Dr. Cabezas-Cornejo, René

Ionic liquids have attracted widespread attention due to their low melting points, low vapor pressure, and non-flammability. However, their application at industrial scale is uncommon due to high costs and low recovering efficiency of the ionic liquids within the process. To reduce the costs and environmental effects of ionic liquids, this study proposes to use industrial microwave irradiation to recover eight different ionic liquids from water. The heating kinetics and identification between dielectric and convective heat properties were studied. Imidazolium-based ionic liquids showed the best results, reaching higher temperatures in shorter periods of time. Ionic liquid (bis(trifluoromethylsulfonyl) trihexyl(tetradecyl) phosphonium imide ([P6,6,6,14][Tf2N]) reached a temperature of 398 K in 360 s). On the other hand, the ionic liquid (1-butyl-3-methylimidazolium methylsulfate ([bmim][CH3OSO3]) reached a temperature of 417 K in 150 s). the ionic liquid Microwave heating experiments (water/ionic liquids) demonstrated a 90% recovery in ∼200 s for 1-octyl-3-methylimidazolium chloride ([omim][Cl]). Finally, the time used to heat-up ionic liquids with microwave irradiation was 15 times shorter than the time employed with vacuum-assisted distillation. Therefore, microwave-assisted heating has shown to be an excellent form to heat ionic liquids to decrease the cost of the extraction process and improve their reusability.

Suture materials based on poly (lactic acid) (PLA) were developed by means of two different methods: extrusion and electrospinning, which were followed by a supercritical CO2 impregnation treatment. Both suture materials obtained by these techniques were impregnated with naproxen and ibuprofen using supercritical CO2 as impregnation medium. The impregnation assays were carried out at two different pressures (12 and 15 MPa), a temperature of 40 °C and, a depressurization rate of 1 MPa/min. Depending on the drugs incorporated into the suture materials, the concentrations varied from 5.60 to 26.73 wt%. The addition of both drugs and, the preparation process itself caused different changes in the structural and thermal properties of the final suture materials. Finally, tests to quantify the kinetic release of both drugs were carried out in vitro by using a Franz diffusion cell, obtaining the concentration profiles of delivered compounds as a function of the time.

In this work, a study on the selective solvent extraction (SX) of molybdenum (Mo) and rhenium (Re) from a synthetic pregnant leach solution (PLS) has been carried out using nine different hydrophobic eutectic solvents (HES). Experiments were carried out using pure HES to evaluate the selective extraction and the subsequent stripping of these metal ions; then, the best HES was dissolved in kerosene to study the SX stoichiometry. Results indicated that only TOPO-based and N8881-Cl-based HES did not form emulsions, third phases or precipitates. These HES achieved a selective extraction because these obtained almost a 100% extraction towards Mo and Re from the PLS and very low extractions for Copper (Cu) and Iron (Fe) in one equilibrium stage. The stripping experiments showed that 95% of Mo and 22% of Re were stripped out from the loaded TOPO-based HDES, respectively, opening the possibility for the selective stripping of the metal species for further purification. Finally, the extraction stoichiometry was proposed based on an experimental slope analysis and the measurement of cations and anions transferred into the aqueous phase in which HES acts as a neutral extractant in the complexation of the Mo and Re salts. These promising results suggest that HES could be attractive for more sustainable mining industry.

In this study, the theoretical design of ionic liquids (ILs) for predicting selective extraction of lithium from brines has been conducted using COSMO-RS. A theoretical model for the solvent extraction (SX) of the metal species present in brines was established considering extraction stoichiometry, the distribution of the extractants between aqueous and IL phases, and IL dissociation in the aqueous phase. Theoretical results were validated using experimental extraction percentages from previous works. Results indicate that, in general, the theoretical results for lithium extraction follow experimental trends, except from magnesium extraction. Finally, based on the model, an IL was proposed that was based on the phosphonium cation as the extractant, along with the phase modifier tributylphosphate (TBP) in an organic diluent in order to improve selectivity for lithium ex- traction over sodium. These results provide an insight for the application of ILs in lithium processing, avoiding the long purification times reported in the conventional process.

The separation of Levulinic (LA) acid and Formic acid (FA) from aqueous streams represents an important and challenging separation in biorefineries, where ionic liquids (ILs) provide a sustainable environment for liquid-liquid extractions of these acids. In this work, a COSMO-RS screening of bis (trifluoromethylsulfonil)imide [Tf2N]− based IL was first conducted and then followed by experimental validation to search for the most suitable cation for this separation. After the screening, ternary liquid-liquid equilibrium experiments at 298.15K and the subsequent data correlation using the Non-Random Two Liquid model (NRTL) were performed for future industrial implementation. Results indicated that the phosphonium cations, especially the trihexylthetradecyl phosphonium cation [P66614]+, produced the highest selectivity rates among all the experimentally measured ILs.

