Imidazolium-based co-poly(ionic liquid) membranes for CO2/N2 separation

Unformatted post printThe development of efficient carbon dioxide capture and separation technologies is at the fore front of the priorities in the climate change policies. Poly(ionic liquid)s (PILs) have been emerging as extremely promising materials for the fabrication of membranes for CO2 separation. This work is a step forward to evaluate the performance of PIL-based copolymers in the preparation of membranes for CO2/N2 separation. In particular, imidazolium-based homo and copolymers were synthesized by RAFT co-polymerization of different imidazolium salts and characterized by nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) analysis. The membrane forming ability of the synthesized PILs, as well as the influence of different side chain groups (ethyl, pentyl, benzyl and napthyl) at imidazolium ring, were evaluated using the solvent casting technique. In order to improve membrane forming ability and CO2 separation performance, different amounts of free ionic liquid (IL), [C2mim][NTf2], were added into the synthesized homo and copolymers, and PIL–IL composite membranes were prepared. The CO2 and N2 permeation properties of the obtained free standing PIL–IL membranes were measured at 20 ºC and 100 kPa and the results obtained compared through the Robeson plot.K. Vijayakrishna and N. Pothanagandhi thank “International Research Staff Exchange Scheme (IRSES) 7th Framework of European Union People-2012-IRSES” (Project No: 318873), for exchange programme. K. Vijayakrishna also thank DST-SERB, India (Project NO: SR/S1/OC-22/2012) for the financial support. L.C. Tomé is grateful to FCT (Fundação para a Ciência e a Tecnologia) for her Post-doctoral research grant (SFRH/BPD/101793/2014). This work was supported by FCT through the project PTDC/CTM-POL/2676/2014 and R&D units UID/Multi/04551/2013 (GreenIT) and UID/QUI/00100/2013 (CQE). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 745734

Layer-by-layer coated imidazolium – styrene copolymers fibers for improved headspace-solid phase microextraction analysis of aromatic compounds

The design of poly(ionic liquids) (PILs) and their application as solid phase microextraction (SPME) fibers has been attracting enormous attention mainly due to the need for new SPME coating materials with improved analytical sensitivity. In this work, the tunability of PILs is explored by preparing different imidazolium monomers bearing benzyl, naphtylmethyl or pentyl pending groups that were subsequently co-polymerized, by reversible addition–fragmentation chain transfer (RAFT) polymerization with styrene. The obtained co-polymers showed excellent thermal stability up to 275 °C, with no melting point up to 250 °C. SPME fibers were prepared by an innovative approach based on layer-by-layer spray coating. The thin (<10 μm) SPME coatings were tested in GC-FID for the detection of volatile aromatic compounds such as benzene (B), toluene (T), ethylbenzene (E) and xylene (X) present in aqueous samples and the extraction parameters optimized. Superior results were obtained when comparing these LbL PILS-based SPME fibers with a commercial fiber composed of poly(dimethylsiloxane), with an increase in the detectable areas of 83%, 69%, 57% and 58% for B, T, E and X, respectively. Low relative standard deviations were obtained for the same fiber (< 5.6%) and also for different fibers (< 9.8%). Furthermore, a spiked soil sample was used to mimic a real contaminated soil sample and excellent recovery results, ranging from 67.0% to 102.2%, were obtained.publishe

Poly(ionic liquid)–ionic liquid membranes with fluorosulfonyl derived anions: characterization and biohydrogen separation

Unformatted postprintClean and sustainable energy production has become a key global issue concerning the world’s energy shortage and environmental problematic. Despite the recognized potential of biohydrogen (bioH2) for sustainable development, there are still issues regarding its production and purification, such as the elimination of CO2, N2, and other impurities (H2O and H2S), so that an enriched H2 stream can be obtained for efficient energy generation. The use of poly(ionic liquid)s (PILs) and their derived composite materials incorporating ionic liquids (PIL–IL) has been considered as a highly promising strategy to design membranes with improved CO2 separation. In this study, membranes of pyrrolidinium-based PILs containing symmetric or asymmetric fluorosulfonyl derived anions, namely bis(fluorosulfonyl)amide ([FSI]–), (trifluoromethyl)sulfonyl-N-cyanoamide ([TFSAM]–) and (trifluoromethyl)sulfonyl-N-trifluoroacetamide ([TSAC]–), were prepared by the incorporation of different amounts of structurally similar ILs. The PIL–IL membranes were characterized by different techniques (TGA, DSC, FT-IR and Raman) and their CO2/H2 and H2/N2 separation performances were investigated. Higher CO2/H2 selectivities were obtained for PIL FSI–40 [C2mim][FSI] (αCO2/H2 = 9.0) and PIL TFSAM–40 [C2mim][TFSAM] (αCO2/H2 = 7.1) compared to those of PIL–IL membranes containing the conventional [TFSI]– anion at similar or even higher amounts of IL’s incorporation.Andreia S. L. Gouveia is grateful to FCT (Fundação para a Ciência e a Tecnologia) for her Doctoral (SFRH/BD/116600/2016) research grant. Liliana C. Tomé has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 745734. This work was supported by FCT through the project PTDC/CTM-POL/2676/2014. Centro de Química Estrutural acknowledges the financial support of Fundação para a Ciência e Tecnologia (UIDB/00100/2020). Elemental analysis and Raman spectroscopy were performed with the financial support from Ministry of Science and Higher Education of the Russian Federation using the equipment of Center for molecular composition studies of INEOS RAS

