Browsing by Author "Anunziata, Oscar Alfredo"
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Item Aniline adsorption and polymerization over gallium modified mesoporous material.(Universidad Tecnológica Nacional., 2018) Martínez , María Laura; Rivoira , Lorena Paola; Beltramone, Andrea Raquel; Anunziata, Oscar Alfredo; Anunziata, Oscar Alfredo; Rivoira , Lorena PaolaIn 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.Item Aniline alkylation with methanol: relationship nature and strength of active sites - catalytic activity(Materials Chemistry, 2019) Juárez, Juliana María; Anunziata, Oscar AlfredoThe products of the alkylation of aniline (A) with methanol (M), both carbon alkylate and N-derivatives are important intermediaries in the organic synthesis. Thus, toluidine (To), N-methylaniline (NMA) and N-dimethylaniline (NNDMA), the main products of this reaction are used as intermediates in the manufacture of dyes, plastics and explosives. The preparation of these products in liquid phase has been widely studied. Naturally, this process in the presence of strong acids generates problems of corrosion and contaminating residues. A comparative analysis between all the reaction products obtained indicates that NMA is the initial product of aniline alkylation with methanol with the highest formation rate. The NNDMA would come from the alkylation of the NMA following a relatively similar behavior. NNDMT follows a particular behavior. It is always secondarily unstable except in SBS-SLS (Strong Bonsted - Strong Lewis site pairs), where it is stable at high conversion levels. To is always an unstable secondary product, except for the SBS-SBS (stable) group, with a maximum formation rate in SBS-SLS between 15-20% of aniline conversion and more than 20% in the neighboring SBS-SBS.Item Controlled drug release system: MCF-Chlorambucil mesoporous foam(2022) Juárez, Juliana M.; Cussa, Jorgelina; Anunziata, Oscar Alfredo; Goméz Costa, Marcos BrunoMesostructured cellular foam (MCF) is a promising material for drug delivery systems due to its high biocompatibi0lity, biodegradability, and low toxicity. Its properties include a large surface area, uniform large pore. In this work, the MCF mesoporous foam was successfully synthesized for its application in drug nanocarriers, specifically Chlorambucil, obtaining the MCF-CLB composite. The synthesis of the mesoporous material and the process of incorporation of Chlorambucil in the pores of the MCF were successful as shown in the XRD, UV Vis Ref. Difusa, TEM analysis and analysis of textural properties. The release of the drug was conducted by simulating the physiological conditions to reproduce the conditions of the organism. The mechanism of drug release from the MCF-CLB host was evaluated. Different mathematical models were used to adjust the experimental data, the best model describing the phenomenon under study over the entire period is the Weibull model. The auspicious results we attained for the release of the drug using the new material, the main advantage of this release is that the rate of release is fast at the beginning and then gradually decreases until 24 h practically all the drug contained in the carrier is released (>95%).Item Controlled drug release system: MCF-Chlorambucil mesoporous foam.(Univesidsad Tecnológica Nacional, 2022) Júarez , Juliana María; Cussa , Jorgelina; Anunziata, Oscar Alfredo; Gómez Costa, Marcos Bruno; Anunziata, Oscar AlfredoMesostructured cellular foam (MCF) is a promising material for drug delivery systems due to its high biocompatibi0lity, biodegradability, and low toxicity. Its properties include a large surface area, uniform large pore. In this work, the MCF mesoporous foam was successfully synthesized for its application in drug nanocarriers, specifically Chlorambucil, obtaining the MCF-CLB composite. The synthesis of the mesoporous material and the process of incorporation of Chlorambucil in the pores of the MCF were successful as shown in the XRD, UV Vis Ref. Difusa, TEM analysis and analysis of textural properties. The release of the drug was conducted by simulating the physiological conditions to reproduce the conditions of the organism. The mechanism of drug release from the MCF-CLB host was evaluated. Different mathematical models were used to adjust the experimental data, the best model describing the phenomenon under study over the entire period is the Weibull model. The auspicious results we attained for the release of the drug using the new material, the main advantage of this release