Browsing by Author "Juárez , Juliana María"

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    Aplicación de materiales nanoestructurados del tipo MCF Y R-MCF para la liberación modificada de ibuprofeno .
    (Univesidsad Tecnológica Nacional, 2014) Cussa , jorgelina; Juárez , Juliana María; Juárez , Juliana María
    Los nuevos materiales mesoporosos, Espuma Celular Mosoporosa (MCF) y su Replica Carbonosa (R MCF) son materiales tridimensionales (3D), con poros ultra-grandes (hasta 500 Å), formados por células esféricas uniformes interconectadas. Debido a su sistema de nanoporos 3D con tamaños de poro sustancialmente más grandes que los de las MCM´s o SBA’s, es un candidato muy prometedor para ser utilizado como hospedaje en aplicaciones bio-nanotecnologicas, ya que proporciona una mejor difusión, disminuyendo así los problemas de transferencia de masa. Los sistemas de liberación de fármacos están formados por un principio activo y un sistema transportador, que puede dirigir la liberación del fármaco al sitio adecuado y en la cantidad apropiada. La Nanotecnología aplicada a la liberación de fármacos incrementa la efectividad del medicamento mediante el control preciso de la dosis requerida y del tamaño, la morfología y las propiedades superficiales del compuesto, ya que posibilita la fabricación de dispositivos a escala nanométrica, permitiendo a estos dispositivos atravesar poros y membranas celulares. La liberación del ibuprofeno se realiza introduciendo las muestras en el medio "Simulating Body Fluid" (SBF). El ensayo es dinámico, con agitación a 60 rpm a 37ºC para reproducir las condiciones de liberación en el cuerpo humano. Se tomaron alicuotas a tiempos programados. La concentración de ibuprofeno se determinó por HPLC. La liberación de ibuprofeno en la MCF es muy alta ya que a la hora se ha liberado mas del 80% del fármaco incluido en el material. En el caso de la R-MCF la liberación del ibuprofeno es mas gradual, liberándose a la hora el 50% y el 90% a las 7 horas, lo cual es absolutamente novedoso. La aplicación de estos materiales como hospedajes-transportadores en el estudio la liberación modificada de Ibuprofeno, posibilitaría manejar una dosis alta y masiva o una dosis gradual y constante en el tiempo.
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    CMK-3 modificada con titanio obtenida mediante un novedoso y rápido método de síntesis aplicada en la desulfuración oxidativa de compuestos organosulfurados.
    (Univesidsad Tecnológica Nacional., 2018) Rivoira , Lorena Paola; Ledesma, Brenda Cecilia; Juárez , Juliana María; Beltramone , Andrea Raquel; Juárez , Juliana María; Ledesma, Brenda
    El nanomoldelado de materiales ha sido el único método para crear materiales mesoporosos de carbono, utilizando plantillas inorgánicas (Ezzeddine et al., 2016). Involucra una última etapa donde se elimina el agente plantilla, lo cual lo hace complicado, largo y de elevado costo. Recientemente Ledesma et al. (2017) demostraron la posibilidad de un método de síntesis más corto para obtener CMK-3 modificada con Ti incorporando las especies de Ti directamente en la estructura del carbón mesoporoso utilizando Ti-SBA-15 como agente plantilla. En la reacción de ODS ocurre la oxidación de aquellos compuestos de S más refractarios en la HDS, utilizando de un agente oxidante en presencia de un catalizador (Subhan et al., 2012). Es necesario agregar un solvente polar al sistema, capaz de extraer las moléculas de S desde la fase diesel para que pueda estar en contacto con el agente oxidante (H2O2, polar) y el catalizador. En el presente trabajo se evalúa la actividad en la ODS de carbón mesoporoso CMK-3 modificado con Ti, sintetizado mediante un novedoso método más corto.
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    Controlled drug release system: cyclophosphamide delivery contained in LP-SBA-15 functionalized with tertbutylamine.
