Investigation On The Optical And Electrical Properties Of Nano-liquid Crystal

The liquid crystal has been well investigated for its excellent properties all over the world, especially in its compounding and applying. The liquid crystal stuff have outstanding performance and the wide application foreground. Liquid-crystalline phases were discovered more than a century ago. Up to now, tens of thousands of organic liquid crystals were discovered. In contrast, only a few mineral liquid crystals were characterized. In comparison to organic liquid crystals, inorganic ones may possess enhanced electrical, optical, magnetic properties and thermal stability. The currently known lyotropic mineral liquid crystals are formed in dispersions of anisometric inorganic particles at some critical concentration. Mineral liquid-crystal moieties can differ in size from one system to another, but they are in a colloidal range. Most liquid crystal unit are in a nanomaterial range.Layered Double Hydroxides (LDHs) are a class of inorganic compounds. They are structurally related to the mineral brucite Mg(OH)₂ with certain Mg2+ ions replaced by trivalent cation of similar size. This replacement results in a net positive charge on the layers, which is compensated by exchangeable anions placed between interlayer. Layered double hydroxides receive extensive attention as they are considered to be used as catalysts, catalyst precursors, catalyst supports, adsorbents, anion exchangers, and promising materials for nanocomposites. Layered double hydroxides particles are often too large, and it is difficult to exfoliate the layers because of the strong electrostatic attraction between the layers and interlayer anions due to the surface charge density. Only a few reports are related to the colloidal domain of LDHs. Layered double hydroxides particles are platelike; such a colloidal system should exhibit liquidcrystalline properties. In this paper, we report the preparation and liquid-crystal phase formation of colloidal Mg/Al Layered double hydroxides.Liquid crystal is an important content of contented matter physics. Biological liquid crystal physics is the actual application of the liquid crystal theory in the life sciences. It is an interdisciplinary subject between biology and physics.It has been proved by experiments that the fluid in organism is not an ordinary fluid, but a kind of liquid crystal. Biological liquid crystal physics mainly focuses on the liquid crystal state changes during the course of organization, disease and aging process of life. Meanwhile, it also investigates the relationship between the texture of biological liquid crystal and the function of biofilm, organism's energy, information transferring process and photosynthesis. The connection between biological structure and liquid crystal has always been the concerned of all circles. It has been confirmed by more and more facts that there are close links between the biological structure and liquid crystal.We performed our work as follows:1. The synthesis of colloidal Mg/Al LDH was carried out using a non-steady coprecipitation method. Atomic Force Microscopy (AFM) investigations were performed with an AJ-III microscopy. The AFM image showed that most particles were roughly monodisperse platelets in shape with diameters between 50 and 80nm (average diameter ₆0 nm).2. Double Maltese Cross of spherical crystal in living organisms is firstly found after chicken bile, fish bile, berry juice was observed by microscopes. 3. Through the research on double Maltese cross on optics, the bio-optical properties of spherical crystal in organism have been further revealed. When the concentration reaches a certain level, the macromolecules congregate at somewhere disorderly. On this disorderly aggregated basis, an optical anisotropy external region is formed. Consequently, the crystal ball is formed. When not being forced by outside forces, the crystal balls continue to maintain their internal disorderly aggregated states. So the so-called "Hollow Maltese Cross" can be observed. When the crystal balls forced by outside force, the macromolecules that are in a disorderly aggregated state will gradually transform to an orderly state at the drive of the outer layer. And finally, it will be transformed to various orderly molecular layers. Thus, a new axis is formed. The new axis is no longer familiar spherical symmetry radioactive axis but a parabolic axis. The projections of the axis from other cross sections of the crystal ball are parabolic optical axis.