is that the rate of release is fast at the beginning and then gradually decreases until 24 h practically all the drug contained in the carrier is released (>95%).Item Desulfuración oxidativa utilizando material mesoporoso Ti-SBA-16(2014) Rivoira, Lorena Paola; Vallés, Verónica; Ledesma, Brenda; Martínez, María Laura; Anunziata, Oscar Alfredo; Beltramone, Andrea RaquelLa oxidación de compuestos organosulfurados conduce a la formación de los sulfóxidos/sulfonas correspondientes, lo que permite que sean fácilmente removidos mediante extracción en solventes polares o por adsorción. El proceso de ODS es llevado a cabo bajo condiciones muy suaves, comparado con el proceso convencional de HDS. El objetivo del presente trabajo es estudiar el efecto del método de preparación de SBA-16 modificada con titanio en el rendimiento de la ODS del DBT con H2O2 y acetonitrilo como solvente en condiciones suaves de reacción. Se estudiaron dos materiales TiO2-SBA-16 obtenido por impregnación húmeda y Ti-SBA-16 obtenido mediante síntesis directa. con una relación de Si/Ti=20. Para la actividad catalítica se lleva a cabo la reacción de oxidación a 70°C y presión atmosférica se utilizó un reactor batch. Se utilizó H2O2 como agente oxidante y acetonitrilo como solvente.Item Direct synthesis of ordered mesoporous carbon applied in hydrogen storage(Springer Science+Business Media, 2018) Juárez, Juliana María; Gómez Costa , Marcos Bruno; Anunziata, Oscar AlfredoIn this work, we present a direct, novel and low cost method for the preparation of an ordered mesoporous carbon (OMC). OMC was successfully synthesized by the carbonization of the silica/triblock copolymer/sucrose composite in the presence of sulfuric acid. The resulting material was characterized by XRD, N2 sorption analysis and TEM techniques. The novel synthesis technique improved significantly the H2 storage properties (3.78 wt%) compared with that of CMK-3 synthesized using the nanocasting strategy (2.2 wt%) at 77 K and 10 bar.Item Drug delivery system: large pore SBA-15 as host for ketorolac tromethamine(2022) Juárez, Juliana María; Cussa, Jorgelina; Anunziata, Oscar Alfredo; Gómez Costa, Marcos BrunoDrug-controlled release systems can keep the level of drugs in precise doses in the body above the optimal level and with low toxicity. We propose the LP-SBA-15 nanomaterial as a promising new host for drug delivery systems because of its high biocompatibility, in vivo biodegradability, and low toxicity. Ketorolac-LP-SBA-15 was prepared and characterized by XRD, FTIR, UV-Vis DRS, TEM, and texture analysis, determining the adsorption capacity and its release, achieving the required therapeutic efficacy. The host shows ordered mesoporous nanochannels with a diameter of 11-12 nm, maintaining the structure with the incorporation of Keto. The mechanism of drug release the LP-SBA-15 host was evaluated. Different mathematical models were used to adjust the experimental data, being the Ritger-Peppas model followed by the Weibull model the best ones. In this work, we show a promising drug storage material for effective encapsulation and controlled release of KETO, achieving the required therapeutic efficacy. Studies indicate that KETO was adsorbed on the channel surface of LP-SBA-15 without affecting the structure or chemical composition of KETO. Controlled drug delivery systems can achieve precise delivery at the time and place of destination, keeping the concentration of the drug at points in the body within the optimal range and below the toxicity threshold. The study also demonstrates the storage capacity and release properties of LPSBA-15 containing KETO. The release of KETO contained in LP-SBA-15 can offer a significant improvement in the controlled release of the drug and the analgesic and anti-inflammatory effects, positively influenced, by the links formed between the host and drug molecules and by diffusion through the host porosity. The promising results we obtained for the release of the drug thoroughly using the new material, reaching a rapid initial release rate, and maintaining a constant rate afterward, allow us to maintain the concentration of the drug in the therapeutic efficacy range, applying it largely to the treatment of diseases that require a rapid response.Item Drug release system. Nanostructured Ketorolactromethamine/MCF composite(CICAT, 2018) Cussa , Jorgelina; Juárez, Juliana María; Prados, Antonela M.; Gómez Costa , Marcos Bruno; Anunziata, Oscar AlfredoLos sistemas controlados de administración de fármacos mantienen la