Expanding the Applicability of Poly(Ionic Liquids) in Solid Phase Microextraction: Pyrrolidinium Coatings

Crosslinked pyrrolidinium-based poly(ionic liquids) (Pyrr-PILs) were synthesized through a fast, simple, and solventless photopolymerization scheme, and tested as solid phase microextraction (SPME) sorbents. A series of Pyrr-PILs bearing three different alkyl side chain lengths with two, eight, and fourteen carbons was prepared, characterized, and homogeneously coated on a steel wire by using a very simple procedure. The resulting coatings showed a high thermal stability, with decomposition temperatures above 350 degrees C, excellent film stability, and lifetime of over 100 injections. The performance of these PIL-based SPME fibers was evaluated using a mixture of eleven organic compounds with different molar volumes and chemical functionalities (alcohols, ketones, and monoterpenes). The Pyrr-PIL fibers were obtained as dense film coatings, with 67 mu m thickness, with an overall sorption increase of 90% and 55% as compared to commercial fibers of Polyacrylate (85 mu m) (PA85) and Polydimethylsiloxane (7 mu m) (PDMS7) coatings, respectively. A urine sample doped with the sample mixture was used to study the matrix effect and establish relative recoveries, which ranged from 60.2% to 104.1%.David J. S. Patinha, and Liliana C. Tome are grateful to FCT (Fundacao para a Ciencia e a Tecnologia) for the PhD research grant SFRH/BD/97042/2013 and the Post-Doctoral research grant (SFRH/BPD/101793/2014), respectively. David J. S. Patinha also thanks the financial support from COST-Exil Project 1206. The NMR data was acquired at CERMAX (Centro de Ressonncia Magnetica Antnio Xavier) which is a member of the National NMR network. This work was partially supported by FCT through Research Unit GREEN-it " Bioresources for Sustainability" (UID/Multi/04551/2013) and the Associate Laboratory CICECO Aveiro Institute of materials (UID/CTM/50011/2013)

Antimicrobial activities of highly bioavailable organic salts and ionic liquids from fluoroquinolones

As the development of novel antibiotics has been at a halt for several decades, chemically enhancing existing drugs is a very promising approach to drug development. Herein, we report the preparation of twelve organic salts and ionic liquids (OSILs) from ciprofloxacin and norfloxacin as anions with enhanced antimicrobial activity. Each one of the fluoroquinolones (FQs) was combined with six di erent organic hydroxide cations in 93–100% yield through a bu er-assisted neutralization methodology. Six of those were isomorphous salts while the remaining six were ionic liquids, with four of them being room temperature ionic liquids. The prepared compounds were not toxic to healthy cell lines and displayed between 47- and 1416-fold more solubility in water at 25 and 37 C than the original drugs, with the exception of the ones containing the cetylpyridinium cation. In general, the antimicrobial activity against Klebsiella pneumoniae was particularly enhanced for the ciprofloxacin-based OSILs, with up to ca. 20-fold decreases of the inhibitory concentrations in relation to the parent drug, while activity against Staphylococcus aureus and the commensal Bacillus subtilis strain was often reduced. Depending on the cation–drug combination, broad-spectrum or strain-specific antibiotic salts were achieved, potentially leading to the future development of highly bioavailable and safe antimicrobial ionic formulations.info:eu-repo/semantics/publishedVersio

Highly water soluble room temperature superionic liquids of APIs

Fundacao para a Ciencia e a Tecnologia through project (PEst-C/LA0006/2013). The authors also thank Prof. Madalena Dionisio and Dr Natalia Correia for their support with the DSC analyses.Herein a straightforward approach for the enhancement of the water solubility of common antibiotic and NSAID active pharmaceutical ingredients (APIs) is presented. The APIs are converted into ionic liquids (API-ILs) and molten salts by combination with the organic superbases TMG, DBU and DBN. The prepared superionic liquids were characterized by 1H and 13C NMR as well as FTIR spectroscopy and elemental analysis. Most products are amorphous non-polymorphic room temperature ionic liquids with very high solubility in water, which may enhance the bioavailability of the API-ILs in comparison with the parent drugs.authorsversionpublishe

High pressure solubility data of carbon dioxide in (tri-iso-butyl(methyl)phosphonium tosylate + water) systems

