Repository logo
Communities & Collections
All of DSpace
  • English
  • العربية
  • বাংলা
  • Català
  • Čeština
  • Deutsch
  • Ελληνικά
  • Español
  • Suomi
  • Français
  • Gàidhlig
  • हिंदी
  • Magyar
  • Italiano
  • Қазақ
  • Latviešu
  • Nederlands
  • Polski
  • Português
  • Português do Brasil
  • Srpski (lat)
  • Српски
  • Svenska
  • Türkçe
  • Yкраї́нська
  • Tiếng Việt
Log In
New user? Click here to register.Have you forgotten your password?
  1. Home
  2. Browse by Author

Browsing by Author "Juárez , Juliana María"

Filter results by typing the first few letters
Now showing 1 - 20 of 34
  • Results Per Page
  • Sort Options
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    Controlled drug release system: cyclophosphamide delivery contained in LP-SBA-15 functionalized with terbutylamine.
    (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.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    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 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.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    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%).
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    Noble-bimetallic supported CMK-3 as a novel catalyst for hydrogenation of tetralin in the presence of sulfur and nitrogen.
    (Univesidsad Tecnológica Nacional., 2016) Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Juárez , Juliana María; Gómez Costa, Marcos Bruno; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Juárez , Juliana María; Ledesma , Brenda Cecilia
    Carbon ordered mesoporous CMK-3 with high surface area and high pore volume promotes a very good dispersion of Pt or Ir monometallic and Pt-Ir-bimetallic crystallites in the carbon framework. High active and stable nanospecies are responsible for the good activity and selectivity found in the hydrogenation of tetralin to decalin in the presence of N as indole and S as dibenzothiophene under mild conditions in a Batch reactor. The catalysts prepared were extensively characterized by XRD, N2 adsorption isotherms, XPS, TEM, ICP, CO Chemisorption and TPR. The analysis showed that the carbon mesoporous structure was maintained after metal incorporation, and very high dispersed metal-supported catalyst was obtained. The activity was compared using the turnover number, Pt-Ir-CMK-3 being the most active cat alyst in the presence of the inhibitors. The bimetallic catalyst showed more resistance to inhibition than monometallic catalysts. The reusability of Pt-Ir-CMK-3 suggests that it is a potential catalyst for hydrotreating reactions.
  • Thumbnail Image
    Item
    Novel and simple one-pot method for the synthesis of Ti02 modified-CMK-3 applied in oxidative desulfurization of refractory organosulfur compounds.
    (Univesidsad Tecnológica Nacional., 2016) Rivoira , Lorena Paola; Ledesma , Brenda Cecilia; Juárez , Juliana María; Beltramone , Andrea Raquel; 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 precursors of silicon, carbon and titanium are incorporated together with the other components during the only step of the synthesis. The method developed here, allows reducing time and energy consumption by 60% and thus, the cost of the overall process of synthesis. 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 dif- ferent methods in order to prepare catalysts to be tested in the oxidative desulfurization (ODS) of sulfur com- pounds. The catalyst prepared by the one-pot method is capable to oxidize high amount of sulfur (2000 ppm) in only 30 min of reaction time at 60–80 °C. 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.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    Novel mesoporpous carbon modified with zirconia for hydrogen adsorption.
    (Univesidsad Tecnológica Nacional., 2021) Venosta, Lisandro; Juárez , Juliana María; Anunziata , Oscar Alfredo; Gómez Costa, Marcos Bruno; Anunziata , Oscar Alfredo; Juárez , Juliana María