concentración de medicamentos en los lugares específicos del cuerpo, mejorando la eficacia terapéutica y reduciendo la toxicidad. El material de espuma celular mesoestructurada (MCF) es un nuevo y prometedor huésped para los sistemas de administración de fármacos debido a su alta biocompatibilidad, biodegradabilidad in vivo y baja toxicidad. El composite Ketorolaco-Tromethamine/MCF fue sintetizado. La síntesis de material y la carga de ketorolacotrometamina en los poros de MCF fueron exitosas, demostrándose mediante XRD, FTIR, TGA, TEM y análisis de textura. Obtuvimos resultados prometedores para la liberación controlada de fármacos utilizando el nuevo material MCF. La aplicación de estos materiales en la liberación de KETO es innovadora, logrando una alta velocidad inicial y luego manteniendo una velocidad constante en tiempos altos. Esto permite mantener la concentración del fármaco dentro del rango de eficacia terapéutica, siendo altamente aplicable para el tratamiento de enfermedades que necesitan una respuesta rápida. La liberación de KETO/MCF se comparó con otro soporte de KETO (KETO / SBA-15) y tabletas comerciales.Item Drug release system: Chlorambucil loaded in mesoporous cellular foam (MCF)(2022) Juárez, Juliana María; Anunziata, Oscar Alfredo; Gómez Costa, Marcos BrunoNanotransporters have received a great deal of research attention because of their promising opportunities in drug delivery [1-5]. Attempting to minimize the secondary adverse events of anticancer drugs and enhance the therapeutic rate, various nanotransporters have been devised, including dendrimers [6, 7], liposomes [8, 9], inorganic nanoparticles, and polymeric nanoparticles [10-13]. Chlorambucil (CLB), is a substance classified as a human carcinogen [14], it is used as a chemotherapy drug administered for treating some types of cancer. It is mainly used to treat chronic lymphocytic leukemia, low-grade nonHodgkin's lymphoma, Hodgkin's lymphoma and ovarian cancer. Chemically, it is 4-[4-bis(2-chloroethyl) amino phenyl butyric acid. MCFs (mesostructured siliceous cellular foams), that can be derived after the inclusion of a bulking medium in the synthesis procedure of SBA-15 [4], are composed of spherically uniform cells 15-50 nm diameter [15], exhibit high surface areas and porosities, and have adjustable pore size distributions [15, 16]. The open large pore system gives MCF unique advantages as catalyst support and separation media for processes involving large molecules. In addition to their specific physicochemical properties, they possess high biocompatibility and low adverse effects, which with their biodegradability, making them attractive for controlled drug release applications.Item Efficient retention of fluorides using SBA-3mesoporous Material.(Univesidsad Tecnológica Nacional, 2022) Cussa, Jorgelina; López , Claudia; Anunziata, Oscar Alfredo; Anunziata, Oscar AlfredoHighly ordered pore mesoporous silica composites, like SBA-3 and hydroxyapatite (HaP) nanocrystals, characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and textural properties, were successfully applied to remove fluoride from contaminated water. The proposed procedure to prepare HaP/SBA-3 was successful, which acts as supports to anchor the HaP crystals, in nanometer-scale (<2 nm), with higher fluoride retention from contaminated water. The free OH- groups of HaP nanocrystals, within the host, facilitated the high-performance fluoride trapping. The fluoride retention activity was much higher than that of pure HaP and the composites HaP/SBA-15 and HaP/MCM-41.Item Eliminación de azufre mediante desulfuración oxidativa con SBA-16 modificada con titanio(2014) Rivoira, Lorena Paola; Vallés, Verónica; Ledesma, Brenda; Martínez, María Laura; Anunziata, Oscar Alfredo; Beltramone, Andrea RaquelLa oxidación de compuestos organosulfurados conduce a la formación de los sulfóxidos/sulfonas correspondientes, los cuales son mucho más polares, lo que permite que sean fácilmente removidos mediante extracción en solventes polares o por adsorción. El proceso de ODS es llevado a cabo bajo condiciones muy suaves (presión atmosférica y 60-90ºC), comparado con el proceso convencional de HDS, donde comúnmente son usadas presiones mayores a los 30 bar y temperaturas desde los 300 a los 380ºC. Resultados recientes muestran que tamices moleculares que contienen Ti exhiben buena reactividad catalítica en la oxidación de sulfuro, mercaptano, tiofeno y derivados (1). El objetivo del presente trabajo es estudiar el efecto del método de preparación de