Lyotropic Liquid Crystals
Mostrando 1-12 de 13 artigos, teses e dissertações.
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1. Caracterização mecânica e estrutural de um dispositivo PDLC baseado em hidrogéis de PAAm e cristal líquido liotrópico LP/DeOH/H2O
In this work, a novel device based on polyacrylamide (PAAm) hydrogels and KL - DeOH - H2O lyotropic liquid crystal (LLC), with potential for application as Polymer Dispersed Liquid Crystals (PDLC), was proposed and its properties characterized. The confinement of LLC promoted significant changes in spectroscopic, morphological, optical, hydrophilic, structur
Quím. Nova. Publicado em: 2014
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2. Desenvolvimento, caracterizaÃÃo e estudo de permeaÃÃo cutÃnea de diclofenaco de dietilamÃnio em sistemas tÃpicos nanoemulsionados
The nanoemulsions (NE) are transparent, isotropic and thermodynamically stable systems, formed spontaneously under a specific set of experimental conditions from mixtures of water and oil phases stabilized by a surfactant or a mixture of surfactant and cosufactant. Because of their properties, especially the ability to carry lipophilic and hydrophilic drugs
Publicado em: 2008
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3. Estudo do equilibrio de fases e de estruturas de complexos formados entre polietilenoiminas e dodecilsulfato / Phase equilibria and structural study of polyethyilenoimine and dodecylsulfate complexes
Polyelectrolytes associate strongly with oppositely charged surfactants in water, being able to generate liquid crystalline phases with interesting supramolecular structures. The geometry of the liquid crystalline phase depends on parameters such as: concentration, surfactant/monomer ratio, polymer characteristics and presence of cosolvents. The objective of
Publicado em: 2007
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4. Nonlinear optical properties of liquid crystals probed by Z-scan technique
We present a review of experimental data on the nonlinear optical properties of thermotropic and lyotropic liquid crystals probed by the Z-scan technique. Depending on the time scale, different processes originate a nonlinear optical response. Particularly, at nanosecond range, the physical processes associated with the nonlinear response in thermotropics ar
Brazilian Journal of Physics. Publicado em: 2003-12
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5. Lyotropic ferronematic liquid crystals based on new Ni, Cu and Zn Ionic magnetic fluids
The properties of lyotropic ferronematic liquid crystals based on new Ni, Cu and Zn ionic magnetic fluids are discussed. The efficiency of these new ferrofluids in the lyotropic nematic liquid crystal doping is verified and compared with the conventional surfacted ferro fluid lyotropic doping. It was observed that the structural characteristics of the lyotro
Brazilian Journal of Physics. Publicado em: 2002-06
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6. Resonance effect in isotropic phase of lyotropic liquid crystal
In this work we present experimental results that show a resonance effect in the isotropic phase of a lyotropic liquid crystal. The lyotropic mixture is made up of Potassium Laurate (KL), Decanol (DeOH) and water with three different relative concentrations: 2.62, 2.79 and 2.90 (C = [KL]/[DeOH], [KL] and [DeOH] in % molar). These mixtures have an isotropic (
Brazilian Journal of Physics. Publicado em: 2002-06
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7. Twenty years of research on cholesteric lyotropic liquid crystals at the Chemistry Institute of the University of São Paulo
In this paper we present a review of twenty years of research on cholesteric liquid crystals at the Chemistry Institute of the University of São Paulo. The results on the interaction forces, responsible for the maintenance of the helical structure, are a function of the chemical variability obtained in these systems. The last results obtained using rheologi
Brazilian Journal of Physics. Publicado em: 2002-06
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8. Thermal lens temperature scanning for quantitative measurements in complex fluids
In this work thermal lens spectrometry is applied to investigate the thermo-optical properties of complex fluids as a function of the temperature. The method is applied in poly(vinyl chloride), in polycarbonate and in lyotropic liquid crystals as the testing samples. The focus of the discussion will be in the temperature range where the phase transitions occ
Brazilian Journal of Physics. Publicado em: 2002-06
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9. Changes in aggregate form, size and flexibility along phase sequences in lyotropic liquid crystals
A comparison is made between existing theories for self-assembling systems and experimental phase diagrams of complex systems made up of amphiphile/water/additives, with emphasis on phase transitions by changes in concentration. Evidence for different types of hexagonal (H) phases, in systems with detergent and lipid amphiphiles, are reviewed. It is shown th
Brazilian Journal of Physics. Publicado em: 2002-06
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10. Estados críticos orientacionais em cristais líquidos liotrópicos induzidos por campos magnéticos. / Orientations critical states in lyotropic liquid crystals induced by magnetic fields.
Liquid crystalline structures are found in materials made from molecules which are anisotropic in shape; such material are characterized mainly by a long range orientational order. In the nematic phase, the rodlike molecules tend to align parallel to each other. The average orientation defines a unit vector, called director n. Lyotropic liquid crystals are u
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/12/2000
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11. Espectroscopia de lente termica : propriedades termicas de cristais liquidos
Liquid Crystals are fluids that present intermediate properties between solid and liquid, and consist of a molecular arrange with structural order. These systems are classified as Thermotropic Liquid Cristals, Lyotropie Liquid Crystals and Plastic Crystals. Since their discovery, these systems have shown to be an important area of condensed matter research.
Publicado em: 1997
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12. Electrophoresis in lyotropic polymer liquid crystals
Excellent electrophoretic separations of a variety of biological molecules can be accomplished by using uncharged, triblock copolymers as the “gel” media. These copolymers form uncrosslinked, lyotropic liquid crystalline phases of large micelles between which molecules must travel. Unlike crosslinked hydrogels in common use, these alternative media have
The National Academy of Sciences.