Chiral Nematic Liquid Crystal Droplets

Abstract

iquid crystal droplets, being L relatively easy to produce, have been of interest since the early days of liquid crystals. This interest is both scientific and practical. Scientifically, we would like to know how confinement can alter the macroscopic properties of materials previously understood only in the bulk. In the case of liquid crystal droplets, the boundary conditions are fundamentally incompatible with parallel orientation in the bulk, which leads to topological defects in the structure. By applying an electric field or increasing the chirality, the situation is further complicated and new textures with new defects may evolve. From a practical standpoint, an understanding of the above processes is necessary when using droplets for applications. Polymer-dispersed nematic liquid crystal

Liquid Crystalline Composites Based on Amorphous Elastic Polysiloxanes Filled with Low-Molecular-Mass Cholesterics

“…2. Идеализированное представление композитов с разной ориентацией ЖК-директора в каплях холестерика с различными граничными условиями: а -Frank-Pryce текстура в случае тангенциальных граничных условий ориентации [10], b -случай с гомеотропными или радиальными граничными условиями [11], c -случай, изображенный на b -в условиях одноосного растяжения. 1 -капля жидкого кристалла с холестерическими «слоями», 2 -полимерная сшитая матрица Fig.…”

“…2. An idealized representation of composites with different orientations of the LC director in cholesteric droplets at different boundary conditions: a -Frank-Pryce texture in the case of tangential boundary conditions of orientation [10], b -the case with homeotropic or radial boundary conditions [11], c -the case shown in b -under uniaxial tension.…”

Heads or tails: investigating the effects of amphiphile features on the distortion of chiral nematic liquid crystal droplets

“…(b) A CLC with a visible long pitch p 0 (order of mm, but significantly less than the droplet radius) initially shows a Frank-Pryce texture, with the helical axis oriented normal to the droplet surface, creating a characteristic''bull's eye'' owing to the pseudolayering created by the helical modulation of the LC. 37,39,40 In presence of 1 mM SDS, the droplet switches to a ''fingerprint'' texture where the helical axis instead sits tangentially along the droplet interface. 41,42 (c) For CLCs with short pitches, comparable to the wavelength of visible light, the responses are manifested in colors in the form of a characteristic ''starburst'' associated with the Frank-Pryce texture and cross-droplet communication 18,37,43 to form a multidomain, diffuse, ''chicken-skin'' pattern 18,23 associated with the degeneracy of the CLC helix axis orientation at the interface.…”

Buckling Mechanics Modulus Measurement of Anisotropic Cellulose Nanocrystal Thin Films

“…For the films produced in the present study, a Maltese cross, indicative of radial alignment, was observed during each birefringence experiment for the 40, 70, and 120 nm thick CNC films (Figure ). The observation of a Maltese cross indicates a symmetry between the particles; however, this characterization cannot identify if the film has radial or a Frank–Pryce structure . Here, the presence of symmetry observed through birefringence is used as evidence of structure.…”

“…The observation of a Maltese cross indicates a symmetry between the particles; however, this characterization cannot identify if the film has radial or a Frank−Pryce structure. 36 Here, the presence of symmetry observed through birefringence is used as evidence of structure. The local variation in the moduli and its agreement with CG-MD results provide further evidence of radial alignment.…”