Person: Cabañas Poveda, Albertina
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First Name
Albertina
Last Name
Cabañas Poveda
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Química Física
Area
Química Física
Identifiers
11 results
Search Results
Now showing 1 - 10 of 11
- Project number: 172
Item Formación en Química Sostenible y su relación con los Objetivos de Desarrollo Sostenible() Cabañas Poveda, Albertina; Pérez Velilla, Eduardo; Vázquez Villa, Henar; García Melo, Fátima; Calvo Garrido, Lourdes; González Mac-Dowell, Luis; Acción Salas, Fernando; Parrón Nieto, Andrea; Valero Herrero, Patricia; Calvo Garrido, María LourdesEn el proyecto se propone la realización de trabajos en grupo dirigidos a los alumnos de Química General de 1º en los que se desarrollen los principios de la Química Sostenible y se relacionen con los Objetivos de Desarrollo Sostenible. Las mejores presentaciones serán grabadas en video para su difusión. Item One-step Sustainable Preparation of Superparamagnetic Iron Oxide Nanoparticles Supported on Mesoporous SiO2(Journal of Supercritical Fluids, 2020) Chamorro, Elena; Granados García Tenorio, María José; Calvo Garrido, María Lourdes; Torralvo Fernández, María José; Sáez Puche, Regino; Cabañas Poveda, AlbertinaSuperparamagnetic iron oxide nanoparticles (SPIONs) supported on high surface area mesoporous SiO2 are advanced materials of great interest in catalysis, adsorption and biomedicine. Here we present a new process to prepare SPION/SiO2 materials by the impregnation and insitu decomposition of Fe(NO3)3.9H2O on mesoporous SiO2 supports in a 25-50% mol ethanol + CO2 mixture at 523 K and 25.0 MPa. -Fe2O3 nanoparticles (NPs) of average size between 6-9 nm were distributed homogeneously on the supports. NPs deposited into the SBA-15 mesopores but mostly on the external surface of MCM-41. Materials prepared with the highest ethanol content were very homogeneous. Magnetic measurements confirmed the superparamagnetic nature of the materials at room temperature. The process proposed is sustainable and scalable, avoids tedious preparations and the additional high temperature treatment under a controlled atmosphere, as the metal decomposition is performed insitu in the CO2-expanded liquid mixture.Item Prediction of the best cosolvents to solubilise fatty acids in supercritical CO2 using the Hansen solubility theory(Chemical Engineering Science, 2018) Tirado Armesto, Diego Felipe; Tenorio, María José; Cabañas Poveda, Albertina; Calvo Garrido, María LourdesCosolvents are employed to improve the extraction efficiency and modify the selectivity of the main solvent. However, choosing a proper cosolvent in supercritical extraction is an arduous task. This study aimed to predict the best cosolvents for the supercritical CO2 extraction of oleic and linoleic acids using the Hansen solubility theory. Calculations were performed for eight organic cosolvents used in food and pharmaceutical production. The best cosolvents for the solubilization of both fatty acids were short-chain alcohols, ethanol and methanol. The predictions were validated with bubble pressures of the mixtures with a 0.003 fatty acid molar fraction at temperatures of 313.2 K and 323.2 K. The experimental results agreed with the predictions. The effect of pressure was well predicted via the direct relationship between pressure and the solvent density. However, the impact of temperature was not properly foreseen because the variation of solute vapour pressure was not considered. The Hansen theory predicted that the miscibility enhancement of the solute in the supercritical mixture is maximum at low pressures and low cosolvent concentrations, as was experimentally confirmed.Item Modelling and Scaling-Up of a Supercritical Fluid Extraction of Emulsions Process(Processes, 2023) Tirado, Diego ; Cabañas Poveda, Albertina; Calvo Garrido, María LourdesSupercritical CO2(scCO2) is utilized in the supercritical fluid extraction of emulsions (SFEE) to swiftly extract the organic phase (O) from an O/W emulsion. The dissolved substances in the organic phase precipitate into small particles and remain suspended in the water (W) with the aid of a surfactant. The process can be continuously conducted using a packed column in a counter-current flow of the emulsion and scCO2, at moderate pressure (8–10 MPa) and temperature (37–40 ◦C). To ensure the commercial viability of this technique, the organic solvent must be separated from the CO2 to facilitate the recirculation of both streams within the process while minimizing environmental impact. Thus, the aim of this work was to design a plant to produce submicron materials using SFEE, integrating the recovery of both solvents. First, experimental equilibrium data of the ternary system involved (CO2/ethyl acetate/water) were fitted with a proper thermodynamic model. Then, simulations of the whole integrated process at different scales were carried out using Aspen Plus®, along with economical evaluations. This work proposes the organic solvent separation with a distillation column. Thus, the two solvents can be recovered and recycled to the process in almost their entirety. Furthermore, the particles in the aqueous raffinate are produced free of solvents and sterilized for further safe use. The costs showed an important economy scale-up. This work could ease the transfer of the SFEE technology to the industry.- Project number: 242
Item Laboratorio integrado de prácticas de simulación de fundamentos y procesos químicos con fluidos supercríticos(2019) Calvo Garrido, Lourdes; Cabañas Poveda, Albertina; Pando García-Pumarino, Concepción; García Baonza, Valentín; González Mac-Dowell, Luis; Tirado Armesto, Diego Felipe; Cuadra Mendoza, Isaac Alfonso; Menéndez Carbajosa, Alicia Marta; Calvo Garrido, María LourdesEl objetivo del proyecto ha sido crear un laboratorio integrado de prácticas de simulación relacionadas con fundamentos termodinámicos y procesos con fluidos supercríticos, destinado a los alumnos de Química e Ingeniería Química. Item Deposition of Au nanoparticles into mesoporous SiO2 SBA-15(The Journal of Supercritical Fluids, 2022) Huerta, Andrea; Torralvo Fernández, María José; Tenorio, María José; Pérez Gómez, Eduardo; Bermúdez, Jonathan; Calvo Garrido, Lourdes; Cabañas Poveda, Albertina; Calvo Garrido, María LourdesAu/SiO2 SBA-15 materials were prepared using supercritical CO2 (scCO2) and by wet impregnation. First, SiO2 SBA-15 was functionalized with thiol groups at different grafting densities using 3-(Mercaptopropyl)trimethoxysilane dissolved in scCO2. The support was then impregnated with HAuCl4·3H2O in scCO2 modified with EtOH. Wet impregnation of the supports with HAuCl4·3H2O in ethanol was also performed. Materials were calcined at 500 ºC to remove the organic matter and promote particle growth. Materials prepared on the highest thiol grafting density support showed Au NP between 2.5-5 nm homogeneously distributed within the mesopores. Slightly larger Au NPs were obtained in scCO2 modified with EtOH. Materials prepared on the low thiol grafting density support showed a bimodal particle size distribution with particles up to 7 nm located inside the mesopores and larger ones of 10-20 nm on the external surface. A possible reaction mechanism was proposed. These materials can be used in catalysis, sensing and biomedicine.Item The parameters that affect the supercritical extraction OF 2,4,6- trichloroanisol from cork(Journal of Supercritical Fluids, 2018) Viguera Sáenz, Miguel; Prieto, C.; Casas, E.; Cabañas Poveda, Albertina; Calvo Garrido, Lourdes; Calvo Garrido, María LourdesThe contamination of wine by 2,4,6-trichloroanisol (TCA) derived from the cork stopper is a huge problem for the wine industry. This work shows the results of TCA extraction using supercritical CO2. Cork granules (6% moisture) were placed forming a fixed bed within a high-pressure vessel. The CO2 was made to continuously flow over this. The TCA removal was compared at different operating conditions (pressure, temperature, flow rate or extraction time). TCA removal was not possible in dried cork. Density had a positive impact in TCA removal due to the solvent capacity increase. An increase in the supercritical fluid temperature over 60 °C impaired the TCA extraction. High residence times benefited the extraction. At high CO2 density of 585 kg m−3 , TCA elimination below the detection level was achieved in 8 min residence time. This required relatively low solvent to cork mass ratios (43 kg CO2 kg−1 ).Item Deposition of Au nanoparticles into mesoporous SiO2 SBA-15(The Journal of Supercritical Fluids, 2022) Huerta, Andrea; Torralvo Fernández, María Josefa; Tenorio, María José; Pérez