We investigate instabilities of smectic A liquid crystals when a magnetic field is applied in the direction parallel to smectic layers. We use the Landau-de Gennes model of smectic A liquid crystals to characterize the critical magnetic field. When smectic A liquid crystals are confined between parallel plates, we derive analytic estimates for the magnetic field strength, at which the undeforme...

The ferroelectric modes of liquid crystals which allow for easy reorientation of the direction of polarization make liquid crystals an attractive element to use for applications such as optical storage, and optical switching. Three schemes for achieving ferroelectricity are discussed: chiral smectic alignment, achiral “banana-shaped” smectic alignment, and the nematic phase that comes from stro...

2014 The temperature and time dependencies of the wavelength of selective light scattering of cholesteric liquid crystals dispersed in various polymers are studied. The stability of liquid crystals is found to be determined by the gas permeability of polymers. The injection of the antioxidants into the polymer increases essentially the lifetime of the capsulated liquid crystals. REVUE DE PHYSIQ...

In the last decade, great effort has been devoted to the study of photonic crystals (PhCs), which are a new class of artificial materials that consist of a periodic arrangement of dielectric or metallic elements in one, two or three dimensions (see Figs. 1-2). The periodicity of these dielectric structures affects the properties of photons in the same way as the periodic potential affects the p...

Inorganic layered crystals exemplified by clay minerals can be exfoliated in solvents to form colloidal dispersions of extremely thin inorganic layers that are called nanosheets. The obtained “nanosheet colloids” form lyotropic liquid crystals because of the highly anisotropic shape of the nanosheets. This system is a rare example of liquid crystals consisting of inorganic crystalline mesogens....

the rapidly increasing interest in functional materials with reversibly switchable physico- chemical properties has led to significant work on the development of stimuli responsive membranes. thermotropic liquid crystals with their exceptional properties have potentials for drug-delivery applications. thermoresponsive liquid-crystal-embedded membranes were investigated for the purpose of develo...

We report on the fabrication and optical characterization of a switchable photonic crystal nanocavity actuated by liquid crystals. This device acts as a filter presenting a transmission peak around the telecom wavelength λ = 1550 nm. Passing from the isotropic to the anisotropic (oriented crystals) state of the liquid crystals, a shift of ∆λ = 13 nm has been measured, which confirms the theoret...

Recently, photonic crystals doped with liquid crystal (LC) material havegained much research interest. In this article new ternary one-dimensional photoniccrystal introduced and studied. The liquid crystal layer of 5CB and 5PCH is sandwichedby two dielectric layers. For the first time, we use four structures SiO2/UCF35/CaF2,SiO2/5CB/CaF2, NFK51/UCF35/NPSK53 and NFK51/5CB/NPSK53. The effect ofte...

Nematic liquid crystals make promising chemoresponsive systems, but their development is currently limited by extensive experimental screening. Here we report a computational model to understand and predict orientational changes of surface-anchored nematic liquid crystals in response to chemical stimuli. In particular, we use first-principles calculations to evaluate the binding energies of ben...

Topological defects in liquid crystals not only affect the optical and rheological properties of the host, but can also act as scaffolds in which to trap nano or micro-sized colloidal objects. The creation of complex defect shapes, however, often involves confining the liquid crystals in curved geometries or adds complex-shaped colloidal objects, which are unsuitable for device applications. Us...