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Sample records for deep eutectic solvents

  1. Electrochemistry in deep eutectic solvents.

    PubMed

    Nkuku, Chiemela A; LeSuer, Robert J

    2007-11-22

    We report the cyclic voltammetry, chronoamperometry, and scanning electrochemical microscopy of ferrocene dissolved in deep eutectic solvents (DES), consisting of choline chloride (ChCl) and either trifluoroacetamide (TFA) or malonic acid as the hydrogen-bond donor. Despite the use of ultramicroelectrodes, which were required due to the modest conductivities of the DES employed, linear diffusion behavior was observed in cyclic voltammetric experiments. The high viscosity of 1:2 ChCl/TFA relative to non-aqueous electrochemical solvents leads to a low diffusion coefficient, 2.7 x 10(-8) cm2 s(-1) for ferrocene in this medium. Because of the difficulties in achieving steady-state conditions, SECM approach curves were tip velocity dependent. Under certain conditions, SECM approach curves to an insulating substrate displayed a positive-feedback response. Satisfactory simulation of this unexpected behavior was obtained by including convection terms into the mass transport equations typically used for SECM theory. The observance of positive-feedback behavior at an insulating substrate can be described in terms of a dimensionless parameter, the Peclet number, which is the ratio of the convective and diffusive timescales. Fitting insulator approach curves of ferrocene in 1:2 ChCl/TFA shows an apparent increase in the diffusion coefficient with increasing tip velocity, which can be explained by DES behaving as a shear thinning non-Newtonian fluid. PMID:17973421

  2. Ferrier reaction in a deep eutectic solvent.

    PubMed

    Rokade, Sunil M; Bhate, Prakash M

    2015-10-13

    A mild and efficient synthesis of 2,3-unsaturated sugar derivatives has been achieved by conducting the Ferrier reaction in a deep eutectic solvent (DES). A wide range of alcohols including primary, secondary, benzylic, and sugar-derived primary alcohols can be used. Advantages include good yields, shorter reaction times and recyclability of DES. PMID:26279523

  3. Deep eutectic solvents: syntheses, properties and applications.

    PubMed

    Zhang, Qinghua; De Oliveira Vigier, Karine; Royer, Sébastien; Jérôme, François

    2012-11-01

    Within the framework of green chemistry, solvents occupy a strategic place. To be qualified as a green medium, these solvents have to meet different criteria such as availability, non-toxicity, biodegradability, recyclability, flammability, and low price among others. Up to now, the number of available green solvents are rather limited. Here we wish to discuss a new family of ionic fluids, so-called Deep Eutectic Solvents (DES), that are now rapidly emerging in the current literature. A DES is a fluid generally composed of two or three cheap and safe components that are capable of self-association, often through hydrogen bond interactions, to form a eutectic mixture with a melting point lower than that of each individual component. DESs are generally liquid at temperatures lower than 100 °C. These DESs exhibit similar physico-chemical properties to the traditionally used ionic liquids, while being much cheaper and environmentally friendlier. Owing to these remarkable advantages, DESs are now of growing interest in many fields of research. In this review, we report the major contributions of DESs in catalysis, organic synthesis, dissolution and extraction processes, electrochemistry and material chemistry. All works discussed in this review aim at demonstrating that DESs not only allow the design of eco-efficient processes but also open a straightforward access to new chemicals and materials. PMID:22806597

  4. Functionalization of graphene using deep eutectic solvents

    NASA Astrophysics Data System (ADS)

    Hayyan, Maan; Abo-Hamad, Ali; AlSaadi, Mohammed AbdulHakim; Hashim, Mohd Ali

    2015-08-01

    Deep eutectic solvents (DESs) have received attention in various applications because of their distinctive properties. In this work, DESs were used as functionalizing agents for graphene due to their potential to introduce new functional groups and cause other surface modifications. Eighteen different types of ammonium- and phosphonium-salt-based DESs were prepared and characterized by FTIR. The graphene was characterized by FTIR, STA, Raman spectroscopy, XRD, SEM, and TEM. Additional experiments were performed to study the dispersion behavior of the functionalized graphene in different solvents. The DESs exhibited both reduction and functionalization effects on DES-treated graphene. Dispersion stability was investigated and then characterized by UV-vis spectroscopy and zeta potential. DES-modified graphene can be used in many applications, such as drug delivery, wastewater treatment, catalysts, composite materials, nanofluids, and biosensors. To the best of our knowledge, this is the first investigation on the use of DESs for graphene functionalization.

  5. Functionalization of graphene using deep eutectic solvents.

    PubMed

    Hayyan, Maan; Abo-Hamad, Ali; AlSaadi, Mohammed AbdulHakim; Hashim, Mohd Ali

    2015-12-01

    Deep eutectic solvents (DESs) have received attention in various applications because of their distinctive properties. In this work, DESs were used as functionalizing agents for graphene due to their potential to introduce new functional groups and cause other surface modifications. Eighteen different types of ammonium- and phosphonium-salt-based DESs were prepared and characterized by FTIR. The graphene was characterized by FTIR, STA, Raman spectroscopy, XRD, SEM, and TEM. Additional experiments were performed to study the dispersion behavior of the functionalized graphene in different solvents. The DESs exhibited both reduction and functionalization effects on DES-treated graphene. Dispersion stability was investigated and then characterized by UV-vis spectroscopy and zeta potential. DES-modified graphene can be used in many applications, such as drug delivery, wastewater treatment, catalysts, composite materials, nanofluids, and biosensors. To the best of our knowledge, this is the first investigation on the use of DESs for graphene functionalization. PMID:26264683

  6. Natural deep eutectic solvents: cytotoxic profile.

    PubMed

    Hayyan, Maan; Mbous, Yves Paul; Looi, Chung Yeng; Wong, Won Fen; Hayyan, Adeeb; Salleh, Zulhaziman; Mohd-Ali, Ozair

    2016-01-01

    The purpose of this study was to investigate the cytotoxic profiles of different ternary natural deep eutectic solvents (NADESs) containing water. For this purpose, five different NADESs were prepared using choline chloride as a salt, alongside five hydrogen bond donors (HBD) namely glucose, fructose, sucrose, glycerol, and malonic acid. Water was added as a tertiary component during the eutectics preparation, except for the malonic acid-based mixture. Coincidentally, the latter was found to be more toxic than any of the water-based NADESs. A trend was observed between the cellular requirements of cancer cells, the viscosity of the NADESs, and their cytotoxicity. This study also highlights the first time application of the conductor-like screening model for real solvent (COSMO-RS) software for the analysis of the cytotoxic mechanism of NADESs. COSMO-RS simulation of the interactions between NADESs and cellular membranes' phospholipids suggested that NADESs strongly interacted with cell surfaces and that their accumulation and aggregation possibly defined their cytotoxicity. This reinforced the idea that careful selection of NADESs components is necessary, as it becomes evident that organic acids as HBD highly contribute to the increasing toxicity of these neoteric mixtures. Nevertheless, NADESs in general seem to possess relatively less acute toxicity profiles than their DESs parents. This opens the door for future large scale utilization of these mixtures. PMID:27386357

  7. Are deep eutectic solvents benign or toxic?

    PubMed

    Hayyan, Maan; Hashim, Mohd Ali; Hayyan, Adeeb; Al-Saadi, Mohammed A; AlNashef, Inas M; Mirghani, Mohamed E S; Saheed, Olorunnisola Kola

    2013-02-01

    In continuation of investigation for environmentally benign protocol for new solvents termed deep eutectic solvents (DESs), it is herein reported results concerning the toxicity and cytotoxicity of choline chloride (ChCl) based DESs with four hydrogen bond donors including glycerine, ethylene glycol, triethylene glycol and urea. The toxicity was investigated using two Gram positive bacteria Bacillus subtilis and Staphylococcus aureus, and two Gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The cytotoxicity effect was tested using the Artemia salina leach. It was found that there was no toxic effect for the tested DESs on all of the studied bacteria confirming their benign effects on these bacteria. Nevertheless, it was found that the cytotoxicity of DESs was much higher than their individual components (e.g. glycerine, ChCl) indicating that their toxicological behavior is different. For our best knowledge this is the first time that toxicity and cytotoxicity of DESs were studied. The toxicity and cytotoxicity of DESs varied depending on the structure of components. Careful usage of the terms non-toxicity and biodegradability must be considered. More investigation on this matter is required. PMID:23200570

  8. Spontaneous vesicle formation in a deep eutectic solvent.

    PubMed

    Bryant, Saffron J; Atkin, Rob; Warr, Gregory G

    2016-02-14

    Solvent penetration experiments and small-angle X-ray scattering reveal that phospholipids dissolved in a deep eutectic solvent (DES) spontaneously self-assemble into vesicles above the lipid chain melting temperature. This means DESs are one of the few nonaqueous solvents that mediate amphiphile self-assembly, joining a select set of H-bonding molecular solvents and ionic liquids. PMID:26701210

  9. Hydrolase-catalyzed biotransformations in deep eutectic solvents.

    PubMed

    Gorke, Johnathan T; Srienc, Friedrich; Kazlauskas, Romas J

    2008-03-14

    Hydrolases show good catalytic activity in deep eutectic solvents, despite the presence of urea, which can denature enzymes, or alcohols, which can interfere with hydrolase-catalyzed reactions. PMID:18309428

  10. Nanoscale Spatial Heterogeneity in Deep Eutectic Solvents.

    PubMed

    Kaur, Supreet; Gupta, Aditya; Kashyap, Hemant K

    2016-07-14

    In this article, we report a molecular dynamics simulation study on the X-ray and neutron scattering structures of deep eutectic solvents (DESs) and show that the DESs studied possess unique spatial heterogeneity on molecular length scales. The simulated X-ray and neutron scattering structure functions (S(q)s) of the DESs made of alkylamide + Li(+)/ClO4(-) display two peaks in the intermolecular region of the S(q)s. As a signature of nanoscale structural organization/heterogeneity, a prepeak is observed at 0.1 < q/Å(-1) < 0.4. The principal peak observed at around 1.2 < q/Å(-1) < 2 is rendered by short-distance inter- and intraspecies correlations. For the DESs studied, we demonstrate that nanoscale spatial heterogeneity is exhibited profoundly by the segregated domains of the constituent electrolyte, and the principal peak in S(q) is because of all sorts of close-contact correlations. The extent of nanoscale morphology as well as the strength of ion pairing is enhanced for the longer-tail alkylamide DES. PMID:27314310

  11. Prebiotic phosphate ester syntheses in a deep eutectic solvent.

    PubMed

    Gull, Maheen; Zhou, Manshui; Fernández, Facundo M; Pasek, Matthew A

    2014-02-01

    We report a route to synthesize a wide range of organophosphates of biological significance in a deep eutectic solvent (2:1 urea and choline chloride), utilizing various orthophosphate sources. Heating an organic alcohol in the solvent along with a soluble phosphorus source yields phosphorus esters of choline as well as that of the added organic in yields between 15 to 99 %. In addition, phosphite analogs of biological phosphates and peptides were also formed by the simple mixing of reagents and heating at 60-70 °C in the deep eutectic solvent. The presented dehydration reactions are relevant to prebiotic and green chemistry in alternative solvents. PMID:24368625

  12. Application of deep eutectic solvents in the extraction and separation of target compounds from various samples.

    PubMed

    Tang, Baokun; Zhang, Heng; Row, Kyung Ho

    2015-03-01

    Deep eutectic solvents, as a new type of eco-friendly solvent, have attracted increasing attention in chemistry for the extraction and separation of target compounds from various samples. To summarize the application of deep eutectic solvents, this review highlights some of the unique properties of deep eutectic solvents and deep-eutectic-solvent-based materials, as well as their applications in extraction and separation. In this paper, the available data and references in this field are reviewed to summarize the application developments of deep eutectic solvents. Based on the development of deep eutectic solvents, the exploitation of new deep eutectic solvents and deep-eutectic-solvent-based materials are expected to diversify into extraction and separation. PMID:25581398

  13. Improving agar electrospinnability with choline-based deep eutectic solvents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One percent agar (% wt) was dissolved in the deep eutectic solvent (DES), (2-hydroxyethyl) trimethylammonium chloride/urea at a 1:2 molar ratio, and successfully electrospun into nanofibers. An existing electrospinning set-up, operated at 50 deg C, was adapted for use with an ethanol bath to collect...

  14. Deep eutectic solvents in countercurrent and centrifugal partition chromatography.

    PubMed

    Roehrer, Simon; Bezold, Franziska; García, Eva Marra; Minceva, Mirjana

    2016-02-19

    Deep eutectic solvents (DESs) were evaluated as solvents in centrifugal partition chromatography, a liquid-liquid chromatography separation technology. To this end, the partition coefficients of ten natural compounds of different hydrophobicity were determined in non-aqueous biphasic systems containing DES. The influence of the composition of DESs and the presence of water in the biphasic system on the partition coefficient were also examined. In addition, several process relevant physical properties of the biphasic system, such as the density and viscosity of the phases, were measured. A mixture of three to four hydrophobic compounds was successfully separated in a centrifugal partition extractor using a heptane/ethanol/DES biphasic system. PMID:26810802

  15. Enhanced electrochemical detection of quercetin by Natural Deep Eutectic Solvents.

    PubMed

    Gomez, Federico José Vicente; Espino, Magdalena; de Los Angeles Fernandez, María; Raba, Julio; Silva, María Fernanda

    2016-09-14

    New trends in analytical chemistry encourage the development of smart techniques and methods aligned with Green Chemistry. In this sense, Natural Deep Eutectic Solvents represents an excellent opportunity as a new generation of green solvents. In this work a new application for them has been proposed and demonstrated. These solvents were synthesized by combinations of inexpensive and natural components like, Glucose, Fructose, Citric acid and Lactic acid. The different natural solvents were easily prepared and added to buffer solution in different concentrations, allowing the enhancement of electrochemical detection of an important representative antioxidant like quercetin (QR) with improved signal up to 380%. QR is a ubiquitous flavonoid widespread in plants and food of plant origin. The proposed method using phosphate buffer with a eutectic mixture of Citric acid, Glucose and water in combination with carbon screen printed electrodes exhibited a good analytical performance. Detection and quantification limits were of 7.97 and 26.3 nM respectively; and repeatability with %RSDs of 1.41 and 7.49 for peak potential and intensity respectively. In addition, it has proved to be faster, greener and cheaper than other sensors and chromatographic methods available with the additional advantage of being completely portable. Furthermore, the obtained results demonstrated that the proposed method is able for the determination of QR in complex food samples. PMID:27566343

  16. Differential Microscopic Mobility of Components within a Deep Eutectic Solvent

    DOE PAGESBeta

    Wagle, Durgesh V.; Baker, Gary A.; Mamontov, Eugene

    2015-07-13

    From macroscopic measurements of deep eutectic solvents such as glyceline (1:2 molar ratio of choline chloride to glycerol), the long-range translational diffusion of the larger cation (choline) is known to be slower compared to that of the smaller hydrogen bond donor (glycerol). However, when the diffusion dynamics are analyzed on the subnanometer length scale, we discover that the displacements associated with the localized diffusive motions are actually larger for choline. This counterintuitive diffusive behavior can be understood as follows. The localized diffusive motions confined in the transient cage of neighbor particles, which precede the cage-breaking long-range diffusion jumps, are moremore » spatially constrained for glycerol than for choline because of the stronger hydrogen bonds the former makes with chloride anions. The implications of differential localized mobility of the constituents should be especially important for applications where deep eutectic solvents are confined on the nanometer length scale and their long-range translational diffusion is strongly inhibited (e.g., within microporous media).« less

  17. Differential Microscopic Mobility of Components within a Deep Eutectic Solvent

    SciTech Connect

    Wagle, Durgesh V.; Baker, Gary A.; Mamontov, Eugene

    2015-07-13

    From macroscopic measurements of deep eutectic solvents such as glyceline (1:2 molar ratio of choline chloride to glycerol), the long-range translational diffusion of the larger cation (choline) is known to be slower compared to that of the smaller hydrogen bond donor (glycerol). However, when the diffusion dynamics are analyzed on the subnanometer length scale, we discover that the displacements associated with the localized diffusive motions are actually larger for choline. This counterintuitive diffusive behavior can be understood as follows. The localized diffusive motions confined in the transient cage of neighbor particles, which precede the cage-breaking long-range diffusion jumps, are more spatially constrained for glycerol than for choline because of the stronger hydrogen bonds the former makes with chloride anions. The implications of differential localized mobility of the constituents should be especially important for applications where deep eutectic solvents are confined on the nanometer length scale and their long-range translational diffusion is strongly inhibited (e.g., within microporous media).

  18. Differential Microscopic Mobility of Components within a Deep Eutectic Solvent.

    PubMed

    Wagle, Durgesh V; Baker, Gary A; Mamontov, Eugene

    2015-08-01

    From macroscopic measurements of deep eutectic solvents such as glyceline (1:2 molar ratio of choline chloride to glycerol), the long-range translational diffusion of the larger cation (choline) is known to be slower compared to that of the smaller hydrogen bond donor (glycerol). However, when the diffusion dynamics are analyzed on the subnanometer length scale, we find that the displacements associated with the localized diffusive motions are actually larger for choline. This counterintuitive diffusive behavior can be understood as follows. The localized diffusive motions confined in the transient cage of neighbor particles, which precede the cage-breaking long-range diffusion jumps, are more spatially constrained for glycerol than for choline because of the stronger hydrogen bonds the former makes with chloride anions. The implications of such differential localized mobility of the constituents should be especially important for applications where deep eutectic solvents are confined on the nanometer length scale and their long-range translational diffusion is strongly inhibited (e.g., within microporous media). PMID:26267182

  19. Deep eutectic solvent pretreatment and subsequent saccharification of corncob.

    PubMed

    Procentese, Alessandra; Johnson, Erin; Orr, Valerie; Garruto Campanile, Anna; Wood, Jeffery A; Marzocchella, Antonio; Rehmann, Lars

    2015-09-01

    Ionic liquid (ILs) pretreatment of lignocellulosic biomass has attracted broad scientific interest, despite high costs, possible toxicity and energy intensive recycling. An alternative group of ionic solvents with similar physicochemical properties are deep eutectic solvents (DESs). Corncob residues were pretreated with three different DES systems: choline chloride and glycerol, choline chloride and imidazole, choline chloride and urea. The pretreated biomass was characterised in terms of lignin content, sugars concentration, enzymatic digestibility and crystallinity index. A reduction of lignin and hemicellulose content resulted in increased crystallinity of the pretreated biomass while the crystallinity of the cellulose fraction could be reduced, depending on DES system and operating conditions. The subsequent enzymatic saccharification was enhanced in terms of rate and extent. A total of 41 g fermentable sugars (27 g glucose and 14 g xylose) could be recovered from 100g corncob, representing 76% (86% and 63%) of the initially available carbohydrates. PMID:26005926

  20. Cellulosic ethanol production from natural deep eutectic solvent-pretreated rice straw

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Natural deep eutectic solvents (NADES) are recently developed “green solvents” consisted of bio-based ionic liquids and deep eutectic solvents mainly from plant based metabolites. NADES are biodegradable, non-toxic and environment-friendly. Conventional chemically synthesized ionic liquids have be...

