Supercapacitors and triboelectric nanogenerators based on electrodes of greener iron nanoparticles/carbon nanotubes composites.

The development of supporting materials based on carbon nanotubes (CNTs) impregnated with iron nanoparticles via a sustainable and green synthesis employing plant extract of Punica granatum L. leaves was carried out for the iron nanoparticle modification and the following impregnation into the carbon nanotubes composites (CNT-Fe) that were also coated with polypyrrole (CNT-Fe + PPy) for use as electrode for supercapacitor and triboelectric nanogenerators. The electrochemical characterization of the materials by cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) assays revealed that the CNT-Fe + PPy gave rise to better performance due to the association of double-layer capacitance behavior of carbon derivative in association with the pseudocapacitance contribution of PPy resulting in an areal capacitance value 202 mF/ cm2 for the overall composite. In terms of the application of electrodes in triboelectric nanogenerators, the best performance for the composite of CNT-Fe + PPy was 60 V for output voltage and power density of 6 µW/cm2. The integrated system showed that the supercapacitors can be charged directly by the nanogenerator from 0 to 42 mV in 300 s. The successful green synthesis of iron nanoparticles on CNT and further PPy coating provides a feasible method for the design and synthesis of high-performance SCs and TENGs electrode materials. This work provides a systematic approach that moves the research front forward by generating data that underpins further research in self-powered electronic devices.

Empowering Adsorption and Photocatalytic Degradation of Ciprofloxacin on BiOI Composites: A Material-by-Design Investigation.

Binary and ternary composites of BiOI with NH2-MIL-101(Fe) and a functionalized biochar were synthesized through an in situ approach, aimed at spurring the activity of the semiconductor as a photocatalyst for the removal of ciprofloxacin (CIP) from water. Experimental outcomes showed a drastic enhancement of the adsorption and the equilibrium (which increased from 39.31 mg g-1 of bare BiOI to 76.39 mg g-1 of the best ternary composite in 2 h time), while the kinetics of the process was not significantly changed. The photocatalytic performance was also significantly enhanced, and the complete removal of 10 ppm of CIP in 3 h reaction time was recorded under simulated solar light irradiation for the best catalyst of the investigated batch. Catalytic reactions supported by different materials obeyed different reaction orders, indicating the existence of different mechanisms. The use of scavengers for superoxide anion radicals, holes, and hydroxyl radicals showed that although all these species are involved in CIP photodegradation, the latter play the most crucial role, as also confirmed by carrying out the reaction at increasing pH conditions. A clear correlation between the reduction of BiOI crystallite sizes in the composites, as compared to the bare material, and the material performance as both adsorbers and photocatalyst was identified.

Detection of nitrification inhibitor dicyandiamide: A direct electrochemical approach.

A single run approach for rapid detection of nitrification inhibitor, dicyandiamide (DCD) using electrogenerated chlorine assisted polymerization through azo bond, under acidic conditions and at a preanodized screen printed carbon electrode (SPCE*) is presented. The role of chloride containing support electrolyte in acidic medium along with oxygen functionalities/edge sites are found to be crucial for the successful oxidative polymerization and subsequent adsorption of oxidized products on the electrode surface. The SEM, cyclic voltammetry and X-ray photoelectron spectroscopy studies were used to characterize the polymer film formation. The system exhibited a linear range between 20 and 170 µM with a detection limit of 3 µM (S/N = 3). The method was successfully tested for the detection of DCD in dairy and water samples. Simultaneous detection of DCD in the presence of melamine has also been demonstrated.

Cellulose Fiber Rejects as Raw Material for Integrated Production of Pleurotus spp. Mushrooms and Activated Biochar for Removal of Emerging Pollutants from Aqueous Media.