SBA-16 modificada con titanio (características de las especies activas de Ti y/o TiO2) en el rendimiento de la ODS del DBT con H2O2 y acetonitrilo como solvente en condiciones suaves de reacción.Item Estudio de la influencia de la temperatura de síntesis y la concentración de surfactante en la síntesis de SBA-3(2014) Ponte, María Virginia; Martínez, María Laura; Gómez Costa, Marcos Bruno; Anunziata, Oscar Alfredo; Beltramone, Andrea RaquelEn este trabajo se presentan resultados de preparación y caracterización de SBA-3, estudiando la variación de la temperatura de síntesis, así como la de la relación molar CTAB/TEOS. Condiciones de síntesis suaves (303 K) y adecuadas relaciones de surfactante/precursor de silicio conducen a un material mesoporoso con un ordenamiento regular hexagonal, característico de SBA-3 con elevada regularidad estructural.Item Fe-CMK-3 nanostructured material applied in hydrogen uptake J.(Catalysis Society of Australia, 2019) Juárez, Juliana María; Gómez Costa , Marcos Bruno; Anunziata, Oscar AlfredoAll over the world in the past decades, one of the most concerning subjects has been fossil fuel reduction, along with the global warming issue. These concerns have made hydrogen an ideal alternative to conventional fossil-fuel resources. Nevertheless, it has serious disadvantages, such as low volumetric and gravimetric densities that limit its storage [1]. One kind of OMC involves the carbon mesostructured from Korea (CMK). CMK-3 was chosen as a support material for hydrogen storage due to its large surface area, high chemical stability, uniform pore diameter, accessible porosity and three-dimensional conducting network [2]. Metal particles dispersed in the porosity of active carbons are largely contributing to enhanced storage abilities. In this work we studied the influence of the incorporation of iron nanoparticles inside the channels of CMK-3. This could help and make it possible storing hydrogen in carbon and silica matrix but with another mechanism, with a better reversibility improving hydrogen adsorption/desorption behavior.Item Ga-SBA-3 A novel nanostructured material: synthesis, characterization and application(IOP Publishing, 2019) Martínez, María Laura; Gómez Costa , Marcos Bruno; Anunziata, Oscar AlfredoThis paper reports for the first time the incorporation of gallium into the structure of the mesoporous SBA-3 material in order to modify the intrinsic acidity of the material. The study indicates the effective incorporation of Ga into a network in tetrahedral form, with most in the interior of the lodging and a low proportion on the external surface. Gallium was introduced via post-synthesis using Ga-nitrate in appropriate conditions. The nanostructured material was characterized by ICP, x-ray diffraction, nuclear magnetic resonance-MAS, x-ray photoelectron spectra, FTIR, SEM, transmission electron microscopy and UV–vis. Pyridine was used as a probe molecule for the determination of its acidity following the amount and type of acidic sites by FTIR. In addition, aniline adsorption/desorption studies and subsequent in situ polymerization, polyaniline (PANI)/Ga-SBA-3, were carried out with the aim of producing a nanocomposite with conductive properties. The original material had good structural regularity and acidity of Brønsted and Lewis; the PANI/Ga-SBA-3 composite also showed a conductivity of 2.5 × 10−3 S cm−1, higher than that of its homologs Al-SBA-3 and Al-MCM- 41.Item H2 storage using Zr-CMK-3 developed by a new synthesis method(2021) Juárez, Juliana María; Venosta, Lisandro F.; Anunziata, Oscar Alfredo; Gómez Costa, Marcos BrunoOne of the biggest problems in using hydrogen as an alternative fuel is that its storage must be safe and portable. This work addresses a new direct synthesis technique used to obtain a novel mesoporous carbon (CMK-3) modified with zirconium oxide. This novel material shows promise for hydrogen adsorption and storage application for energy harvesting. Zirconium oxide (Zr-CMK-3) material is achieved through successful synthesis and characterized by XRD, SEM, Raman, BET, UV-Vis-DRS, XPS and TEM analyses. Zr-CMK-3 signifi- cantly improved H2 storage performance (reaching at 77 K and 10 bar 4.6 wt%) compared to the pristine CMK-3. The novel material is favorable for H2 uptake by using weak bonding (physisorption). A hydrogen uptake mechanistic approach is proposed and the role of the Zr+4 cation in hydrogen adsorption is discussed.Item H2 storage using Zr-CMK-3 developed by a new synthesis method.