  1. Improving agar electrospinnability with choline-based deep eutectic solvents.

    PubMed

    Sousa, Ana M M; Souza, Hiléia K S; Uknalis, Joseph; Liu, Shih-Chuan; Gonçalves, Maria P; Liu, LinShu

    2015-09-01

    Very recently our group has produced novel agar-based fibers by an electrospinning technique using water as solvent and polyvinyl alcohol (PVA) as co-blending polymer. Here, we tested the deep eutectic solvent (DES), (2-hydroxyethyl)trimethylammonium chloride/urea prepared at 1:2 molar ratio, as an alternative solvent medium for agar electrospinning. The electrospun materials were collected with an ethanol bath adapted to a previous electrospinning set-up. One weight percent agar-in-DES showed improved viscoelasticity and hence, spinnability, when compared to 1 wt% agar-in-water and pure agar nanofibers were successfully electrospun if working above the temperature of sol-gel transition (∼80 °C). By changing the solvent medium we decreased the PVA concentration (5 wt% starting solution) and successfully produced composite fibers with high agar contents (50/50 agar/PVA). Best composite fibers were formed with the 50/50 and 30/70 agar/PVA solutions. These fibers were mechanically resistant, showed tailorable surface roughness and diverse size distributions, with most of the diameters falling in the sub-micron range. Both nano and micro forms of agar fibers (used separately or combined) may have potential for the design of new and highly functional agar-based materials. PMID:26116384

  2. Properties of Polyvinylpyrrolidone in a Deep Eutectic Solvent.

    PubMed

    Sapir, Liel; Stanley, Christopher B; Harries, Daniel

    2016-05-19

    Deep eutectic solvents (DES) are mixtures of two or more components with high melting temperatures, which form a liquid at room temperature. These DES hold great promise as green solvents for chemical processes, as they are inexpensive and environmentally friendly. Specifically, they present a unique solvating environment to polymers that is different from water. Here, we use small angle neutron scattering to study the polymer properties of the common, water-soluble, polyvinylpyrrolidone (PVP) in the prominent DES formed by a 1:2 molar mixture of choline chloride and urea. We find that the polymer adopts a slightly different structure in DES than in water, so that at higher concentrations the polymer favors a more expanded conformation compared to the same concentration in water. Yet, the osmotic pressure of PVP solutions in DES is very similar to that in water, indicating that both solvents are of comparable quality and that the DES components interact favorably with PVP. The osmotic pressure measurements within this novel class of promising solvents should be of value toward future technological applications as well as for osmotic stress experiments in nonaqueous environments. PMID:26963367

  3. The electrodeposition of silver composites using deep eutectic solvents.

    PubMed

    Abbott, Andrew P; El Ttaib, Khalid; Frisch, Gero; Ryder, Karl S; Weston, David

    2012-02-21

    Silver is an important metal for electronic connectors, however, it is extremely soft and wear can be a significant issue. This paper describes how improved wear resistant silver coatings can be obtained from the electrolytic deposition of silver from a solution of AgCl in an ethylene glycol/choline chloride based Deep Eutectic Solvent. An up to 10-fold decrease in the wear volume is observed by the incorporation of SiC or Al(2)O(3) particles. The work also addresses the fundamental aspect of speciation of silver chloride in solution using EXAFS to probe solution structure. The size but not the nature of the composite particles is seen to change the morphology and grain size of the silver deposit. Grain sizes are shown to be consistent with previous nucleation studies. The addition of LiF is found to significantly affect the deposit morphology and improve wear resistance. PMID:22249451

  4. Electroplated Fe films prepared from a deep eutectic solvent

    NASA Astrophysics Data System (ADS)

    Yanai, T.; Shiraishi, K.; Shimokawa, T.; Watanabe, Y.; Ohgai, T.; Nakano, M.; Suzuki, K.; Fukunaga, H.

    2014-05-01

    Electroplating of Fe films was carried out from choline chloride-ethylene glycol types of DES (Deep Eutectic Solvent). We investigated magnetic properties of the plated Fe films and evaluated the productivity for the electroplating process. Consequently, we found that surface morphology and current efficiency of the plated films were affected by the bath temperature. We obtained the Fe films with relatively smooth surface and high current efficiency in the bath temperature range from 70 to 110 °C. The deposition rate for our process depended on the current density, and we obtained high deposition rate value of approximately 120 μm/h. We also obtained high current efficiency values of approximately 90% in the wide range of plating time. These results indicate that the DES-based bath has industrial advantages for mass-producing Fe films. Therefore, we conclude that the DES-based bath is an attractive plating bath for Fe films.

  5. Double layer effects on metal nucleation in deep eutectic solvents.

    PubMed

    Abbott, Andrew P; Barron, John C; Frisch, Gero; Gurman, Stephen; Ryder, Karl S; Fernando Silva, A

    2011-06-01

    The electrodeposition of zinc has been studied in two deep eutectic solvents. Unlike the metals studied to date in these liquids, zinc electrodeposition is not mass transport limited and the morphology of the deposit differs in the two liquids. This study shows that changing the concentration of solute affects the physical properties of the liquid to different extents although this is found to not effect the morphology of the metal deposited. EXAFS was used to show that the speciation of zinc was the same in both liquids. Double layer capacitance studies showed differences between the two liquids and these are proposed to be due to the adsorption of a species on the electrode which is thought to be chloride. The differences in zinc morphology is attributed to blocking of certain crystal faces leading to deposition of small platelet shaped crystals in the glycol based liquid. PMID:21519629

  6. Assessing the toxicity and biodegradability of deep eutectic solvents.

    PubMed

    Wen, Qing; Chen, Jing-Xin; Tang, Yu-Lin; Wang, Juan; Yang, Zhen

    2015-08-01

    Deep eutectic solvents (DESs) have emerged as a new type of promising ionic solvents with a broad range of potential applications. Although their ecotoxicological profile is still poorly known, DESs are generally regarded as "green" because they are composed of ammonium salts and H-bond donors (HBDs) which are considered to be eco-friendly. In this work, cholinium-based DESs comprised of choline chloride (ChCl) and choline acetate (ChAc) as the salt and urea (U), acetamide (A), glycerol (G) and ethylene glycol (EG) as the HBD were evaluated for their toxic effects on different living organisms such as Escherichia coli (a bacterium), Allium sativum (garlic, a plant) and hydra (an invertebrate), and their biodegradabilities were assessed by means of closed bottle tests. These DESs possessed an anti-bacterial property and exhibited inhibitory effects on the test organisms adopted, depending on the composition and concentration of the DES. The mechanism for the impact of DESs and their components on different living organisms can be associated to their interactions with the cellular membranes. Not all DESs can be considered readily biodegradable. By extending the limited knowledge about the toxicity and biodegradation of this particular solvent family, this investigation on DESs provides insight into our structure-based understanding of their ecotoxicological behavior. PMID:25800513

  7. How polar are choline chloride-based deep eutectic solvents?

    PubMed

    Pandey, Ashish; Rai, Rewa; Pal, Mahi; Pandey, Siddharth

    2014-01-28

    Developing and characterizing green solvents with low toxicity and cost is one of the most important issues in chemistry. Deep Eutectic Solvents (DESs), in this regard, have shown tremendous promise. Compared to popular organic solvents, DESs possess negligible VOCs and are non-flammable. Compared to ionic liquids, which share many characteristics but are ionic compounds and not ionic mixtures, DESs are cheaper to make, much less toxic and mostly biodegradable. An estimate of the polarity associated with DESs is essential if they are to be used as green alternatives to common organic solvents in industries and academia. As no one physical parameter can satisfactorily represent solute-solvent interactions within a medium, polarity of DESs is assessed through solvatochromic optical spectroscopic responses of several UV-vis absorbance and molecular fluorescence probes. Information on the local microenvironment (i.e., the cybotactic region) that surrounds several solvatochromic probes [betaine dye, pyrene, pyrene-1-carboxaldehyde, 1-anilino-8-naphthalene sulfonate (ANS), p-toluidinyl-6-naphthalene sulfonate (TNS), 6-propionyl-2-(dimethylaminonaphthalene) (PRODAN), coumarin-153, and Nile Red] for four common and popular DESs formed from choline chloride combined with 1,2-ethanediol, glycerol, urea, and malonic acid, respectively, in 1 : 2 molar ratios termed ethaline, glyceline, reline, and maline is obtained and used to assess the effective polarity afforded by each of these DESs. The four DESs as indicated by these probe responses are found to be fairly dipolar in nature. Absorbance probe betaine dye and fluorescence probes ANS, TNS, PRODAN, coumarin-153, and Nile Red, whose solvatochromic responses are based on photoinduced charge-transfer, imply ethaline and glyceline, DESs formed using alcohol-based H-bond donors, to be relatively more dipolar in nature as compared to reline and maline. The pyrene polarity scale, which is based on polarity-induced changes in

  8. Protease activation in glycerol-based deep eutectic solvents.

    PubMed

    Zhao, Hua; Baker, Gary A; Holmes, Shaletha

    2011-11-01

    Deep eutectic solvents (DESs) consisting of mixtures of a choline salt (chloride or acetate form) and glycerol are prepared as easily accessible, biodegradable, and inexpensive alternatives to conventional aprotic cation-anion paired ionic liquids. These DES systems display excellent fluidity coupled with thermal stability to nearly 200 °C. In this work, the transesterification activities of cross-linked proteases (subtilisin and α-chymotrypsin), immobilized on chitosan, were individually examined in these novel DESs. In the 1:2 molar ratio mixture of choline chloride/glycerol containing 3% (v/v) water, cross-linked subtilisin exhibited an excellent activity (2.9 μmo l min(-1) g(-1)) in conjunction with a selectivity of 98% in the transesterification reaction of N-acetyl-L-phenylalanine ethyl ester with 1-propanol. These highly encouraging results advocate more extensive exploration of DESs in protease-mediated biotransformations of additional polar substrates and use of DESs in biocatalysis more generally. PMID:21909232

  9. Protease activation in glycerol-based deep eutectic solvents

    PubMed Central

    Zhao, Hua; Baker, Gary A.; Holmes, Shaletha

    2011-01-01

    Deep eutectic solvents (DESs) consisting of mixtures of a choline salt (chloride or acetate form) and glycerol are prepared as easily accessible, biodegradable, and inexpensive alternatives to conventional aprotic cation-anion paired ionic liquids. These DES systems display excellent fluidity coupled with thermal stability to nearly 200 °C. In this work, the transesterification activities of cross-linked proteases (subtilisin and α-chymotrypsin), immobilized on chitosan, were individually examined in these novel DESs. In the 1:2 molar ratio mixture of choline chloride/glycerol containing 3% (v/v) water, cross-linked subtilisin exhibited an excellent activity (2.9 μmo l min−1 g−1) in conjunction with a selectivity of 98% in the transesterification reaction of N-acetyl-L-phenylalanine ethyl ester with 1-propanol. These highly encouraging results advocate more extensive exploration of DESs in protease-mediated biotransformations of additional polar substrates and use of DESs in biocatalysis more generally. PMID:21909232

  10. Prussian blue nanospheres synthesized in deep eutectic solvents

    NASA Astrophysics Data System (ADS)

    Sheng, Qinglin; Liu, Ruixiao; Zheng, Jianbin

    2012-10-01

    A novel route for controlled synthesis of Prussian blue nanospheres (PB NSs) with different sizes by using deep eutectic solvents (DES) as both solvent and template provider was demonstrated. The size-controlled PB NSs were obtained directly by the coordination of Fe(CN)64- ion with Fe3+ ion in the DES. The probable mechanism of formation of PB NSs was discussed based on the characterization results of UV-visible, X-ray diffraction, X-ray photoelectronic spectrum and transfer electron microscopy. Furthermore, the electrochemical and electrocatalytic properties of the synthesized PB NSs were investigated, and it has demonstrated that the PB NSs exhibited excellent catalytic activity for H2O2 reduction, and then extended this strategy to glucose sensing, by detecting H2O2 formed from the enzymatic reaction of glucose oxidase with its substrate glucose. The linear calibration range for glucose was from 0.9 μM to 0.12 mM, with a correlation coefficient of 0.998. The limit of detection was 0.3 μM and the sensitivity was 61.7 A cm-2 M-1. The present study provides a general platform for the controlled synthesis of novel nanomaterials in DES and can be extended to other optical, electronic and magnetic nanocompounds.A novel route for controlled synthesis of Prussian blue nanospheres (PB NSs) with different sizes by using deep eutectic solvents (DES) as both solvent and template provider was demonstrated. The size-controlled PB NSs were obtained directly by the coordination of Fe(CN)64- ion with Fe3+ ion in the DES. The probable mechanism of formation of PB NSs was discussed based on the characterization results of UV-visible, X-ray diffraction, X-ray photoelectronic spectrum and transfer electron microscopy. Furthermore, the electrochemical and electrocatalytic properties of the synthesized PB NSs were investigated, and it has demonstrated that the PB NSs exhibited excellent catalytic activity for H2O2 reduction, and then extended this strategy to glucose sensing, by

  11. Deep eutectic solvents as novel extraction media for phenolic compounds from model oil.

    PubMed

    Gu, Tongnian; Zhang, Mingliang; Tan, Ting; Chen, Jia; Li, Zhan; Zhang, Qinghua; Qiu, Hongdeng

    2014-10-11

    Deep eutectic solvents (DES) as a new kind of green solvent were used for the first time to excellently extract phenolic compounds from model oil. It was also proved that DES could be used to extract other polar compounds from non-polar or weakly-polar solvents by liquid-phase microextraction. PMID:25144155

  12. Deep eutectic solvents as novel extraction media for protein partitioning.

    PubMed

    Zeng, Qun; Wang, Yuzhi; Huang, Yanhua; Ding, Xueqin; Chen, Jing; Xu, Kaijia

    2014-05-21

    Four kinds of green deep eutectic solvent (DES) were synthesized, including choline chloride (ChCl)-urea, tetramethylammonium chloride (TMACl)-urea, tetrapropylammonium bromide (TPMBr)-urea and ChCl-methylurea. An aqueous two-phase system (ATPS) based ChCl-urea DES was studied for the first time for the extraction of bovine serum albumin (BSA). Single factor experiments proved that the extraction efficiency of BSA was influenced by the mass of the DES, concentration of K2HPO4 solution, separation time and extraction temperature. The optimum conditions were determined through an orthogonal experiment with the four factors described above. The results showed that under the optimum conditions, the average extraction efficiency could reach up to 99.94%, 99.72%, 100.05% and 100.05% (each measured three times). The relative standard deviations (RSD) of extraction efficiencies in precision, repeatability and stability experiments were 0.5533% (n = 5), 0.8306% (n = 5) and 0.9829% (n = 5), respectively. UV-vis and FT-IR spectra confirmed that there were no chemical interactions between BSA and the DES in the extraction process, and the CD spectra proved that the conformation of BSA did not change after extraction. The conductivity, DLS and TEM were combined to investigate the microstructure of the top phase and the possible mechanism for the extraction. The results showed that hydrophobic interactions, hydrogen bonding interactions and the salting-out effect played important roles in the transfer process, and the aggregation and surrounding phenomenon were the main driving forces for the separation. All of these results proved that ionic liquid (IL)-based ATPSs could potentially be substituted with DES-based ATPSs to offer new possibilities in the extraction of proteins. PMID:24699681

  13. Deep eutectic solvents: sustainable media for nanoscale and functional materials.

    PubMed

    Wagle, Durgesh V; Zhao, Hua; Baker, Gary A

    2014-08-19

    Deep eutectic solvents (DESs) represent an alternative class of ionic fluids closely resembling room-temperature ionic liquids (RTILs), although, strictly speaking, they are distinguished by the fact that they also contain an organic molecular component (typically, a hydrogen bond donor like a urea, amide, acid, or polyol), frequently as the predominant constituent. Practically speaking, DESs are attractive alternatives to RTILs, sharing most of their remarkable qualities (e.g., tolerance to humidity, negligible vapor pressure, thermostability, wide electrochemical potential windows, tunability) while overcoming several limitations associated with their RTIL cousins. Particularly, DESs are typically, less expensive, more synthetically accessible (typically, from bulk commodity chemicals using solvent/waste-free processes), nontoxic, and biodegradable. In this Account, we provide an overview of DESs as designer solvents to create well-defined nanomaterials including shape-controlled nanoparticles, electrodeposited films, metal-organic frameworks, colloidal assemblies, hierarchically porous carbons, and DNA/RNA architectures. These breakthroughs illustrate how DESs can fulfill multiple roles in directing chemistry at the nanoscale: acting as supramolecular template, metal/carbon source, sacrificial agent (e.g., ammonia release from urea), and/or redox agent, all in the absence of formal stabilizing ligand (here, solvent and stabilizer are one and the same). The ability to tailor the physicochemical properties of DESs is central to controlling their interfacial behavior. The preorganized "supramolecular" nature of DESs provides a soft template to guide the formation of bimodal porous carbon networks or the evolution of electrodeposits. A number of essential parameters (viscosity, polarity, surface tension, hydrogen bonding), plus coordination with solutes/surfaces, all play significant roles in modulating species reactivity and mass transport properties governing the

  14. Phase behavior of elastin-like synthetic recombinamers in deep eutectic solvents.

    PubMed

    Nardecchia, Stefania; Gutiérrez, María C; Ferrer, M Luisa; Alonso, Matilde; López, Isabel M; Rodríguez-Cabello, J Carlos; del Monte, Francisco

    2012-07-01

    Deep eutectic solvents promoted the stabilization of the collapsed state of elastin-like recombinamers - and the subsequent formation of aggregates - upon the loss of the structural water molecules involved in hydrophobic hydration. Cryo-etch scanning electron microscopy allowed the observation of these aggregates in neat deep eutectic solvents. The suppression of the lower critical solution temperature transition, observed by differential scanning calorimetry and dynamic light scattering, confirmed the presence of the elastin-like recombinamers in their collapsed state. Actually, the transition from the collapsed to the expanded state was suppressed even after moderate aqueous dilution - for water contents ranging from nil to ca. 45 wt % - and it was only recovered upon further addition of water - above 50 wt %. These features revealed the preferred stabilization of the collapsed state in not only neat deep eutectic solvents but also partially hydrated deep eutectic solvents. We consider that the capability to trigger the lower critical solution temperature transition by partial hydration of deep eutectic solvent may open interesting perspectives for nano(bio)technological applications of elastin-like recombinamers. PMID:22632070

  15. A novel green approach for the chemical modification of silica particles based on deep eutectic solvents.

    PubMed

    Gu, Tongnian; Zhang, Mingliang; Chen, Jia; Qiu, Hongdeng

    2015-06-18

    Deep eutectic solvents (DESs), as a novel class of green solvents, were successfully applied as eco-friendly and sustainable reaction media for fast surface modification of spherical porous silica, resulting in stationary phases for high-performance liquid chromatography. The new reaction media were advantageous over organic solvents in many aspects, such as the high dispersibility of silica spheres and their non-volatility. PMID:25985926

  16. Natural deep eutectic solvents as new potential media for green technology.

    PubMed

    Dai, Yuntao; van Spronsen, Jaap; Witkamp, Geert-Jan; Verpoorte, Robert; Choi, Young Hae

    2013-03-01

    Developing new green solvents is one of the key subjects in Green Chemistry. Ionic liquids (ILs) and deep eutectic solvents, thus, have been paid great attention to replace current harsh organic solvents and have been applied to many chemical processing such as extraction and synthesis. However, current ionic liquids and deep eutectic solvents have still limitations to be applied to a real chemical industry due to toxicity against human and environment and high cost of ILs and solid state of most deep eutectic solvents at room temperature. Recently we discovered that many plant abundant primary metabolites changed their state from solid to liquid when they were mixed in proper ratio. This finding made us hypothesize that natural deep eutectic solvents (NADES) play a role as alternative media to water in living organisms and tested a wide range of natural products, which resulted in discovery of over 100 NADES from nature. In order to prove deep eutectic feature the interaction between the molecules was investigated by nuclear magnetic resonance spectroscopy. All the tested NADES show clear hydrogen bonding between components. As next step physical properties of NADES such as water activity, density, viscosity, polarity and thermal properties were measured as well as the effect of water on the physical properties. In the last stage the novel NADES were applied to the solubilization of wide range of biomolecules such as non-water soluble bioactive natural products, gluten, starch, and DNA. In most cases the solubility of the biomolecules evaluated in this study was greatly higher than water. Based on the results the novel NADES may be expected as potential green solvents at room temperature in diverse fields of chemistry. PMID:23427801

  17. Efficient continuous synthesis of high purity deep eutectic solvents by twin screw extrusion.

    PubMed

    Crawford, D E; Wright, L A; James, S L; Abbott, A P

    2016-03-18

    Mechanochemical synthesis has been applied to the rapid synthesis of Deep Eutectic Solvents (DESs), including Reline 200 (choline chloride : urea, 1 : 2), in a continuous flow methodology by Twin Screw Extrusion (TSE). This gave products in higher purity and with Space Time Yields (STYs), four orders of magnitude greater than for batch methods. PMID:26911554

  18. Natural deep eutectic solvents as a new extraction media for phenolic metabolites in Carthamus tinctorius L.

    PubMed

    Dai, Yuntao; Witkamp, Geert-Jan; Verpoorte, Robert; Choi, Young Hae

    2013-07-01

    Developing green solvents with low toxicity and cost is an important issue for the biochemical industry. Synthetic ionic liquids and deep eutectic solvents have received considerable attention due to their negligible volatility at room temperature, high solubilization ability, and tunable selectivity. However, the potential toxicity of the synthetic ionic liquids and the solid state at room temperature of most deep eutectic solvents hamper their application as extraction solvents. In this study, a wide range of recently discovered natural ionic liquids and deep eutectic solvents (NADES) composed of natural compounds were investigated for the extraction of phenolic compounds of diverse polarity. Safflower was selected as a case study because its aromatic pigments cover a wide range of polarities. Many advantageous features of NADES (such as their sustainability, biodegradability combined with acceptable pharmaceutical toxicity profiles, and their high solubilization power of both polar and nonpolar compounds) suggest their potential as green solvents for extraction. Experiments with different NADES and multivariate data analysis demonstrated that the extractability of both polar and less polar metabolites was greater with NADES than conventional solvents. The water content in NADES proved to have the biggest effect on the yield of phenolic compounds. Most major phenolic compounds were recovered from NADES with a yield between 75% and 97%. This study reveals the potential of NADES for applications involving the extraction of bioactive compounds from natural sources. PMID:23710664

  19. Ionic liquids and deep eutectic mixtures: sustainable solvents for extraction processes.

    PubMed

    Pena-Pereira, Francisco; Namieśnik, Jacek

    2014-07-01

    In recent years, ionic liquids and deep eutectic mixtures have demonstrated great potential in extraction processes relevant to several scientific and technological activities. This review focuses on the applicability of these sustainable solvents in a variety of extraction techniques, including but not limited to liquid- and solid-phase (micro) extraction, microwave-assisted extraction, ultrasound-assisted extraction and pressurized liquid extraction. Selected applications of ionic liquids and deep eutectic mixtures on analytical method development, removal of environmental pollutants, selective isolation, and recovery of target compounds, purification of fuels, and azeotrope breaking are described and discussed. PMID:24811900

  20. A novel group of quaternary ammonium salts as ionic liquids and deep eutectic solvents

    NASA Astrophysics Data System (ADS)

    Sparrow, Christopher R.