    (Univesidsad Tecnológica Nacional, 2023) Cussa, Jorgelina; Juárez , Juliana María; Gómez Costa, Marcos Bruno; Anunziata, Oscar Alfredo; Anunziata, Oscar Alfredo; Juárez , Juliana María
    Controlled drug administration systems can keep the level of drugs in specific locations in the organism with low toxicity and above the optimal level. We suggest the LP-SBA15 material as a auspicious new host for drug delivery systems because of its low toxicity high biocompatibility and in vivo biodegradability. LP-SBA-15 materials were synthesized and functionalized using 0-15-30% of tert-butylamine (TBA) and used as effective drug delivery systems. The anticancer drug Cyclophosphamide (CP) is an alkylating compound which is a phosphoramide derivative and is habitually used in autoimmune diseases. Reactive oxygen species production has been related to the mechanism of CP-induced cell death or tumor cell killing. The activated metabolites of CP are released in both healthy and tumor tissues and destroy the cellular DNA and proteins as well as mitochondrial and lysosomal membranes. CP was loaded into the nanomaterial of the transporters and characterized by XRD, FTIR, TGA, TEM and texture, determining the adsorption capacity and its release. The release of the drug was studied for each material by simulating the physiological conditions and submerging the composite, at 37 °C with constant stirring, in a HCl solution (0.1 M) for the first two hours and in Buffer solution pH = 7 the following hours to simulate the conditions of the organism. Release experiment were conducted to determine the requisite efficacy of treatment. The study was performed by UV-Vis spectrophotometry to evaluate the amount of CP released. The mechanism of drug release from the LP-SBA-15 matrix was evaluated by adjusting the experimental data, being the Ritger-Peppas. The promising results we obtained for the controlled release of the drug in a controlled manner using the new material, reaching a quick initial release rate and maintaining a constant rate at high moments, allow us to keep the concentration of the drug in the therapeutic efficacy range, applying it to a great extent to the treatment of diseases that require a rapid response. Lastly, it was suggested that the LP-SBA-15 nanomaterial functionalized with 15% TBA was the most desirable system due to they had adequate amounts of both drug loading and release.
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    Direct Synthesis of ordered mesoporous carbon as support of Ir-Catalyst and its application in hydrodenitrogenation of indole.
    (Univesidsad Tecnológica Nacional., 2018) Ledesma, Brenda Cecilia; Juárez , Juliana María; Beltramone, Andrea Raquel; Juárez , Juliana María
    An ordered mesoporous carbon (OMC) modified with titania was prepared using a novel and shorter synthesis method. OMC was successfully synthesized by the carbonization of the silica/TEOT/triblock copolymer/sucrose composite in the presence of sulfuric acid. This novel material was modified with the incorporation of nanoparticles of Iridium. Structural and textural characterization of the catalyst was performed by means of N2 adsorption, XRD, UV–Vis–DRS, Raman spectroscopy, XPS, TEM and H2 Chemisorption. The characterization results indicated that the textural and structural properties of the support synthesized by the short time method are comparable with the properties of the support prepared by the hard template method. Ir-Ti-OMC catalyst obtained by short time synthesis was active and selective in the hydrogenation of indole. Main advantage of the present study is the reduction of time and cost in the synthesis of the new material and the applicability for HDT reactions.
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    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 Alfredo
    One 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.
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    Iron modified mesoporous materials as catalysts for ODS of sulfur compounds.
    (Univesidsad Tecnológica Nacional., 2018) Rivoira , Lorena Paola; Juárez , Juliana María; Martínez , María Laura; Beltramone, Andrea Raquel; Martínez , María; Juárez , Juliana María
    Se aplicaron catalizadores mesoporosos modificados con Fe en la reacción de ODS de DBTs, utilizando H2O2 como oxidante y acetonitrilo como solvente. Los soportes utilizados fueron SBA-15, MCM-48, CMK-3 y CMK-1.El hierro se incorporó mediante impregnación húmeda utilizando nitrato de hierro. Los catalizadores se caracterizaron por XRD, isotermas de N2, TEM, XPS e ICP. Hemos desarrollado catalizadores con gran área específica y volumen de poro, distribución estrecha del tamaño de mesoporos y especies de hierro altamente dispersas. Se probaron los catalizadores en desulfuración oxidativa de diferentes compuestos de azufre tales como benzotiofeno (BT), dibenzotiofeno (DBT) y 4,6-dimetil dibenzotiofeno 4,6-DMDBT). El catalizador preparado con CMK-3 como soporte fue el más activo para la reacción de ODS. La buena actividad se relacionó con la elevada dispersión de óxidos de hierro, principalmente en la fase magnetita. En la oxidación de DBT y utilizando Fe-CMK-3 se estudiaron la temperatura, peróxido de hidrogeno y concentración inicial de azufre. Se determinaron las condiciones óptimas de operación. Fe-CMK-3 es un catalizador activo y estable para ser aplicado en el proceso industrial de ODS. Palabras clave: SBA-15, MCM-48, CMK-3, CMK-1, Fe.
