In this thesis Johanna Bruckner reports the discovery of the lyotropic counterpart of the thermotropic SmC* phase, which has become famous as the only spontaneously polarized, ferroelectric fluid in nature. By means of polarizing optical microscopy, X-ray diffraction and electro-optic experiments she firmly establishes aspects of the structure of the novel lyotropic liquid crystalline phase and elucidates its fascinating properties, among them a pronounced polar electro-optic effect, analogous to the ferroelectric switching of its thermotropic counterpart. The helical ground state of the mesophase raises the fundamental question of how chiral interactions are "communicated" across layers of more or less disordered and achiral solvent molecules which are located between adjacent bi-layers of the chiral amphiphile molecules. This thesis bridges an important gap between thermotropic and lyotropic liquid crystals and pioneers a new field of liquid crystal research.

Auteur
Johanna R. Bruckner studied chemistry at the University of Stuttgart and received her diploma in 2010. For her PhD she then started working at the Institute of Physical Chemistry in the group of Prof. Dr. F. Gießelmann investigating amphoteric liquid crystals at the borderline between lyotropic and thermotropic mesophases. Afterwards she continued working as a post-doctoral researcher in the Physics and Material Science Unit at the University of Luxembourg. There, in the experimental soft matter physics group of Prof. Dr. J. Lagerwall, she focuses on solvent effects in suspensions of cellulose nanocrystals.

Contenu
Introduction.- Aims and scope of this thesis .- Thermotropic and lyotropic liquid crystals .- Materials and experimental techniques .- Results and discussion .- Summary.- References .- Appendix A.- Appendix B.