    2011-12-01

    A growing number of non-toxic and biodegradable deep eutectic solvents (DES) have been discovered in recent years. This group encompasses the solidified crystalline material 3-(2-aminopyrimidin-1-yl)propanoate (3-2AP), a primary ammonium cation that is a construct of a typical DES. Synthesis of 3-(2-aminopyrimidin-1-yl)propanoate by quarternerization of the amine in the aromatic ring creates a novel deep eutectic solvent. An additional alteration to the DES construct is observed with the formation of a zwitterion between the positively charged quartenary amine group and the negatively charged carboxylate counter ion. The molecular arrangement, or construct, of a deep eutectic solvent will determine both its structure and application in industry. This report describes the synthesis and characterization of an 80:20 urea/3-2AP eutectic mixture with a melting point of 50°C, nearly 120°C lower than the melting temperature of 3-2AP (172.5°C). A cytotoxicity profile for 3-2AP exposed to A549 bronchoaveolar carcinoma cells revealed an LD50 of 337.65 mug/ml.

  1. Micelle structure in a deep eutectic solvent: a small-angle scattering study.

    PubMed

    Sanchez-Fernandez, A; Edler, K J; Arnold, T; Heenan, R K; Porcar, L; Terrill, N J; Terry, A E; Jackson, A J

    2016-05-18

    In recent years many studies into green solvents have been undertaken and deep eutectic solvents (DES) have emerged as sustainable and green alternatives to conventional solvents since they may be formed from cheap non-toxic organic precursors. In this study we examine amphiphile behaviour in these novel media to test our understanding of amphiphile self-assembly within environments that have an intermediate polarity between polar and non-polar extremes. We have built on our recently published results to present a more detailed structural characterisation of micelles of sodium dodecylsulfate (SDS) within the eutectic mixture of choline chloride and urea. Here we show that SDS adopts an unusual cylindrical aggregate morphology, unlike that seen in water and other polar solvents. A new morphology transition to shorter aggregates was found with increasing concentration. The self-assembly of SDS was also investigated in the presence of water; which promotes the formation of shorter aggregates. PMID:27157993

  2. In situ PM-IRRAS of a glassy carbon electrode/deep eutectic solvent interface.

    PubMed

    Vieira, Luciana; Schennach, Robert; Gollas, Bernhard

    2015-05-21

    The interface of a 1 : 2 molar choline chloride/ethylene glycol deep eutectic solvent with a glassy carbon electrode has been investigated by polarization modulation reflection-absorption spectroscopy (PM-IRRAS). Temporal spectral changes at open circuit potential show the experiments to be surface sensitive and indicate slow adsorption of electrolyte molecules on the electrode surface. In situ spectroelectrochemical PM-IRRAS measurements reveal characteristic potential-dependent changes of band intensities and wavenumber-shifts in the surface spectra. The potential dependent spectral changes are discussed in terms of adsorption, reduction, desorption and reorientation of choline cations at the interface. Analogies are drawn to the ionic layer structure proposed for the architecture of electrode/ionic liquid interfaces. The results show that in situ PM-IRRAS is generally applicable to glassy carbon electrodes and to electrode interfaces with deep eutectic solvents. PMID:25908481

  3. Characterization of thermal behavior of deep eutectic solvents and their potential as drug solubilization vehicles.

    PubMed

    Morrison, Henry G; Sun, Changquan C; Neervannan, Sesha

    2009-08-13

    Deep eutectic solvent (DES) is a new class of solvents typically formed by mixing choline chloride with hydrogen bond donors such as amines, acids, and alcohols. Most DES's are non-reactive with water, biodegradable, and have acceptable toxicity profiles. Urea-choline chloride and malonic acid-choline chloride eutectic systems were characterized using differential scanning calorimetry (DSC) and thermal microscopy. A potential new 2:1 urea-choline chloride cocrystal with a melting point of 25 degrees C was characterized at the eutectic composition. The formation of this cocrystal suggests that DES should not be universally explained by simple eutectic melting, and may be useful in guiding the search for new DES systems. The lack of nucleation of the malonic acid-choline chloride system prohibited the construction of a phase diagram for this system using DSC. We also investigated possible uses of DES in solubilizing poorly soluble compounds for enhanced bioavailability in early drug development such as toxicology studies. For five poorly soluble model compounds, solubility in DES is 5 to 22,000 folds more than that in water. Thus, DES can be a promising vehicle for increasing exposure of poorly soluble compounds in preclinical studies. PMID:19477257

  4. Green extraction of grape skin phenolics by using deep eutectic solvents.

    PubMed

    Cvjetko Bubalo, Marina; Ćurko, Natka; Tomašević, Marina; Kovačević Ganić, Karin; Radojčić Redovniković, Ivana

    2016-06-01

    Conventional extraction techniques for plant phenolics are usually associated with high organic solvent consumption and long extraction times. In order to establish an environmentally friendly extraction method for grape skin phenolics, deep eutectic solvents (DES) as a green alternative to conventional solvents coupled with highly efficient microwave-assisted and ultrasound-assisted extraction methods (MAE and UAE, respectively) have been considered. Initially, screening of five different DES for proposed extraction was performed and choline chloride-based DES containing oxalic acid as a hydrogen bond donor with 25% of water was selected as the most promising one, resulting in more effective extraction of grape skin phenolic compounds compared to conventional solvents. Additionally, in our study, UAE proved to be the best extraction method with extraction efficiency superior to both MAE and conventional extraction method. The knowledge acquired in this study will contribute to further DES implementation in extraction of biologically active compounds from various plant sources. PMID:26830574

  5. Natural deep eutectic solvents providing enhanced stability of natural colorants from safflower (Carthamus tinctorius).

    PubMed

    Dai, Yuntao; Verpoorte, Robert; Choi, Young Hae

    2014-09-15

    A certain combination of natural products in the solid state becomes liquid, so called natural deep eutectic solvents (NADES). Recently, they have been considered promising new green solvents for foods, cosmetics and pharmaceuticals due to their unique solvent power which can dissolve many non-water-soluble compounds and their low toxicity. However, in addition to the features as solvents, the stabilisation ability of NADES for compounds is important for their further applications. In the study, the stability analysis demonstrates that natural pigments from safflower are more stable in sugar-based NADES than in water or 40% ethanol solution. Notably, the stabilisation capacity of NADES can be adjusted by reducing water content with increasing viscosity. The strong stabilisation ability is due to the formation of strong hydrogen bonding interactions between solutes and NADES molecules. The stabilising ability of NADES for phenolic compounds shows great promise for their applications in food, cosmetic and pharmaceutical industries. PMID:24767033

  6. Thermal unfolding and refolding of lysozyme in deep eutectic solvents and their aqueous dilutions.

    PubMed

    Esquembre, Rocio; Sanz, Jesus M; Wall, J Gerard; del Monte, Francisco; Mateo, C Reyes; Ferrer, M Luisa

    2013-07-21

    The stability of hen's egg white lysozyme in different choline chloride-based pseudo-concentrated and neat deep eutectic solvents (DESs) has been studied by means of intrinsic fluorescence and CD spectroscopy. Thermal unfolding experiments carried out in non-diluted urea:choline chloride and glycerol:choline chloride eutectic solvents (UCCl-DES and GCCl-DES, respectively) showed the accumulation at certain temperatures of discrete, partially folded intermediates that displayed a high content of secondary structure and a disrupted tertiary structure. Reversibility of the unfolding process was incomplete in these circumstances, with the urea-based DES showing higher protein structure destabilization upon thermal treatment. On the other hand, aqueous dilution of the eutectic mixtures allowed the recovery of a reversible, two-state denaturation process. Lysozyme activity was also affected in neat and pseudo-concentrated GCCl-DES, with an increasing recovery of activity upon aqueous dilution, and full restoration after DES removal through extensive dialysis. These results suggest that protein interactions at room temperature are reversible and depend on the DES components and on the aqueous content of the original DES dilution. PMID:23722327

  7. Magnetic deep eutectic solvents molecularly imprinted polymers for the selective recognition and separation of protein.

    PubMed

    Liu, Yanjin; Wang, Yuzhi; Dai, Qingzhou; Zhou, Yigang

    2016-09-14

    A novel and facile magnetic deep eutectic solvents (DES) molecularly imprinted polymers (MIPs) for the selective recognition and separation of Bovine hemoglobin (BHb) was prepared. The new-type DES was adopted as the functional monomer which would bring molecular imprinted technology to a new direction. The amounts of DES were optimized. The obtained magnetic DES-MIPs were characterized with fourier transform infrared spectrometry (FT-IR), thermogravimetric analysis (TGA), field emission scanning electron microscope (FESEM), dynamic light scattering (DLS), elemental analysis and vibrating sample magnetometer (VSM). The results suggested that the imprinted polymers were successfully formed and possessed a charming magnetism. The maximum adsorption capability (Qmax) and dissociation constant (KL) were analyzed by Langmuir isotherms (R(2) = 0.9983) and the value were estimated to be 175.44 mg/g and 0.035 mg/mL for the imprinted particles. And the imprinted particles showed a high imprinting factor of 4.77. In addition, the magnetic DES-MIPs presented outstanding recognition specificity and selectivity so that it can be utilized to separate template protein from the mixture of proteins and real samples. Last but not least, the combination of deep eutectic solvents and molecular imprinted technology in this paper provides a new perspective for the recognition and separation of proteins. PMID:27566352

  8. Alcohol based-deep eutectic solvent (DES) as an alternative green additive to increase rotenone yield

    NASA Astrophysics Data System (ADS)

    Othman, Zetty Shafiqa; Hassan, Nur Hasyareeda; Zubairi, Saiful Irwan

    2015-09-01

    Deep eutectic solvents (DESs) are basically molten salts that interact by forming hydrogen bonds between two added components at a ratio where eutectic point reaches a melting point lower than that of each individual component. Their remarkable physicochemical properties (similar to ionic liquids) with remarkable green properties, low cost and easy handling make them a growing interest in many fields of research. Therefore, the objective of pursuing this study is to analyze the potential of alcohol-based DES as an extraction medium for rotenone extraction from Derris elliptica roots. DES was prepared by a combination of choline chloride, ChCl and 1, 4-butanediol at a ratio of 1/5. The structure of elucidation of DES was analyzed using FTIR, 1H-NMR and 13C-NMR. Normal soaking extraction (NSE) method was carried out for 14 hours using seven different types of solvent systems of (1) acetone; (2) methanol; (3) acetonitrile; (4) DES; (5) DES + methanol; (6) DES + acetonitrile; and (7) [BMIM] OTf + acetone. Next, the yield of rotenone, % (w/w), and its concentration (mg/ml) in dried roots were quantitatively determined by means of RP-HPLC. The results showed that a binary solvent system of [BMIM] OTf + acetone and DES + acetonitrile was the best solvent system combination as compared to other solvent systems. It contributed to the highest rotenone content of 0.84 ± 0.05% (w/w) (1.09 ± 0.06 mg/ml) and 0.84 ± 0.02% (w/w) (1.03 ± 0.01 mg/ml) after 14 hours of exhaustive extraction time. In conclusion, a combination of the DES with a selective organic solvent has been proven to have a similar potential and efficiency as of ILs in extracting bioactive constituents in the phytochemical extraction process.

  9. Alcohol based-deep eutectic solvent (DES) as an alternative green additive to increase rotenone yield

    SciTech Connect

    Othman, Zetty Shafiqa; Hassan, Nur Hasyareeda; Zubairi, Saiful Irwan

    2015-09-25

    Deep eutectic solvents (DESs) are basically molten salts that interact by forming hydrogen bonds between two added components at a ratio where eutectic point reaches a melting point lower than that of each individual component. Their remarkable physicochemical properties (similar to ionic liquids) with remarkable green properties, low cost and easy handling make them a growing interest in many fields of research. Therefore, the objective of pursuing this study is to analyze the potential of alcohol-based DES as an extraction medium for rotenone extraction from Derris elliptica roots. DES was prepared by a combination of choline chloride, ChCl and 1, 4-butanediol at a ratio of 1/5. The structure of elucidation of DES was analyzed using FTIR, {sup 1}H-NMR and {sup 13}C-NMR. Normal soaking extraction (NSE) method was carried out for 14 hours using seven different types of solvent systems of (1) acetone; (2) methanol; (3) acetonitrile; (4) DES; (5) DES + methanol; (6) DES + acetonitrile; and (7) [BMIM] OTf + acetone. Next, the yield of rotenone, % (w/w), and its concentration (mg/ml) in dried roots were quantitatively determined by means of RP-HPLC. The results showed that a binary solvent system of [BMIM] OTf + acetone and DES + acetonitrile was the best solvent system combination as compared to other solvent systems. It contributed to the highest rotenone content of 0.84 ± 0.05% (w/w) (1.09 ± 0.06 mg/ml) and 0.84 ± 0.02% (w/w) (1.03 ± 0.01 mg/ml) after 14 hours of exhaustive extraction time. In conclusion, a combination of the DES with a selective organic solvent has been proven to have a similar potential and efficiency as of ILs in extracting bioactive constituents in the phytochemical extraction process.

  10. Deep eutectic solvents formed between choline chloride and carboxylic acids: versatile alternatives to ionic liquids.

    PubMed

    Abbott, Andrew P; Boothby, David; Capper, Glen; Davies, David L; Rasheed, Raymond K

    2004-07-28

    Deep Eutectic Solvents (DES) can be formed between a variety of quaternary ammonium salts and carboxylic acids. The physical properties are significantly affected by the structure of the carboxylic acid but the phase behavior of the mixtures can be simply modeled by taking account of the mole fraction of carboxylic acid in the mixture. The physical properties such as viscosity, conductivity, and surface tension of these DES are similar to ambient temperature ionic liquids and insight into the cause of these properties is gained using hole-theory. It is shown that the conductivity and viscosity of these liquids is controlled by ion mobility and the availability of voids of suitable dimensions, and this is consistent with the fluidity of other ionic liquids and molten salts. The DES are also shown to be good solvents for metal oxides, which could have potential application for metal extraction. PMID:15264850

  11. Tailoring properties of natural deep eutectic solvents with water to facilitate their applications.

    PubMed

    Dai, Yuntao; Witkamp, Geert-Jan; Verpoorte, Robert; Choi, Young Hae

    2015-11-15

    Previously it was demonstrated that natural deep eutectic solvents (NADES) are promising green solvents for the extraction of natural products. However, despite their potential, an obvious disadvantage of NADES is the high viscosity. Here we explored the dilution effect on the structures and physicochemical properties of NADES and their improvements of applications using quercetin and carthamin. The results of FT-IR and (1)H NMR experiments demonstrated that there are intensive H-bonding interactions between the two components of NADES and dilution with water caused the interactions weaken gradually and even disappeared completely at around 50% (v/v) water addition. A small amount of water could reduce the viscosity of NADES to the range of water and increase the conductivity by up to 100 times for some NADES. This study provides the basis for modulating NADES in a controllable way for their applications in food processing, enzyme reactions, pharmaceuticals and cosmetics. PMID:25976992

  12. Investigation on drug solubility enhancement using deep eutectic solvents and their derivatives.

    PubMed

    Li, Zheng; Lee, Ping I

    2016-05-30

    Deep eutectic solvent (DES) is a room temperature liquid typically formed by mixing two solid compounds, such as a quaternary ammonium salt (QAS) (e.g. choline chloride) and a hydrogen bond donor (HBD) (e.g. urea or a carboxylic acid) at their eutectic composition. Very often, a range of room temperature liquids can also be obtained near the eutectic composition. Hence, it is more convenient to introduce a more general term deep eutectic solvent derivatives (DESDs) to describe a wide range of DES-like derivatives including those derived from ternary mixtures. The melting point of the mixture is lowered because the hydrogen bonding between DESD components reduces the lattice energy of components of the eutectic system. Based on the analysis of available data for 22 such choline chloride-based DES pairs, we found that the observed melting point depression can be statistically correlated with the difference between the hydrogen bonding contribution (δh) and the polar contribution (δp) to the solubility parameter of the hydrogen bond donor (HBD) component. The correlation was validated with a new DESD based on glycolic acid and choline chloride, which form DESDs at a molar ratio between 1:1 and 1:4 with DES-like properties. As a room temperature liquid, this DESD exhibits a wide range of solubility enhancement on several weakly basic poorly water-soluble drugs. For example, the solubility of itraconazole, piroxicam, lidocaine, and posaconazole has been observed to increase by 6700, 430, 28, and 6400-fold, respectively as compared to their aqueous solubility at room temperature. Furthermore, another new ternary DESD based on choline chloride, glycolic acid, and oxalic acid at a molar ratio of 1:1.6:0.4 is shown to further increase the solubility of itraconazole to a remarkable level of 5.36mg/mL (a 53,600-fold increase!). Because the components of such DESDs can include those biodegradable ones that had previously been used in formulated human products, the potential

  13. Folding and imaging of DNA nanostructures in anhydrous and hydrated deep-eutectic solvents.

    PubMed

    Gállego, Isaac; Grover, Martha A; Hud, Nicholas V

    2015-06-01

    There is great interest in DNA nanotechnology, but its use has been limited to aqueous or substantially hydrated media. The first assembly of a DNA nanostructure in a water-free solvent, namely a low-volatility biocompatible deep-eutectic solvent composed of a 4:1 mixture of glycerol and choline chloride (glycholine), is now described. Glycholine allows for the folding of a two-dimensional DNA origami at 20 °C in six days, whereas in hydrated glycholine, folding is accelerated (≤3 h). Moreover, a three-dimensional DNA origami and a DNA tail system can be folded in hydrated glycholine under isothermal conditions. Glycholine apparently reduces the kinetic traps encountered during folding in aqueous solvent. Furthermore, folded structures can be transferred between aqueous solvent and glycholine. It is anticipated that glycholine and similar solvents will allow for the creation of functional DNA structures of greater complexity by providing a milieu with tunable properties that can be optimized for a range of applications and nanostructures. PMID:25900011

  14. Physicochemical characterisation and antimicrobial phototoxicity of an anionic porphyrin in natural deep eutectic solvents.