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    Iron-modified mesoporous materials as catalysts for ODS of sulfur compounds.
    (Univesidsad Tecnológica Nacional, 2018) Rivoira , Lorena Paola; Juárez , Juliana María; Martínez , María Laura; Beltramone , Andrea Raquel; Juárez , Juliana María
    Mandatory environmental regulations have been legislated all over the world so the top permitted content of sulfur in diesel is 15 ppm. ODS is the oxidation of sulfur compounds present in diesel to form sulfoxides and sulfones. These substances are highly polar and hence easily removed by extraction with solvent. Oxidant agent commonly used are peroxides such as hydrogen peroxide and tert-butylhydroperoxide (Di Giusepe et al., 2009). Since Diesel is a non-polar liquid while H2O2 is a polar liquid, a polar solvent is needed. The formed polar products can be easily removed from the operation unit by liquid liquid extraction. Mesoporous materials have been tried showing potential catalytic applications. Transition metals are commonly used as catalyst in ODS such as Mo, Mn, Sn, Fe, Zn, V and Ti (Cedeño-Caero et al., 2011). In this work, we propose the application of different supports as SBA-15, MCM-48, CMK-1 and CMK-3 for the preparation of Fe-catalysts.
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    Ketorolac-tromethamine contained in SBA-15 host as a drug release system,
    (Univesidsad Tecnológica Nacional, 2017) Cussa , jorgelina; Prados, Antonella; Juárez , Juliana María; Gómez Costa , Marcos Bruno; Anunziata , Oscar Alfredo; Anunziata , Oscar Alfredo; Juárez , Juliana María
    Drug delivery is an emerging field mainly focused on targeting drugs. The goal of this targeted delivery is to transport an amount of drugs to desirable sites (such as tumors and diseased tissues) while minimizing unwanted side effects of the drugs on other tissues[1]. Controlled drug delivery systems can achieve precise spatial and temporal delivery of therapeutic agents to the target site[2]. The ordered mesoporous silica SBA-15 has been applied in studies of ketorolac tromethamine adsorption and release. The SBA-15 materials with hexagonal and regular structure were obtained using a triblock copolymer Pluronic P123 as a template and TEOS as a silica source[3]. Ketorolac tromethamine was adsorbed into SBA-15 silica nanochannels using ethanol as solvent. The physicochemical and textural properties of SBA-15 and ketorolac tromethamine/SBA-15 were characterized by X-ray diffraction, thermogravimetric analysis, transmission electron microscopy, Fourier transform infrared spectroscopy and BET surface studies. Drug release was evaluated by soaking the loaded silica mesoporous material into a solution of HCl (0.1N) at initial time (0 - 2 h) and buffer pH 7 at high times at 37 ºC under continuous stirring. Oral commercial Keto tablets (Dolten®) and Keto solution (Keto power) were study for the contrast. Release studies were performed in order to evaluate the required therapeutic efficacy. In this work, we have shown a promising drug storage material for the effective encapsulation and controlled release of KETO, achieving the required therapeutic efficacy. SBA-15/KETO shows characteristic bands of both, drug materials and the inorganic framework. This indicates that KETO was adsorbed into SBA-15 channel surface without affecting the chemical structure or composition of KETO. The study also demonstrates the storage capacity and release properties of SBA-15 containing KETO. The release of KETO contained in SBA-15 can offer significant improve in controlled drug release and enhance a good analgesia effect.
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    LP-SBA-15/Ketorolac Nanocomposite: Development, Characterization, and Mathematical Modeling of Controlled Keto Release.
    (Univesidsad Tecnológica Nacional, 2023) Cussa, jorgelina; Juárez , Juliana María; Gómez Costa, Marcos Bruno; Anunziata, Oscar Alfredo
    Drug-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 nanomaterial LP-SBA-15 as an attractive new host for drug delivery systems due to its high biocompatibility, in vivo biodegradability, and low toxicity. LP-SBA-15/Ketorolac was prepared and characterized by XRD, FTIR, UV-Vis DRS, TEM, and texture analysis, determining the adsorption capacity and its release and achieving the required therapeutic efficacy. The host shows the ordered mesoporous nanochannels with a diameter of 11-12 nm, maintaining the structure with the incorporation of Keto. The mechanism of drug release from the LP-SBA-15 host was evaluated. Different mathematical models were used to adjust the experimental data, the Ritger-Peppas model followed by the Weibull model the best ones. 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.