Cellulose fiber rejects from industrial-scale recycling of waste papers were dried and de-ashed using a combined cyclone-drying and sieving process. The upgraded fiber reject was used as a component of substrates for the cultivation of Pleurotus ostreatus and Pleurotus eryngii mushrooms. Acetic acid (AA) and acid whey (AW) were used to adjust the pH of fiber reject-based substrates. Spent substrate (SMS) was used for the production of activated biochar using H3PO4 and KOH as activating agents and pyrolysis temperatures of 500, 600, and 700 °C. The effectiveness of the biochars in removing pollutants from water was determined using acetaminophen and amoxicillin. By using a feeding rate of 250 kg/h and a drying air temperature of 70 °C, the moisture content of the raw fiber rejects (57.8 wt %) was reduced to 5.4 wt %, and the ash content (39.2 wt %) was reduced to 21.5 wt %. Substrates with 60 and 80 wt % de-ashed cellulose fiber were colonized faster than a birch wood-based control substrate. The adjustment of the pH of these two substrates to approximately 6.5 by using AA led to longer colonization times but biological efficiencies (BEs) that were higher or comparable to that of the control substrate. The contents of ash, crude fiber, crude fat, and crude protein of fruit bodies grown on fiber reject-based substrates were comparable to that of those grown on control substrates, and the contents of toxic heavy metals, that is, As, Pb, Cd, and Hg, were well below the up-limit values for food products set in EC regulations. Activated biochar produced from fiber reject-based SMS at a temperature of 700 °C resulted in a surface area (BET) of 396 m2/g (H3PO4-activated biochar) and 199 m2/g (KOH-activated biochar). For both activated biochars, the kinetics of adsorption of acetaminophen and amoxicillin were better described using the general order model. The isotherms of adsorption were better described by the Freundlich model (H3PO4-activated biochar) and the Langmuir model (KOH-activated biochar).

How Different Electrolytes Can Influence the Aqueous Solution Behavior of 1-Ethyl-3-Methylimidazolium Chloride: A Volumetric, Viscometric, and Infrared Spectroscopy Approach.

The density, sound velocity, and viscosity of 1-ethyl-3-methylimidazolium chloride [C2mim]Cl in pure water and aqueous solutions of some electrolytes such as potassium chloride, potassium carbonate, and potassium phosphate (weight fraction of salt fixed at w s = 0. 11) have been measured over a wide range of temperatures from 298.15 to 318.15 K. The obtained experimental data have been used to compute various volumetric, compressibility, and viscometric parameters, e.g., apparent molar properties, limiting apparent molar and transfer properties. The co-sphere overlap model was employed to describe the dominant intermolecular interactions in the ternary solutions. Additionally, the structure making/breaking nature of the [C2mim]Cl in the ternary solutions has been discussed in terms of Hepler's constant and the temperature derivative of viscosity B-coefficient (dB/dT). The activation free energy of solvent and solute, activation enthalpy, and activation entropy have been calculated by the application of transition state theory. The calculated parameters have been interpreted in the sense of solvent-solute and solute-solute interactions. The Fourier transform infrared (FTIR) studies also have been done for the studied systems. Volumetric, acoustic, viscometric, and spectroscopic studies can render some evidence and help to understand the aqueous solution behavior of ionic liquids.

Production of C-14 Levulinate Ester from Glucose Fermentation Liquors Catalyzed by Acidic Ionic Liquids in a Solvent-Free Self-Biphasic System.

Herein, we present the C-14 levulinate ester of 2,3-butanediol as the product of sugar fermentation liquors. The designed Brønsted acidic ionic liquid (BAIL) catalysts enable self-induced phase separation with ester products, and the role of anions has been investigated. Esterification reactions were carried out by 2,3-butanediol (2,3-BDO) and levulinic acid in solvent-free media and low temperatures (60-105 °C). For comparison, sulfuric acid, amberlite IR-120, and sulfonic acid-functionalized pyridinium ionic liquids with different anions were utilized as a catalyst upon esterification reaction. The diester product, namely, butane-2,3-diyl bis(4-oxopentanoate), was formed with a good yield (85%) and selectivity (85%) after complete conversion of 2,3-BDO in 24 h at 80 °C. The low yield (8%) of the monoester was observed. The monoester and diester were separated by a liquid-liquid extraction method. The ester products were characterized by various instrumental techniques such as 1H and 13C NMR, GC-FID, LC-MS, and FT-IR spectroscopy. The Hammett acidity functions of BAILs were determined from UV-vis spectroscopy. The catalyst was successfully recycled and reused in the processes. The spent BAILs were reused in six consecutive cycles with only a ∼7% diminished diester yield and selectivity. The produced levulinate ester will be useful as biofuel additives, solvents, plasticizers, and other applications.

Use of Ionic Liquids in Protein and DNA Chemistry.