    PubMed

    Wikene, Kristine Opsvik; Rukke, Håkon Valen; Bruzell, Ellen; Tønnesen, Hanne Hjorth

    2016-08-01

    Natural deep eutectic solvents (NADES) are a newly discovered group of eutectics which has shown promise as a solvent in antimicrobial photodynamic therapy (aPDT). The purpose of this study was to investigate preparations of an anionic porphyrin, meso-tetra-(4-carboxyphenyl)-porphine (TCPP), solubilised in NADES, with regard to their physicochemical and antibacterial properties. The NADES CS (pH∼0), ChX (pH∼4) and MFG (pH∼1) solubilised TCPP with absorption maximum ∼443nm and emission maximum ∼678nm, indicating formation of the TCPP dication. Dilution of TCPP-NADES>1:1 (water) reduced the physical stability of the preparations. The photostability half-lives of TCPP in methanol, MFG, and CS were ∼9h, 6.9h and 3.2h, respectively. Nanomolar concentrations of TCPP solubilised in diluted MFG combined with ⩽27J/cm(2) blue light increased Gram-positive and Gram-negative bacterial phototoxicity, >99.98% and 96% bacterial reduction, respectively, compared to TCPP in PBS/ethanol under equivalent treatment conditions. TCPP solubilised in diluted CS was toxic to bacteria both in the absence (36-72% reduction) and presence of light. TCPP in CS, and in the CS component citric acid, induced a TCPP-concentration dependent increase in Gram-negative phototoxicity relative to controls, which was most pronounced for TCPP-CS. The mechanism behind the increased toxicity is unknown. PMID:27269504

  15. EXAFS study into the speciation of metal salts dissolved in ionic liquids and deep eutectic solvents.

    PubMed

    Hartley, Jennifer M; Ip, Chung-Man; Forrest, Gregory C H; Singh, Kuldip; Gurman, Stephen J; Ryder, Karl S; Abbott, Andrew P; Frisch, Gero

    2014-06-16

    The speciation of metals in solution controls their reactivity, and this is extremely pertinent in the area of metal salts dissolved in ionic liquids. In the current study, the speciation of 25 metal salts is investigated in four deep eutectic solvents (DESs) and five imidazolium-based ionic liquids using extended X-ray absorption fine structure. It is shown that in diol-based DESs M(I) ions form [MCl2](-) and [MCl3](2-) complexes, while all M(II) ions form [MCl4](2-) complexes, with the exception of Ni(II), which exhibits a very unusual coordination by glycol molecules. This was also found in the X-ray crystal structure of the compound [Ni(phen)2(eg)]Cl2·2eg (eg = ethylene glycol). In a urea-based DES, either pure chloro or chloro-oxo coordination is observed. In [C6mim][Cl] pure chloro complexation is also observed, but coordination numbers are smaller (typically 3), which can be explained by the long alkyl chain of the cation. In [C2mim][SCN] metal ions are entirely coordinated by thiocyanate, either through the N or the S atom, depending on the hardness of the metal ion according to the hard-soft acid-base principle. With weaker coordinating anions, mixed coordination between solvent and solute anions is observed. The effect of hydrate or added water on speciation is insignificant for the diol-based DESs and small in other liquids with intermediate or strong ligands. One of the main findings of this study is that, with respect to metal speciation, there is no fundamental difference between deep eutectic solvents and classic ionic liquids. PMID:24897923

  16. Doubly ionic hydrogen bond interactions within the choline chloride-urea deep eutectic solvent.

    PubMed

    Ashworth, Claire R; Matthews, Richard P; Welton, Tom; Hunt, Patricia A

    2016-07-21

    Deep eutectic solvents (DESs) are exemplars of systems with the ability to form neutral, ionic and doubly ionic H-bonds. Herein, the pairwise interactions of the constituent components of the choline chloride-urea DES are examined. Evidence is found for a tripodal CHCl doubly ionic H-bond motif. Moreover it is found that the covalency of doubly ionic H-bonds can be greater than, or comparable with, neutral and ionic examples. In contrast to many traditional solvents, an "alphabet soup" of many different types of H-bond (OHO[double bond, length as m-dash]C, NHO[double bond, length as m-dash]C, OHCl, NHCl, OHNH, CHCl, CHO[double bond, length as m-dash]C, NHOH and NHNH) can form. These H-bonds exhibit substantial flexibility in terms of number and strength. It is anticipated that H-bonding will have a significant impact on the entropy of the system and thus could play an important role in the formation of the eutectic. The 2 : 1 urea : choline-chloride eutectic point of this DES is often associated with the formation of a [Cl(urea)2](-) complexed anion. However, urea is found to form a H-bonded urea[choline](+) complexed cation that is energetically competitive with [Cl(urea)2](-). The negative charge on [Cl(urea)2](-) is found to remain localised on the chloride, moreover, the urea[choline](+) complexed cation forms the strongest H-bond studied here. Thus, there is potential to consider a urea[choline](+)·urea[Cl](-) interaction. PMID:27328990

  17. Self-aggregation of sodium dodecyl sulfate within (choline chloride + urea) deep eutectic solvent.

    PubMed

    Pal, Mahi; Rai, Rewa; Yadav, Anita; Khanna, Rajesh; Baker, Gary A; Pandey, Siddharth

    2014-11-11

    Deep eutectic solvents (DESs) have shown tremendous promise as green solvents with low toxicity and cost. Understanding molecular aggregation processes within DESs will not only enhance the application potential of these solvents but also help alleviate some of the limitations associated with them. Among DESs, those comprising choline chloride and appropriate hydrogen-bond donors are inexpensive and easy to prepare. On the basis of fluorescence probe, electrical conductivity, and surface tension experiments, we present the first clear lines of evidence for self-aggregation of an anionic surfactant within a DES containing a small fraction of water. Namely, well-defined assemblies of sodium dodecyl sulfate (SDS) apparently form in the archetype DES Reline comprising a 1:2 molar mixture of choline chloride and urea. Significant enhancement in the solubility of organic solvents that are otherwise not miscible in choline chloride-based DESs is achieved within Reline in the presence of SDS. The remarkably improved solubility of cyclohexane within SDS-added Reline is attributed to the presence of spontaneously formed cyclohexane-in-Reline microemulsions by SDS under ambient conditions. Surface tension, dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), density, and dynamic viscosity measurements along with responses from the fluorescence dipolarity and microfluidity probes of pyrene and 1,3-bis(1-pyrenyl)propane are employed to characterize these aggregates. Such water-free oil-in-DES microemulsions are appropriately sized to be considered as a new type of nanoreactor. PMID:25314953

  18. Ionic liquids in biotransformations: from proof-of-concept to emerging deep-eutectic-solvents.

    PubMed

    Domínguez de María, Pablo; Maugeri, Zaira

    2011-04-01

    Ionic liquids (ILs) have been extensively assessed in biotransformations with different purposes, for example, non-conventional (co-)solvents, performance additives, coating agents for immobilizing/stabilizing enzymes, and IL-membrane-based processes. Fuelled by their premature labelling as 'green solvents', academic research has flourished. However, in recent years environmental aspects related to ILs have been strongly addressed, stating that many ILs commonly used cannot be regarded as 'green derivatives'. Likewise, ILs costs are still a barrier for practical uses. Attempting to combine sustainability with the promising added-values of ILs, the third generation of ILs is currently under development. Likewise, deep-eutectic-solvents (DESs) appear in the horizon as an attractive and cost-effective option for using ionic solvents in biotransformations. DESs are often produced by gently warming and stirring two (bio-based and cheap) salts (e.g. choline chloride and urea). First successful uses of DES in biotransformations were reported recently. It may be expected that knowledge accumulated in (second generation) ILs and biotransformations could be turned into real applications by using these DESs, and third generation ILs, in the coming years. PMID:21112808

  19. One-pot synthesis of per-O-acetylated hemiacetals from free sugars in a deep eutectic solvent.

    PubMed

    Rokade, Sunil M; Bhate, Prakash M

    2015-10-30

    Free sugars reacted with acetic anhydride in a deep eutectic solvent made from choline chloride and ZnCl2 at 90 °C to afford the corresponding peracetates that on further heating to 100 °C underwent selective deacetylation at the anomeric position to furnish the corresponding peracetylated hemiacetals in good yield. PMID:26335374

  20. Tetrabutylammonium bromide (TBABr)-based deep eutectic solvents (DESs) and their physical properties.

    PubMed

    Yusof, Rizana; Abdulmalek, Emilia; Sirat, Kamaliah; Rahman, Mohd Basyaruddin Abdul

    2014-01-01

    Density, viscosity and ionic conductivity data sets of deep eutectic solvents (DESs) formed by tetrabutylammonium bromide (TBABr) paired with ethlyene glycol, 1,3-propanediol, 1,5-pentanediol and glycerol hydrogen bond donors (HBDs) are reported. The properties of DES were measured at temperatures between 303 K and 333 K for HBD percentages of 66.7% to 90%. The effects of HBDs under different temperature and percentages are systematically analyzed. As expected, the measured density and viscosity of the studied DESs decreased with an increase in temperature, while ionic conductivity increases with temperature. In general, DESs made of TBABr and glycerol showed the highest density and viscosity and the lowest ionic conductivity when compared to other DESs. The presence of an extra hydroxyl group on glycerol in a DES affected the properties of the DES. PMID:24932572

  1. Imidazole-based deep eutectic solvents for starch dissolution and plasticization.

    PubMed

    Zdanowicz, Magdalena; Spychaj, Tadeusz; Mąka, Honorata

    2016-04-20

    Potato starch and high-amylose starch were treated with imidazole-based deep eutectic solvents (DESs) as dissolution and plasticization media. Beside imidazole (IM) for two-component DESs preparation choline chloride (CC), glycerol (G) or carboxylic acids (citric or malic) were used. An influence of water content in starch (as well as an extra water in the starch/DES system) on polymer dissolution and plasticization processes was investigated. Dissolution and gelatinization of starch in DESs were followed via DSC and laser scanning microscopy. A rheometric characteristics revealed an influence of starch/DES system storage time on the plasticization process. The tendency to recrystallization of compression-molded-starch films was evaluated using XRD technique. High dissolution and plasticization effectiveness of CC/IM and G/IM and a low tendency to film retrogradation of thermoplasticized starch were noted. PMID:26876869

  2. Applicability evaluation of Deep Eutectic Solvents-Cellulase system for lignocellulose hydrolysis.

    PubMed

    Gunny, Ahmad Anas Nagoor; Arbain, Dachyar; Nashef, Enas Muen; Jamal, Parveen

    2015-04-01

    Deep Eutectic Solvents (DESs) have recently emerged as a new generation of ionic liquids for lignocellulose pretreatment. However, DESs contain salt components which tend to inactivate cellulase in the subsequent saccharification process. To alleviate this problem, it is necessary to evaluate the applicability of the DESs-Cellulase system. This was accomplished in the present study by first studying the stability of cellulase in the presence of selected DESs followed by applicability evaluation based on glucose production, energy consumption and kinetic performance. Results showed that the cellulase was able to retain more than 90% of its original activity in the presence of 10% (v/v) for glycerol based DES (GLY) and ethylene glycol based DES (EG). Furthermore, both DESs system exhibited higher glucose percentage enhancement and lower energy consumption as compared to diluted alkali system. Among the two DESs studied, EG showed comparatively better kinetic performance. PMID:25661309

  3. Selected issues related to the toxicity of ionic liquids and deep eutectic solvents--a review.

    PubMed

    Kudłak, Błażej; Owczarek, Katarzyna; Namieśnik, Jacek

    2015-08-01

    Green Chemistry plays a more and more important role in implementing rules of sustainable development to prevent environmental pollution caused by technological processes, while simultaneously increasing the production yield. Ionic liquids (ILs) and deep eutectic solvents (DESs) constitute a very broad group of substances. Apart from many imperfections, ILs and DESs have been the most promising discoveries in the world of Green Chemistry in recent years. The main advantage of ILs is their unique physicochemical properties-they are very desirable from the technological point of view, but apart from these benefits, ILs appear to be highly toxic towards organisms from different trophic levels. DES areas of usage are very spread, because they cover organic synthesis, extraction processes, electrochemistry, enzymatic reactions and many others. Moreover, DESs seem to be a less toxic alternative to ionic liquids. New possibilities of applications and future development trends are sought and presented, including such important solutions of life branches as pharmaceuticals' production and medicine. PMID:26040266

  4. Design of controlled release systems for THEDES-Therapeutic deep eutectic solvents, using supercritical fluid technology.

    PubMed

    Aroso, Ivo M; Craveiro, Rita; Rocha, Ângelo; Dionísio, Madalena; Barreiros, Susana; Reis, Rui L; Paiva, Alexandre; Duarte, Ana Rita C

    2015-08-15

    Deep eutectic solvents (DES) can be formed by bioactive compounds or pharmaceutical ingredients. A therapeutic DES (THEDES) based on ibuprofen, a non-steroidal anti-inflammatory drug (NSAID), and menthol was synthesized and its thermal behavior was analyzed by differential scanning calorimetry (DSC). A controlled drug delivery system was developed by impregnating a starch:poly-ϵ-caprolactone polymeric blend (SPCL 30:70) with the menthol:ibuprofen THEDES in different ratios (10 and 20 wt%), after supercritical fluid sintering at 20 MPa and 50 °C. The morphological characterization of SPCL matrices impregnated with THEDES was performed by scanning electron microscopy (SEM) and micro-computed tomography (micro-CT). Drug release studies were carried out in a phosphate buffered saline. The results obtained provide important clues for the development of carriers for the sustainable delivery of bioactive compounds. PMID:26142248

  5. Deep-eutectic solvents playing multiple roles in the synthesis of polymers and related materials.

    PubMed

    Carriazo, Daniel; Serrano, María Concepción; Gutiérrez, María Concepción; Ferrer, María Luisa; del Monte, Francisco

    2012-07-21

    The aim of this review is to provide an exposition of some of the most recent applications of deep-eutectic solvents (DESs) in the synthesis of polymers and related materials. We consider that there is plenty of room for the development of fundamental research in the field of DESs because their compositional flexibility makes the number of DESs susceptible of preparation unlimited and so do the range of properties that DESs can attain. Ultimately, these properties can be transferred into the resulting materials in terms of both tailored morphologies and compositions. Thus, interesting applications can be easily envisaged, especially in those fields in which the preparation of high-tech products via low cost processes is critical. We hope that the preliminary work surveyed in this review will encourage scientists to explore the promising perspectives offered by DESs. PMID:22695767

  6. Surfactant Behavior of Sodium Dodecylsulfate in Deep Eutectic Solvent Choline Chloride/Urea.

    PubMed

    Arnold, T; Jackson, A J; Sanchez-Fernandez, A; Magnone, D; Terry, A E; Edler, K J

    2015-12-01

    Deep eutectic solvents (DES) resemble ionic liquids but are formed from an ionic mixture instead of being a single ionic compound. Here we present some results that demonstrate that surfactant sodium dodecyl sulfate (SDS) remains surface-active and shows self-assembly phenomena in the most commonly studied DES, choline chloride/urea. X-ray reflectivity (XRR) and small angle neutron scattering (SANS) suggest that the behavior is significantly different from that in water. Our SANS data supports our determination of the critical micelle concentration using surface-tension measurements and suggests that the micelles formed in DES do not have the same shape and size as those seen in water. Reflectivity measurements have also demonstrated that the surfactants remain surface-active below this concentration. PMID:26540438

  7. Characterization and antimicrobial phototoxicity of curcumin dissolved in natural deep eutectic solvents.

    PubMed

    Wikene, Kristine Opsvik; Bruzell, Ellen; Tønnesen, Hanne Hjorth

    2015-12-01

    Natural deep eutectic solvents (NADES) are a novel class of eutectics which show a unique potential as solubilizer of water insoluble compounds. The purpose of the current study was to evaluate the potential of NADES as a solvent for the hydrophobic photosensitizer curcumin for use in antimicrobial photodynamic therapy (aPDT). Two of the seventeen NADES initially prepared (i.e., NADES GS and MC3) solubilized >0.05mg/ml curcumin and were further characterized. The hydrolytic stability (i.e., t1/2) of curcumin in NADES was comparable to or up to 2-10 times higher than previously reported results in cyclodextrins and up to >1300 times higher than results reported in buffer at pH8. The photolytic stability increased by a factor 5.6-10 in GS compared to the most photostable cyclodextrin and surfactant preparations reported previously. This NADES seemed to lock curcumin in its colorless diketo conformer, resulting in higher photostability than in ethanol and in the NADES MC3. The curcumin-NADES preparations dissolved rapidly in aqueous media and formed supersaturated solutions of curcumin. Precipitation of curcumin was observed after ≤1h depending on the dilution factor (pH<8). The NADES MC3 containing curcumin photoinactivated Escherichia coli at a lower curcumin concentration (1.25μM) than in any previously investigated preparations of curcumin. The ability of NADES to lock curcumin within one specific molecular conformation and also to potentiate the phototoxic effect of this photosensitizer emphasizes the unique properties of the NADES as a solvent. PMID:26410725

  8. Enzymatic selective synthesis of 1,3-DAG based on deep eutectic solvent acting as substrate and solvent.

    PubMed

    Zeng, Chao-Xi; Qi, Sui-Jian; Xin, Rui-Pu; Yang, Bo; Wang, Yong-Hua

    2015-11-01

    In this study, enzymatic selective esterification of oleic acid with glycerol based on deep eutectic solvent acting as substrate and solvent was studied. As choline chloride (ChCl) or betaine can effectively change the chemical reaction characteristics of glycerol when they are mixed with a certain molar ratio of glycerol, several factors crucial to the lipase catalytic esterification of glycerol with oleic acid was investigated. Results showed that, betaine had more moderate effects than ChCl on the lipase, and water content had an important influence of the esterification and the enzyme selectivity. Significant changes of the glyceride compositions and enzyme selectivity were found in ChCl adding system compared with pure glycerol system; optimum accumulation of DAG especially 1,3-DAG because of the eutectic effect of ChCl was found in this system. Furthermore, in a model 1,3-DAG esterification synthesis system catalyzed by Novozym 435, high content (42.9 mol%) of the 1,3-DAG could be obtained in ChCl adding system within 1 h. PMID:26210852

  9. Preparation of Magnesium, Cobalt and Nickel Ferrite Nanoparticles from Metal Oxides using Deep Eutectic Solvents.

    PubMed

    Söldner, Anika; Zach, Julia; Iwanow, Melanie; Gärtner, Tobias; Schlosser, Marc; Pfitzner, Arno; König, Burkhard

    2016-09-01

    Natural deep eutectic solvents (DESs) dissolve simple metal oxides and are used as a reaction medium to synthesize spinel-type ferrite nanoparticles MFe2 O4 (M=Mg, Zn, Co, Ni). The best results for phase-pure spinel ferrites are obtained with the DES consisting of choline chloride (ChCl) and maleic acid. By employing DESs, the reactions proceed at much lower temperatures than usual for the respective solid-phase reactions of the metal oxides and at the same temperatures as synthesis with comparable calcination processes using metal salts. The method therefore reduces the overall required energy for the nanoparticle synthesis. Thermogravimetric analysis shows that the thermolysis process of the eutectic melts in air occurs in one major step. The phase-pure spinel-type ferrite particles are thoroughly characterized by X-ray diffraction, diffuse-reflectance UV/Vis spectroscopy, and scanning electron microscopy. The properties of the obtained nanoparticles are shown to be comparable to those obtained by other methods, illustrating the potential of natural DESs for processing metal oxides. PMID:27514793

  10. Vibrational analysis and formation mechanism of typical deep eutectic solvents: An experimental and theoretical study.