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    Mesoporous Cellular Foam (MCF): an efcient and biocompatible nanomaterial for the controlled release of Chlorambucil.
    (Univesidsad Tecnológica Nacional, 2022) Juárez , Juliana María; Cussa , jorgelina; Gómez Costa, Marcos Bruno
    Nanotransporters have entered a great deal of exploration attention because of their promising openings in medicine delivery. We propose in this work, the Mesostructured siliceous cellular (MCFs) nanomaterial as a promising new hostfor drug delivery systems because both their specific physicochemical properties, in addition to the high biocompatibility, biodegradability, and low toxicity, make them seductive for controlled medicine release operations. Chlorambucil, is used as a chemotherapy drug administered for treating some types of cancer, chronic lymphocytic leukemia, low-grade non Hodgkin’s lymphoma, Hodgkin’s lymphoma and ovarian cancer. Chlorambucil-loaded Mesostructured cellular foam (MCF-CLB) was prepared and characterized by XRD, TEM, UV Vis DRS, FTIR, and texture analysis determining the adsorption capacity and its release, achieving the required therapeutic efficacy. 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%).
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    Multiple-wall carbon nanotubes obtained with mesoporous material decorated with caria-zirconia.
    (Univesidsad Tecnológica Nacional, 2020) Rodríguez , Miguel Angel; Anunziata , Oscar Alfredo; Beltramone, Andrea Raquel; Juárez , Juliana María; Juárez , Juliana María; Anunziata , Oscar Alfredo
    In this work, Ceria-Zirconia on ordered Santa Barbara mesoporous silica (Ce-Zr-SBA-15), has been used directly as a catalyst for the synthesis of carbon nanotubes (CNTs) through Chemical Vapor Deposition (CVD). In addition to cerium oxide, it contains zirconium oxide nano crystallites, which act as catalysts for carbon nanostructures. The catalytic performance of this material was evaluated for the decomposi- tion of ethanol at 900 °C, with N2 flow. The carbon decomposed from absolute ethanol diffuses through the surface of the nanostructured catalytic material and precipitates in the form of MWCNT structures, which could be identified by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), showing average diameters of 30–35 nm.
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    Nanostructured SBA-15 host: synthesis, characterization and application in ketorolac-tromethamine release system.
    (Univesidsad Tecnológica Nacional, 2016) Cussa , jorgelina; Juárez , Juliana María; Gómez Costa, Marcos Bruno; Anunziata , Oscar Alfredo; Anunziata , Oscar Alfredo; Juárez , Juliana María
    The ordered mesoporous silica SBA-15 has been applied in studies of ketorolac tromethamine adsorption and release. The SBA-15 materials with hexagonal and regular structure were obtained using a triblock copolymer Pluronic P123 as template and TEOS as a silica source[1]. Drug delivery is an emerging field mainly focused on aiming drugs. The goal of this targeted delivery is to transport an amount of drugs to desirable sites (such as tumors and diseased tissues) while minimizing unwanted side effects of the drugs on other tissues [2]. Controlled drug delivery systems can achieve precise spatial and temporal delivery of therapeutic agents to the target site. Ketorolac tromethamine was adsorbed into SBA-15 silica nanochannels using ethanol as solvent. The physicochemical and textural properties of SBA-15 and ketorolac tromethamine/SBA-15 were characterized by X-ray diffraction, thermogravimetric analysis, transmission electron microscopy, Fourier transform infrared spectroscopy and BET surface studies. Drug release was evaluated by soaking the loaded silica mesoporous material into a solution of HCl (0.1N) at 37 ºC under continuous stirring. Release studies were performed in order to evaluate the required therapeutic efficacy. SBA-15 provides significant improvement in the controlled release of ketorolac tromethamine [3]. In this work, we have shown a promising drug storage material for the effective encapsulation and controlled release of KETO, achieving the required therapeutic efficacy. SBA-15/KETO shows characteristic bands of both, drug materials and the inorganic framework. This indicates that KETO was adsorbed into SBA-15 channel surface without affecting the chemical structure or composition of KETO. The study also demonstrates the storage capacity and release properties of SBA-15 containing KETO. The release of KETO contained in SBA-15 can offer significant improve in controlled drug release and enhance a good analgesia effect.