Velilla, Eduardo; Bermúdez, Jonathan; Calvo Garrido, María Lourdes; Cabañas Poveda, AlbertinaAu/SiO2 SBA-15 materials were prepared using supercritical CO2 (scCO2) and by wet impregnation. First, SiO2 SBA-15 was functionalized with thiol groups at different grafting densities using 3-(Mercaptopropyl)trimethoxysilane dissolved in scCO2. The support was then impregnated with HAuCl4·3H2O in scCO2 modified with EtOH. Wet impregnation of the supports with HAuCl4·3H2O in ethanol was also performed. Materials were calcined at 500 °C to remove the organic matter and promote particle growth. Materials prepared on the highest thiol grafting density support showed Au NP between 2.5 and 5 nm homogeneously distributed within the mesopores. Slightly larger Au NPs were obtained in scCO2 modified with EtOH. Materials prepared on the low thiol grafting density support showed a bimodal particle size distribution with particles up to 7 nm located inside the mesopores and larger ones of 10–20 nm on the external surface. A possible reaction mechanism was proposed. These materials can be used in catalysis, sensing and biomedicine.Item Supercritical fluid impregnation of naproxen into mesoporous SiO2 SBA-15(Journal of CO2 utilization, 2023) González, Juan; Pérez Velilla, Eduardo; Pepczynska, Marzena; Calvo Garrido, María Lourdes; Cabañas Poveda, AlbertinaNaproxen was impregnated into mesoporous SiO2 SBA-15 using the Supercritical Solution Impregnation (SSI) technique. Experiments were performed at 50–70ºC and 15–25 MPa in pure CO2 and CO2 modified with ethanol, ethyl acetate and menthol. Materials were also impregnated from liquid solutions in ethanol and chloroform. In the SSI experiments, naproxen was deposited on the internal surface of the mesopores as shown by N2-adsorption experiments. The percentage of naproxen impregnated decreased from 11.1% to 7.4% mass as the CO2 density increased. Likewise, adding ethanol, ethyl acetate or menthol to CO2 decreased the percentage of naproxen adsorbed on the support. Thermal analysis showed that naproxen impregnated on SiO2 by SSI became amorphous. FTIR and XRD confirmed the loss of crystallinity of naproxen and its interaction with the SiO2 support. Samples impregnated in liquid medium however kept partially their crystallinity. Release tests of naproxen on SiO2 SBA-15 prepared by SSI followed an almost zero-order release profile; the drug is released at a constant rate into a PBS pH= 7.4 medium. The release rate slowed down in comparison to that of pure naproxen, due to the interaction of the drug with the support and the diffusion of the drug outside the support mesopores. Thus, a sustained release system was achieved, which may help to attain a longer therapeutic effect with a lower naproxen dose.Item Current Treatments for COVID-19: Application of Supercritical Fluids in the Manufacturing of Oral and Pulmonary Formulations(Pharmaceutics, 2022) Ruiz Saldaña, Helga Karina; Serrano, Dolores ; Calvo Garrido, María Lourdes; Cabañas Poveda, AlbertinaEven though more than two years have passed since the emergence of COVID-19, the research for novel or repositioned medicines from a natural source or chemically synthesized is still an unmet clinical need. In this review, the application of supercritical fluids to the development of novel or repurposed medicines for COVID-19 and their secondary bacterial complications will be discussed. We envision three main applications of the supercritical fluids in this field: (i) drug micronization, (ii) supercritical fluid extraction of bioactives and (iii) sterilization. The supercritical fluids micronization techniques can help to improve the aqueous solubility and oral bioavailability of drugs, and consequently, the need for lower doses to elicit the same pharmacological effects can result in the reduction in the dose administered and adverse effects. In addition, micronization between 1 and 5 µm can aid in the manufacturing of pulmonary formulations to target the drug directly to the lung. Supercritical fluids also have enormous potential in the extraction of natural bioactive compounds, which have shown remarkable efficacy against COVID-19. Finally, the successful application of supercritical fluids in the inactivation of viruses opens up an opportunity for their application in drug sterilization and in the healthcare field.