Facultad Regional Córdoba

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    Aniline adsorption and polymerization over gallium modified mesoporous material.
    (Univesidsad Tecnológica Nacional., 2018) Martínez , María Laura; Rivoira , Lorena Paola; Beltramone, Andrea Raquel; Anunziata , Oscar Alfredo; Anunziata , Oscar Alfredo; Rivoira , Lorena Paola
    In this work we study aniline polymerization over a mesoporous Ga-SBA-3 synthesized in our laboratory. In order to modify the intrinsic acidity of the mesoporous material gallium was incorporated into the structure by post synthesis wet impregnation method using gallium nitrate. Structural and textural characterization of the materials was performed by X-ray diffraction (XRD), ICP and EDX analysis, N2 adsorption-desorption and BET area analysis, FTIR and scanning electron microscopy (SEM). The catalytic material presented a ratio Si/Ga=32. Aniline is a weak organic base and an amphiprotic compound, so it can accept or donate protons. The polyaniline (PANI) exists in diverse ways presenting different chemical and physical properties. The protonated polyaniline feature the conductivity of a semiconductor material, over 100 S/cm. Toward achieve aniline adsorption, the solid gallium silicate was exposed to aniline vapours. The aniline adsorption was studied by infrared spectroscopy and the results obtained were evaluated so as to been able to polymerize it over the mesoporous material generating a unique polyaniline-host composite with new properties. Those polyaniline/hosts composites obtained by a polymerization in-situ technique were characterized by infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. Comparing to previous results FTIR analysis of the polyaniline/Ga SBA-3 composite (PANI/Ga-SBA-3) showed characteristics bands attributed to the quinoidal stretching (N=Q=N) and C-C stretching of the benzene ring. The low angle XRD analysis showed that the mesoporous structure was maintained in spite of the gallium incorporation. The absence of PANI peaks and G2O3 in the wide angle XRD pattern confirms that the polyaniline is adsorbed over the gallium silicate mesoporous surface and the gallium is well dispersed over the support.
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    Synthesis and characteristics of CMK-3 modified with magnetite nanoparticles for application in hydrogen storage.
    (Univesidsad Tecnológica Nacional, 2020) Venosta, Lisandro; Juárez , Juliana María; Anunziata , Oscar Alfredo; Bercoff, Paula; Gómez Costa , Marcos Bruno; Anunziata , Oscar Alfredo; Juárez , Juliana María
    : In this work, we report the synthesis and characterization of iron oxide nanoparticles supported in nanostructured carbon (CMK-3). This material is promising in the application of hydrogen adsorption for energy storage. The material with iron oxide nano particles (Fe-CMK-3) was successfully synthesized and characterized by X-ray diffraction, textural properties analysis, transmission and scanning electron microsco py, X-ray photoelectron spectroscopy, and magnetiza tion studies. A large amount of the iron incorporated as iron oxide nanoparticles was in the magnetite phase. The incorporation of magnetite on the CMK-3 carbon surface significantly improved the storage capacity of hydrogen (4.45 wt% at 77 K and 10 bar) compared with the CMK-3 framework alone (2.20 wt% at 77 K and 10 bar). The synthesized material is promising for hy drogen adsorption by weak bond forces (physisorption). A hydrogen adsorption mechanism was proposed in which the nanoparticles of magnetite have an important role.
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    Synthesis and characteristics of CMK-3 modified with magnetite nanoparticles for application in hydrogen storage
    (2022) Juárez, Juliana María; Cussa, Jogelina; Anunziata, Oscar Alfredo; Gómez Costa, Marcos Bruno
    In this work, we report the synthesis and characterization of iron oxide nanoparticles supported in nanostructured carbon (CMK-3). This material is promising in the application of hydrogen adsorption for energy storage. The material with iron oxide nano- particles (Fe-CMK-3) was successfully synthesized and characterized by X-ray diffraction, textural properties analysis, transmission and scanning electron microsco- py, X-ray photoelectron spectroscopy, and magnetiza- tion studies. A large amount of the iron incorporated as iron oxide nanoparticles was in the magnetite phase. The incorporation of magnetite on the CMK-3 carbon surface significantly improved the storage capacity of hydrogen (4.45 wt% at 77 K and 10 bar) compared with the CMK-3 framework alone (2.20 wt% at 77 K and 10 bar). The synthesized material is promising for hy- drogen adsorption by weak bond forces (physisorption). A hydrogen adsorption mechanism was proposed in which the nanoparticles of magnetite have an important role.
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    Óxidos mixtos de CoFe y MgFe utilizados en la remediación de agua contaminada con ársenico
    (2014) Heredia, Angélica; Agu, Ulises Ariel; Ullan, María Luz; Herrero, Eduardo R.; Crivello, Mónica Elsie
    La contaminación de agua subterránea con arsénico (As) es un problema muy extendido en el territorio Argentino, la misma es de origen natural y afecta la región norte y centro del país. Los compuestos hidrotalcitas (HT) son una clase de arcilla aniónica bidimensional cuya fórmula general puede ser descrita como: [M(II)1-xM(III)x (OH)2](An-)n/x.mH2O, donde M(II) y M(III) son metales +2 y +3 mientras que A = (CO3)=. La descomposición térmica a 450 °C genera óxidos mixtos de gran área superficial. Las HT se sintetizaron por coprecipitación utilizando metales Mg, Co, Fe, Al. Todas las muestras fueron calcinadas en atmosfera de aire a 450 ºC por 9 hs y se evaluaron en la remoción de arsénico en agua subterránea contaminada. El material fue caracterizado por DRX, área superficial y UV-Vis con reflectancia difusa. La remoción de As se llevó a cabo en un reactor tipo Batch agitado magnéticamente a temperatura ambiente, se utilizó 0.1 g de óxidos con 70 ml de solución de concentración 0.1 mg/L de As (III). Los tiempos de análisis fueron a 5 y 10 minutos. Se pudo observar que los oxidos de MgFe mostraron una mayor adsorción que los óxidos de CoFe. Las muestras se analizaron mediante Test colorimétrico de Arsénico Merckoquant. La concentración de As disminuyó por debajo de 0,01 mg/L (límite establecido por la Organización Mundial de la Salud, la EPA y el Código Alimentario Argentino) en 10 minutos de contacto, con las muestras de MgFe.