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    Novel and simple one-pot method for the synthesis of titanium modified-CMK-3 applied in desulfurization of refractory oeganosulfur compounds.
    (Univesidsad Tecnológica Nacional., 2018) Rivoira , Lorena Paola; Ledesma , Brenda Cecilia; Juárez , Juliana María; Beltramone, Andrea Rauqel; Juárez , Juliana María; Ledesma , Brenda Cecilia
    Ti-CMK-3 carbon mesoporous was prepared using a novel synthesis method. This new method avoids the hard template synthesis used commonly. The method developed here, allows reducing time, energy consumption and cost. Our primary aim in this work is to evaluate the ODS activity of the Ti-modified mesoporous carbon CMK-3, synthesized by the short time method, in order to achieve total removal of sulfur compounds from diesel fuel. The catalytic oxidation of the sulfur compound with hydrogen peroxide was carried out in a glass batch reactor, equipped with a magnetic stirrer, a thermometer and a condenser. In a typical run, the solid catalyst (60 mg) was suspended under stirring (750 rpm) in 20 mL of a solution of 500 ppm of S as DBT (or other) in acetonitrile. Then, appropriate amount of 30% aqueous H2O2 was added at constant temperature. The experiments were performed in a three-phase liquid-liquid-solid (L (oil) –L (solvent) –S (catalyst)) system, acetonitrile was used as solvent and dodecane as oil phase. Solution samples were recovered at various times. The products were analyzed by GC HP 5890 Series II with a HP-5 column and connected to FID and PFPD detectors, after filtration and eventually decantation step. The products were confirmed using a Shimadzu GCMS. Structural and textural characterization of the titanium modified-mesoporous carbon was performed by N2 adsorption, XRD, UV-Vis-DRS, XPS, Raman spectroscopy and TEM. The characterization results indicated that the textural and structural properties of the material synthesized by the short time method are comparable with the properties of the material prepared by the hard template method. Ti modified-mesoporous carbon was synthesized by different methods in order to prepare catalysts to be tested in the oxidative desulfurization (ODS) of sulfur compounds. The good performance and stability of the catalyst prepared using a novel synthesis method was attributed to well dispersed anatase nanospecies over the high area mesoporous carbon. Main advantage of the present study is the reduction of time and cost in the synthesis of the new material and the applicability for ODS reactions.
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    Novel preparation of titania-modified CMK-3 nanostructured material as support for Ir catalyst applied in hydrodenitrogenation of indole.
    (Univesidsad Tecnológica Nacional., 2018) Ledesma , Brenda Cecilia; Juárez , Juliana María; Vallés , Verónica Alejandra; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Vallés , Verónica Alejandra; Juárez , Juliana María
    Iridium catalyst was prepared using a novel titanium oxide-CMK-3 support synthesized as a replica of Ti-SBA-15. The catalyst was applied in the hydrodenitrogenation of indole. The activity was compared with an iridium catalyst supported over a grafted titanium CMK-3. Structural and textural characterization of the catalysts was performed by means of N2 adsorption, XRD, UV–Vis–DRS, Raman spectroscopy, XPS, TEM and H2 Chemisorption. Ir-Ti-CMK-3 was the most active catalyst for the hydrodenitrogenation 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
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    Ordered mesoporous SBA-15 host for Ketorolac-Tromethamine loading and release behavior.
    (Univesidsad Tecnológica Nacional, 2017) Cussa , jorgelina; Juárez , Juliana María; Gómez Costa , Marcos Bruno; Anunziata , Oscar Alfredo; Anunziata , Oscar Alfredo; Juárez , Juliana María
    The ordered mesoporous silica SBA-15 has been applied in studies of ketorolac tromethamine adsorption and release. The SBA-15 materials with hexagonal and regular structure were obtained using a triblock copolymer Pluronic P123 as a template and TEOS as a silica source. Ketorolac tromethamine was adsorbed into SBA-15 silica nanochannels using ethanol as solvent. The physicochemical and textural properties of SBA-15 and ketorolac tromethamine/SBA-15 were characterized by X-ray diffraction, thermogravimetric analysis, transmission electron microscopy, Fourier transform infrared spectroscopy and BET surface studies. The composite SBA-15/KETO shows characteristic bands of both, drug materials and the inorganic framework. This indicates that KETO was adsorbed into SBA-15 channel surface without affecting the chemical structure or composition of KETO. Drug release was evaluated by soaking the loaded silica mesoporous material into a solution of HCl (0.1N) at initial time (0 - 2 h) and buffer pH 7 at high times at 37 ºC under continuous stirring. Oral commercial Keto tablets (Dolten®) and Keto solution (Keto power) were study for the contrast. Release studies were performed in order to evaluate the required therapeutic efficacy. SBA-15 provides significant improvement in the controlled release of ketorolac tromethamine and enhance a good analgesia effect.
