Browsing by Subject "Ionic liquid"

Now showing 1 - 7 of 7
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    Biocatalytic transesterification of salmon oil in ionic liquid media to obtain concentrates of omega-3 polyunsaturated fatty acids
    (Springer, 2024-06) Fuster, M.G.; Moulefera, I.; García Montalbán, Mercedes; Víllora Cano, Gloria; Ingeniería Química
    In this study, a biphasic system combining oil and ionic liquid was utilized for lipase-catalyzed transesterifcation of salmon oil and alcohol to concentrate n-3 PUFAs, notably EPA and DHA. Various process variables, such as enzyme type, quantity, alcohol chain length, temperature, reactant proportions, and ionic liquid selection, were systematically assessed to optimize the process and enhance the yield of these valuable fatty acids. It was found that the Novozym 435 and Lipolase 100L Type EX emerged as the most efective enzymes. The impact of varying alcohol chain lengths (C1–C8) was examined, revealing that the Novozym 435 enzyme displayed its peak synthetic activity with 2-propanol. The results revealed a substantial increase in the overall activity during the transesterifcation reaction when employing ILs featuring hydrophobic cations and anions with low nucleophilicity. Specifcally, the [omim+][NTf2 −] ionic liquid exhibited the highest level of activity. This research holds promise for more efciently and sustainably obtaining concentrated n-3 PUFAs from fsh oil while reducing environmental impact relative to other existing concentration processes.
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    In vitro cytotoxicity assessment of monocationic and dicationic pyridinium-based ionic liquids on HeLa, MCF-7, BGM and EA.hy926 cell lines
    (Elsevier, 2019-10-24) Pérez, S. A.; García Montalbán, Mercedes; Carissimi, Guzmán; Licence, P.; Víllora Cano, Gloria; Ingeniería Química
    Dicationic ionic liquids (ILs) generally possess higher thermal and electrochemical stability than the analogous monocationic ILs, which makes them more suitable for high-temperature applications as solvents for organic reactions, lubricants or stationary phase in gas chromatography. However, knowledge on dicationic IL cytotoxicity is still scarce. Here we explore the cytotoxicity of twelve mono- and dicationic pyridinium-based ILs on HeLa, MCF-7, BGM and EA.hy926 cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cell cycle arrest assays, apoptosis experiments and orange staining were carried out. The results showed that dicationic ILs are generally less cytotoxic than their monocationic counterparts. In monocationic ILs, cytotoxicity was stronger when they contain long alkyl chains, because of their higher lipophilicity. However, the full effect of the length of the linkage alkyl chain of dicationic ILs on cytotoxicity is not clear probably because the chain is “trapped” between both cationic moieties. IL cytotoxicity is highly dependent on the cell type, and HeLa cells exposed to [C12Pyr]Br die via apoptosis. The present study increases our knowledge of IL cytotoxicity on human and monkey cells and clarifies the cell death mechanism. The results suggest that dicationic ILs offer the potential to replace some monocationic ILs because of their lower cytotoxicity.
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    Innovative application of graphene nanoplatelet-based ionanofluids as heat transfer fluid in hybrid photovoltaic-thermal solar collectors
    (Nature, 2025) Moulefera, I.; Delgado Marín, J. J.; Cascales, A.; Montalbán, M. G.; Alarcón, M.; Víllora Cano, Gloria; Ingeniería Química; Facultad de Química
    The ongoing pursuit of efficient solar thermal energy systems has driven significant interest in the development of advanced nanofluids, particularly those utilizing carbon-based nanostructures such as graphene nanoplatelets (GNP) and carbon nanotubes (CNTs). These materials, when dispersed in base fluids like water or ionic liquids, have gained attention for their tunable thermophysical properties, including thermal conductivity, viscosity, and specific heat capacity. This has positioned them as promising candidates for enhancing the thermal performance of solar collectors. However, literature examining direct experimental comparisons between the thermophysical behavior of GNP-based and CNT-based nanofluids, particularly in both water and ionic liquid media, remains sparse. Similarly, studies evaluating how such nanofluids affect the overall efficiency of solar collectors are limited and fragmented. This study investigates, for the first time, the application of GNP-based ionanofluids (INFs) in commercial hybrid photovoltaic-thermal (PVT) solar collectors. INFs were prepared using GNP and 1-ethyl-3-methylimidazolium acetate ([Emim] Ac) ionic liquid. Their thermophysical properties, including density, viscosity, thermal conductivity, and specific heat capacity, were comprehensively characterized. Long-term stability was also assessed to ensure consistent performance over time. Comparative tests with water and pure ionic liquid as base fluids revealed that INFs exhibited a significantly higher temperature rise within the collector, attributed to their lower specific heat capacity. This resulted in an exergy efficiency improvement of over 5% compared to the ionic liquid alone, underscoring the potential of INFs as advanced heat transfer fluids for high-temperature solar systems. These findings highlight the novelty of using GNP-based INFs in solar applications and pave the way for future research in optimizing nanofluid compositions for renewable energy systems.