Ionic liquids (ILs) have been receiving much attention as solvents in various areas of biochemistry because of their various beneficial properties over the volatile solvents and ILs availability in myriad variants (perhaps as many as 108) owing to the possibility of paring one cation with several anions and vice-versa as well as formulations as zwitterions. Their potential as solvents lies in their tendency to offer both directional and non-directional forces toward a solute molecule. Because of these forces, ionic liquids easily undergo intermolecular interactions with a range of polar/non-polar solutes, including biomolecules such as proteins and DNA. The interaction of genomic species in aqueous/non-aqueous states assists in unraveling their structure and functioning, which have implications in various biomedical applications. The charge density of ionic liquids renders them hydrophilic and hydrophobic, which retain intact over long-range of temperatures. Their ability in stabilizing or destabilizing the 3D-structure of a protein or the double-helical structure of DNA has been assessed superior to the water and volatile organic solvents. The aptitude of an ion in influencing the structure and stability of a native protein depends on their ranking in the Hofmeister series. However, at several instances, a reverse Hofmeister ordering of ions and specific ion-solute interaction has been observed. The capability of an ionic liquid in terms of the tendency to promote the coiling/uncoiling of DNA structure is noted to rely on the basicity, electrostatic interaction, and hydrophobicity of the ionic liquid in question. Any change in the DNA's double-helical structure reflects a change in its melting temperature (T m), compared to a standard buffer solution. These changes in DNA structure have implications in biosensor design and targeted drug-delivery in biomedical applications. In the current review, we have attempted to highlight various aspects of ionic liquids that influence the structure and properties of proteins and DNA. In short, the review will address the issues related to the origin and strength of intermolecular interactions, the effect of structural components, their nature, and the influence of temperature, pH, and additives on them.

Is basicity the sole criterion for attaining high carbon dioxide capture in deep-eutectic solvents?

A critical analysis of the role of Hammett basicity (H-) and aqueous basicity (pKa) in CO2 uptake in deep-eutectic solvents (DESs) suggests that neither H- nor pKa correlates with the CO2 w/w% capacity in the studied DESs. Instead, strong "synergistic interactions" between donor and acceptor moieties satisfactorily relate to the w/w% of CO2 in DESs.

SO3H-Containing Functional Carbon Materials: Synthesis, Structure, and Acid Catalysis.

The "sulfonated carbons" are a new class of metal-free solid protonic acids characterized by their unique carbon structure and Brønsted acidity (-H0 = 8-11) on par to concentrated H2SO4. These carbon materials covalently functionalized with SO3H groups via C-PhSO3H or C-SO3H linkages can act as versatile water-tolerant solid acids. Due to their low production costs, unique surface chemistry, high chemical and thermal stability, as well as tailorable pore structures they are regarded as potential substitutes to liquid H2SO4. Catalysis, in particular, biomass and large molecule catalysis, is one of the important areas in which acidic carbons have demonstrated exceptional activity and selectivity, outperforming traditional solid acid catalysts (cation-exchange resins, sulfated oxides, and acidic zeolites). In this review we address developments in the different types SO3H- and PhSO3H-functionalized acidic carbon materials, their structure, active sites, and surface properties, applications in catalysis, as well as activation and deactivation characteristics covering important literature since 2004. In particular, we aim to provide a systematic discussion on the specific merits and demerits of such materials obtained from different carbon precursors and functionalization methods which directly influence the structure-stability-acidic properties and catalytic performance.

Improvement of ethanol production from birch and spruce pretreated with 1-H-3-methylmorpholinium chloride

Background: Pretreatment is the critically important step for the production of ethanol from lignocelluloses. In this study, hardwood birch (Betula pendula) and softwood spruce (Norway spruce) woods were pretreated with a newly synthesized morpholinium ionic liquid, 1-H-3-methylmorpholinium chloride ([HMMorph][Cl]), followed by enzymatic hydrolysis and fermentation to ethanol. Results: [HMMorph][Cl] was synthesized using inexpensive raw materials, i.e., hydrochloric acid and N-methyl morpholine, following a simple process. The influence of pretreatment time (2, 3, 5, and 8 h) and temperature (120 and 140°C) in terms of hydrolysis efficiency was investigated. Glucose yields from enzymatic hydrolysis were improved from 13.7% to 45.7% and 12.9% to 51.8% after pretreatment of birch and spruce woods, respectively, under optimum pretreatment conditions (i.e., at 140°C for 3 h) as compared to those from pristine woods. Moreover, the yields of ethanol production from birch and spruce were increased to 34.8% and 44.2%, respectively, while the yields were negligible for untreated woods. Conclusions: This study demonstrated the ability of [HMMorph][Cl] as an inexpensive agent to pretreat both softwood and hardwood.