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    Óxidos de vanadio y titanio soportados sobre CMK-3 como un nuevo catalizador para la desulfuración oxidativa de DBT.
    (Univesidsad Tecnológica Nacional., 2016) Rivoira , Lorena Paola; Juárez , Juliana María; Falcón, Horacio; Gómez Costa, Marcos Bruno; Anunziata , Oscar Alfredo; Beltramone, Andrea Raquel; Anunziata , Oscar Alfredo; Juárez , Juliana María
    En el presente trabajo se estudiaron catalizadores de vanadio soportados sobre el carbón mesoporosos CMK 3 con diferentes contenidos de Vanadio (1-7 % p/p) en la desulfurización oxidativa de dibenzotiofeno (DBT) como modelo de compuestos sulfurados. La actividad catalítica se comparó con catalizadores de Titanio soportados en CMK-3. Las propiedades estructurales y texturales de los catalizadores se analizaron mediante estudios de adsorción de N2, XRD, UV-Vis-DRS y TEM. Tanto la dispersión como la actividad catalítica dependen fuertemente del contenido de vanadio. La muestra que contiene el 7% p/p de Vanadio es el catalizador con mejor actividad catalítica para la reacción de ODS de DBT utilizando peróxido de hidrógeno ((H2O2) como oxidante y acetonitrilo como solvente. El 100% de la eliminación de DBT se alcanzó a corto plazo en condiciones suaves. El carbon mesoporoso CMK-3 con una alta área superficial y gran volumen de poros promueve el anclaje del metal en la red de carbono, lo que permite alcanzar una alta distribución de sitios activos y nanoclusters más estables. La reutilización del catalizador indica que V-CMK-3 es un catalizador potencial para los ODS de dibenzotiofeno.
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    Preparation and characterization of activated CMK-3 modified with vanadium applied in hydrogen storage.
    (Univesidsad Tecnológica Nacional, 2024) Juárez , Juliana María; Gómez Costa, Marcos Bruno; Cussa , jorgelina; Anunziata , Oscar Alfredo; Anunziata , Oscar Alfredo; Cussa , jorgelina
    The aim of this work is to synthesize a nanostructured Carbon CMK-3 modified with V in order to increase its capacity in hydrogen storage. The approach that we have followed includes synthesis of nanostructures with the experimental study of its adsorption capacity and storage properties. Ordered nanoporous carbon CMK-3 was synthesized via a two-step impregnation of the SBA-15 mesopores with a solution of sucrose using an incipient wetness method. The sucrose–silica composite was heated at 1173 K for 4 h under nitrogen flow. The silica template was dissolved with 5 wt% hydrofluoric acid in order to remove the silica. The template-free carbon product thus obtained was filtered, washed with deionized water and ethanol, and dried. [1] V-CMK-3 was prepared by wetness impregnation using VCl3 as source of Vanadium in order to increase the amount of hydrogen adsorbed. The sample of V-CMK-3 was treated under H2 flow two times at 1173 K. Porous carbon CMK-3 and the sample modified with V were characterized by XRD, FTIR, XPS, BET, TEM and SEM. These studies indicate that it was possible to obtain a CMK-3 replica successfully from SBA-15, using sucrose as a carbon precursor. [2] The surface areas are 1320 m2/g and 1050 m2/g for CMK-3 and V-CMK-3, respectively. While the nanomaterial area is significantly smaller with the incorporation of the metal, CMK-3`s characteristic structure is maintained after the metal is within the host, in agreement with the XRD studies. Measurements of hydrogen adsorption at cryogenic temperatures and low pressures were performed. The nanoparticles of V incorporated onto the nanostructured carbon CMK-3 showed higher hydrogen uptake at low and high pressures than CMK-3. (3.4 wt% and 2.2 wt% respectively of H2 sorption at 10 bar and 77 K).
