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Porous thin lms with engineered microstructures have been fabricated using glancing angle deposition (GLAD). GLAD lms with chiral microstructures have been previously shown to exhibit unique chiral optical response. The pores of these lms were embedded with (non-chiral) nematic liquid crystals (LCs) to produce a new composite optical material wherein the GLAD lm induces chiral nematic-like LC orientation. We demonstrate here reversible electro-optic switching of the LC component of these hybrid lms. Unaddressed, cells of GLAD/LC hybrid lms show enhanced chiral optic response compared with the un lled GLAD lm. When addressed, the chiral optic response vanishes.

Liquid crystalline polymethacrylates with benzanilide and photochromic azobenzene side groups and a related terpolymer containing an additional side group with a phenylethynyl substituted anthracene chromophore were oriented by the irradiation with linearly polarized light. The orientation of both polymers were compared irradiating with polarized visible or, alternatively, UV light. Caused by the co-operativity of the photoorientation process, the light-induced orientation of the azobenzene groups is connected to the alignment of the non-photochromic side groups below the glass transition temperature. The light-induced order generated in the glassy state was significantly amplified by the subsequent annealing of the irradiated films at temperatures in the mesophases. Factors of amplification of about 30 were found in the case of both polymers. The photo-induction process and its amplification by thermotropic self-organization were investigated in dependence on the polym er composition, the irradiation dose and the wavelength of the incident light with respect to the absorption of the dye and its limited photo-stability. The required dose or the irradiation time, respectively, were significantly reduced by the optimization of the light-induced and thermal processing. In this way, dichroic films of co- and terpolymers were created. However, the green fluorescence of the anthracene chromophore is effectively quenched by the azobenzene side group within the film

A new linearly polarized light emitting lightguide system is presented, consisting of a micro-structured anisotropic polymer film which is coated with an isotropic layer and adhered to a transparent polymeric substrate. With conventional edge-lighting of the lightguide very high polarized contrasts are realized, exceeding 100. A gain in efficiency can be achieved by recycling of the trapped light with the orthogonal polarization.

A backlight for liquid crystal display illumination is presented, consisting of a commercial birefringent liquid crystalline polymeric layer innovatively laminated onto a micro‐structured plastic light guide. S‐polarized light is preferentially extracted from the light guide, and the efficiency was measured to be 1.78 time higher than in for a conventional unpolarized light emitting backlight.

We report on the photoinitiated polymerization of phenyl benzoate-based liquid crystalline (LC) thiol-ene monomers in isotropic and anisotropic solvents. The mixing behavior of the thiol-ene monomers with anisotropic cyanobiphenyl solvents was investigated, and unique reactive LC mixtures are formed that exhibit variable mesophases at ambient temperatures. Using size exclusion chromatography, the conversion of the thiol-ene monomers was studied in isotropic solvents and in anisotropic solvents as a function of several parameters, such as the irradiation time, polymerization temperature, and monomer concentration. Indications for the existence of a polymerization ceiling temperature effect were observed which was more pronounced for lower initial monomer concentrations. The in situ photopolymerization of the LC thiol-ene monomers in anisotropic media leads to a variety of morphological structures, ranging from intriguing threadlike architectures to dendritic crystalline structures. The morphological changes that occur during the polymerization process are complex, and several approaches toward the enhanced control over the resulting morphologies are discussed. The results and insights presented here could potentially lead to new architectures and enhanced optical and electrooptical properties of devices.

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