Unusual temperature-promoted carbon dioxide capture in deep-eutectic solvents: the synergistic interactions.

A series of novel ethylenediamine (EDA)-based deep-eutectic solvents (DESs) gave rise to unexpectedly large carbon dioxide (CO2) capture capacities at higher temperatures owing to the "synergistic interaction" between the donor and acceptor moieties.

Metal free synthesis of ethylene and propylene carbonate from alkylene halohydrin and CO2 at room temperature.

Herein we describe a metal free and one-pot pathway for the synthesis of industrially important cyclic carbonates such as ethylene carbonate (EC) and propylene carbonates (PC) from molecular CO2 under mild reaction conditions. In the actual synthesis, the alkylene halohydrins such as alkylene chloro- or bromo or iodohydrin and organic superbase, 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) reacted equivalently with CO2 at room temperature. The syntheses of cyclic carbonates were performed in DMSO as a solvent. Both 1,2 and 1,3 halohydrin precursors were converted into cyclic carbonates except 2-bromo- and iodoethanol, which were reacted equivalently with DBU through n-alkylation and formed corresponding n-alkylated DBU salts instead of forming cyclic carbonates. NMR analysis was used to identify the reaction components in the reaction mixture whereas this technique was also helpful in terms of understanding the reaction mechanism of cyclic carbonate formation. The mechanistic study based on the NMR analysis studies confirmed that prior to the formation of cyclic carbonate, a switchable ionic liquid (SIL) formed in situ from alkylene chlorohydrin, DBU and CO2. As a representative study, the synthesis of cyclic carbonates from 1,2 chlorohydrins was demonstrated where the synthesis was carried out using chlorohydrin as a solvent as well as a reagent. In this case, alkylene chlorohydrin as a solvent not only replaced DMSO in the synthesis but also facilitated an efficient separation of the reaction components from the reaction mixture. The EC or PC, [DBUH][Cl] as well as an excess of the alkylene chlorhydrin were separated from each other following solvent extraction and distillation approaches. In this process, with the applied reaction conditions, >90% yields of EC and PC were achieved. Meanwhile, DBU was recovered from in situ formed [DBUH][Cl] by using NaCl saturated alkaline solution. Most importantly here, we developed a metal free, industrially feasible CO2 capture and utilization approach to obtain EC and PC under mild reaction conditions.

Intermolecular interactions upon carbon dioxide capture in deep-eutectic solvents.

Herein we report the CO2 uptake in potential deep-eutectic solvents (DESs) formed between hydrogen bond acceptors (HBAs) such as monoethanolammonium chloride ([MEA·Cl]), 1-methylimidazolium chloride ([HMIM·Cl]) and tetra-n-butylammonium bromide ([TBAB]) and hydrogen bond donors (HBDs) like ethylenediamine ([EDA]), diethylenetriamine ([DETA]), tetraethylenepentamine ([TEPA]), pentaethylenehexamine ([PEHA]), 3-amino-1-propanol ([AP]) and aminomethoxypropanol ([AMP]) and analyzed the outcome in terms of the specific polarity parameters. Among various combinations of HBAs and HBDs, [MEA·Cl][EDA]-, [MEA·Cl][AP]-, [HMIM·Cl][EDA]- and [HMIM·Cl][AP] showed excellent CO2 uptake which was further improved upon increasing the mole ratio of HBA : HBD from 1 : 1 to 1 : 4. The lowest CO2 uptake in [MEA·Cl][PEHA] (12.7 wt%) and [HMIM·Cl][PEHA] (8.4 wt%) despite the highest basicity of [PEHA] infers that the basicity is not the sole criteria for guiding the CO2 uptake but, in reality, CO2 capture in a DES relies on the interplay of H-bonding interactions between each HBA and HBD. The role of HBAs in guiding CO2 uptake was more prominent with weak HBDs such as [TEPA] and [PEHA]. The speciation of absorbed CO2 into carbamate, carbonate, and bicarbonate was favorable in DES characterized by comparable hydrogen bond donor acidity (α) and hydrogen bond acceptor basicity (ß) values, whereas the conversion of carbamate to carbonate/bicarbonate was observed to depend on α. The addition of water in DES resulted in lower CO2 uptake due to the decreased basicity (ß).

