Liquid Crystal
Mostrando 1-12 de 160 artigos, teses e dissertações.
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1. Validation of an UHPLC-MS/MS Method for the Determination of Malachite Green, Leucomalachite Green, Crystal Violet, and Leucocrystal Violet in Shrimp, Fish, and Salmon Muscle Using a Modified QuEChERS Approach
A quantitative and confirmatory method for detecting the presence of triphenylmethane dyes in shrimp muscle using ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) and a quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction approach was validated. The method exhibited linearity and selectivity and the coeffici
J. Braz. Chem. Soc.. Publicado em: 2021-04
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2. Crystal Structure and Hirshfeld Surface Analysis of 1,4-Pentadien-3-one, (1E,4E)-1,5-diphenyl-2-(2,4-dinitrophenyl)hydrazone
The compound 1,4-pentadien-3-one,(1E,4E)-1,5-diphenyl-2-(2,4-dinitrophenyl)hydrazone presents the molecular formula C23H18N4O4 and was prepared in an undergraduate laboratory. The hydrazone was synthesized from the condensation between dibenzalacetone and 2,4-dinitrophenylhydrazine (DNPH) and crystallized employing water/acetone liquid-liquid diffusion. The
J. Braz. Chem. Soc.. Publicado em: 2021-02
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3. Blue Glow Sticks: Cinnamic Acids and Arylacrylonitriles with Liquid-Crystalline Properties and Highly Fluorescent
Five new π-conjugated chromophores derived from acrylic acid and acrylonitrile were synthesized and their thermal and photophysical behaviors were analyzed. They were designed and synthesized through Knoevenagel condensations between arylacetylenebenzaldehydes and a methylene group activated from cyanoacetic and malonic acids. The characterization of the ta
J. Braz. Chem. Soc.. Publicado em: 2021-01
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4. Rheo-Squeeze Casting of High-Silicon Aluminium Alloy Pipes with Gradient Structures and Their Mechanical Properties
Three different compositions of high-Si Al alloy pipe, with a gradient structure, were produced through semi-solid rheological squeeze casting, the microstructural characteristics of which were investigated. The mechanism of gradient structure formation and the effect of acicular Fe-rich phases on liquid segregation were revealed. Meanwhile, the crystal stru
Mat. Res.. Publicado em: 11/06/2018
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5. Structural Invariance of a ZnII Coordination Polymer with 5-Aminoisophthalic Acid under Different Synthetic Conditions
A same coordination polymer [Zn(aip)(DMSO)] (aip: 5-aminoisophthalate and DMSO: dimethylsulfoxide) was synthesized using the same reactants (ZnSO4, aip and H2O/DMSO) but in different conditions, in which the stoichiometry (1:1-4:1 metal:ligand ratio), temperature (70 and 100 °C) and synthetic method (liquid-liquid diffusion, solvothermal and conventional wi
J. Braz. Chem. Soc.. Publicado em: 2017-11
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6. Sodium Chloride Crystallization by Electric Discharge in Brine
Electrical discharges in liquids are currently used to synthesize nanoparticles. The plasma-liquid interaction is complex, where parameters such as electric field, ion charges and other species present are important. In order to understand the mechanism of crystallization, mother liquor (saturated solution of NaCl, MgCl2 and KCl) was used to study the effect
Mat. Res.. Publicado em: 06/07/2017
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7. Evaluation of a Thermochromic Liquid Crystal for Use as a Temperature Sensor for Components of Electrical Systems
Connectors used in electrical power distribution systems should allow the passage of electricity continuously and without interruption. However, this does not always occur due to failure caused by improper assembly and/or corrosion of the materials employed, which reflects the quality of service. Notable among the new detection technologies that have been st
Mat. Res.. Publicado em: 22/05/2017
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8. Green tea glycolic extract-loaded liquid crystal systems: development, characterization and microbiological control
ABSTRACT Liquid crystal systems (LCSs) have interesting cosmetic applications because of their ability to increase the therapeutic efficiency and solubility of active ingredients. The aim of the present research was to develop green tea glycolic extract-loaded LCSs, to characterize and to perform microbiological control. The ternary phase diagram was constru
Braz. J. Pharm. Sci.. Publicado em: 2016-09
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9. Self-Organization in Ionic Liquids: From Bulk to Interfaces and Films
In this contribution we present an overview on the relation between the complex structure of ionic liquids (ILs) and its impact in the field of surface science. The results herein described result mainly from modeling and simulation work carried out at Centro de Química Estrutural, Universidade de Lisboa, complemented in some cases by experimental results o
J. Braz. Chem. Soc.. Publicado em: 2016-02
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10. Estudio de estructuras de cis- y trans-estilbeno mediante microscopiade fuerza atómica
ABSTRACTNanotechnology is a multidisciplinary field that emerged in recent years due to the development of tools to "see", study and manipulate matter at atomic and molecular levels. Stilbene and some of its derivatives are organic molecules found in nature, which have chemical structures of interest in nano-fabrication of molecular machine building blocks (
Matéria (Rio J.). Publicado em: 2015-09
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11. REAÇÃO DE CONDENSAÇÃO DO GLICEROL COM COMPOSTOS CARBONÍLICOS. SÍNTESE, CARACTERIZAÇÃO E APLICAÇÃO EM CRISTAIS LÍQUIDOS
Condensation reactions of glycerol with aldehydes and ketones were performed under thermal heating and microwave irradiation regimes. Homogeneous and heterogeneous catalysts were tested in both conditions. A silica sulfated (SiO2-SO3H) heterogeneous catalyst demonstrated the best performance relative to a selectivity of >95% in favor of 5-membered ketals. Fo
Quím. Nova. Publicado em: 2015-09
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12. Quinolines by Three-Component Reaction: Synthesis and Photophysical Studies
The synthesis of five quinolines 8-octyloxy-4-[4-(octyloxy)phenyl]quinoline and 6-alkoxy- 2-(4-alkoxyphenyl)-4-[(4-octyloxy)aryl]quinolines are described by three-component coupling reaction mediated by Lewis acid FeCl3 and Yb(OTf)3. 4-n-octyloxybenzaldehyde, anisaldehyde, 4-n-octyloxyaniline p-anisidine, and 1-ethynyl-4-heptyloxybenzene, 1-ethynyl-4-octylox
J. Braz. Chem. Soc.. Publicado em: 2015-03