    PubMed

    Zhu, Siwen; Li, Hongping; Zhu, Wenshuai; Jiang, Wei; Wang, Chao; Wu, Peiwen; Zhang, Qi; Li, Huaming

    2016-07-01

    Deep eutectic solvents (DESs), as ionic liquid analogues for green solvents, have gained increasing attentions in chemistry. In this work, three typical kinds of DESs (ChCl/Gly, ChCl/AcOH and ChCl/Urea) were successfully synthesized and characterized by Fourier transform infrared spectroscopy (FTIR) and Raman. Then comprehensive and systematical analyses were performed by the methods of density functional theory (DFT). Two methods (B3LYP/6-311++G(2d,p) and dispersion-corrected B3LYP-D3/6-311++G(2d,p)) were employed to investigate the structures, vibrational frequencies and assign their ownership of vibrational modes for the DESs, respectively. Nearly all the experimental characteristic peaks of IR and Raman were identified according to the calculated results. By linear fitting of the combined calculated vs experimental vibration frequencies, it can be found that both of the two methods are excellent to reproduce the experimental results. Besides, hydrogen bonds were proved to exist in DESs by IR spectrum, structure analysis and RDG analysis. This work was aimed at predicting and understanding the vibrational spectra of the three typical DESs based on DFT methods. Moreover, by comparing experimental and theoretical results, it provides us a deep understanding of the formation mechanisms of DESs. PMID:27450770

  11. Choline chloride-thiourea, a deep eutectic solvent for the production of chitin nanofibers.

    PubMed

    Mukesh, Chandrakant; Mondal, Dibyendu; Sharma, Mukesh; Prasad, Kamalesh

    2014-03-15

    Deep eutectic solvents (DESs) consisting of the mixtures of choline halide (chloride/bromide)-urea and choline chloride-thiourea were used as solvents to prepare α-chitin nanofibers (CNFs). CNFs of diameter 20-30 nm could be obtained using the DESs comprising of the mixture of choline chloride and thiourea (CCT 1:2); however, NFs could not be obtained using the DESs having urea (CCU 1:2) as hydrogen bond donor. The physicochemical properties of thus obtained NFs were compared with those obtained using a couple of imidazolium based ionic liquids namely, 1-butyl-3-methylimidazolium hydrogen sulphate [(Bmim)HSO4] and 1-methylimidazolium hydrogen sulphate [(Hmim)HSO4] as well as choline based bio-ILs namely, choline hydrogen sulphate [(Chol)HSO4] and choline acrylate. The CNFs obtained using the DES as a solvent were used to prepare calcium alginate bio-nanocomposite gel beads having enhanced elasticity in comparison to Ca-alginate beads. The bio-nanocomposite gel beads thus obtained were used to study slow release of 5-fluorouracil, an anticancer drug. PMID:24528755

  12. Tailoring and recycling of deep eutectic solvents as sustainable and efficient extraction media.

    PubMed

    Jeong, Kyung Min; Lee, Min Sang; Nam, Min Woo; Zhao, Jing; Jin, Yan; Lee, Dong-Kyu; Kwon, Sung Won; Jeong, Ji Hoon; Lee, Jeongmi

    2015-12-11

    The present study demonstrates that deep eutectic solvents (DESs) with the highest extractability can be designed by combining effective DES components from screening diverse DESs. The extraction of polar ginseng saponins from white ginseng was used as a way to demonstrate the tuneability as well as recyclability of DESs. A newly designed ternary DES (GPS-5) composed of glycerol, l-proline, and sucrose at 9:4:1 was used as a sustainable and efficient extraction medium. Based on the anti-tumor activity on HCT-116 cancer cells, it was confirmed that GPS-5 was merely an extraction solvent with no influence of the bioactivity of the ginsenosides extracted. Excellent recovery of the extracted saponins was easily achieved through solid-phase extraction (SPE). Recycling of the DES was accomplished by simple freeze-drying of the washed solutions from the SPE. The extraction efficiencies of the DESs recycled once, twice, and thrice were 92%, 85%, and 83% of that of the freshly synthesized solvent. PMID:26585205

  13. Comparative in vitro study of cholinium-based ionic liquids and deep eutectic solvents toward fish cell line.

    PubMed

    Radošević, Kristina; Železnjak, Jelena; Cvjetko Bubalo, Marina; Radojčić Redovniković, Ivana; Slivac, Igor; Gaurina Srček, Višnja

    2016-09-01

    With the advent of ionic liquids, much was expected concerning their applicability as an alternative to organic solvents in the chemical technology and biotechnology fields. However, the most studied and commonly used ionic liquids based on imidazolium and pyridinium were found not to be as environmentally friendly as it was first expected. Therefore, a new generation of alternative solvents named natural ionic liquids and deep eutectic solvents, composed of natural and/or renewable compounds, have come into focus in recent years. Since the number of newly synthesized chemicals increases yearly, simple and reliable methods for their ecotoxicological assessment are necessary. Permanent fish cell lines can serve as a test system for the evaluation of a chemical's cytotoxicity. This paper presents research results on the cytotoxic effects on Channel Catfish Ovary (CCO) cell line induced by fifteen cholinium-based ionic liquids and deep eutectic solvents. Based on the decrease in cell viability, the most obvious toxic effect on CCO cells was caused by ionic liquid choline oxalate, while other solvents tested exhibited low cytotoxicity. Therefore, we can conclude that cholinium-based ionic liquids and deep eutectic solvents are comparatively less toxic to CCO cells than conventional ionic liquids. PMID:27179607

  14. Deep eutectic solvents as efficient solvent system for the extraction of κ-carrageenan from Kappaphycus alvarezii.

    PubMed

    Das, Arun Kumar; Sharma, Mukesh; Mondal, Dibyendu; Prasad, Kamalesh

    2016-01-20

    Three different deep eutectic solvents (DESs) prepared by the complexation of choline chloride with urea, ethylene glycol and glycerol along with their hydrated counterparts were used for the selective extraction of κ-carrageenan from Kappaphycus alvarezii. Upon comparison of the quality of the polysaccharide with the one obtained using water as extraction media as well as the one extracted using widely practiced conventional method, it was found that, the physicochemical as well as rheological properties of κ-carrageenan obtained using DESs as solvents was at par to the one obtained using conventional method and was superior in quality when compared to κ-carrageenan obtained using water as solvent. Considering the tedious nature of the extraction method employed in conventional extraction process, the DESs can be considered as suitable alternative solvents for the facile extraction of the polysaccharide directly from the seaweed. However, among the hydrated and non-hydrated DESs, the hydrated ones were found to be more effective in comparison to their non-hydrated counterparts. PMID:26572431

  15. Hydrothermal liquefaction of de-oiled Jatropha curcas cake using Deep Eutectic Solvents (DESs) as catalysts and co-solvents.

    PubMed

    Alhassan, Yahaya; Kumar, Naveen; Bugaje, Idris M

    2016-01-01

    Biomass liquefaction using ionic liquids (ILs) as catalysts has received appreciable attention, in renewable fuels and chemicals production, recently. However, issues associated with the production cost, long reaction time and use of volatile solvents are undeniably challenging. Thus, Deep Eutectic Solvents (DESs) emerged as promising and potential ILs substitutes. The hydrothermal liquefaction of de-oiled Jatropha curcas cake was catalyzed by four synthesized DESs as catalysts and co-solvents for selective extraction. Proximate and ultimate analyses including ash, moisture and carbon contents of bio-crude produced varied slightly. The higher heating values found ranges from 21.15 ± 0.82 MJ/kg to 24.30 ± 0.98 MJ/kg. The bio-crude yields obtained using ChCl-KOH DES was 43.53 wt% and ChCl-p-TsOH DES was 38.31 wt%. Bio-crude yield using ChCl-FeCl3 DES was 30.80 wt%. It is suggested that, the selectivity of bio-crude could be improved, by using DESs as catalyst and co-solvent in HTL of biomass such as de-oiled J. curcas cake. PMID:26276400

  16. Evaluation of toxicity and biodegradability of choline chloride based deep eutectic solvents.

    PubMed

    Radošević, Kristina; Bubalo, Marina Cvjetko; Srček, Višnje Gaurina; Grgas, Dijana; Dragičević, Tibela Landeka; Redovniković, Ivana Radojčić

    2015-02-01

    Deep eutectic solvents (DESs) have been dramatically expanding in popularity as a new generation of environmentally friendly solvents with possible applications in various industrial fields, but their ecological footprint has not yet been thoroughly investigated. In the present study, three choline chloride-based DESs with glucose, glycerol and oxalic acid as hydrogen bond donors were evaluated for in vitro toxicity using fish and human cell line, phytotoxicity using wheat and biodegradability using wastewater microorganisms through closed bottle test. Obtained in vitro toxicity data on cell lines indicate that choline chloride: glucose and choline chloride:glycerol possess low cytotoxicity (EC50>10 mM for both cell lines) while choline chloride:oxalic acid possess moderate cytotoxicity (EC50 value 1.64 mM and 4.19 mM for fish and human cell line, respectively). Results on phytotoxicity imply that tested DESs are non-toxic with seed germination EC50 values higher than 5000 mg L(-1). All tested DESs were classified as'readily biodegradable' based on their high levels of mineralization (68-96%). These findings indicate that DESs have a green profile and a good prospect for a wider use in the field of green technologies. PMID:25463852

  17. Improved antibacterial phototoxicity of a neutral porphyrin in natural deep eutectic solvents.

    PubMed

    Wikene, Kristine Opsvik; Bruzell, Ellen; Tønnesen, Hanne Hjorth

    2015-07-01

    Neutral porphyrins for antibacterial photodynamic therapy (aPDT) have received little attention due to their tendency to aggregate in aqueous media and reports of low phototoxic effect. These compounds may be less toxic to cells than positively and negatively charged photosensitisers. The preparation of highly bacterial phototoxic formulations of neutral porphyrins remains an open field of research with great potential if achievable. The purpose of this study was to develop novel hydrophilic formulations of the neutral porphyrin 5,10,15,20-tetrakis(4-hydroxyphenyl)-porphyrin (THPP) by use of natural deep eutectic solvents (NADES) prepared by the solvent evaporation method. Physical and photochemical stability and in vitro photoinactivation of Enterococcus faecalis and Escherichia coli were investigated. Two of the 15 NADES investigated demonstrated superior solubilising properties of THPP. The photostability of THPP was higher in NADES than in methanol. A 100-fold dilution of the preparations with buffer to a final concentration of 0.5-5 nM THPP resulted in complete photoinactivation of E. faecalis and E. coli both in their exponential and stationary phase. THPP demonstrated significantly higher phototoxicity when formulated in NADES than in other aqueous preparations like phosphate buffered saline. NADES as a formulation concept for photosensitisers shows a great potential in aPDT. PMID:25966307

  18. Countercurrent assisted quantitative recovery of metabolites from plant-associated natural deep eutectic solvents.

    PubMed

    Liu, Yang; Garzon, Jahir; Friesen, J Brent; Zhang, Yu; McAlpine, James B; Lankin, David C; Chen, Shao-Nong; Pauli, Guido F

    2016-07-01

    NAtural Deep Eutectic Solvents (NADES) are chemically simple but physiologically important plant constituents that exhibit unique solubilizing properties of other metabolites, including bioactive constituents. The high polarity of NADES introduces a challenge in the ability of conventional solid-support based chromatography to recover potential bioactive metabolites. This complicates the systematic explanation of the NADES' functions in botanical extracts. The present study utilizes countercurrent separation (CCS) methodology to overcome the recovery challenge. To demonstrate its feasibility, Glucose-Choline chloride-Water (GCWat, 2:5:5, mole/mole) served as a model NADES, and four widely used marker flavonoids with different polarities (rutin, quercetin, kaempferol, and daidzein) were chosen as model target analytes. In order to prepare GCWat with high consistency, a water drying study was performed. The unique capabilities of the recently introduced CherryOne system, offering volumetric phase metering, were used to monitor the CCS operations. The collected fractions were analyzed using UHPLC and NMR/quantitative NMR. CCS was able to recover the analytes from the NADES matrix with quantitative recoveries of 95.7%, 94.6%, 97.0%, and 96.7% for rutin, quercetin, kaempferol, and daidzein respectively. The CCS strategy enables recovery of target metabolites from NADES-containing crude extracts as well as from other chemical mixtures, and moreover offers a means of using NADES as environmentally friendly extraction solvents. PMID:27118320

  19. An Expeditious and Greener Synthesis of 2-Aminoimidazoles in Deep Eutectic Solvents.

    PubMed

    Capua, Martina; Perrone, Serena; Perna, Filippo Maria; Vitale, Paola; Troisi, Luigino; Salomone, Antonio; Capriati, Vito

    2016-01-01

    A high-yield one-pot two-step synthesis of 2-aminoimidazoles (2-AI), exploiting an under-air heterocyclodehydration process between α-chloroketones and guanidine derivatives, and using deep eutectic solvents (DESs) as nonconventional, "green" and "innocent" reaction media, has been accomplished successfully. The combination of either glycerol or urea with choline chloride (ChCl) proved to be effective for decreasing the reaction time to about 4-6 h in contrast to the 10-12 h usually required for the same reaction run in toxic and volatile organic solvents and under an argon atmosphere. In addition, the use of the ChCl-urea as a DES also enables the direct isolation of triaryl-substituted 2-AI derivatives by means of a simple work-up procedure consisting in filtration and crystallization, and allows the recycle of the DES mixture. A plausible mechanism highlighting the potential role played by hydrogen bonding catalysis has also been illustrated. PMID:27438810

  20. Extraction of phenolic compounds from virgin olive oil by deep eutectic solvents (DESs).

    PubMed

    García, Aránzazu; Rodríguez-Juan, Elisa; Rodríguez-Gutiérrez, Guillermo; Rios, José Julian; Fernández-Bolaños, Juan

    2016-04-15

    Deep eutectic solvents (DESs) are "green" solvents, applied in this study for the extraction of phenolic compounds from virgin olive oil (VOO). Different combinations of DES consisting of choline chloride (ChCl) in various mixing ratios with sugars, alcohols, organic acids, and urea, as well as a mixture of three sugars were used. The yields of the DES extractions were compared with those from conventional 80% (v/v) methanol/water. DES showed a good solubility of phenolic compounds with different polarities. The two most abundant secoiridoid derivatives in olive oil, oleacein and oleocanthal, extracted with ChCl/xylitol and ChCl/1,2-propanediol showed an increase of 20-33% and 67.9-68.3% with respect to conventional extraction, respectively. To our knowledge, this is the first time that phenolic compounds have been extracted from VOO oil using DES. Our results suggest that DES offers an efficient, safe, sustainable, and cost effective alternative to methanol for extraction of bioactive compounds from VOO. PMID:26616988

  1. Solvatochromic probe behavior within choline chloride-based deep eutectic solvents: effect of temperature and water.

    PubMed

    Pandey, Ashish; Pandey, Siddharth

    2014-12-18

    Deep eutectic solvents (DESs) have shown potential as promising environmentally friendly alternatives to conventional solvents. Many common and popular DESs are obtained by simply mixing a salt and a H-bond donor. Properties of such a DES depend on its constituents. Change in temperature and addition of water, a benign cosolvent, can change the physicochemical properties of DESs. The effect of changing temperature and addition of water on solvatochromic probe behavior within three DESs formed from choline chloride combined with 1,2-ethanediol, glycerol, and urea, respectively, in 1:2 mol ratios termed ethaline, glyceline, and reline is presented. Increase in temperature results in reduced H-bond donating acidity of the DESs. Dipolarity/polarizability and H-bond accepting basicity do not change with changing temperature of the DESs. The response of the fluorescence probe pyrene also indicates a decrease in the polarity of the DESs as temperature is increased. Addition of water to DES results in increased dipolarity/polarizability and a decrease in H-bond accepting basicity. Except for pyrene, solvatochromic probes exhibit responses close to those predicted from ideal-additive behavior with slight preferential solvation by DES within the aqueous mixtures. Pyrene response reveals significant preferential solvation by DES and/or the presence of solvent-solvent interactions, especially within aqueous mixtures of ethaline and glyceline, the DESs constituted of H-bond donors with hydroxyl functionalities. FTIR absorbance and Raman spectroscopic measurements of aqueous DES mixtures support the outcomes from solvatochromic probe responses. Aqueous mixtures of ethaline and glyceline possess relatively more interspecies H-bonds as compared to aqueous mixtures of reline, where interstitial accommodation of water within the reline molecular network appears to dominate. PMID:25418894

  2. Simultaneous extraction of flavonoids from Chamaecyparis obtusa using deep eutectic solvents as additives of conventional extractions solvents.

    PubMed

    Tang, Baokun; Park, Ha Eun; Row, Kyung Ho

    2015-01-01

    Three flavones (quercetin, myricetin and amentoflavone) were extracted from Chamaecyparis obtusa leaves using deep eutectic solvents (DESs) as additives to conventional extractions solvents. Sixteen DESs were synthesized from different salts and hydrogen bond donors. In addition, C. obtusa was extracted under optimal conditions of methanol as the solvent in the heating process (60°C) for 120 min at a solid/liquid ratio of 80%. Under these optimal conditions, a good linear relationship was observed at analyte concentrations ranging from 5.0 to 200.0 μg/mL (R(2) > 0.999). The extraction recovery ranged from 96.7 to 103.3% with the inter- and intraday relative standard deviations of <4.97%. Under the optimal conditions, from C. obtusa, the quantities of quercetin, myricetin and amentoflavone extracted were 325.90, 8.66 and 50.34 µg/mL, respectively. Overall, DESs are expected to have a wide range of applications. PMID:25228687

  3. Deep eutectic solvents in polymerizations: a greener alternative to conventional syntheses.

    PubMed

    del Monte, Francisco; Carriazo, Daniel; Serrano, María C; Gutiérrez, María C; Ferrer, M Luisa

    2014-04-01

    The use of deep eutectic solvents (DESs) that act as all-in-one solvent-template-reactant systems offers an interesting green alternative to conventional syntheses in materials science. This Review aims to provide a comprehensive overview to emphasize the similarities and discrepancies between DES-assisted and conventional syntheses and rationalize certain green features that are common for the three DES-assisted syntheses described herein: one case of radical polymerization and two cases of polycondensations. For instance, DESs contain the precursor itself and some additional components that either provide certain functionality (e.g., drug delivery and controlled release, or electrical conductivity) to the resulting materials or direct their formation with a particular structure (e.g., hierarchical-type). Moreover, DESs provide a reaction medium, so polymerizations are ultimately carried out in a solventless fashion. This means that DES-assisted syntheses match green chemistry principles 2 and 5 because of the economy of reagents and solvents, whereas the functionality incorporated by the second component allows the need for any post-synthesis derivatization to be minimized or even fully avoided (principle 8). DESs also provide new precursors that favor more efficient polymerization (principle 6) by decreasing the energy input required for reaction progress. Finally, the use of mild reaction conditions in combination with the compositional versatility of DESs, which allows low-toxic components to be selected, is also of interest from the viewpoint of green chemistry because it opens up the way to design biocompatible and/or eco-friendly synthetic methods (principle 3). PMID:24376090

  4. A green deep eutectic solvent-based aqueous two-phase system for protein extracting.

    PubMed

    Xu, Kaijia; Wang, Yuzhi; Huang, Yanhua; Li, Na; Wen, Qian

    2015-03-15

    As a new type of green solvent, deep eutectic solvent (DES) has been applied for the extraction of proteins with an aqueous two-phase system (ATPS) in this work. Four kinds of choline chloride (ChCl)-based DESs were synthesized to extract bovine serum albumin (BSA), and ChCl-glycerol was selected as the suitable extraction solvent. Single factor experiments have been done to investigate the effects of the extraction process, including the amount of DES, the concentration of salt, the mass of protein, the shaking time, the temperature and PH value. Experimental results show 98.16% of the BSA could be extracted into the DES-rich phase in a single-step extraction under the optimized conditions. A high extraction efficiency of 94.36% was achieved, while the conditions were applied to the extraction of trypsin (Try). Precision, repeatability and stability experiments were studied and the relative standard deviations (RSD) of the extraction efficiency were 0.4246% (n=3), 1.6057% (n=3) and 1.6132% (n=3), respectively. Conformation of BSA was not changed during the extraction process according to the investigation of UV-vis spectra, FT-IR spectra and CD spectra of BSA. The conductivity, dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to explore the mechanism of the extraction. It turned out that the formation of DES-protein aggregates play a significant role in the separation process. All the results suggest that ChCl-based DES-ATPS are supposed to have the potential to provide new possibilities in the separation of proteins. PMID:25732422

  5. Magnetic solid-phase extraction of protein with deep eutectic solvent immobilized magnetic graphene oxide nanoparticles.

    PubMed

    Xu, Kaijia; Wang, Yuzhi; Ding, Xueqin; Huang, Yanhua; Li, Na; Wen, Qian

    2016-02-01

    As a new type of green solvent, four kinds of choline chloride (ChCl)-based deep eutectic solvents (DESs) have been synthesized, and then a core-shell structure magnetic graphene oxide (Fe3O4-NH2@GO) nanoparticles have been prepared and coated with the ChCl-based DESs. Magnetic solid-phase extraction (MSPE) based Fe3O4-NH2@GO@DES was studied for the first time for the extraction of proteins. The characteristic results of vibrating sample magnetometer (VSM), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FT-IR), thermal gravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM) indicated the successful preparation of Fe3O4-NH2@GO@DES. The concentrations of proteins in studies were determined by a UV-vis spectrophotometer. The advantages of Fe3O4-NH2@GO@DES in protein extraction were compared with Fe3O4-NH2@GO and Fe3O4-NH2, and Fe3O4-NH2@GO@ChCl-glycerol was selected as the suitable extraction solvent. The influence factors of the extraction process such as the pH value, the temperature, the extraction time, the concentration of protein and the amount of Fe3O4-NH2@GO@ChCl-glycerol were evaluated. Desorption experimental result showed 98.73% of BSA could be eluted from the solid extractant with 0.1 mol/L Na2HPO4 solution contained 1 mol/L NaCl. Besides, the conformation of BSA was not changed during the elution by the investigation of circular dichromism (CD) spectra. Furthermore, the analysis of real sample demonstrated that the prepared magnetic nanoparticles did have extraction ability on proteins in bovine whole blood. PMID:26653436

  6. A facile approach to prepare a dual functionalized DNA based material in a bio-deep eutectic solvent.

    PubMed

    Mondal, Dibyendu; Bhatt, Jitkumar; Sharma, Mukesh; Chatterjee, Shruti; Prasad, Kamalesh

    2014-04-18

    DNA (Salmon testes) was functionalized by Fe3O4 nanoparticles and protonated layered dititanate sheets (H2·Ti2O5·H2O) in a mixture of choline chloride and ethylene glycol (a deep eutectic solvent) to yield a hybrid material having magnetic and antibacterial properties. Ti sheets were found to interact with the phosphate moieties, while Fe interacted with the base pair of DNA in the hybrid material. PMID:24609301

  7. Magnetic Fe-Co films electroplated in a deep-eutectic-solvent-based plating bath

    NASA Astrophysics Data System (ADS)

    Yanai, T.; Shiraishi, K.; Watanabe, Y.; Ohgai, T.; Nakano, M.; Suzuki, K.; Fukunaga, H.

