Quasicrystalline Ordering in Thin Liquid Crystal Films

Abstract

Quasicrystalline ordering was first observed in synthetic multi-component metallic alloys. These solid state materials exhibit quasicrystalline atomic ordering at nanometer length scales. Softmatter systems are another class of versatile materials that can exhibit quasicrystalline ordering across supra-nanometer (>10 nm) to supra-micrometer (>10 µm) length scales as recently observed in materials like-supramolecular dendritic molecules, ABC star polymers, binary nanoparticle systems and block co-polymers in condensed matter systems. The underlying mechanism in most of these soft quasicrystals seems to be the presence of two or more length scales in the system. Another class of development in self-assembled quasicrystals in softmatter is being observed in low molecular weight chiral and achiral nematic liquid crystals. Liquid crystal forms an efficient matrix for selfand directed-assemblies of colloidal structures where surface and geometry-tuning the particles in nematic liquid crystals gives rise to complex inter-particle interactions while the long-range order results in self-assembled structures of higher order rotational symmetries. Furthermore, there has also been attempts to generate colloidal quasicrystalline defect structures by directing the assemblies using multiple and single beam lasing techniques. In the present article, we will review self-and assisted-assembly of quasicrystalline structures in nematic liquid crystals (both chiral and achiral) and discuss the underlying mechanisms.

Quasicrystalline Arrays and Moiré Patterns in Nematic Liquid Crystals for Soft Photonics

“…showed theoretically how LCs can drive the assembly of platelets to form a 2D quasicrystal. [ 18,19 ] By choosing carefully the geometry of the colloidal particles, Senyuk et al. showed how the LC elastic forces could drive the quasicrystalline assembly of truncated pyramids.…”

“…[17] Using the elastic field created by LCs to drive selfassembly in the microscale, Dontabhaktuni et al showed theoretically how LCs can drive the assembly of platelets to form a 2D quasicrystal. [18,19] By choosing carefully the geometry of the colloidal particles, Senyuk et al showed how the LC elastic forces could drive the quasicrystalline assembly of truncated pyramids. [20] One of the characteristics of quasicrystals is the unique diffraction pattern that matches their intrinsic symmetry.…”

A fivefold UO22+ node is a path to dodecagonal quasicrystal approximants in coordination polymers

“…Since then, some known structures have been revisited (4,5), pointing toward a larger scale of QC networks that, so far, remain hidden. Besides intermetallics, quasicrystalline ordering has been detected, but only rarely, in chalcogenides (6,7), mesoscale materials (8), terpolymers (9), liquid crystals (10,11), colloids (12), thin films (13,14), proteins (15), or nanoparticle assemblies (16). QC approximants (ACs) represent crystalline materials compositionally and structurally approaching the atomic self-organization present in QCs but with long-range translational order.…”

“…Stable dodecagonal (DD; 12-fold) QCs could be observed in bulk chalcogenides (6,7). A limited number of thermodynamically metastable DDQCs and DDACs have been discovered in complex metallic alloys (18)(19)(20), and a few have been discovered in soft QC systems (9)(10)(11)(12).…”