Development of Nanostructured Water Treatment Membranes Based on Thermotropic Liquid Crystals: Molecular Design of Sub-Nanoporous Materials.

Supply of safe fresh water is currently one of the most important global issues. Membranes technologies are essential to treat water efficiently with low costs and energy consumption. Here, the development of self-organized nanostructured water treatment membranes based on ionic liquid crystals composed of ammonium, imidazolium, and pyridinium moieties is reported. Membranes with preserved 1D or 3D self-organized sub-nanopores are obtained by photopolymerization of ionic columnar or bicontinuous cubic liquid crystals. These membranes show salt rejection ability, ion selectivity, and excellent water permeability. The relationships between the structures and the transport properties of water molecules and ionic solutes in the sub-nanopores in the membranes are examined by molecular dynamics simulations. The results suggest that the volume of vacant space in the nanochannel greatly affects the water and ion permeability.

Orientation control and fixation of discotic liquid crystal.

We established hybrid, horizontal, vertical, and vertical-twisted alignment of discotic liquid crystals on web-coating thin film. Newly developed materials are the photopolymerizable discotic liquid crystals, in order to fix desired novel alignment, the alignment promoters that deposit toward air surface during web coating, followed by drying of solvent, and then accomplish desired alignment of liquid crystals, the alignment layers that promote desired alignment of liquid crystals from the substrate side and the chiral agents, which have strong chiral powers in small amounts. Hybrid aligned discotic liquid crystal thin film has proven quite effective in expanding the viewing angle of thin film transistor liquid crystal displays.