Hydrogen sulfide gas capture by organic superbase 1,8-diazabicyclo-[5.4.0]-undec-7-ene through salt formation: salt synthesis, characterization and application for CO2 capture.

Hydrogen sulfide (H2S) is a toxic and environment polluting gas like other acid gases and hence its capture and sequestration is equally important before release into the atmosphere. In this regard, solvent-based processes involving aqueous tertiary amine systems were extensively studied and used. Herein, in line with an analogous pathway, we report capture of H2S gas in the form of its salt with an organic superbase such as 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) and the obtained salt was thoroughly studied. Spectroscopic analyses such as NMR and FTIR analyses confirmed that the H2S molecule formed an ionic solid adduct with DBU through protonation of its sp2-hybridized N atom. The stability of formed [DBUH][SH] salt in aqueous solution as well as under thermal treatment was also studied and monitored by NMR and thermogravimetric analysis (TGA), respectively. In aqueous medium, compared to DBU, the [DBUH][SH] salt exhibited long term stability without decomposition whereas under thermal treatment both DBU and its salt with H2S turned out to be thermally unstable where salt showed a volatile nature like a sublimized solid. Dissolution feasibility of [DBUH][SH] salt was also compared with DBU in polar as well as non-polar solvents and even though the [DBUH][SH] salt had an ionic nature, like DBU, it was also found soluble in various polar and non-polar solvents. Considering the stability of [DBUH][SH] salt in aqueous medium, its aqueous solution was further explored as a solvent media for CO2 capture where the influence of process parameters such as the influence of concentration of water in the solvent and CO2 flow rate was studied. Most importantly, here we demonstrated the synthesis of [DBUH][SH] salt for easy capture of H2S gas following reaction with DBU under ambient reaction conditions.

Microbial mineralization of cellulose in frozen soils.

High-latitude soils store ~40% of the global soil carbon and experience winters of up to 6 months or more. The winter soil CO2 efflux importantly contributes to the annual CO2 budget. Microorganisms can metabolize short chain carbon compounds in frozen soils. However, soil organic matter (SOM) is dominated by biopolymers, requiring exoenzymatic hydrolysis prior to mineralization. For winter SOM decomposition to have a substantial influence on soil carbon balances it is crucial whether or not biopolymers can be metabolized in frozen soils. We added 13C-labeled cellulose to frozen (-4 °C) mesocosms of boreal forest soil and followed its decomposition. Here we show that cellulose biopolymers are hydrolyzed under frozen conditions sustaining both CO2 production and microbial growth contributing to slow, but persistent, SOM mineralization. Given the long periods with frozen soils at high latitudes these findings are essential for understanding the contribution from winter to the global carbon balance.

Robust hierarchical 3D carbon foam electrode for efficient water electrolysis.

Herein we report a 3D heterostructure comprising a hierarchical macroporous carbon foam that incorporates mesoporous carbon nanotubes decorated with cobalt oxide nanoparticles as an unique and highly efficient electrode material for the oxygen evolution reaction (OER) in electrocatalytic water splitting. The best performing electrode material showed high stability after 10 h, at constant potential of 1.7 V vs. RHE (reversible hydrogen electrode) in a 0.1 M KOH solution and high electrocatalytic activity in OER with low overpotential (0.38 V vs RHE at 10 mA cm-2). The excellent electrocatalytic performance of the electrode is rationalized by the overall 3D macroporous structure and with the firmly integrated CNTs directly grown on the foam, resulting in a large specific surface area, good electrical conductivity, as well as an efficient electrolyte transport into the whole electrode matrix concurrent with an ability to quickly dispose oxygen bubbles into the electrolyte. The eminent properties of the three-dimensional structured carbon matrix, which can be synthesized through a simple, scalable and cost effective pyrolysis process show that it has potential to be implemented in large-scale water electrolysis systems.

Carbon Dioxide Capture with Ionic Liquids and Deep Eutectic Solvents: A New Generation of Sorbents.

