New structural model of a chiral cubic liquid crystalline phase.

We have studied properties of novel thermotropic mesogenic materials that exhibit both an achiral double gyroid (Ia3[combining macron]d symmetry) and chiral cubic phase (previously assigned the Im3[combining macron]m symmetry). We argue that in the chiral cubic phase molecules form micelles and channels arranged into continuously interconnected hexagons. From the X-ray diffraction experiment supported by modelling, exact positions of hexagons and their connections were deduced and showed to be embedded on a WP (degenerated Neovius) minimal primitive surface.

Bi-continuous orthorhombic soft matter phase made of polycatenar molecules.

We report an observation of a new type of a continuous soft matter phase with an orthorhombic symmetry made of polycatenar molecules. The bi-continuous orthorhombic structure with the Pcab symmetry appears by deformation of a double gyroid cubic structure with the Ia3[combining macron]d symmetry.

Monolayer Filaments versus Multilayer Stacking of Bent-Core Molecules.

Bent-core materials exhibiting lamellar crystals (B4 phase), when dissolved in organic solvents, formed gels with helical ribbons made of molecular monolayers and bilayers, whereas strongly deformed stacks of 5-6 layers were found in the bulk samples. The width and pitch of the helical filaments were governed by molecular length; they both increased with terminal-chain elongation. It was also found that bulk samples were optically active, in contrast to the corresponding gels, which lacked optical activity.

Liquid-crystalline phases made of gold nanoparticles.

Spontaneous formation of smectic and columnar structures was observed when spherical gold nanoparticles were functionalized with mesogenic thiols (see layered structure and X-ray pattern of a sample in smectic phase). The particle ordering is stimulated by softening of the interparticle potential and flexibility for deformation of the grafting layer.

Molecular factors responsible for the formation of the axially polar columnar mesophase Col(h)P(A).

The structure of hexacatenar bent-shape molecules has been systematically modified in order to determine the main molecular factors responsible for the appearance of the axially polar columnar mesophase. It was found that the stability of the polar phase is very sensitive to the subtle modifications of the molecular shape: the phase is solely preserved if the modification is made at the terminal parts of the mesogenic core, whilst any other modifications destabilize the phase. It can be concluded that the main factor driving the transition between the phase made of flat supramolecular discs and the axially polar phase made of the cone-like units is the ability to fulfill close packing conditions in order to eliminate voids between neighboring molecular rigid cores.

Polar order in columnar phase made of polycatenar bent-core molecules.

Columnar phases made of polycatenar molecules with bent-shaped mesogenic cores are studied. The polar order in this system is associated with the change of the column building blocks from flat disks (Colh phase) into cones (Colh PA phase), which allows for axial polarization of the columns. The nature of the Colh and Colh PA phase transition changes from first order for short homologues to continuous for the longest one.

Axially polar columnar phase made of polycatenar bent-shaped molecules.

The polycatenar bent-shaped molecules are able to form columnar phases with column stratum built of few molecules, arranged in coplanar or conelike geometry. In the latter case, the phase becomes axially polar, with electric spontaneous polarization reorientable in the electric field by flipping the cone axis. The phase is antiferroelectric; in the plane perpendicular to columns, the ferroelectric hexagonal order exists, but the columns are broken along the z direction and the polarization direction alternates between the blocks.