    2015-05-01

    We fabricated Fe-Co films from a deep eutectic solvent (DES)-based plating bath and investigated magnetic properties of the plated films. The plating baths were obtained by stirring the mixture of choline chloride, ethylene glycol, FeCl2.4H2O, and CoCl2.6H2O. The composition of the plated films depended on the amount of FeCl2.4H2O in the plating bath, and Fe content of the films was varied from 0 to 100 at. %. Depending on the Fe content, the saturation magnetization and the coercivity of the films varied. The Fe76Co24 film shows high saturation magnetization and smooth surface, and the change in the saturation magnetization shows good agreement with the expected change by the Slater-Pauling curve. High current efficiency (>90%) could be obtained in the wide film composition. From these results, we concluded that the DES-based plating bath is one of effective baths for the Fe-Co films with high current efficiency.

  8. Enhancing cellulose accessibility of corn stover by deep eutectic solvent pretreatment for butanol fermentation.

    PubMed

    Xu, Guo-Chao; Ding, Ji-Cai; Han, Rui-Zhi; Dong, Jin-Jun; Ni, Ye

    2016-03-01

    In this study, an effective corn stover (CS) pretreatment method was developed for biobutanol fermentation. Deep eutectic solvents (DESs), consisted of quaternary ammonium salts and hydrogen donors, display similar properties to room temperature ionic liquid. Seven DESs with different hydrogen donors were facilely synthesized. Choline chloride:formic acid (ChCl:formic acid), an acidic DES, displayed excellent performance in the pretreatment of corn stover by removal of hemicellulose and lignin as confirmed by SEM, FTIR and XRD analysis. After optimization, glucose released from pretreated CS reached 17.0 g L(-1) and yield of 99%. The CS hydrolysate was successfully utilized in butanol fermentation by Clostridium saccharobutylicum DSM 13864, achieving butanol titer of 5.63 g L(-1) with a yield of 0.17 g g(-1) total sugar and productivity of 0.12 g L(-1)h(-1). This study demonstrates DES could be used as a promising and biocompatible pretreatment method for the conversion of lignocellulosic biomass into biofuel. PMID:26597485

  9. Quantum Chemical Insight into the Interactions and Thermodynamics Present in Choline Chloride Based Deep Eutectic Solvents.

    PubMed

    Wagle, Durgesh V; Deakyne, Carol A; Baker, Gary A

    2016-07-14

    We report quantum chemical calculations performed on three popular deep eutectic solvents (DESs) in order to elucidate the molecular interactions, charge transfer interactions, and thermodynamics associated with these systems. The DESs studied comprise 1:2 choline chloride/urea (reline), 1:2 choline chloride/ethylene glycol (ethaline), and 1:1 choline chloride/malonic acid (maloline). The excellent correlation between calculated and experimental vibrational spectra allowed for identification of dominant interactions in the DES systems. The DESs were found to be stabilized by both conventional hydrogen bonds and C-H···O/C-H···π interactions between the components. The hydrogen-bonding network established in the DES is clearly distinct from that which exists within the neat hydrogen-bond donor dimer. Charge decomposition analysis indicates significant charge transfer from choline and chloride to the hydrogen-bond donor with a higher contribution from the cation, and a density of states analysis confirms the direction of the charge transfer. Consequently, the sum of the bond orders of the choline-Cl(-) interactions in the DESs correlates directly with the melting temperatures of the DESs, a correlation that offers insight into the effect of the tuning of the choline-Cl(-) interactions by the hydrogen-bond donors on the physical properties of the DESs. Finally, the differences in the vibrational entropy changes upon DES formation are consistent with the trend in the overall entropy changes upon DES formation. PMID:27268431

  10. Electrochemical fabrication of nanoporous copper films in choline chloride-urea deep eutectic solvent.

    PubMed

    Zhang, Q B; Abbott, Andrew P; Yang, C

    2015-06-14

    Nanoporous copper films were fabricated by a facile electrochemical alloying/dealloying process without the need of a template. A deep eutectic solvent made from choline chloride (ChCl) and urea was used with zinc oxide as the metal salt. Cyclic voltammetry was used to characterise the electrochemical reduction of zinc and follow Cu-Zn alloy formation on the copper substrate at elevated temperatures from 353 to 393 K. The alloy formation was confirmed by X-ray diffraction spectra. 3D, open and bicontinuous nanoporous copper films were obtained by in situ electrochemically etching (dealloying) of the zinc component in the Cu-Zn surface alloys at an appropriate potential (-0.4 V vs. Ag). This dealloying process was found to be highly temperature dependent and surface diffusion controlled, which involved the self-assembly of copper atoms at the alloy/electrolyte interface. Additionally, the effects of the deposition parameters, including deposition temperature, current density as well as total charge density on resulting the microstructure were investigated by scanning electron microscopy, and atomic force microscope. PMID:25972227

  11. Deep eutectic solvents (DESs) are viable cosolvents for enzyme-catalyzed epoxide hydrolysis.

    PubMed

    Lindberg, Diana; de la Fuente Revenga, Mario; Widersten, Mikael

    2010-06-01

    A special group of ionic liquids, deep eutectic solvents (DESs) have been tested as cosolvents in enzyme-catalyzed hydrolysis of a chiral (1,2)-trans-2-methylstyrene oxide. The choline chloride:ethane diol (ET), choline chloride:glycerol (GLY) and choline:chloride:urea (REL) DESs were included in the reaction mixtures with epoxide and the potato epoxide hydrolase StEH1. The effect of the DESs on enzyme function was primarily elevations of K(M) (up to 20-fold) and with lesser effects on turnover numbers (twofold variation). The regioselectivity in hydrolysis of the (1R,2R)-2-trans-methylstyrene oxide was altered in the presence of GLY or ET to favor epoxide ring opening at the benzylic carbon (R=2.33), enhancing the regioselectivity observed in buffer-only systems (R=1.35). The DES solutions dissolved 1.5-fold higher epoxide concentrations as compared to phosphate buffer. The total conversion of high concentration (40 g/l) of (1S,2S)-MeSO was not negatively affected by addition of 40% GLY. PMID:20438773

  12. In situ electrochemical digital holographic microscopy; a study of metal electrodeposition in deep eutectic solvents.

    PubMed

    Abbott, Andrew P; Azam, Muhammad; Ryder, Karl S; Saleem, Saima

    2013-07-16

    This study has shown for the first time that digital holographic microscopy (DHM) can be used as a new analytical tool in analysis of kinetic mechanism and growth during electrolytic deposition processes. Unlike many alternative established electrochemical microscopy methods such as probe microscopy, DHM is both the noninvasive and noncontact, the unique holographic imaging allows the observations and measurement to be made remotely. DHM also provides interferometric resolution (nanometer vertical scale) with a very short acquisition time. It is a surface metrology technique that enables the retrieval of information about a 3D structure from the phase contrast of a single hologram acquired using a conventional digital camera. Here DHM has been applied to investigate directly the electro-crystallization of a metal on a substrate in real time (in situ) from two deep eutectic solvent (DES) systems based on mixture of choline chloride and either urea or ethylene glycol. We show, using electrochemical DHM that the nucleation and growth of silver deposits in these systems are quite distinct and influenced strongly by the hydrogen bond donor of the DES. PMID:23751128

  13. Synthesis and thermo-physical properties of deep eutectic solvent-based graphene nanofluids.

    PubMed

    Fang, Y K; Osama, M; Rashmi, W; Shahbaz, K; Khalid, M; Mjalli, F S; Farid, M M

    2016-02-19

    This study introduces a new class of heat transfer fluids by dispersing functionalised graphene oxide nanoparticles (GNPs) in ammonium and phosphonium-based deep eutectic solvents (DESs) without the aid of a surfactant. Different molar ratios of salts and hydrogen bond donors (HBD) were used to synthesise DESs for the preparation of different concentrations of graphene nanofluids (GNFs). The concentrations of GNPs were 0.01 wt%, 0.02 wt% and 0.05 wt %. Homogeneous and stable suspensions of nanofluids were obtained by high speed homogenisation and an ultrasonication process. The stability of the GNFs was determined through visual observation for 4 weeks followed by a centrifugal process (5000-20,000 rpm) for 30 min in addition to zeta potential studies. Dispersion of the GNPs in DES was observed using an optical microscope. The synthesised DES-based GNFs showed no particle agglomeration and formation of sediments in the nanofluids. Thermo-physical properties such as thermal conductivity and specific heat of the nanofluids were also investigated in this research. The highest thermal conductivity enhancement of 177% was observed. The findings of this research provide a new class of engineered fluid for heat transfer applications as a function of temperature, type and composition DESs as well as the GNPs concentration. PMID:26766874

  14. Micellization of long-chain ionic liquids in deep eutectic solvents.

    PubMed

    Tan, Xiuniang; Zhang, Jianling; Luo, Tian; Sang, Xinxin; Liu, Chengcheng; Zhang, Bingxing; Peng, Li; Li, Wei; Han, Buxing

    2016-06-28

    The aggregation behavior of the ionic liquid (IL) 1-alkyl-3-methylimidazolium chloride with different alkyl chain lengths in a deep eutectic solvent (DES, composed of choline chloride and glycerol in a 1 : 2 mole ratio) was studied for the first time. The critical micellar concentration, micellar size and intermolecular interactions in IL/DES solutions were investigated by different techniques including the fluorescence probe technique, small angle X-ray scattering and Fourier transform infrared spectroscopy. The solvophobic effect dominates the micellization of CnmimCl in DES and the intermolecular hydrogen-bond interaction plays a positive role to promote micelle formation. The micellar solutions were utilized for the synthesis of the water-unstable metal-organic framework Cu3(BTC)2 (BTC = 1,3,5-benzenetricarboxylate) at room temperature. X-Ray diffraction, scanning electron microscopy, transmission electron microscopy and nitrogen adsorption-desorption isotherms confirm the formation of crystalline Cu3(BTC)2 nanocrystals with mesoporous structures. The morphologies and porosity properties of Cu3(BTC)2 nanocrystals can be modulated by varying the concentration of CnmimCl. PMID:27222006

  15. Imidazole tailored deep eutectic solvents for CO2 capture enhanced by hydrogen bonds.

    PubMed

    Cao, Lingdi; Huang, Junhua; Zhang, Xiangping; Zhang, Suojiang; Gao, Jubao; Zeng, Shaojuan

    2015-11-01

    Deep eutectic solvents (DESs) have emerged as promising alternative candidates for CO2 capture in recent years. In this work, several novel DESs were firstly prepared to enhance CO2 absorption. Structural and physical properties of DESs were investigated, as well as their absorption performance of CO2. A distinct depression in the melting point up to 80 K of DESs was observed compared with that of BMIMCl. The observed red shifts of the C2H group in an imidazolium ring and its chemical shifts downfield in NMR spectra are indicative of a hydrogen bond interaction between BMIMCl and MEA. In particular, CO2 uptake in MEA : ILs (4 : 1) at room temperature and atmospheric pressure is up to 21.4 wt%, which is higher than that of 30 wt% MEA (13%). A hydrogen bond related mechanism was proposed in which ILs act as a medium to improve CO2 uptake through hydrogen bonds. Finally, the firstly reported overall heat of CO2 absorption is slightly higher than that of 30 wt% MEA, implying that the hydrogen bonds of DESs contribute to the overall heat of CO2 absorption. This study reveals that the heat of CO2 absorption can be tailored by the proper molar ratio of MEA and ILs. PMID:26435384

  16. Enzyme-Catalyzed Henry Reaction in Choline Chloride-Based Deep Eutectic Solvents.

    PubMed

    Tian, Xuemei; Zhang, Suoqin; Zheng, Liangyu

    2016-01-01

    The enzyme-catalyzed Henry reaction was realized using deep eutectic solvents (DESs) as a reaction medium. The lipase from Aspergillus niger (lipase AS) showed excellent catalytic activity toward the substrates aromatic aldehydes and nitromethane in choline chloride:glycerol at a molar ratio of 1:2. Addition of 30 vol% water to DES further improved the lipase activity and inhibited DES-catalyzed transformation. A final yield of 92.2% for the lipase AS-catalyzed Henry reaction was achieved under optimized reaction conditions in only 4 h. In addition, the lipase AS activity was improved by approximately 3-fold in a DES-water mixture compared with that in pure water, which produced a final yield of only 33.4%. Structural studies with fluorescence spectroscopy showed that the established strong hydrogen bonds between DES and water may be the main driving force that affects the spatial conformation of the enzyme, leading to a change in lipase activity. The methodology was also extended to the aza-Henry reaction, which easily occurred in contrast to that in pure water. The enantioselectivity of both Henry and aza-Henry reactions was not found. However, the results are still remarkable, as we report the first use of DES as a reaction medium in a lipase-catalyzed Henry reaction. PMID:26437947

  17. Deep Eutectic Solvents Modified Molecular Imprinted Polymers for Optimized Purification of Chlorogenic Acid from Honeysuckle.

    PubMed

    Li, Guizhen; Wang, Wei; Wang, Qian; Zhu, Tao

    2016-02-01

    Deep eutectic solvents (DES) were synthesized with choline chloride (ChCl), and DES modified molecular imprinted polymers (DES-MIPs), DES modified non-imprinted polymers (DES-NIPs, without template), MIPs and NIPs were prepared in an identical procedure. Fourier transform infrared spectrometer (FT-IR) and field emission scanning electron microscopy (FE-SEM) were used to characterize the obtained polymers. Rebinding experiment and solid-phase extraction (SPE) were used to prove the high selectivity adsorption properties of the polymers. Box-Behnken design (BBD) with three factors was used to optimize the extraction condition of chlorogenic acid (CA) from honeysuckles. The optimum extraction conditions were found to be ultrasonic time optimized (20 min), the volume fraction of ethanol (60%) and ratio of liquid to material (15 mL g(-1)). Under these conditions, the mean extraction yield of CA was 12.57 mg g(-1), which was in good agreement with the predicted BBD model value. Purification of hawthorn extract was achieved by SPE process, and SPE recoveries of CA were 72.56, 64.79, 69.34 and 60.08% by DES-MIPs, DES-NIPs, MIPs and NIPs, respectively. The results showed DES-MIPs had potential for promising functional adsorption material for the purification of bioactive compounds. PMID:26347506

  18. [Deep eutectic solvent: a new kind of mobile phase modifier for hydrophilic interaction liquid chromatography].

    PubMed

    Tan, Ting; Qiao, Xin; Wan, Yiqun; Qiu, Hongdeng

    2015-09-01

    Deep eutectic solvents (DESs) were used as a new kind of mobile phase modifier in hydrophilic interaction liquid chromatography (HILIC). In our experiment, a SiO2 column (150 mm x 4.6 mm, 3 µm) was selected to separate several nucleobases and nucleosides by using the mixed solution of acetonitrile and DES (choline chloride-ethylene glycol (1:3, mol/mol) ) as mobile phase. Subsequently, the concentrations of DESs in acetonitrile and the column temperature on the effect of separation were investigated. According to the experimental results, better separation of nucleobases and nucleosides was obtained by using acetonitrile and DESs mixed solution as mobile phase than that using traditional water-based solution. For example, a baseline separation between cytosine and cytidine cannot be achieved by HILIC with water-based mobile phase, however, greater improvement was gained by HILIC with modified DES-acetonitrile mobile phase. Meanwhile, the retention times of nucleobases and nucleosides decreased as the proportion of DESs in acetonitrile increased, the most significant decrease of which was with cytidine. Similar retention behavior took place with the effect of column temperature. Decreased retention times of the analytes were observed as column temperature increased. The experimental results indicated that this new method may solve some separation difficulties in traditional water-based HILIC, which also successfully verify the feasibility of DESs as mobile phase modifiers. PMID:26753279

  19. Ultrasound assisted-deep eutectic solvent extraction of iron from sheep, bovine and chicken liver samples.

    PubMed

    Yilmaz, Erkan; Soylak, Mustafa

    2015-05-01

    A green, novel and effective ultrasound assisted-deep eutectic solvent (DES) extraction (UA-DES-E) procedure was developed for extraction of iron from sheep, bovine and chicken liver samples. The analytical parameters including type and composition DES, volume of DES, ultrasonication time and ratio of sample to DES were optimized by using 50mg of the NIST SRM 1577b bovine liver certified reference material. The limit of detection (LOD) and the limit of quantification (LOQ) were found as 0.026µg mL(-1) and 0.085µg mL(-1), respectively. The relative standard deviation (RSD) as a result of 7 replicates of 50mg of certified reference material was 1.4%. The accuracy of proposed method was checked by the addition/recovery tests to NIST SRM 1577b bovine liver and a sheep liver. The extraction method was applied to extraction of iron from bovine, sheep and chicken liver samples retail from markets at Kayseri, Turkey with satisfactory results (recoveries higher than 95%). PMID:25702999

  20. Synthesis and thermo-physical properties of deep eutectic solvent-based graphene nanofluids

    NASA Astrophysics Data System (ADS)

    Fang, Y. K.; Osama, M.; Rashmi, W.; Shahbaz, K.; Khalid, M.; Mjalli, F. S.; Farid, M. M.

    2016-02-01

    This study introduces a new class of heat transfer fluids by dispersing functionalised graphene oxide nanoparticles (GNPs) in ammonium and phosphonium-based deep eutectic solvents (DESs) without the aid of a surfactant. Different molar ratios of salts and hydrogen bond donors (HBD) were used to synthesise DESs for the preparation of different concentrations of graphene nanofluids (GNFs). The concentrations of GNPs were 0.01 wt%, 0.02 wt% and 0.05 wt %. Homogeneous and stable suspensions of nanofluids were obtained by high speed homogenisation and an ultrasonication process. The stability of the GNFs was determined through visual observation for 4 weeks followed by a centrifugal process (5000-20 000 rpm) for 30 min in addition to zeta potential studies. Dispersion of the GNPs in DES was observed using an optical microscope. The synthesised DES-based GNFs showed no particle agglomeration and formation of sediments in the nanofluids. Thermo-physical properties such as thermal conductivity and specific heat of the nanofluids were also investigated in this research. The highest thermal conductivity enhancement of 177% was observed. The findings of this research provide a new class of engineered fluid for heat transfer applications as a function of temperature, type and composition DESs as well as the GNPs concentration.