(Univesidsad Tecnológica Nacional, 2021) Juárez , Juliana María; Venosta , Lisandro; Anunziata, Oscar Alfredo; Gómez Costa , Marcos Bruno; Anunziata, Oscar AlfredoOne of the biggest problems in using hydrogen as an alternative fuel is that its storage must be safe and portable. This work addresses a new direct synthesis technique used to obtain a novel mesoporous carbon (CMK-3) modified with zirconium oxide. This novel material shows promise for hydrogen adsorption and storage application for energy harvesting. Zirconium oxide (Zr-CMK-3) material is achieved through successful synthesis and characterized by XRD, SEM,Raman, BET, UV-Vis-DRS, XPS and TEM analyses. Zr-CMK-3 signifi- cantly improved H2 storage performance (reaching at 77 K and 10 bar 4.6 wt%) comparedto the pristine CMK-3. The novel material is favorable for H2 uptake by using weak bonding (physisorption). A hydrogen uptake mechanistic approach is proposed and the role of the Zr+4 cation in hydrogen adsorption is discussed.Item HaP/SBA-3 Nanostructured Composite to Remove Fluoride Effectively from Contaminated Water.(Univesidsad Tecnológica Nacional, 2021) Cussa, Jorgelina; López , Claudia; Anunziata, Oscar Alfredo; Anunziata, Oscar AlfredoHighly ordered pore mesoporous silica composites, like SBA-3 and hydroxyapatite (HaP) nanocrystals, characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and textural properties, were successfully applied to remove fluoride from contaminated water. The proposed procedure to prepare HaP/SBA-3 wassuccessful, which acts as supports to anchor the HaP crystals, in nanometer-scale (<2nm), with higher fluoride retention from contaminated water. The free OH- groups of HaP nanocrystals, within the host, facilitated the high-performance fluoride trapping. The fluoride retention activity was much higher than that of pure HaP and the composites HaP/SBA-15 and HaP/MCM-41.Item HDN of indole over Ir-modified Ti-SBA-15.(Universidad Tecnológica Nacional Regional Córdoba., 2017) Ledesma , Brenda Cecilia; Anunziata, Oscar Alfredo; Beltramone , Andrea RaquelIridium catalyst was prepared using a novel tita nium oxide-CMK-3 support synthesized as a replica of Ti SBA-15. The catalyst was applied in the hydrodenitrogena tion of indole. The activity was compared with an iridium catalyst supported over a grafted titanium-CMK-3. Struc tural and textural characterization of the catalysts was per formed by means of N2 adsorption, XRD, UV–Vis–D Raman spectroscopy, XPS, TEM and H2 Chemisorption. Ir-Ti-CMK-3 was the most active catalyst for the hydro denitrogenation reaction at mild conditions. Titanium oxide contained in carbon ordered mesoporous CMK-3 promotes a very good anchorage of iridium metallic clusters in the carbon framework reaching high active site distribution and more stable nanoclusters.Item Hidrogenación de tetralin en presencia de quinolina sobre Ir/SBA-16 modificada con titanio(2014) Ledesma, Brenda; Vallés, Verónica; Rivoira, Lorena Paola; Anunziata, Oscar Alfredo; Beltramone, Andrea RaquelEn el presente trabajo informamos resultados de la hidrogenación efectiva de tetralin en presencia de quinolina, en condiciones menos severas que las industriales; para lo cual desarrollamos un nuevo material catalítico mesoporoso Ir/SBA-16 modificado con titanio. La incorporación de Ti facilitó la mayor y mejor homogeneidad en la dispersión de partículas de Ir metálico (Ir0). Para conocer el efecto en la dispersión del metal de transición (1), el Ti fue incorporado vía post síntesis como TiO2 y en red empleando el método sol-gel obteniendo así los catalizadores Ir/TiO2-SBA-16 e Ir/Ti-SBA-16.Item Hidrogenación de tetralin utilizando un catalizador bifuncional de iridio/platino-SBA-15(2014) Vallés, Verónica; Ledesma, Brenda; Rivoira, Lorena Paola; Cussa, Jorgelina; Martínez, María Laura; Anunziata, Oscar Alfredo; Beltramone, Andrea RaquelLos catalizadores bimetálicos de Pt–Pd han recibido considerable atención debido a que demuestran tener una alta actividad en una amplia variedad de aplicaciones catalíticas (1). Con alta actividad, selectividad y estabilidad, comparada con catalizadores monometálicos de Pt y Pd. Por ejemplo, catalizadores bimetálicos Pt-Pd muestran tener mayor resistencia frente a envenenamientos en comparación con catalizadores de Pt (2-4). Las características estudiadas del catalizador serán correlacionadas con su performance catalítica en la hidrogenación del tetralin. El objetivo final es encontrar la proporción óptima de cada uno de los metales de forma de lograr la mayor actividad en dicho proceso.