GISAXS in the study of supramolecular and hybrid liquid crystals

Ungar, Goran; Liu, Feng; Zeng, Xiangbing; Glettner, Benjamin; Prehm, Marko; Kieffer, R.; Tschierske, Carsten

doi:10.1088/1742-6596/247/1/012032

Cited by 13 publications

(16 citation statements)

References 45 publications

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“…An example is given in Figure , which shows the GISAXS patterns of the stretched hexagonal honeycombs in compounds 1e and 1f discussed in Section 2.3. The models of the honeycombs in Figure 20c,d give a rational explanation of the different orientations observed in the diffraction patterns 42, 43…”

Section: Self‐assembly Of T‐shaped and X‐shaped Polyphiles At Intementioning

confidence: 73%

“… Comparison of the two different types of giant hexagonal cylinder structures of compounds 1e (hexagons with 10 molecules around the circumference, 2‐2‐1, left column) and 1f (hexagons with 8 molecules around the circumference, 2‐1‐1, right column): a,b) electron‐density maps reconstructed from powder X‐ray patterns; c) stretching of regular hexagonal cylinders (1‐1‐1) of a Col hex phase either perpendicular to a side or along a diagonal gives rise to two different cylinder phases with c 2 mm symmetry (see also Section 6.1 ). a,c) Reproduced with permission 42, 43. Copyright 2007, Wiley‐VCH.…”

Section: Soft Matter Structures Of Ternary T‐shaped Amphiphilesmentioning

confidence: 99%

“…Three adjacent sides of a 10‐hexagon contain, respectively, 2, 2, and 1 molecules lengthwise, hence this structure is labelled 2‐2‐1. By analogy the 8‐hexagons are labelled 2‐1‐1 42, 43. Giant pentagonal cylinders, where each side contains two end‐to‐end molecules, represent another mode of organization of ten molecules in the circumference (see Figure 1h) 8a.…”

Section: Soft Matter Structures Of Ternary T‐shaped Amphiphilesmentioning

confidence: 99%

“… a,b) GISAXS patterns of rectangular columnar c2mm phases in a) compound 1e at 60 °C and b) compound 1f at 115 °C (see Figure 8 for chemical structures). c,d) Structures of the stretched hexagonal honey‐comb phases resting on the substrate surface 42, 43. Reproduced with permission 43.…”

Section: Self‐assembly Of T‐shaped and X‐shaped Polyphiles At Intementioning

confidence: 99%

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Self‐Assembly at Different Length Scales: Polyphilic Star‐Branched Liquid Crystals and Miktoarm Star Copolymers

Ungar

Tschierske

Abetz

et al. 2011

Adv Funct Materials

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of the original manuscript:Ungar, G.; Tschierske, C.; Abetz, V.; Holyst, R.; Bates, M.A.; Lui, F.; Prehm, M.; Kieffer, R.; Zeng, X.; Walker, M.; Glettner, B.; Zywocinski, A.: Keywords: columnar liquid crystals, polygonal honeycombs, polyphiles, miktoarm star terpolymers, simulation, Langmuir films, rod-coil molecules, surface alignment Abstract: This article reviews the diversity of phase morphologies observed recently in starbranched liquid crystalline and polymeric compounds containing at least three immiscible segments. Bolaamphiphiles and facial amphiphiles with a rod-like aromatic core, two endgroups and one (T-shape) or two chains (X-shape) attached laterally to the core form numerous honeycomb-like liquid crystal phases, as well as a variety of novel lamellar and 3D-ordered mesophases. Molecular self-organization is described in bulk phases and in thin films on solid and liquid surfaces, as well as in Langmuir-Blodgett films. The remarkably reversible formation of mono-and tri-layer films is highlighted. In the bulk, T-shaped "rod-coil" molecules without the appended end-groups form predominantly lamellar phases if the core is a straight rod, but the bent-core variety forms hexagonal honeycombs. Furthermore, selfassembly of "Janus"-type molecules, such as those with Y-shaped star mesogens bearing different mutually incompatible side-groups, is discussed. Also covered is the diversity of morphologies observed in miktoarm star terpolymers i.e. polymers with three different and 3 incompatible arms of well-defined lengths. A range of bulk phases with 3D or 2D order are observed, combining layers, cylinders and cocontinuous networks. Similarities and differences are highlighted between the liquid crystal morphologies on the 3-15 nm scale and the polymer morphologies on the scale 10-100 nm. A separate section is dedicated to computer simulations of such systems, particularly those using dissipative particle and molecular dynamics. Of special interest are the recently synthesised X-shaped tetraphilic molecules, where two different and incompatible side-chains are attached at opposite sides of the rod-like core. The tendency for their phase separation produces LC honeycombs with cells of different compositions that can be represented as paving a plane with different color tiles. Self-Assembly at Different Length Scales: Polyphilic StarBranched Liquid Crystals and Miktoarm Star CopolymersThe independent variation of chain length and "color" creates the potential for developing a considerable range of complex new 2d-and 3d soft nanostructures. Analogous X-shaped rodcoil compounds with unequal side groups are also of considerable interest, forming tubular lyotropic structures capable of confining strings of guest molecules.