High cost and high energy penalty for CO2 uptake from flue gases are important obstacles in large-scale industrial applications, and developing efficient technology for CO2 capture from technical and economic points is crucial. Ionic liquids (ILs) show the potential for CO2 separation owing to their inherent advantages, and have been proposed as alternatives to overcome the drawbacks of conventional sorbents. Chemical modification of ILs to improve their performance in CO2 absorption has received more attention. Deep eutectic solvents (DESs) as a new generation of ILs are considered as more economical alternatives to cope with the deficiencies of high cost and high viscosity of conventional ILs. This Review discusses the potential of functionalized ILs and DESs as CO2 sorbents. Incorporation of CO2 -philic functional groups, such as amine, in cation and/or anion moiety of ILs can promot their absorption capacity. In general, the functionalization of the anion part of ILs is more effective than the cation part. DESs represent favorable solvent properties and are capable of capturing CO2 , but the research work is scarce and undeveloped compared to the studies conducted on ILs. It is possible to develop novel DESs with promising absorption capacity. However, more investigation needs to be carried out on the mechanism of CO2 sorption of DESs to clarify how these novel sorbents can be adjusted and fine-tuned to be best tailored as optimized media for CO2 capture.

Deconstruction of Nordic hardwood in switchable ionic liquids and acylation of the dissolved cellulose.

Nordic hardwood (Betula pendula) was fractionated in a batch autoclave equipped with a custom-made SpinChem(®) rotating bed reactor, at 120 °C using CO2 and CS2-based switchable ionic liquids systems. Analyses of the non-dissolved wood after treatment showed that 64 wt% of hemicelluloses and 70 wt% of lignin were removed from the native wood. Long processing periods or successive short-time treatments using fresh SILs further decreased the amount of hemicelluloses and lignin in the non-dissolved fraction to 12 and 15 wt%, respectively. The cellulose-rich fraction was partially dissolved in an organic superbase and an ionic liquid system for further derivatization. Homogeneous acylation of the dissolved cellulose in the presence or absence of catalyst resulted in cellulose acetates with variable degree of substitution (DS), depending on the treatment conditions. By varying the reaction conditions, the cellulose acetate with the desired DS could be obtained under mild conditions.

Ionic liquid mediated technology for synthesis of cellulose acetates using different co-solvents.

In this work, cellulose acetate was synthesized under homogeneous conditions. Cellulose was first dispersed in acetone, acetonitrile, 1,5-diazabicyclo(4.3.0)non-5-ene (DBN) or dimethyl sulphoxide (DMSO) and the resulting suspension was dissolved in an ionic liquid, 1,5-diazabicyclo(4.3.0)non-5-enium acetate [HDBN][OAc] at 70°C for 0.5h. It was possible to dissolve more than 12wt% cellulose with a degree of polymerization in the range of 1000-1100. The dissolved cellulose was derivatized with acetic anhydride (Ac2O) to yield acetylated cellulose. As expected, the use of the co-solvents improved the acetylation process significantly. In fact, cellulose acetates with different properties could be obtained in half an hour, thus facilitating rapid processing. When DBN was used as the dispersing agent (the precursor of the ionic liquid), the problems associated with recycling of the ionic liquid were significantly reduced. In fact, additional [HDBN][OAc] was obtained from the interaction of the DBN and the by-product, acetic acid (from Ac2O). However, the cellulose acetate obtained in this manner had the lowest DS. Consequently, the native cellulose and acetylated celluloses were characterized by means of (1)H- and (13)C-NMR, FT-IR, GPC/SEC and by titration. The cellulose acetates produced were soluble in organic solvents such as acetone, chloroform, dichloromethane and DMSO which is essential for their further processing. It was demonstrated that the ionic liquid can be recovered from the system by distillation and re-used in consecutive acetylation batches.

Realtime (31)P†NMR Investigation on the Catalytic Behavior of the Enzyme Adenylate kinase in the Matrix of a Switchable Ionic Liquid.

The integration of highly efficient enzymatic catalysis with the solvation properties of ionic liquids for an environmentally friendly and efficient use of raw materials such as wood requires fundamental knowledge about the influence of relevant ionic liquids on enzymes. Switchable ionic liquids (SIL) are promising candidates for implementation of enzymatic treatments of raw materials. One industrially interesting SIL is constituted by monoethanol amine (MEA) and 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) formed with sulfur dioxide (SO2) as the coupling media (DBU-SO2-MEASIL). It has the ability to solubilize the matrix of lignocellulosic biomass while leaving the cellulose backbone intact. Using a novel (31)P NMR-based real-time assay we show that this SIL is compatible with enzymatic catalysis because a model enzyme, adenylate kinase, retains its activity in up to at least 25 wt % of DBU-SO2-MEASIL. Thus this SIL appears suitable for, for example, enzymatic degradation of hemicellulose.