    Nanostructured carbon material (CMK-3) modified with zirconium oxide was synthesized by a new direct synthesis technique. Zirconium oxide dispersed in carbon materials (Zr-CMK-3) were characterized by X-ray diffraction, textural properties, UV-Vis-DRS, XPS, and transmission electron microscopy analysis. The goal of this new synthesis method is to avoid the use of inorganic siliceous template (SBA-15), which leads to a shorter and cheaper way to obtain mesoporous carbon, and at the same time incorporate into the framework Zirconium atoms. Zr-CMK-3 material significantly improved H2 storage behaviour (4.6% by weight at 77 K and 10 bar) compared to CMK-3 support. The synthesized material is promising in the absorption of hydrogen by weak bonding forces (physisorption). The activity of the samples to the adsorption of hydrogen molecules is attributed to the improved dispersion of the zirconium oxide, as well as the appropriate use of support, which can probably disperse the zirconium on its large surface area, allowing a great dispersion of the zirconium. The Zr+4 cation is an active species to absorb and store hydrogen through a physisorption process and the carbon plays an important role in the dispersion and size of metal particles. A hydrogen storage mechanism on the active surface of the ZrO2 clusters was proposed. First layer of hydrogen molecules can react with the metal cation through a dihydrogen complex (Kubas interaction). The second layer of hydrogen molecules adsorbed around the metal oxide clusters is due to dipole-like interactions, this is because the metal particle induces dipole forces on the hydrogen molecule. The other layers could also interact by dipole forces; however, the interaction force decreases as the distance to the surface increases. The upper layers could interact with the metal cation by dipole-induced bonding; however, the interaction force decreases as the distance to the surface increases.
  • Thumbnail Image
    Item
    Novel preparation of CMK-3 nanostructured material modified with titania applied in hydrogen uptake and storage.
    (Univesidsad Tecnológica Nacional., 2016) Juárez , Juliana María; Ledesma , Brenda Cecilia; Gómez Costa, Marcos Bruno; Beltramone, Andrea Raquel; Anunziata , Oscar Alfredo; Anunziata , Oscar Alfredo; Ledesma , Brenda Cecilia
    This work deals with the development of a novel procedure to synthesize titania-modified nano structured carbon employing Ti-SBA-15 as hard template. The new mesoporous carbon displays high specific surface area of 1044 m2/g and large pore volume of 0.7 cm3/g. XRD pattern of Ti-CMK-3 indicates that the ordered structure of this material is similar to the CMK-3. XRD, XPS and UVeVis-DRS analysis indicated that Ti is highly dispersed as anatase phase in Ti-CMK-3. The synthesized Ti-CMK-3 exhibited significantly enhanced H2 storage properties (2.6 wt%, equivalent to 13 mmol/g) compared with CMK-3 without Ti (2.2 wt%, 11 mmol/g) at 77 K and 10 bar.
  • Thumbnail Image
    Item
    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
  • Thumbnail Image
    Item
    Novel preparation of titania-modified CMK-3 nanostructured material as support for Ir catalyst applied in hydrodenitrogenation of indole.
    (Universidad Tecnológica Nacional., 2017) 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.
  • Thumbnail Image
    Item
    Novel preparation of titania-modified CMK-3 nanostructured material as support for Ir catalyst applied in hydrodenitrogenation of indole.
    (Univesidsad Tecnológica Nacional., 2017) Ledesma , Brenda Cecilia; Juárez , Juliana María; Vallés , Verónica Alejandra; Anunziata , Oscar Alfredo; Beltramone, Andrea Raquel
    Abstract Iridium 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–DRS, 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.
  • «
  • 1 (current)
  • 2
  • »

 

UTN | Rectorado

Sarmiento 440

(C1041AAJ)

Buenos Aires, Argentina

+54 11 5371 5600

SECRETARÍAS
  • Académica
  • Administrativa
  • Asuntos Estudiantiles
  • Ciencia y Tecnología
  • Consejo Superior
  • Coordinación Universitaria
  • Cultura y Extensión Universitaria
  • Igualdad de género y Diversidad
  • Planeamiento Académico y Posgrado
  • Políticas Institucionales
  • Relaciones Internacionales
  • TIC
  • Vinculación Tecnológica
  • Comité de Seguridad de la Información
ENLACES UTN
  • DASUTeN
  • eDUTecNe
  • APUTN
  • ADUT
  • FAGDUT
  • FUT
  • SIDUT
ENLACES EXTERNOS
  • Secretaría de Educación
  • CIN
  • CONFEDI
  • CONEAU
  • Universidades