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    Non-chromatographic speciation of arsenic by successive dispersive liquidliquid microextraction and in situ formation of an ionic liquid in water samples
    (Elsevier, 2020-05-30) Vicente Martínez, Yésica; Química Analítica
    Arsenic is an element present in waters in its different species which can cause a serious risk to human health due to the consumption of these waters. However, the toxicity of each species is very different. Because of that, in analytical chemistry there is a great interest in developing methods that allow the quantification of low concentrations and speciation of arsenic. Accordingly, this work introduces a novel method applied to determine very low concentrations of arsenic species (As (III), As (V), monomethylarsonic acid (MA), dimethylarsinic acid (DMA) and arsenobetaine (AB)) in water samples. The procedure provides high enrichment factors and great sensitivity in a simple and non-chromatographic way using electrothermal atomic absorption spectrometry. The in-situ formation of an ionic liquid (IL) results in a dispersion through the formation of a cloud of IL droplets that allows the instantaneous extraction of the arsenic species. After centrifugation, they can be quantified by direct injection of the extract (IL+arsenic species) into the detector. The different experimental conditions such as pH and the use of complexing agents allow the selective extraction of each species. An enrichment factor of 295 is obtained by using this procedure. Additionally, high sensitivity and a low detection limit (0.02 μg L−1) for all species are achieved, enabling the method as an alternative for the chromatographic techniques.
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    Novel application for graphene oxide-based ionanofluids in flat plate solar thermal collectors
    (Nature Research, 2024-07-30) Moulefera, I.; Pastor, A.R.; Fuster, M.G.; Delgado Marín, J.J.; García Montalbán, Mercedes; Rodríguez Pastor, I.; López Pérez, A.; Martin Gullón, I.; Ramallo González, Alfonso Pablo; Alarcón García, Mariano; Víllora Cano, Gloria; Ingeniería Química
    This study presents new ionanofluids (INF) composed of 1-ethyl-3-methylimidazolium acetate ionic liquid (IL) and graphene oxide (GO) nanoparticles which have been assessed for the first time in an experimental flat plate solar thermal collector (FPSC). For this purpose, four types of INFs were synthesized, maintaining a constant concentration of GO nanoparticles dispersed in different base fluids: ionic liquid (IL/GO), a mixture of ionic liquid and water in varying concentrations (IL-water (75–25)%/GO and IL-water (50–50)%/GO), and water (Water/GO). These four INFs were characterized and their thermophysical and physicochemical properties were determined. The results indicated a 37.4% improvement in efficiency and up to a 2.5-fold increase in temperature within the collector when the IL was applied exclusively as the base fluid, compared to water. Furthermore, IL/GO demonstrated excellent stability, showing no signs of deterioration or nanoparticle precipitation two years after preparation and testing. These findings suggest that INFs based on IL and GO nanoparticles significantly enhance the efficiency of FPSC, presenting a promising option for solar energy applications and opening a new research avenue for INFs in the production of domestic hot water.
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    Synthesis of Cellulose Nanoparticles from Ionic Liquid Solutions for Biomedical Applications
    (MDPI, 2023-01-23) Fuster, M. G.; Moulefera, I.; Muñoz, M. N.; Montalbán, M. G.; Víllora Cano, Gloria; Ingeniería Química; Facultad de Química
    A method for the synthesis of cellulose nanoparticles using the ionic liquid 1-ethyl-3- methylimidazolium acetate has been optimised. The use of a highly biocompatible biopolymer such as cellulose, together with the use of an ionic liquid, makes this method a promising way to obtain nanoparticles with good capability for drug carrying. The operating conditions of the synthesis have been optimised based on the average hydrodynamic diameter, the polydispersity index, determined by Dynamic Light Scattering (DLS) and the Z-potential, obtained by phase analysis light scattering (PALS), to obtain cellulose nanoparticles suitable for use in biomedicine. The obtained cellulose nanoparticles have been characterised by Fourier transform infrared spectroscopy (FTIR) with attenuated total reflectance (ATR), field emission scanning electron microscopy (FESEM) and thermogravimetric analysis (TGA/DTA). Finally, cell viability studies have been performed with a cancer cell line (HeLa) and with a healthy cell line (EA.hy926). These have shown that the cellulose nanoparticles obtained are not cytotoxic in the concentration range of the studied nanoparticles. The results obtained in this work constitute a starting point for future studies on the use of cellulose nanoparticles, synthesised from ionic liquids, for biomedical applications such as targeted drug release or controlled drug release.
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    Thermoplastic starch/polyvinyl alcohol blends modification by citric acid–glycerol polyesters
    (MDPI, 2023-04-04) Castro, J. M.; Montalbán, M. G.; Domene-López, D.; Martin-Gullon, I.; García-Quesada, J. C.; Ingeniería Química; Facultad de Química
    The first step towards the production and marketing of bioplastics based on renewable and sustainable materials is to know their behavior at a semi-industrial scale. For this reason, in this work, the properties of thermoplastic starch (TPS)/polyvinyl alcohol (PVA) films plasticized by a green solvent, as the 1-ethyl-3-methylimidazolium acetate ([Emim+][Ac􀀀]) ionic liquid, produced by melt-mixing were studied. These blends were prepared with a different content of [Emim+][Ac􀀀] (27.5–42.5 %wt.) as a unique plasticizer. According to the results, this ionic liquid is an excellent plasticizer due to the transformation of the crystalline structure of the starch to an amorphous state, the increase in flexibility, and the drop in Tg, as the [Emim+][Ac􀀀] amount increases. These findings show that the properties of these biomaterials could be modified in the function of [Emim+][Ac􀀀] content in the formulations of TPS, depending on their final use, thus becoming a functional alternative to conventional polymers.