  1. Toxicity profile of choline chloride-based deep eutectic solvents for fungi and Cyprinus carpio fish.

    PubMed

    Juneidi, Ibrahim; Hayyan, Maan; Mohd Ali, Ozair

    2016-04-01

    An investigation on the toxicological assessment of 10 choline chloride (ChCl)-based deep eutectic solvents (DESs) towards four fungi strains and Cyprinus carpio fish was conducted. ChCl was combined with materials from different chemical groups such as alcohols, sugars, acids and others to form DESs. The study was carried out on the individual DES components, their aqueous mixture before DES formation and their formed DESs. The agar disc diffusion method was followed to investigate their toxicity on four fungi strains selected as a model of eukaryotic microorganisms (Phanerochaete chrysosporium, Aspergillus niger, Lentinus tigrinus and Candida cylindracea). Among these DESs, ChCl:ZnCl2 exhibited the highest inhibition zone diameter towards the tested fungi growth in vitro, followed by the acidic group (malonic acid and p-toluenesulfonic acid). Another study was conducted to test the acute toxicity and determine the lethal concentration at 50 % (LC50) of the same DESs on C. carpio fish. The inhibition range and LC50 of DESs were found to be different from their individual components. DESs were found to be less toxic than their mixture or individual components. The LC50 of ChCl:MADES is much higher than that of ChCl:MAMix. Moreover, the DESs acidic group showed a lower inhibition zone on fungi growth. Thus, DESs should be considered as new components with different physicochemical properties and toxicological profiles, and not merely compositions of compounds. PMID:26743645

  2. Aqueous Ionic Liquids and Deep Eutectic Solvents for Cellulosic Biomass Pretreatment and Saccharification

    PubMed Central

    Xia, Shuqian; Baker, Gary A.; Li, Hao; Ravula, Sudhir; Zhao, Hua

    2014-01-01

    Ionic liquids (ILs) have proven effective solvents for pretreating lignocellulose, leading to the fast saccharification of cellulose and hemicellulose. However, the high current cost of most ILs remains a major barrier to commercializing this recent approach at a practical scale. As a strategic detour, aqueous solutions of ILs are also being explored as less costly alternatives to neat ILs for cellulose pretreatment. However, limited studies on a few select IL systems are known and there remains no systematic survey of various ILs, eluding an in-depth understanding of pretreatment mechanisms afforded by aqueous IL systems. As a step toward filling this gap, this study presents results for Avicel cellulose pretreatment by neat and aqueous solutions (1.0 and 2.0 M) of 20 different ILs and three deep eutectic solvents, correlating enzymatic hydrolysis rates of pretreated cellulose with various IL properties such as hydrogen-bond basicity, polarity, Hofmeister ranking, and hydrophobicity. The pretreatment efficiencies of neat ILs may be loosely correlated to the hydrogen-bond basicity of the constituent anion and IL polarity; however, the pretreatment efficacies for aqueous ILs are more complicated and cannot be simply related to any single IL property. Several aqueous IL systems have been identified as effective alternatives to neat ILs in lignocellulose pretreatment. In particular, this study reveals that aqueous solutions of 1-butyl-3-methylimidazolium methanesulfonate ([BMIM][MeSO3]) are effective for pretreating switchgrass (Panicum virgatum), resulting in fast saccharification of both cellulose and hemicellulose. An integrated analysis afforded by X-ray diffraction, scanning electron microscopy, thermogravimetric analysis and cellulase adsorption isotherm of lignocellulose samples is further used to deliver a more complete view of the structural changes attending aqueous IL pretreatment. PMID:24729865

  3. Effects of ultrasound and temperature on copper electro reduction in Deep Eutectic Solvents (DES).

    PubMed

    Mandroyan, Audrey; Mourad-Mahmoud, Mahmoud; Doche, Marie-Laure; Hihn, Jean-Yves

    2014-11-01

    This paper concerns a preliminary study for a new copper recovery process from ionic solvent. The aim of this work is to study the reduction of copper in Deep Eutectic Solvent (choline chloride-ethylene glycol) and to compare the influence of temperature and the ultrasound effects on kinetic parameters. Solutions were prepared by dissolution of chloride copper salt CuCl2 (to obtain Copper in oxidation degree II) or CuCl (to obtain Copper in oxidation degree I) and by leaching metallic copper directly in DES. The spectrophotometry UV-visible analysis of the leached solution showed that the copper soluble form obtained is at oxidation degree I (Copper I). Both cyclic voltammetry and linear voltammetry were performed in the three solutions at three temperatures (25, 50 and 80°C) and under ultrasonic conditions (F=20kHz, PT=5.8W) to calculate the mass transfer diffusion coefficient kD and the standard rate coefficient k°. These parameters are used to determine that copper reduction is carried out via a mixed kinetic-diffusion control process. Temperature and ultrasound have the same effect on mass transfer for reduction of Cu(II)/Cu(I). On the other hand, temperature is more beneficial than ultrasound for mass transfer of Cu(I)/Cu. Standard rate constant improvement due to temperature increase is of the same order as that obtained with ultrasound. But, by combining higher temperature and ultrasound (F=20kHz, PT=5.6W at 50°C), reduction limiting current is increased by a factor of 10 compared to initial conditions (T=25°C, silent), because ultrasonic stirring is more efficient in lower viscosity fluid. These values can be considered as key-parameters in the design of copper recovery in global processes using ultrasound. PMID:24629581

  4. Deep eutectic solvent-assisted synthesis of biodegradable polyesters with antibacterial properties.

    PubMed

    García-Argüelles, Sara; Serrano, M Concepción; Gutiérrez, María C; Ferrer, M Luisa; Yuste, Luis; Rojo, Fernando; del Monte, Francisco

    2013-07-30

    Bacterial infection related to the implantation of medical devices represents a serious clinical complication, with dramatic consequences for many patients. In past decades, numerous attempts have been made to develop materials with antibacterial and/or antifouling properties by the incorporation of antibiotic and/or antiseptic compounds. In this context, deep eutectic solvents (DESs) are acquiring increasing interest not only as efficient carriers of active principle ingredients (APIs) but also as assistant platforms for the synthesis of a wide repertoire of polymer-related materials. Herein, we have successfully prepared biodegradable poly(octanediol-co-citrate) polyesters with acquired antibacterial properties by the DES-assisted incorporation of quaternary ammonium or phosphonium salts into the polymer network. In the resulting polymers, the presence of these salts (i.e., choline chloride, tetraethylammonium bromide, hexadecyltrimethylammonium bromide, and methyltriphenylphosphonium bromide) inhibits bacterial growth in the early postimplantation steps, as tested in cultures of Escherichia coli on solid agar plates. Later, positive polymer cytocompatibility is expected to support cell colonization, as anticipated from in vitro preliminary studies with L929 fibroblasts. Finally, the attractive elastic properties of these polyesters permit matching those of soft tissues such as skin. For all of these reasons, we envisage the utility of some of these antibacterial, biocompatible, and biodegradable polyesters as potential candidates for the preparation of antimicrobial wound dressings. These results further emphasize the enormous versatility of DES-assisted synthesis for the incorporation, in the synthesis step, of a wide palette of APIs into polymeric networks suitable for biomedical applications. PMID:23808373

  5. In Vitro and In Vivo toxicity profiling of ammonium-based deep eutectic solvents.

    PubMed

    Hayyan, Maan; Looi, Chung Yeng; Hayyan, Adeeb; Wong, Won Fen; Hashim, Mohd Ali

    2015-01-01

    The cytotoxic potential of ammonium-based deep eutectic solvents (DESs) with four hydrogen bond donors, namely glycerine (Gl), ethylene glycol (EG), triethylene glycol (TEG) and urea (U) were investigated. The toxicity of DESs was examined using In Vitro cell lines and In Vivo animal model. IC50 and selectivity index were determined for the DESs, their individual components and their combinations as aqueous solutions for comparison purposes. The cytotoxicity effect of DESs varied depending on cell lines. The IC50 for the GlDES, EGDES, UDES and TEGDES followed the sequence of TEGDES< GlDES< EGDES< UDES for OKF6, MCF-7, A375, HT29 and H413, respectively. GlDES was selective against MCF-7 and A375, EGDES was selective against MCF-7, PC3, HepG2 and HT29, UDES was selective against MCF-7, PC3, HepG2 and HT29, and TEGDES was selective against MCF-7 and A375. However, acute toxicity studies using ICR mice showed that these DESs were relatively toxic in comparison to their individual components. DES did not cause DNA damage, but it could enhance ROS production and induce apoptosis in treated cancer cells as evidenced by marked LDH release. Furthermore, the examined DESs showed less cytotoxicity compared with ionic liquids. To the best of our knowledge, this is the first time that combined In Vitro and In Vivo toxicity profiles of DESs were being demonstrated, raising the toxicity issue of these neoteric mixtures and their potential applicability to be used for therapeutic purposes. PMID:25679975

  6. Electrodeposition, Morphology, Composition, and Corrosion Performance of Zn-Mn Coatings from a Deep Eutectic Solvent

    NASA Astrophysics Data System (ADS)

    Fashu, S.; Gu, C. D.; Zhang, J. L.; Zheng, H.; Wang, X. L.; Tu, J. P.

    2015-01-01

    Different Zn-Mn coatings were successfully electrodeposited on copper substrates from deep eutectic solvent-based electrolytes containing boric acid as an additive. The main objective of this work was to optimize the Zn/Mn ratios and morphologies of the as-electrodeposited Zn-Mn films in order to obtain better corrosion protection performance coatings. The electrodeposition behaviors of Zn-Mn alloys as studied by cyclic voltammetry showed that with increase in electrolyte Mn(II) concentration, Zn(II) ion reduction occurs at higher overpotentials while Mn reduction occurs at lower overpotentials, and this in turn enhances Mn incorporation into the deposit. Characterization results showed that the electrodeposition potential and electrolyte Mn(II) concentration significantly affects the Mn content, crystal structure, surface morphology, and corrosion performance of the deposits. With increase in electrodeposition potential and electrolyte Mn(II) concentration, the alloy Mn increased and the grain morphology was refined. The crystal structure of Zn-Mn deposits consists of Zn and hexagonal close packed ɛ-phase Zn-Mn at low electrodeposition potentials and low electrolyte Mn(II) content. However, at high electrodeposition potentials and electrolyte Mn(II) contents, the crystal structure was only composed of hexagonal close packed ɛ-phase Zn-Mn. Corrosion measurements show that all the Zn-Mn samples have a passivating behavior and exhibits higher corrosion resistances when compared to those from aqueous solutions. Thus, optimum electrodeposition potential and electrolyte Mn(II) concentration were determined producing compact Zn-Mn films with the best corrosion resistance.

  7. In Vitro and In Vivo Toxicity Profiling of Ammonium-Based Deep Eutectic Solvents

    PubMed Central

    Hayyan, Maan; Looi, Chung Yeng; Hayyan, Adeeb; Wong, Won Fen; Hashim, Mohd Ali

    2015-01-01

    The cytotoxic potential of ammonium-based deep eutectic solvents (DESs) with four hydrogen bond donors, namely glycerine (Gl), ethylene glycol (EG), triethylene glycol (TEG) and urea (U) were investigated. The toxicity of DESs was examined using In Vitro cell lines and In Vivo animal model. IC50 and selectivity index were determined for the DESs, their individual components and their combinations as aqueous solutions for comparison purposes. The cytotoxicity effect of DESs varied depending on cell lines. The IC50 for the GlDES, EGDES, UDES and TEGDES followed the sequence of TEGDES< GlDES< EGDES< UDES for OKF6, MCF-7, A375, HT29 and H413, respectively. GlDES was selective against MCF-7 and A375, EGDES was selective against MCF-7, PC3, HepG2 and HT29, UDES was selective against MCF-7, PC3, HepG2 and HT29, and TEGDES was selective against MCF-7 and A375. However, acute toxicity studies using ICR mice showed that these DESs were relatively toxic in comparison to their individual components. DES did not cause DNA damage, but it could enhance ROS production and induce apoptosis in treated cancer cells as evidenced by marked LDH release. Furthermore, the examined DESs showed less cytotoxicity compared with ionic liquids. To the best of our knowledge, this is the first time that combined In Vitro and In Vivo toxicity profiles of DESs were being demonstrated, raising the toxicity issue of these neoteric mixtures and their potential applicability to be used for therapeutic purposes. PMID:25679975

  8. PC-SAFT Modeling of CO2 Solubilities in Deep Eutectic Solvents.

    PubMed

    Zubeir, Lawien F; Held, Christoph; Sadowski, Gabriele; Kroon, Maaike C

    2016-03-10

    Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT), a physically based model that accounts for different molecular interactions explicitly, was applied to describe for the first time the phase behavior of deep eutectic solvents (DESs) with CO2 at temperatures from 298.15 to 318.15 K and pressures up to 2 MPa. DESs are mixtures of two solid compounds, a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA), which form liquids upon mixing with melting points far below that of the individual compounds. In this work, the HBD is lactic acid and the HBAs are tetramethylammonium chloride, tetraethylammonium chloride, and tetrabutylammonium chloride. Two different modeling strategies were considered for the PC-SAFT modeling. In the first strategy, the so-called pseudo-pure component approach, a DES was considered as a pseudo-pure compound, and its pure-component parameters were obtained by fitting to pure DES density data. In the second strategy, the so-called individual-component approach, a DES was considered to consist of two individual components (HBA and HBD), and the pure-component parameters of the HBA and HBD were obtained by fitting to the density of aqueous solutions containing only the individual compounds of the DES. In order to model vapor-liquid equilibria (VLE) of DES + CO2 systems, binary interaction parameters were adjusted to experimental data from the literature and to new data measured in this work. It was concluded that the individual-component strategy allows quantitative prediction of the phase behavior of DES + CO2 systems containing those HBD:HBA molar ratios that were not used for k(ij) fitting. In contrast, applying the pseudo-pure component strategy required DES-composition specific k(ij) parameters. PMID:26814164

  9. Evidence of self-aggregation of cationic surfactants in a choline chloride+glycerol deep eutectic solvent.

    PubMed

    Pal, Mahi; Singh, Ranjan K; Pandey, Siddharth

    2015-08-24

    Based on fluorescence probe, electrical conductivity, surface tension, small-angle X-ray/dynamic light scattering, and transmission electron microscopy experiments, we present the first clear lines of evidence for self-aggregation of cationic surfactants of the n-alkyltrimethylammonium family within an archetypical deep eutectic solvent comprised of a 1:2 molar mixture of choline chloride and glycerol. Estimated thermodynamic parameters suggest this self-aggregation process to be less entropically driven than that in water. These novel water-free self-assemblies might serve as dynamic soft templates to direct the growth of size- or shape-tailored nanoparticles within water-restricted media. PMID:26080073

  10. Green synthesis of polymer monoliths incorporated with carbon nanotubes in room temperature ionic liquid and deep eutectic solvents.

    PubMed

    Zhang, Li-Shun; Gao, Shu-Ping; Huang, Yan-Ping; Liu, Zhao-Sheng

    2016-07-01

    In this work, an efficient method to prepare polymer monoliths with incorporated carbon nanotubes in a mixture of room temperature ionic liquid and deep eutectic solvents was developed. With assistance of the binary green solvent, 1-butyl-3-methylimidazolium tetrafluoroborate and choline chloride/ethylene glycol, single-walled carbon nanotubes were dispersed successfully in pre-polymerization mixture without need of oxidative cutting of carbon nanotubes, which may allow depletion of the emission of volatile organic compounds into environment. The novel single-walled carbon nanotubes monolith was evaluated by capillary electrochromatography. Compared with the monolith made without single-walled carbon nanotubes, the monolith with the incorporation of single-walled carbon nanotubes exhibited high column efficiency (251,000plates/m) in the chromatographic separation. The morphology of the monolith can be tuned by the composition of mixture of ionic liquids and deep eutectic solvents to afford good column permeability and excellent separation ability for small molecules of alkyl phenones and alkyl benzenes. The results demonstrated that the method is a green strategy for the fabrication of multifunctional polymer monoliths. PMID:27154683

  11. Towards green analysis of virgin olive oil phenolic compounds: Extraction by a natural deep eutectic solvent and direct spectrophotometric detection.

    PubMed

    Paradiso, Vito Michele; Clemente, Antonia; Summo, Carmine; Pasqualone, Antonella; Caponio, Francesco

    2016-12-01

    The determination of phenolic compounds in extra virgin olive oils (EVOO) by means of rapid, low-cost, environment-free methods would be a desirable achievement. A natural deep eutectic solvent (DES) based on glucose and lactic acid was considered as extraction solvent for phenolic compounds in EVOO. DESs are green solvents characterized by high availability, biodegradability, safety, and low cost. The spectrophotometric characteristics of DES extracts of 65 EVOO samples were related to the total phenolic content of the oils, assessed by methanol-water extraction coupled to the Folin-Ciocalteu assay. A regression model (ncalibration=45, nvalidation=20), including the absorbance at two wavelengths (257, 324nm), was obtained, with an adjusted R(2)=0.762. Therefore the DES could provide a promising and viable approach for a green screening method of phenolic compounds in EVOO, by means of simple spectrophotometric measurements of extracts, even for on-field analysis (for example in olive mills). PMID:27374504

  12. RETRACTED: Neoteric FT-IR investigation on the functional groups of phosphonium-based deep eutectic solvents.

    PubMed

    Aissaoui, Tayeb; AlNashef, Inas M; Hayyan, Maan; Hashim, Mohd Ali

    2015-10-01

    Deep eutectic solvents (DESs) are novel solvent media that are currently under investigation as an alternative to ionic liquids and conventional solvents. The physical properties of DESs as well as their mild environmental footprint and potentially critical industrial application necessitate understanding the interaction of functional groups on both the salt and hydrogen bond donor (HBD). In this study, four DESs were prepared by mixing triethylenglycol, diethylenglycol, ethylenglycol, and glycerol as HBDs with methyltriphenylphosphonium bromide as a salt at a molar ratio of 1:4. Fourier transform infrared spectroscopy was conducted to highlight the chemical structure and mechanism of the combination of the four DESs. New spectra illustrating the combination of the functional groups of the HBDs and salt were observed and interpreted. This study is the first to investigate the properties of neoteric phosphonium-based DESs. PMID:25985123

  13. Main chemical species and molecular structure of deep eutectic solvent studied by experiments with DFT calculation: a case of choline chloride and magnesium chloride hexahydrate.

    PubMed

    Zhang, Chao; Jia, Yongzhong; Jing, Yan; Wang, Huaiyou; Hong, Kai

    2014-08-01

    The infrared spectrum of deep eutectic solvent of choline chloride and magnesium chloride hexahydrate was measured by the FTIR spectroscopy and analyzed with the aid of DFT calculations. The main chemical species and molecular structure in deep eutectic solvent of [MgClm(H2O)6-m]2-m and [ChxCly]x+y complexes were mainly identified and the active ion of magnesium complex during the electrochemical process was obtained. The mechanism of the electrochemical process of deep eutectic solvent of choline chloride and magnesium chloride hexahydrate was well explained by combination theoretical calculations and experimental. Besides, based on our results we proposed a new system for the dehydration study of magnesium chloride hexahydrate. PMID:25031082

  14. Fast environment-friendly ball mill-assisted deep eutectic solvent-based extraction of natural products.

    PubMed

    Wang, Man; Wang, Jiaqin; Zhang, Yue; Xia, Qian; Bi, Wentao; Yang, Xiaodi; Chen, David Da Yong

    2016-04-22

    A fast environment-friendly extraction method, ball mill-assisted deep eutectic solvent-based extraction, was used for the extraction of natural products from plants. In this study, tanshinones were selected as target compounds to evaluate the efficiency of the developed extraction method. Under the optimized experimental conditions, cryptotanshinone (0.176 mg/g), tanshinone I (0.181 mg/g), and tanshinone II A (0.421 mg/g) were extracted from Salvia miltiorrhiza Bunge, and the developed method was found to be greener, more efficient, and faster than conventional, environmentally harmful extraction methods such as methanol-based ultrasound-assisted extraction and heat reflux extraction. The analytical performances including recovery, reproducibility (RSD, n=5), correlation of determination (r(2)), and the limit of detection, with the ranges of 96.1-103.9%, 1.6-1.9%, 0.9973-0.9984, and 5-8 ng/mL, were respectively obtained. Application of ball mill-assisted deep eutectic solvent-based extraction may fundamentally shape the future development of extraction methods. PMID:27033981

  15. Development of green betaine-based deep eutectic solvent aqueous two-phase system for the extraction of protein.

    PubMed

    Li, Na; Wang, Yuzhi; Xu, Kaijia; Huang, Yanhua; Wen, Qian; Ding, Xueqin

    2016-05-15

    Six kinds of new type of green betaine-based deep eutectic solvents (DESs) have been synthesized. Deep eutectic solvent aqueous two-phase systems (DES-ATPS) were established and successfully applied in the extraction of protein. Betaine-urea (Be-U) was selected as the suitable extractant. Single factor experiments were carried out to determine the optimum conditions of the extraction process, such as the salt concentration, the mass of DES, the separation time, the amount of protein, the temperature and the pH value. The extraction efficiency could achieve to 99.82% under the optimum conditions. Mixed sample and practical sample analysis were discussed. The back extraction experiment was implemented and the back extraction efficiency could reach to 32.66%. The precision experiment, repeatability experiment and stability experiment were investigated. UV-vis, FT-IR and circular dichroism (CD) spectra confirmed that the conformation of protein was not changed during the process of extraction. The mechanisms of extraction were researched by dynamic light scattering (DLS), the measurement of the conductivity and transmission electron microscopy (TEM). DES-protein aggregates and embraces phenomenon play considerable roles in the separation process. All of these results indicated that betaine-based DES-ATPS may provide a potential substitute new method for the separation of proteins. PMID:26992491

  16. Experimental evidence for the participation of deep eutectic solvents in silver chloride crystal formation at low temperature

    NASA Astrophysics Data System (ADS)

    Bhatt, Jitkumar; Mondal, Dibyendu; Prasad, Kamalesh

    2016-05-01

    Deep eutectic solvents (DESs) obtained by the complexation of choline chloride (ChoCl) as hydrogen bond acceptor and hydrogen bond donors such as ethylene glycol (ChoCl-EG 1:2) and glycerol (ChoCl-Gly 1:2) were used as media for the formation of AgCl crystals. Although formation of AgCl crystals was observed in both the solvents but the rate of formation of crystals was faster in ChoCl-EG 1:2 at low temperature (4-5 °C). In the crystals, cholinium cations were found to be present with chloride ions bridged with Ag ions resulting generation of 1D network of AgCl2 anions.

