https://hdl.handle.net/20.500.12008/26173 Incluye artículos, objetos de conferencias, seminarios y jornadas, reportes técnicos, comunicaciones y otros Sat, 14 Feb 2026 10:31:59 GMT 2026-02-14T10:31:59Z https://hdl.handle.net/20.500.12008/53501 Título: Síntesis de materiales porosos heteroestructurados a partir de arcilla natural Autor: Méndez, Noelia; Romero, Mariano; Bussi, Juan; De León, Andrea Resumen: Las heteroestructuras de arcilla porosa (PCH, porous clay heterostructure) son materiales que se caracterizan por su elevada superficie y porosidad, con una estructura micro y mesoporosa combinada, alta estabilidad térmica y mecánica, y acidez superficial. Estos materiales inorgánicos están generando un gran interés por su potencial aplicación como catalizadores, soporte de catalizadores, adsorbentes, tamices moleculares y matrices porosas para el encapsulado de drogas [1,2]. Su síntesis implica la modificación de un silicato laminar catiónico con un surfactante y un precursor de sílice, en general tetraetoxisilano (TEOS). Las propiedades de los materiales que pueden obtenerse varían según las condiciones de síntesis. En el presente trabajo se sintetizaron PCHs a partir de una arcilla natural uruguaya, una montmorillonita cálcica con escazas impurezas, pretratada mediante secado y molienda. La arcilla se intercambió con una solución acuosa del surfactante cloruro de hexadeciltrimetilamonio (CTAC), seguido de la incorporación de TEOS y posterior tratamiento térmico en aire a 650 C. Se emplearon diferentes concentraciones de CTAC (0.1, 0.2 y 0.3 mol/L) y se evaluó la incorporación de hexadecilamina como co-surfactante. La arcilla y los PCHs se caracterizaron mediante ATG, isotermas de adsorción-desorción de nitrógeno, DRX, FRX y MEB. Los resultados de DRX y FRX permitieron confirmar la incorporación de sílice en la arcilla durante la síntesis de los PCHs. El aumento de la concentración de CTAC de 0.1 a 0.2 mol L-1 permitió incrementar el área específica BET de 427 a 479 m2/g y el volumen de microporos y mesoporos de 0.130 y 0.187 cm3/g a 0.159 y 0.207 cm3/g, respectivamente. Un posterior incremento de la concentración de CTAC a 0.3 mol/L fue en detrimento de estos parámetros. A su vez, el uso de la hexadecilamina tuvo un efecto positivo sobre las propiedades texturales de los materiales obtenidos. Mon, 01 Jan 2024 00:00:00 GMT https://hdl.handle.net/20.500.12008/53501 2024-01-01T00:00:00Z https://hdl.handle.net/20.500.12008/53500 Título: Synthesis of iron-modified porous clay heterostructures (Fe-PCHs) from a raw Uruguayan montmorillonite Autor: Méndez, Noelia; Romero, Mariano; Bussi, Juan; De León, Andrea Resumen: Porous clay heterostructures (PCH) are nanoporous materials that exhibit a high specific surface area, a combined microporous and mesoporous structure, and high thermal and mechanical stability. These materials are of great interest due to their potential application as adsorbents, catalyst supports and porous matrices for the encapsulation and controlled release of drugs [1,2]. PCHs are obtain by the modification of a cationic layered silicate with a surfactant and a silica precursor, followed by heat treatment to remove the surfactant. The aim of this work was to prepare iron-modified PCHs (Fe-PCHs) from a Uruguayan raw montmorillonite, with potential application as catalysts in Fenton process. Fe-PCHs were prepared by exchange the raw clay with a solution of hexadecyltrimethylammonium and hexadecylamine as co-surfactant, followed by the incorporation of tetraethoxysilane. Finally, the solid was exchanged with a ferric nitrate solution using different concentrations: 1 and 4 mol/L and thermally treated at 650 ºC in air to obtain Fe-PCH-1 and Fe-PCH-4, respectively. The characterization of the clay and the catalysts involved: XRD, XRF, TGA and nitrogen adsorption isotherm techniques. The Fe content for Fe-PCH-1 and Fe-PCH-4 is 1.55 and 1.75%, respectively, thus confirming the effective incorporation of iron. Due to the generation of the nanoporous structure, the Fe-PCHs have significantly higher surface area (386 and 378 m2/g) and pore volume (0.294 and 0.306 cm3/g) than the clay (28 m2/g and 0.043 cm3/g). These properties suggest that Fe-PCHs are suitable candidates for catalytic processes that involve iron as active species. Mon, 01 Jan 2024 00:00:00 GMT https://hdl.handle.net/20.500.12008/53500 2024-01-01T00:00:00Z https://hdl.handle.net/20.500.12008/53331 Título: Self-assembly of lanthanide-based single-ion magnets (SIMs) into 1D networks via Re(IV)-based metalloligands Autor: Ferrari-Argachá, Carolina; Valiero, Santiago; Rojas-Dotti, Carlos; Loaces, Aparicio; Chiozzone, Raúl; Moliner, Nicolás; Suescun, Leopoldo; Cano, Joan; Lloret, Francesc; Martínez-Lillo, José; González, Ricardo Resumen: Within the research field of Molecular Magnetism, single-ion magnets (SIMs) are of particular interest due to their ability to retain magnetic memory at the molecular level. At the same time, one-dimensional coordination polymers enable controlled spatial arrangement of magnetic centers, making them valuable models for investigating magneto-structural correlations. Here, we report the synthesis, crystal structure, magnetic properties and theoretical calculations of a family of five one-dimensional Re(IV)-Ln(III) coordination complexes obtained by using the “complex-as-ligand” strategy and based on the pyridinedicarboxylic acid derivatives, that form the [ReBr5(3,4-pydcH2)]- and [ReBr5(3,5-pydcH2)]- metalloligands, with general formula (NBu4)2{Ln(EtOH)(dpkOEt)[ReBr5(3,5-Hpydc)]2}n·3.5H2O·MeOH [Ln = Dy(2), Tb(3)] and {Ln[ReBr5(3,4-pydc)](dmf)3(MeOH)}n·dmf [Ln = Dy(4), Tb(5), Gd(6)]. Two of these Re(IV)-Ln(III) compounds —[Dy(EtOH)(dpkOEt){ReBr₅(3,5-Hpydc)}₂]n (2) and [Dy{ReBr₅(3,4-pydc)}(dmf)₃(MeOH)]n (4) — exhibit slow relaxation of the magnetisation, which is characteristic of SIM behaviour and accounted for ac magnetic susceptibility measurements. Structural analyses suggest that intra- and intermolecular halogen–halogen (Br···Br) interactions may influence the magneto-structural properties of 2-6. These findings demonstrate the potential of Re(IV)-Ln(III) hybrid systems as candidates for developing magnetically addressable molecular materials. Descripción: Versión aceptada. Wed, 01 Jan 2025 00:00:00 GMT https://hdl.handle.net/20.500.12008/53331 2025-01-01T00:00:00Z https://hdl.handle.net/20.500.12008/53010 Título: Procesos de oxidación avanzada como estrategia para la eliminación de pesticidas obsoletos : imidacloprid como caso de estudio Autor: Pereira, Maytena; Archondo, Lucas; Rodríguez, Juan; Cesio, Verónica; Heinzen, Horacio; De León, Andrea; Besil, Natalia Wed, 01 Jan 2025 00:00:00 GMT https://hdl.handle.net/20.500.12008/53010 2025-01-01T00:00:00Z