ISBN-13: 9783639088571 / Angielski / Miękka / 2008 / 204 str.
In recent years bent-core (BC) liquid crystals have begun to mature into a relevant subfield of research. The shape and symmetry of BC molecules offers a wealth of new questions not presented by calamitic liquid crystals, many of which have yet to be addressed. In this work, I use magnetic field induced birefringence, dynamic light scattering, and density measurements to provide evidence of a transition between two optically isotropic phases in two BC liquid crystals, and to show that this transition can be understood in the framework of the theoretically predicted, but previously unobserved tetrahedratic - isotropic transition. Also, four distinct, frequency dependent, regions of electrohydrodynamic convection (EHC) were characterized in a BC liquid crystal, which showed two frequency dependent changes in the sign of the electrical conductivity anisotropy. This work looks into some exciting behaviors in novel BC liquid crystal materials and should be of interest those involved with EHC or BC liquid crystals."
In recent years bent-core (BC) liquid crystals have begun to mature into a relevant subfield of research. The shape and symmetry of BC molecules offers a wealth of new questions not presented by calamitic liquid crystals, many of which have yet to be addressed. In this work, I use magnetic field induced birefringence, dynamic light scattering, and density measurements to provide evidence of a transition between two optically isotropic phases in two BC liquid crystals, and to show that this transition can be understood in the framework of the theoretically predicted, but previously unobserved tetrahedratic - isotropic transition. Also, four distinct, frequency dependent, regions of electrohydrodynamic convection (EHC) were characterized in a BC liquid crystal, which showed two frequency dependent changes in the sign of the electrical conductivity anisotropy. This work looks into some exciting behaviors in novel BC liquid crystal materials and should be of interest those involved with EHC or BC liquid crystals.