Person:
Calvo Garrido, María Lourdes

First Name

María Lourdes

Last Name

Calvo Garrido

URI

https://hdl.handle.net/20.500.14352/76255

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Químicas

Department

Ingeniería Química y de Materiales

Area

Ingeniería Química

Identifiers

Full item page

Search Results

Now showing 1 - 10 of 23

The Selective Supercritical Extraction of High-value Fatty Acids from Tetraselmis suecica using the Hansen Solubility Theory
(Chemical engineering transactions, 2019) Calvo Garrido, María Lourdes; Tirado Armesto, Diego Felipe; Rousset, Amandine
The aim of this work was to test the utility of the Hansen theory to predict the best cosolvent for supercritical carbon dioxide (sc-CO2) to reach the selective extraction of fatty acids from Tetraselmis suecica. The order in the cosolvent power was established with five organic solvents used in food production: acetone, diethyl ether, ethanol, n-hexane and methanol. Predictions focused on the selective extraction of oleic, linoleic and αlinolenic acid. The cosolvent power depended on the fatty acid, but in general, the best cosolvent for the three target compounds was ethanol. Predictions were validated through equilibrium data and extraction yields from T. suecica. Operating at 305.15 K and 20 MPa, the extracted oil with the sc-CO2-ethanol (5 % mass fraction) mixture significantly improved the content of the target fatty acids compared with pure sc-CO2; e.g. the αlinolenic acid content was 16 % in the oil obtained with pure sc-CO2 while it was 25 % in the oil obtained with sc-CO2 + 5 % ethanol. However, the Hansen theory predicted that the miscibility enhancement of the fatty acids caused by increasing ethanol concentrations in the supercritical solvent mixture was not progressive. In fact, at high pressures and high ethanol concentrations, it was predicted up to less than half the miscibility enhancement.
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, Albertina
Au/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.
Sterilization of Biological Weapons in Technical Clothing and Sensitive Material by High-Pressure CO2 and Water
(Industrial & Engineering Chemistry Research, 2018) Calvo Garrido, María Lourdes; Casas Huertas, Javier
This work explores the effectiveness of highpressure CO2 on inactivation of Bacillus thuringiensis spores as a surrogate of B. anthracis spores (anthrax). The investigation was done in combatant equipment and several electronic devices. It was possible to sterilize this sensitive material by the environmentally friendly mixture formed by high-pressure CO2 and water. The presence of water in mass proportions ranging from 20 to 30% relative to the material was essential. However, it was continuously introduced in small amounts (<4% in relation to CO2), entrained by the CO2, so as not to have an adverse impact on materials. A low external pH enhanced the inactivation. Therefore, by using CO2 mixed with water acidified with citric acid to 3.3, the spores were killed at only 45 °C. The much less aggressive conditions of the treatment allowed preservation of the quality of the technical fabrics and the functionality of the electronic devices.
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, Albertina
Superparamagnetic 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.
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 Lourdes
Cosolvents 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.
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 Lourdes
The 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
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 Lourdes
The 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.
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 Lourdes
The 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.
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, Albertina
Naproxen 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.
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, Albertina
Even 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.