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Section: Self‐assembly Of T‐shaped and X‐shaped Polyphiles At Intementioning

confidence: 73%

Section: Soft Matter Structures Of Ternary T‐shaped Amphiphilesmentioning

confidence: 99%

Section: Soft Matter Structures Of Ternary T‐shaped Amphiphilesmentioning

confidence: 99%

Section: Self‐assembly Of T‐shaped and X‐shaped Polyphiles At Intementioning

confidence: 99%

See 2 more Smart Citations

Self‐Assembly at Different Length Scales: Polyphilic Star‐Branched Liquid Crystals and Miktoarm Star Copolymers

Ungar

Tschierske

Abetz

et al. 2011

Adv Funct Materials

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“…S8). As observed previously 35 , if lying with their long axis parallel to the substrate (planar anchoring), the cylinders choose to lie on a side that maximizes their polar groups' contact with the polar substrate. At the same time, the contact with the substrate should cause minimum lattice distortion.…”

Section: Resultsmentioning

confidence: 90%

Arrays of giant octagonal and square cylinders by liquid crystalline self-assembly of X-shaped polyphilic molecules

et al. 2012

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nanopatterning by molecular self-assembly has been a topic of intense research in pursuit of 'bottom-up' methods of generating structures for use in nanotechnology. The systems most widely studied have been two-and three-dimensional morphologies of block copolymers. However, T-and X-shaped polyphilic liquid crystals have recently been shown to have great potential for generating soft honeycomb-like structures, surpassing those of polymers in both complexity and degree of order. The cell cross-section of the liquid crystals honeycombs has so far been limited by small molecular size. Here we overcome this limitation by exploiting the inability of the polyphiles to simultaneously achieve optimal packing and complete nanophase separation. This frustration results in a two-dimensional periodic honeycomb consisting of giant octagonal and square cylinders with circumferences of 12 and 8 molecules, respectively. In addition to forming large cells, the two-molecule-long bendy walls give this structure extra versatility and stability.

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Side‐Branched Polyphiles and Polygonal Cylinder Phases

Tschierske

Ungar

2014

Handbook of Liquid Crystals

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GISAXS in the study of supramolecular and hybrid liquid crystals

Cited by 13 publications

References 45 publications

Self‐Assembly at Different Length Scales: Polyphilic Star‐Branched Liquid Crystals and Miktoarm Star Copolymers

Self‐Assembly at Different Length Scales: Polyphilic Star‐Branched Liquid Crystals and Miktoarm Star Copolymers

Arrays of giant octagonal and square cylinders by liquid crystalline self-assembly of X-shaped polyphilic molecules

Side‐Branched Polyphiles and Polygonal Cylinder Phases

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