2,2'–(2,5-bisoctyloxy-1,4-phenylenvinylidene)bis-8-acetoxyquinoline (TrimQ1), 2,2’-(2,5-bisoctyloxy-1,4-phenylendivinylene)bis-6-bromoquinoline (TrimQ2) 2,2'–(2,5-bisoctyloxy-1,4-phenylendivinylene)bis(8-acetoxy-5,7-dichloro)quinoline(TrimQ3), were synthesized and characterized by different spectroscopic methods. The fluorescent properties of these bisphenylenvinylenquinoline oligomers were analyzed by fluorescence spectroscopy and then the quantum yields were calculated. The order of light emitting properties: (TrimQ3) (quantum yield, 75%) > (TrimQ2) (quantum yield, 21% ) > (TrimQ1) (quantum yield, 5%), showing that TrimQ3 is more suitable for OLED construction than other compounds. Thin films were prepared by spin coating from concentrated solutions of the compounds using a polystyrene (PS) matrix on glass. Prototypes of diodes were fabricated using ITO/organic film/In-Ga a configuration. For all the devices, electroluminescence properties also were analyzed through applying a voltage larger than 8 V and a current of 4 mA.
En el presente trabajo se realizó la lixiviación de los metales no nobles en el sistema O2-H2SO4 a diferentes concentraciones de [H3O+], tales como: 1x10-0.3 M, 1x10-1 M, 1x10-2 M, 1x10-2.5 M, 1x10-3 M, 1x10-4 M. Observándose que las constantes de velocidad aumentan al incrementar la concentración de ácido, favoreciéndose la velocidad de la lixiviación del Cu, Ni y Zn; el orden reacción para cada metal a es de: Cu, n = 0.65037, Ni, n = 0.1368 y Zn, n = 0.0895. En todos los casos al final del proceso de lixiviación se obtuvo un polvo sólido dorado, el cual al ser caracterizado por microscopía electrónica de barrido mediante espectroscopía de rayos X de energía dispersa, SEM-EDS, se determinó que se trata de oro metálico con una pureza del 99.6%.
El presente artículo muestra el diseño y análisis de esfuerzos de un dado de compactación para la obtención de materiales compuestos de metal – polímero, mediante prensado uniaxial. Adicionalmente, son analizadas y discutidas las propiedades más relevantes de algunos materiales compuestos metal – polímero con potencial de ser usados como concentradores de flujo magnético.
This lab-scale experimental study presents a novel combined hydrometallurgical and electrochemical process for gold and non-precious metals (Cu, Ni, Pb and Zn) recovery, from waste printed circuit boards (PCB´s). First, a leaching of pins from PCB´s has been carried out and complete gold extraction was obtained using H2SO4 0.5 M (pH ≈ 1.5)/O2 (1 atm) in the temperature range from 288 to 343 K. The activation energies found showed values of 97.2 kJ∙mol-1, 86 kJ∙mol-1 and 93.6 kJ∙mol-1 for Cu, Ni and Zn respectively. Afterwards, leaching liquor was treated electrochemically in several conditions: selective Cu and Pb removal was performed at pH 1.5 and Ni and Zn removal was also obtained when pH increased to 5. All processes involved here are friendly, and even, final liquor could be reutilized.
Enzymes are found in nature as part of living systems and perform essential functions for nature. Enzyme technology is an interdisciplinary field recognized by the Organization for Economic Cooperation and Development (OECD) as an important component of industrial development. Processes involving industrial processes, pharmaceutical development and discovery, as well as genetic engineering.
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