Polymer-stabilized chromonic liquid-crystalline polarizer

Robust coatable polarizer is fabricated by the self-assembly of lyotropic chromonic liquid crystals and subsequent photo-polymerizing processes. Their molecular packing structures and optical behaviors are investigated by the combined techniques of microscopy, scattering and spectroscopy. To stabilize the oriented Sunset Yellow FCF (H-SY) films and to minimize the possible defects generated during and after the coating, acrylic acid (AA) is added to the H-SY/H₂O solution and photo-polymerized. Utilizing cross-polarized optical microscopy, phase behaviors of the H-SY/H₂O/AA solution are monitored by varying the compositions and temperatures of the solution. Based on the experimental results of two-dimensional wide angle X-ray diffraction and selected area electron diffraction, the H-SY crystalline unit cell is determined to be a monoclinic structure with the dimensions of a = 1.70 nm, b = 1.78 nm, c = 0.68 nm, α = β = 90.0° and γ = 84.5°. The molecular arrangements in the oriented H-SY films were further confirmed by polarized Fourier-transform infrared spectroscopy. The polymer-stabilized H-SY films show good mechanical and chemical stabilities with a high polarizability. Additionally, patterned polarizers are fabricated by applying a photo-mask during the photo-polymerization of AA, which may open new doors for practical applications in electro-optic devices. A robust coatable polarizer is fabricated by the self-assembly of lyotropic chromonic liquid crystals and subsequent photo-polymerizing processes. Their molecular packing structures and optical behaviors are investigated with microscopy, scattering, and spectroscopy.