Fluorinated liquid crystals: design of soft nanostructures and increased complexity of self-assembly by perfluorinated segments.

The effects of perfluorinated and semiperfluorinated hydrocarbon units on the self-assembly of rod-like, disc-like, polycatenar, taper- and star-shaped, dendritic, and bent-core liquid crystalline (LC) materials is reviewed. The influence of fluorinated segments is analyzed on the basis of their contributions to the cohesive energy density, molecular shape, conformational flexibility, micro-segregation, space filling, and interface curvature. Though the focus is on recent progress in the last decade, previous main contributions, general aspects of perfluorinated organic molecules, and the basics of LC self-assembly are also briefly discussed to provide a complete overall picture. The main focus is on structure-property-relations and the use of micro-segregation to tailor mesophase morphologies. Especially polyphilic molecules with perfluorinated segments provide new modes of LC self-assembly, leading to ordered fluids with periodic multi-compartment structures and enhanced complexity compared to previously known systems.