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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 characterization of a nanoporous carbon CMK-3 modified with iron for the ODS of DBT.
    (Univesidsad Tecnológica Nacional., 2017) Juárez , Juliana María; Rivoira , Lorena Paola; Gómez Costa, Marcos Bruno; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Rivoira , Lorena Paola
    A nanostructured Carbon CMK-3 modified with Fe by using different sources of Fe, were used in the oxidative desulfurization (ODS) of dibenzothiophene as a model sulfur compound. Ordered mesoporous carbon CMK-3 was synthesized via a two-step impregnation of the SBA-15 silica mesonanopores with a solution of sucrose using an incipient wetness method. The sucrose–silica composite was heated at 1173 K for 4 h under nitrogen flow. The silica template was dissolved in 5 wt.% hydrofluoric acid in order to remove the silica. The template-free carbon product thus obtained was filtered, washed with deionized water and ethanol and dried. Fe-CMK-3 was prepared by wetness impregnation using FeCl3.6H2O and FeNO3.9H2O as different sources of Fe. A solution of FeCl3.6H2O/ FeNO3.9H2O in ethanol was mixed with the carbon solution at room temperature. The solution was placed in a rotary evaporator to remove excess of ethanol at about 333 K and 60 rpm. Afterwards, the sample was dried at 373 K for 18 h and was thermally treated in a dynamic inert (N2) atmosphere. The percentage of Fe has been 2 wt.% with respect to carbon in the final FeCl3-CMK-3 and FeNO3-CMK 3 material. Porous carbon CMK-3 and the samples modified with Fe were characterized by XRD, FTIR, XPS, BET, TEM and SEM. These studies indicated that it was possible to obtain a CMK-3 replica successfully from SBA-15, using sucrose as a carbon precursor. Wide angle XRD pattern of the sample modified with FeCl3.6H2O implies the formation of the magnetite phase in the silica channels. The surface areas were 1320 m2/g for the CMK-3 and 1240 m2/g and 609 m2/g for FeCl3- CMK-3 and FeNO3-CMK-3, respectively. While the nanomaterial area is significantly smaller with the incorporation of the metal, CMK-3`s characteristic structure is maintained after the metal is within the host, in agreement with the XRD studies. The catalytic activity was improved when the nanoporous carbon was modified with Fe. The sample modified with FeCl3.6H2O was the most active catalyst for ODS of DBT, using hydrogen peroxide (H2O2) as oxidant and acetonitrile as solvent. 100% of DBT elimination was attained at a short time in mild conditions.
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    Synthesis, characterization of nanoporous SBA-15 host and application in Ketorolac-Tromethamine release system.
    (Univesidsad Tecnológica Nacional, 2016) Juárez , Juliana María; Cussa , jorgelina; Gómez Costa , Marcos Bruno; Anunziata , Oscar Alfredo; Anunziata , Oscar Alfredo; Cussa , jorgelina
    Controlled release technologies are growing in importance in modern medication and pharmaceutical industries. Drug delivery is an emerging field mainly focused on targeting drugs. The goal of this targeted delivery is to transport an amount of drugs to desirable sites (such as tumors and diseased tissues) while minimizing unwanted side effects of the drugs on other tissues [1]. Generally, controlled drug delivery systems can maintain the concentration of drugs in the precise sites of the body within the optimum range and under the toxicity threshold, improving therapeutic efficacy and reducing toxicity [2]. Nanotechnology will produce significant results; hence, the drug is controlled during days or even weeks, depending on the disease that needs to be treated. In recent years mesoporous silicas have been used for hosting and further delivery of various biomolecules and drugs [3]. SBA-15 is a crystalline mesoporous molecular framework with an ordered and precise mesoporous hexagonally system. This material shows uniform channels and a pore diameter that can be varied systematically between 1.5 and 10 nm with surfactant as the template, auxiliary chemicals and reaction conditions. Ketorolac tromethamine (KETO) is a pyrrolizine carboxylic acid derivative of NSAIDs with potent analgesic and moderate anti-inflammatory activity; it is a relatively favorable therapeutic agent for the treatment of moderate to severe pain. The main goal of this study is the adsorption capacity and storage properties of SBA-15/ KETO release in achieving the required therapeutic efficacy