedral metallomesogenic liquid crystals can spontaneously resolve into helical columnar phases with net chirality in the mesogenic cores. This effect is highly dependent on the symmetry of the mesophase and is favored in columnar hexagonal phases. It is also proposed that mixtures of materials with opposite chirality may assemble into well-defined hexagonal columnar superlattices. Polymerization of the major component of these superlattices is proposed as a route to novel porous chiral materials.%%%The liquid crystals developed will have electro-optical properties. Such materials are of growing importance in information processing and transmission technologies (optical computation and fiber optics). The design of helical columnar liquid crystals that can be transformed into porous materials has the potential for the formation of new generation of enantioselective and separation materials. Such processes will impact a broad range of societal needs including the production of synthetic intermediates for the formation of drugs, polymers, artificial flavors, and other materials.