Person: Calvo Garrido, María Lourdes
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First Name
María Lourdes
Last Name
Calvo Garrido
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Ingeniería Química y de Materiales
Area
Ingeniería Química
Identifiers
14 results
Search Results
Now showing 1 - 10 of 14
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 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 Josefa; 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 Inactivation of Clostridium Spores in Honey with Supercritical CO2 and in Combination with Essential Oils(Processes, 2022) Dacal Gutierrez, Alejandro; Tirado Armesto, Diego Felipe; Calvo Garrido, María LourdesThe presence of tens of Clostridium botulinum spores per gram of honey can cause infantile botulism. Thermal treatment is insufficient to inactivate these resistant forms. This study explored the effectiveness of supercritical CO2 (scCO2 ) on its own and combined with lemon (LEO), clove (CLEO), and cinnamon (CEO) essential oils on the inactivation of Clostridium sporogenes (CECT 553) as a surrogate of Clostridium botulinum. In water, the degree of inactivation at 10 MPa after 60 min increased with the increasing temperature, reducing the population by 90% at 40 ◦C and by 99.7% at 80 ◦C. In contrast, when applied to honey, scCO2 did not inactivate Clostridium spores satisfactorily at temperatures below 70 ◦C, which was related to the protective effect of honey. Meanwhile, scCO2 modified with CEOItem Enzymatic Production of Biodiesel From Alperujo Oil in Supercritical CO2(The Journal of Supercritical Fluids, 2021) Quintana-Gómez, Laura; Ladero Galán, Miguel; Calvo Garrido, María LourdesThe synthesis of fatty acid methyl esters (FAMEs) as biodiesel from alperujo oil was studied in scCO2 using a mixture of Novozym 435 and Lipozyme TL IM at 10% as a catalyst to enhance the productivity. The reaction performance was investigated at different temperatures (40–60 °C), reaction times (1–48 h) and with a mixture of methylating agents in molar ratios of oil:methanol:methyl acetate from 1:0:40 to 1:5:35. Conversion of triglycerides achieved values up to 96% at>50 °C and reaction times of 24 h with FAMEs yields of over 90%. The presence of methyl acetate and the use of scCO2 as solvent improved the oil conversion and FAMEs yield in comparison with other works. The residual activity of the enzymes dropped at high reaction temperatures (>40 °C), reaction times (>1 h) and if the molar oil: methanol ratio was increased from 1:1 to 1:2 or higher.Item The encapsulation of hydroxytyrosol-rich olive oil in Eudraguard® protect via supercritical fluid extraction of emulsions(Journal of Food Engineering, 2021) Tirado, Diego ; Latini, Angela; Calvo Garrido, María LourdesThe SFEE technology was used to micronize the food-approved-biopolymer Eudraguard® protect. After setting the ratio of emulsion phases to 20:80 ethyl acetate:water, higher surfactant (0.1–10.0%) and lower polymer (1–10%) concentrations reduced the size of the particles. By halving the stirring speed to 1250 rpm during the homogenization of the emulsion, larger particles were formed. All these manipulations allowed the creation of particles ranging from 10 nm to 200 nm. A higher viscosity of the organic phase, achieved with 2% vitamin E, increased the particle size to 300 nm. Afterwards, SFEE was used to encapsulate hydroxytyrosol-rich olive oil (HT-oil), obtained from alperujo, in Eudraguard® protect for its preservation. Spherical non-aggregate particles were formed with an average of 230 nm. High degrees of encapsulation were possible (up to 99%) resulting in loadings of HT-oil in the obtained particles of 39% with 0.7 mg HT per g of particle.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.Item Inactivation of clostridium spores in honey with supercritical CO2 and in combination with essential oils(Processes, 2022) Dacal-Gutiérrez, Alejandro; Tirado, Diego ; Calvo Garrido, María LourdesThe presence of tens of Clostridium botulinum spores per gram of honey can cause infantile botulism. Thermal treatment is insufficient to inactivate these resistant forms. This study explored the effectiveness of supercritical CO2 (scCO2) on its own and combined with lemon (LEO), clove (CLEO), and cinnamon (CEO) essential oils on the inactivation of Clostridium sporogenes (CECT 553) as a surrogate of Clostridium botulinum. In water, the degree of inactivation at 10 MPa after 60 min increased with the increasing temperature, reducing the population by 90% at 40 °C and by 99.7% at 80 °C. In contrast, when applied to honey, scCO2 did not inactivate Clostridium spores satisfactorily at temperatures below 70 °C, which was related to the protective effect of honey. Meanwhile, scCO2 modified with CEO (<0.4% mass) improved the inactivation degree, with a 1.3-log reduction achieved at 60 °C. With this same mixture, a reduction of 3.7 logs was accomplished in a derivative with 70% moisture. Honey was very sensitive to the temperature of the applied CO2. The obtained product could be used as a novel food, food ingredient, cosmetic, or medicine.Item Inactivation of Legionella in aqueous media by high-pressure carbon dioxide(The Journal of Supercritical Fluids, 2022) Martín-Muñoz, David; Tirado, Diego ; Calvo Garrido, María LourdesThis work aimed to investigate the inactivation of Legionella in aqueous media using high-pressure carbon di- oxide (HPCD). Both discontinuous and continuous operations were tested. During batch treatments, the increased pressure improved the inactivation of Legionella, probably due to better dispersion and dissolution of the HPCD in the aqueous medium. Inactivation also increased with temperature. After 10 min and 26 ◦C it was not necessary to exceed 20 MPa, where reductions higher than 4.2 log were reached. At 10 MPa, reductions higher than 3.1 log were reached, good enough for real aqueous environments, which rarely exceed 102 CFU mL−1. Total inactivation was reached at 38 ◦C at all pressures. For a given temperature, treatment with HPCD was always much more effective than thermal treatment. During continuous treatments, a contact time of 1 min at 28 ◦C and 10 MPa were enough for the total inactivation of Legionella in co-current flow with a CO2/suspension mass ratio of 1. Simulation with Aspen Plus® revealed that depressurization of the sterile water to remove gaseous CO2 cooled it sufficiently to be used as a cooling service.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 Gómez, 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 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.