Ionic liquids are attracting great attention nowadays due to their interesting properties which make them useful in a broad range of applications including reaction media or separation/capture of environmentally hazardous gases such as carbon dioxide. In many cases, for practical and/or economical reasons, the use of aqueous solutions of ILs would be preferable to their use as pure compounds. In this work, high pressure equilibrium data for the {carbon dioxide (CO2) + tri-iso-butyl(methyl)phosphonium tosylate [iBu3MeP][TOS] + water system were measured at temperatures ranging from (276 to 370) K and pressures up to 100 MPa. Measurements were performed using a high-pressure cell with a sapphire window that allows direct observation of the liquid–vapour transition. Mixtures with different IL concentrations were studied in order to check the influence of the amount of IL on the solubility of CO2 in the aqueous mixture. The results show that the presence of IL enhances the solubility of CO2 in the (IL + water) system revealing a salting-in effect of the IL on the solubility of CO2. The appearance of a three phase region was observed for IL concentrations higher than 4 mol% of IL in water when working at pressures between 4 and 8 MPa and temperatures between (280 and 305) K. In this range, the upper limit of the VLE region observed is shown to increase with the temperature being almost independent of the IL initial concentration in the mixture.Fundação para a Ciência e a Tecnologia (FCT)FEDERCICECO, University of Aveir

Screening polymeric ionic liquids for chromatography-based purification of bacteriophage M13

M13 bacteriophage is a key instrument in phage display applications, as well as a possible antibacterial therapeutic agent due to its highly restrictive bacterial pathogenesis, and other applications. The traditional phage purification process is usually achieved by gradient ultracentrifugation or a combination of precipitation, centrifugation and microfiltration. These approaches easily lead to long process times, high operational costs, phage aggregation and consequent product loss (approximately 60%). This work is thus focused on an alternative potential large-scale process to achieve high yield and purity while minimizing the operational costs. Electrostatic-based separation processes are also common biomolecules purification techniques. Although anion exchange chromatography has been used before to purify several viral particles, this technique has been poorly reported for the purification of M13 phage. In a recent work, our group has demonstrated the use of a predominant anion exchange process, where a polymeric ionic liquid (PIL) was used as an alternative separation matrix for M13 bacteriophage. In this work, a variety of system parameters was studied, including chemical structure of the cation and the anion, the crosslinker nature and its concentration, either in batch adsorption/elution or chromatographic operation mode. The PIL-based chromatographic operation mode revealed to be a suitable separation process for M13 from directly filtered E. coli supernatant, reaching over 70% M13 recovery and 4.6 purification factor in a single step. To our knowledge, this is the first time that PILs have been reported as separation agents for bioproducts from complex mixtures.publishe

Poly(ionic liquid)-based engineered mixed matrix membranes for CO2/H2 separation

Unformatted preprintPoly(ionic liquid)s (PIL) have emerged as a class of versatile polyelectrolites, that can be used to prepare new materials able to achieve superior performances compared to conventional polymers. The combination of PILs with ionic liquids (ILs) may serve as a suitable matrix for the preparation of membranes for gas separation. In this work, mixed matrix membranes (MMMs) combining a pyrrolidinium-based PIL, an IL and three highly CO2-selective metal organic frameworks (MOFs) were prepared. The different MOFs (MIL-53, Cu3(BTC)2 and ZIF-8) were used as fillers, aiming to maximize the membranes performance towards the purification of syngas. The influence of different MOFs and loadings (0, 10, 20 and 30 wt.%) on the thermal and mechanical stabilities of the membranes and their performance in terms of CO2 permeability and CO2/H2 ideal selectivity was assessed. The compatibility between the materials was confirmed by SEM-EDS and FTIR spectroscopy. The prepared MMMs revealed to be thermally stable within the temperature range of the syngas stream, with a loss of mechanical stability upon the MOF incorporation. The increasing MOF content in the MMMs, resulted in an improvement of both CO2 permeability and CO2/H2 ideal selectivity. Among the three MOFs studied, membranes based on ZIF-8 showed the highest permeabilities (up to 97.2 barrer), while membranes based on MIL-53 showed the highest improvement in selectivity (up to 13.3). Remarkably, all permeation results surpass the upper bound limit for the CO2/H2 separation, showing the membranes potential for the desired gas separation.This work was partially supported by R&D Units UID/Multi/04551/2013 (Green-it), UID/QUI/00100/2013 (CQE), and the Associated Laboratory Research Unit for Green Chemistry, Technologies and Clean Processes, LAQV which is financed by national funds from FCT/MCTES(UID/QUI/50006/2013) and co-financed by the ERDF under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007265). Ana R. Nabais, Luísa A. Neves and Liliana C. Tomé acknowledge FCT/MCTES for financial support through project PTDC/CTM-POL/2676/2014, FCT Investigator Contract IF/00505/2014 and Post-doctoral research grant SFRH/BDP/101793/2014, respectively. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 745734