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Detecting the chirality of material is very important in material science, chemistry, pharmacology, and biomaterial science because it is useful for identifying and discarding unintended side effects. Here, directly visualized is the optical activity of chiral samples using an orientation‐controlled helical nanofilament (HNF, B4) liquid crystal (LC) phase made of achiral bent‐shaped molecules. The vertical orientation of the HNFs is induced by shining unpolarized UV light. Right‐ or left‐handed domains of the HNFs are formed because of the lack of molecular chirality, each single‐handed domain is large enough to be seen with the naked eye, up to ≈several mm2. The periodic arrays of aligned HNFs reflect a specific color, here green, due to the Bragg reflection. Such a reflector enables an easy detection of optical activity of a sample placed on it. The device is tested with naturally chiral substances, like fructose and glucose, which exhibit opposite sense of optical activity, as well as with structurally chiral nematic LC phase and reveals high sensitivity of a detection.

The color change of photonic crystal (PC) has been widely studied due to its beauty and anti-counterfeiting purpose. Here we demonstrated security codes based on chiral PCs that are not...

As Internet of Things-based technologies continue to digitalize our society, the development of secure and robust identification systems against evolving adversaries remains a grave challenge. Recently, physical unclonable functions (PUFs)...

Self-organization of gold nanoparticles depends strongly on their organic coating. Lamellar structures were obtained by using double graftingsmall Au nanoparticles were covered with n-alkyl thiol molecules and further with monomeric or dimeric type mesogenic molecules. Apart from positional correlations of metallic centres the structures also showed orientational order of mesogenic ligands manifested as optical birefringence.

Gyroid cubic phases are interesting for both scientists and engineers due to possible applications in electronic devices. New series of dimeric molecules, despite their flexible molecular structure, can display double gyroid cubic phase with Ia3d symmetry and lattice parameter corresponding to double molecular length. The cubic phase is structurally related to columnar phase and both phases often coexist in the same temperature window. Apparently, for studied compounds stronger molecular asymmetry promotes cubic structure. Interestingly, for the examined compounds the transition between two isotropic liquids was observed.

New hybrid materials made of gold nanoparticles functionalized by mesogenic ligands form laminated smectic phases. Mechanical shearing produces macro size domains with uniformly oriented layers with the layer normal either perpendicular (perpendicular mode) or parallel (transverse mode) to the shearing direction. This is in contrast to low weight and polymer liquid crystals which usually show parallel mode of orientation.

Herein, it is reported that the polymorphismin the helical nanofilament (HNF,B 4 )l iquid-crystallinep hase depends on the fabrication methods, that is, UV-driven formation andt emplate-assisted self-assembly in the nanoconfined geometry. As aresult, uniaxially oriented HNFs with different helical structures wereo btained, in which generation of the twisted-ribbon and cylindrical-ribbonp olymorphs showed that even the molecular lattice has ad ifferent orientation.T he detailed structures were directly observed by SEM and grazing-incidence X-ray diffractionw ith synchrotron radiation. Ther esultant polymorphs could be used in chiro-optical applicationsd ue to the capability for fine control of the helical structures.