Aqueous and ethanolic extracts of tomato pomace were examined with the aim of optimizing the extraction process of compounds with cardioprotective activity. Once the results of the ORAC response variables, total polyphenols, ◦Brix, and antiplatelet activity of the extracts were obtained, a multivariate statistical analysis was performed using the Statgraphics Centurion XIX software. This analysis showed that the most relevant positive effects in the inhibition of platelet aggregation were 83 ± 2% when using the agonist TRAP-6, when the working conditions were the type of tomato pomace conditioning (drum-drying process at 115 ◦C), phase ratio (1/8), type of solvent (ethanol 20%), and type of extraction (ultrasound-assisted solid–liquid extraction). The extracts with the best results were microencapsulated and characterized by HPLC. The presence of chlorogenic acid (0.729 mg/mg of dry sample) was found, a compound that has a potential cardioprotective effect documented in various studies, in addition to rutin (2.747 mg/mg of dry sample) and quercetin (0.255 mg/mg of dry sample). These results show that the extraction efficiency of compounds with cardioprotective activity depends largely on the polarity of the solvent, thus playing an important role in the antioxidant capacity of the extracts of tomato pomace.

Melissa officinalis L. is a medicinal plant used worldwide for ethno-medical purposes. Today, it is grown everywhere; while it is known to originate from Southern Europe, it is now found around the world, from North America to New Zealand. The biological properties of this medicinal plant are mainly related to its high content of phytochemical (bioactive) compounds, such as flavonoids, polyphenolic compounds, aldehydes, glycosides and terpenes, among many other groups of substances. Among the main biological activities associated with this plant are antimicrobial activity (against fungi and bacteria), and antispasmodic, antioxidant and insomnia properties. Today, this plant is still used by society (as a natural medicine) to alleviate many other illnesses and symptoms. Therefore, in this perspective, we provide an update on the phytochemical profiling analysis of this plant, as well as the relationships of specific biological and pharmacological effects of specific phytochemicals. Currently, among the organic solvents, ethanol reveals the highest effectiveness for the solvent extraction of precious components (mainly rosmarinic acid). Additionally, our attention is devoted to current developments in the extraction and fractionation of the phytochemicals of M. officinalis, highlighting the ongoing progress of the main strategies that the research community has employed. Finally, after analyzing the literature, we suggest potential perspectives in the field of sustainable extraction and purification of the phytochemical present in the plant. For instance, some research gaps concern the application of cavitation-assisted extraction processes, which can effectively enhance mass transfer while reducing the particle size of the extracted material in situ. Meanwhile, membrane-assisted processes could be useful in the fractionation and purification of obtained extracts. On the other hand, further studies should include the application of ionic liquids and deep eutectic solvents (DES), including DESs of natural origin (NADES) and hydrophobic DESs (hDES), as extraction or fractionating solvents, along with new possibilities for effective extraction related to DESs formed in situ, assisted by mechanical mixing (mechanochemistry-based approach).

With the target of fabricating healthier products, food manufacturing companies look for natural-based nutraceuticals that can potentially improve the physicochemical properties of food systems while being nutritive to the consumer and providing additional health benefits (biological activities). In this regard, Mangiferin joins all these requirements as a potential nutraceutical, which is typically contained in Mangifera indica products and its by-products. Unfortunately, knowing the complex chemical composition of Mango and its by-products, the extraction and purification of Mangiferin remains a challenge. Therefore, this comprehensive review revises the main strategies proposed by scientists for the extraction and purification of Mangiferin. Importantly, this review identifies that there is no report reviewing and criticizing the literature in this field so far. Our attention has been targeted on the timely findings on the primary extraction techniques and the relevant insights into isolation and purification. Our discussion has emphasized the advantages and limitations of the proposed strategies, including solvents, extracting conditions and key interactions with the target xanthone. Additionally, we report the current research gaps in the field after analyzing the literature, as well as some examples of functional food products containing Mangiferin.

This work assesses the prediction capability of COSMO-RS for solvent selection in dispersive liquid phase microextraction systems. The assessment is performed by comparing experimental partition ratios from previous works and calculated ones for different systems, including pesticides, herbicides, polyaromatic aromatic hydrocarbons, and halogen-containing pollutants from water samples. Results indicate that COSMO-RS mainly overestimates the partition ratios. Despite this, a priori analysis was carried out for conventional solvents used as extractants. Results showed that for pesticides and herbicides, COSMORS predictions agree just for a few extractants. For polyaromatic hydrocarbons (PAHs), the ring structure is a crucial parameter in extractants’ selection, and for Halogenated pollutants, the halogen content and kind of substitution are crucial to correct trend prediction. Besides this, ILs also were studied, finding that COSMO-RS overestimates the use of ILs, and higher deviations are found for longer alkyl chain cations. However, the Dichlorodiphenyltrichloroethane (DDT) metabolite extraction with ILs is well predicted. Dispersants were also evaluated, but depending on the kind of pollutant, different deviations were found.

The dehydration of fructose to selectively produce 5‐HMF was catalytically developed in a new type of ionic liquids based on triazoles supported on alumina (Al2O3). The synthesis of triazoles by 1,3‐dipolar cycloaddition allows for creating a tailor‐made triazole, that was eventually used to design catalysts based on triazolium‐based ionic liquids. In this work, four catalysts based on triazolium‐ionic liquids supported on Al2O3 were synthesized to produce 5‐HMF from fructose in DMSO as the reaction solvent. According to their molecular structure, the catalysts were tagged as TR1/Al2O3, TR1‐HSO4/Al2O3, TR2/Al2O3, and TR2‐HSO4/Al2O3.