Examinando por Materia "Aromatic compounds"

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    Effect of CeO2 content in morphology and optoelectronic properties of TiO2-CeO2 nanoparticles in visible light organic degradation
    (ELSEVIER SCI LTD, 2019-02-01) Cano-Franco, JC; Alvarez-Lainez, M; Universidad EAFIT. Departamento de Ingeniería de Diseño; Ingeniería de Diseño (GRID)
    TiO2 is a semiconductor widely used in photocatalytic degradation of organic pollutants due to its band gap energy. However, its absorption range is restricted only to UV radiation that is less than 10% of solar light. With the aim of increasing the adsorption area on TiO2 nanoparticles a modified sol-gel method was used to produce a smaller particle size, and to extend the absorption range to the visible spectrum, TiO2 nanoparticles were synthesized with different CeO2 contents to generate semiconductor heterojunction between them. The crystallographic, morphological, and optoelectronic characteristics of these TiO2-CeO2 nanoparticles were studied, and two crystalline phases were differentiated: anatase for TiO2 and fluorite for CeO2. An increase in the CeO2 content produced crystallite sizes between 6.5 nm and 12.0 nm. TiO2-CeO2 nanoparticles showed morphological properties such as small particle size, heterogeneous surface and high BET surface area compared to bare commercial TiO2. These features involve a positive effect of CeO2 in TiO2 nanoparticles surface, thus TiO2-CeO2 nanoparticles exhibit enhanced optoelectronic properties caused by a decrease in the effective band gap and red-shift in the electromagnetic spectrum. In addition, methylene blue degradation showed that TiO2-CeO2 nanoparticles are suitable for high photocatalytic activity application under visible light. © 2018 Elsevier Ltd
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    Evaluación de la actividad antimalárica y citotóxica de estirilquinolinas obtenidas a partir de 8-hidroxiquinaldina con aldehídos aromáticos
    (Centro de Informacion Tecnologica, 2014-01-01) Torres, O.L.; Espinosa, R.D.; Saez, A.A.; Santafé, G.G.; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)
    This study reports the synthesis of five (E)-Styrylquinolines (Q.1, Q.2, Q.3, Q.5, Q.6) and three O-alkylated derivatives (Q.1a, Q.6a, Q 6 b) and the evaluation of its antimalarial activity and cytotoxic in vitro. For Styrylquinolines Perkin condensation reaction type from 8-hydroxyquinaldine with aromatic aldehydes was used. Antimalarial activity was performed using the method Radioisotope with FCB-2 strains of Plasmodium falciparum (chloroquine-resistant) and for the cytotoxic activity the MTT method with HepG2 cells was employed. Most compounds showed to be active antimalarial. Those with higher activity were Q.3 (IC50 6.4µM) and Q.5 (IC50 10.8 µM), although all of them were cytotoxic at concentrations above 1 µg / mL. The structures of these compounds were confirmed using infrared spectroscopy techniques and MRI in one and two dimensions. © 2014, Centro de Informacion Tecnologica. All rigths reserved.
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    Extracción de compuestos aromáticos con furfural en aceites lubricantes recuperados
    (Universidad EAFIT, 2015) Meléndez Hernández, Marianna Andrea; Sánchez Cossio, Javier Arley
    Se presenta un estudio experimental y diseño conceptual con especificación de equipos y análisis económico de un proceso de extracción con furfural de compuestos aromáticos presentes en la base lubricante recuperada, para su decoloración y desodorización, después del proceso de regeneración de aceites usados en la empresa Biochemical Group -- Se realiza un diseño de experimentos factorial 32 para evaluar el proceso determinando la composición de hidrocarburos aromáticos en el extracto y refinado, se tiene en cuenta los factores de relación solvente/base lubricante y temperatura de operación -- De acuerdo a los resultados obtenidos en el diseño experimental la concentración adecuada es 50% de base lubricante recuperada y 50% de furfural, a una temperatura de 90°C obteniendo una remoción de 0,034 mL, equivalente al 0,04% de compuestos aromáticos