  17. The ionothermal synthesis of metal organic frameworks, Ln(C 9O 6H 3)((CH 3NH) 2CO) 2, using deep eutectic solvents

    NASA Astrophysics Data System (ADS)

    Himeur, Farida; Stein, Irene; Wragg, David S.; Slawin, Alexandra M. Z.; Lightfoot, Philip; Morris, Russell E.

    2010-04-01

    Three new isostructural materials Ln(TMA)(DMU) 2 (Ln(C 9O 6H 3)((CH 3NH) 2CO) 2; Ln: La 1, Nd 2, Eu 3; TMA: trimesate, DMU: dimethylurea) have been synthesised ionothermally using a choline chloride/dimethylurea deep eutectic mixture as the solvent. Normally in ionothermal synthesis the urea portion of the deep eutectic solvent is unstable, breaking down to release ammonium cations that act as templates. In the case of 1- 3, however, the dimethylurea remains intact and is incorporated into the final structure.

  18. Highly efficient extraction of anthocyanins from grape skin using deep eutectic solvents as green and tunable media.

    PubMed

    Jeong, Kyung Min; Zhao, Jing; Jin, Yan; Heo, Seong Rok; Han, Se Young; Yoo, Da Eun; Lee, Jeongmi

    2015-12-01

    Deep eutectic solvents (DESs) were investigated as tunable, environmentally benign, yet superior extraction media to enhance the extraction of anthocyanins from grape skin, which is usually discarded as waste. Ten DESs containing choline chloride as hydrogen bond acceptor combined with different hydrogen bond donors were screened for high extraction efficiencies based on the anthocyanin extraction yields. As a result, citric acid, D-(+)-maltose, and fructose were selected as the effective DES components, and the newly designed DES, CM-6 that is composed of citric acid and D-(+)-maltose at 4:1 molar ratio, exhibited significantly higher levels of anthocyanin extraction yields than conventional extraction solvents such as 80% aqueous methanol. The final extraction method was established based on the ultrasound-assisted extraction under conditions optimized using response surface methodology. Its extraction yields were double or even higher than those of conventional methods that are time-consuming and use volatile organic solvents. Our method is truly a green method for anthocyanin extraction with great extraction efficiency using a minimal amount of time and solvent. Moreover, this study suggested that grape skin, the by-products of grape juice processing, could serve as a valuable source for safe, natural colorants or antioxidants by use of the eco-friendly extraction solvent, CM-6. PMID:26534763

  19. Utilization of deep eutectic solvents as novel mobile phase additives for improving the separation of bioactive quaternary alkaloids.

    PubMed

    Tan, Ting; Zhang, Mingliang; Wan, Yiqun; Qiu, Hongdeng

    2016-03-01

    Deep eutectic solvents (DESs) were used as novel mobile phase additives to improve chromatographic separation of four quaternary alkaloids including coptisine chloride, sanguinarine, berberine chloride and chelerythrine on a C18 column. DESs as a new class of ionic liquids are renewably sourced, environmentally benign, low cost and easy to prepare. Seven DESs were obtained by mixing different hydrogen acceptors and hydrogen-bond donors. The effects of organic solvents, the concentration of DESs, the types of DESs and the pH values of the buffer solution on the separation of the analytes were investigated. The composition of acetonitrile and 1.0% deep eutectic solvents aqueous solution (pH 3.3, adjusted with hydrochloric acid) in a 32:68 (v/v) ratio was used as optimized mobile phase, with which four quaternary alkaloids were well separated. When a small amount of DESs was added in the mobile phase for the separation of alkaloids on the C18 column, noticeable improvements were distinctly observed such as decreasing peak tailing and improving resolution. The separation mechanism mediated by DESs as mobile phase additives can be attributed to combined effect of both hydrogen acceptors and hydrogen-bond donors. For example, choline chloride can effectively cover the residual silanols on silica surface and ethylene glycol can reduce the retention time of analytes. The proposed method has been applied to determine BerbC in Lanqin Chinese herbal oral solution and BerbC tablet. Utilization of DESs in mobile phase can efficiently improve separation and selectivity of analytes from complex samples. PMID:26717817

  20. Ionic liquids and deep eutectic mixtures as new solvents for the synthesis of vanadium fluorides and oxyfluorides.

    PubMed

    Aidoudi, Farida H; Byrne, Peter J; Allan, Pheobe K; Teat, Simon J; Lightfoot, Philip; Morris, Russell E

    2011-04-28

    An exploratory study of the synthesis of vanadium (oxy)fluorides (VOFs) using ionic liquids (ILs) and deep eutectic mixtures (DESs) as a solvent yielded 10 different materials. The previously reported chain type: (NH(4))(2)VF(5) (1), (NH(4))(2)VOF(4) (2), NH(4)VO(3) (3) and (H(2)NH(2)(CH(2))(2)NH(2))VF(5) (9) have been successfully produced for the first time using ILs as the reaction media. The monomeric (HNH(2)CH(3))(2)VOF(4)(H(2)O) (4), the dimer (HNH(2)CH(3))(4)V(2)O(2)F(8) (5) and the 1D chains (HNH(2)CH(3))(2)VF(5) (6), (H(2)O)(2)VF(3) (7), α-(H(2)NH(2)(CH(2))(2)NH(2))VOF(4) (8) and β-(H(2)NH(2)(CH(2))(2)NH(2))VOF(4) (10) are novel materials. Template control has also been achieved by the selective choice of ILs or the appropriate deep eutectic mixture, where the expected template is delivered to the reaction by the partial breakdown of the urea derivative portion of the DES. PMID:21409203

  1. Theoretical evidence of charge transfer interaction between SO₂ and deep eutectic solvents formed by choline chloride and glycerol.

    PubMed

    Li, Hongping; Chang, Yonghui; Zhu, Wenshuai; Wang, Changwei; Wang, Chao; Yin, Sheng; Zhang, Ming; Li, Huaming

    2015-11-21

    The nature of the interaction between deep eutectic solvents (DESs), formed by ChCl and glycerol, and SO2 has been systematically investigated using the M06-2X density functional combined with cluster models. Block-localized wave function energy decomposition (BLW-ED) analysis shows that the interaction between SO2 and DESs is dominated by a charge transfer interaction. After this interaction, the SO2 molecule becomes negatively charged, whereas the ChCl-glycerol molecule is positively charged, which is the result of Lewis acid-base interaction. The current result affords a theoretical proof that it is highly useful and efficient to manipulate the Lewis acidity of absorbents for SO2 capture. Moreover, hydrogen bonding as well as electrostatic interactions may also contribute to the stability of the complex. Structure analysis shows that solvent molecules will adjust their geometries to interact with SO2. In addition, the structure of SO2 is barely changed after interaction. The interaction energy between different cluster models and SO2 ranges from -6.8 to -14.4 kcal mol(-1). It is found that the interaction energy is very sensitive to the solvent structure. The moderate interaction between ChCl-glycerol and SO2 is consistent with the concept that highly efficient solvents for SO2 absorption should not only be solvable but also regenerable. PMID:26446782

  2. Versatile structure-directing roles of deep-eutectic solvents and their implication in the generation of porosity and open metal sites for gas storage.

    PubMed

    Zhang, Jian; Wu, Tao; Chen, Shumei; Feng, Pingyun; Bu, Xianhui

    2009-01-01

    Trap it in and burn it out: A deep-eutectic solvent provides a versatile medium for the creation of highly stable porous frameworks encapsulating neutral coordinating ligand molecules, which can escape intact from the pores upon heating to form crystals directly, leaving behind permanent porosity and coordinatively unsaturated metal sites with potential applications in gas storage and catalysis. PMID:19343752

  3. Versatile Structure-directing Roles of Deep Eutectic Solvents and Their Implication in Generation of Porosity and Open Metal Sites for Gas Storage**

    PubMed Central

    Zhang, Jian; Wu, Tao; Chen, Shumei; Feng, Pingyun; Bu, Xianhui

    2009-01-01

    Trap it in and burn it out: the deep eutectic solvent provides a versatile route for the creation of highly stable porous frameworks encapsulating neutral coordinating ligand molecule, which can escape intact from the pore upon heating to directly become crystals, leaving behind permanent porosity and coordinatively unsaturated metal sites with potential applications in gas storage and catalysis. PMID:19343752

  4. Electrochemically shape-controlled synthesis in deep eutectic solvents: triambic icosahedral platinum nanocrystals with high-index facets and their enhanced catalytic activity.

    PubMed

    Wei, Lu; Zhou, Zhi-You; Chen, Sheng-Pei; Xu, Chang-Deng; Su, Dangsheng; Schuster, Manfred Erwin; Sun, Shi-Gang

    2013-12-11

    Pt triambic icosahedral nanocrystals (TIH NCs) enclosed by {771} high-index facets were successfully synthesized electrochemically, for the first time, in ChCl-urea based deep eutectic solvents, and exhibited higher electrocatalytic activity and stability towards ethanol electrooxidation than a commercial Pt black catalyst. PMID:24084858

  5. Synthesis of gold microstructures with surface nanoroughness using a deep eutectic solvent for catalytic and diagnostic applications.

    PubMed

    Oh, Ju-Hwan; Lee, Jae-Seung

    2014-05-01

    We synthesized highly monodisperse gold microparticles (AuMPs) using a deep eutectic solvent (DES) which composed of choline chloride and malonic acid as both a reaction medium and structure-directing agent. These microparticles exhibit distinctive surface nanoroughness and highly defined diameters that can be precisely controlled over a range of a few micrometers under different reductive conditions. The internal and external structures of the particles are thoroughly investigated by electron microscopy, which is further analyzed in association with their optical properties. We also investigate the gold microparticle concentration-dependent catalytic property employing a reductive reaction of 4-nitrophenol to 4-aminopenol as a model system. Importantly, the gold microparticles are densely functionalized with DNA and reversibly assemble with DNA-gold nanoparticle conjugate probes for the colorimetric detection of target DNA sequences, demonstrating that these novel structures can be utilized as platforms that quickly regulate the optical properties of plasmonic nanoparticles for diagnostic applications. PMID:24734628

  6. Fabrication of PbS thin films composed of highly (200)-oriented nano-/micro-rods in deep eutectic solvent

    NASA Astrophysics Data System (ADS)

    Chen, Jun; Zhang, Jianjun; Xu, Huifang; Ouyang, Yan; Zhan, Funan; Li, Qiang

    2015-08-01

    PbS thin films composed of highly (200)-oriented shuttle-like nano-/micro-rods were successfully fabricated on glass substrates by the environment friendly ionothermal method at 140 °C in deep eutectic solvent (DES). The as-prepared products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), ultraviolet-visible (UV-vis) and photoluminescence (PL) spectra, respectively. The possible mechanism of the oriented growth of PbS nano-/micro-rods was discussed. The PbS thin films composed of shuttle-like nano-/micro-rods exhibited a large absorbance property in the wavelength range of 350-1100 nm, and moreover, the PL spectrum had a broad emission band centered at 490 nm. The shuttle-like PbS nano-/micro-rods-based thin films might have potential application in solar cells.

  7. Electrochemical exfoliation of graphite in quaternary ammonium-based deep eutectic solvents: a route for the mass production of graphane.

    PubMed

    Abdelkader, Amr M; Patten, Hollie V; Li, Zheling; Chen, Yiqiang; Kinloch, Ian A

    2015-07-14

    We demonstrate a facile and scalable electrochemical approach to exfoliate graphite, which permits in situ hydrogenation of the resultant graphene via a solvated NR(4+) graphite compound in quaternary ammonium-based deep eutectic solvents. Spectroscopic studies reveal the presence of sp(3) C-H bonds in the hydrogenated graphene. The resulting materials consist of micrometre-sized and predominantly monolayer to few layers thick hydrogenated graphenic flakes. A large band gap (∼4 eV) further establishes the high level of hydrogenation. It is also possible to tune the band gap introduced to the graphene by controlling the level of hydrogenation. The mechanism of the exfoliation and hydrogenation is also discussed. PMID:26074262

  8. Ultrasound and deep eutectic solvent (DES): a novel blend of techniques for rapid and energy efficient synthesis of oxazoles.

    PubMed

    Singh, Balvant S; Lobo, Hyacintha R; Pinjari, Dipak V; Jarag, Krishna J; Pandit, Aniruddha B; Shankarling, Ganapati S

    2013-01-01

    The present work deals with the synthesis of novel oxazole compounds by using effective combination of ultrasound (US) and deep eutectic solvent (DES). The reaction was also conducted by thermal method (NUS) and the comparative studies are provided. It was observed that applying ultrasound not only improved yields and reduced reaction times but also saved more than 85% energy as shown by energy consumption calculations. The advantages of using DES as reaction medium is highlighted from the fact that it is bio-degradable, non-toxic, recyclable and could be easily prepared using inexpensive raw materials. The recyclability for DES was studied wherein it was found that ultrasound has no negative effects on DES even up to four runs. In addition, the present work is the first report on the combinative use of DES and US in organic synthesis. PMID:22784641

  9. Microwave heating synthesis and formation mechanism of chalcopyrite structured CuInS{sub 2} nanorods in deep eutectic solvent

    SciTech Connect

    Zhang, Jianjun Chen, Jun; Li, Qiang

    2015-03-15

    Graphical abstract: Chalcopyrite structured CuInS{sub 2} nanorods were synthesized by an environmentally friendly microwave heating method in deep eutectic solvent. Results show that microwave heating time plays an important role in the formation of CuInS{sub 2} nanostructure phase. The SEM results indicated that the obtained CuInS{sub 2} nanostructures display rod-like morphology with diameters of about 40 nm and lengths of about 400 nm. The UV–vis spectrum results indicated that the CuInS{sub 2} nanorods exhibit strong absorption from the entire visible light region to the near-infrared region beyond 1100 nm. The possible growth mechanism of CuInS{sub 2} nanorods was discussed. - Abstract: Chalcopyrite structured CuInS{sub 2} nanorods were synthesized by an environmentally friendly microwave heating method in deep eutectic solvent. The as-synthesized CuInS{sub 2} nanorods were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The results indicated that the obtained CuInS{sub 2} nanostructures display rod-like morphology with diameters of about 40 nm and lengths of about 400 nm. The influences of microwave heating time on the formation of CuInS{sub 2} phase were discussed. Ultraviolet–visible (UV–vis) and photoluminescence (PL) spectra were utilized to investigate the optical properties of CuInS{sub 2} nanorods. The results showed that the as-synthesized CuInS{sub 2} nanorods exhibit strong absorption from the entire visible light region to the near-infrared region beyond 1100 nm. PL spectrum of the as-synthesized CuInS{sub 2} nanorods displays an emission peak centered at 580 nm under excitation wavelength of 366 nm at room temperature. The possible growth mechanism of CuInS{sub 2} nanorods was discussed.

  10. Electrodeposition of copper composites from deep eutectic solvents based on choline chloride.

    PubMed

    Abbott, Andrew P; El Ttaib, Khalid; Frisch, Gero; McKenzie, Katy J; Ryder, Karl S

    2009-06-01

    Here we describe for the first time the electrolytic deposition of copper and copper composites from a solution of the metal chloride salt in either urea-choline chloride, or ethylene glycol-choline chloride based eutectics. We show that the deposition kinetics and thermodynamics are quite unlike those in aqueous solution under comparable conditions and that the copper ion complexation is also different. The mechanism of copper nucleation is studied using chronoamperometry and it is shown that progressive nucleation leads to a bright nano-structured deposit. In contrast, instantaneous nucleation, at lower concentrations of copper ions, leads to a dull deposit. This work also pioneers the use of the electrochemical quartz crystal microbalance (EQCM) to monitor both current efficiency and the inclusion of inert particulates into the copper coatings. This technique allows the first in situ quantification or particulate inclusion. It was found that the composition of composite material was strongly dependent on the amount of species suspended in solution. It was also shown that the majority of material was dragged onto the surface rather than settling on to it. The distribution of the composite material was found to be even throughout the coating. This technology is important because it facilitates deposition of bright copper coatings without co-ligands such as cyanide. The incorporation of micron-sized particulates into ionic liquids has resulted, in one case, in a decrease in viscosity. This observation is both unusual and surprising; we explain this here in terms of an increase in the free volume of the liquid and local solvent perturbation. PMID:19458829

  11. Evaluation of alcohol-based deep eutectic solvent in extraction and determination of flavonoids with response surface methodology optimization.

    PubMed

    Bi, Wentao; Tian, Minglei; Row, Kyung Ho

    2013-04-12

    Deep eutectic solvents (DESs) are emerging rapidly as a new type of green solvent instead of an ionic liquid (IL), and are typically formed by mixing choline chloride with hydrogen bond donors. Few studies have applied DESs to the extraction and determination of bioactive compounds. Therefore, in the present study, DESs were used to extract flavonoids (myricetin and amentoflavone), which are well known and widely used antioxidants, to extend their applications. A range of alcohol-based DESs with different alcohols to choline chloride (ChCl) mixing ratios were used for extraction using several extraction methods. Other factors, such as temperature, time, water addition and solid/liquid ratio, were examined systematically using a response surface methodology (RSM). A total of 0.031 and 0.518 mg g(-1) of myricetin and amentoflavone were extracted under the optimized conditions: 35 vol% of water in ChCl/1,4-butanediol (1/5) at 70.0 °C for 40.0 min and a solid/liquid ratio of 1/1 (g 10 mL(-1)). Good linearity was obtained from 0.1 × 10(-3) to 0.1 mg mL(-1) (r(2)>0.999). The excellent properties of DESs highlight their potential as promising green solvents for the extraction and determination of a range of bioactive compounds or drugs. PMID:23481471

  12. Extraction of phenolic compounds from extra virgin olive oil by a natural deep eutectic solvent: Data on UV absorption of the extracts.

    PubMed

    Paradiso, Vito Michele; Clemente, Antonia; Summo, Carmine; Pasqualone, Antonella; Caponio, Francesco

    2016-09-01

    This data article refers to the paper "Towards green analysis of virgin olive oil phenolic compounds: extraction by a natural deep eutectic solvent and direct spectrophotometric detection" [1]. A deep eutectic solvent (DES) based on lactic acid and glucose was used as green solvent for phenolic compounds. Eight standard phenolic compounds were solubilized in the DES. Then, a set of extra virgin olive oil (EVOO) samples (n=65) were submitted to liquid-liquid extraction by the DES. The standard solutions and the extracts were analyzed by UV spectrophotometry. This article reports the spectral data of both the standard solutions and the 65 extracts, as well as the total phenolic content of the corresponding oils, assessed by the Folin-Ciocalteu assay. PMID:27504478

  13. Deep eutectic solvents for the self-assembly of gold nanoparticles: a SAXS, UV-Vis, and TEM investigation.

    PubMed

    Raghuwanshi, Vikram Singh; Ochmann, Miguel; Hoell, Armin; Polzer, Frank; Rademann, Klaus

    2014-06-01

    In this work, we report the formation and growth mechanisms of gold nanoparticles (AuNPs) in eco-friendly deep eutectic solvents (DES; choline chloride and urea). AuNPs are synthesized on the DES surface via a low-energy sputter deposition method. Detailed small angle X-ray scattering (SAXS), UV-Vis, and cryogenic transmission electron microscopy (cryo-TEM) investigations show the formation of AuNPs of 5 nm diameter. Data analysis reveals that for a prolonged gold-sputtering time there is no change in the size of the particles. Only the concentration of AuNPs increases linearly in time. More surprisingly, the self-assembly of AuNPs into a first and second shell ordered system is observed directly by in situ SAXS for prolonged gold-sputtering times. The self-assembly mechanism is explained by the templating nature of DES combined with the equilibrium between specific physical interaction forces between the AuNPs. A disulfide-based stabilizer, bis((2-mercaptoethyl)trimethylammonium) disulfide dichloride, was applied to suppress the self-assembly. Moreover, the stabilizer even reverses the self-assembled or agglomerated AuNPs back to stable 5 nm individual particles as directly evidenced by UV-Vis. The template behavior of DES is compared to that of nontemplating solvent castor oil. Our results will also pave the way to understand and control the self-assembly of metallic and bimetallic nanoparticles. PMID:24814886

  14. Lipase-catalyzed (trans)esterification of 5-hydroxy- methylfurfural and separation from HMF esters using deep-eutectic solvents.

    PubMed

    Krystof, Monika; Pérez-Sánchez, María; Domínguez de María, Pablo

    2013-04-01

    5-Hydroxymethylfurfural (HMF) is a valuable biomass-derived building block. Among possible HMF valorization products, a broad range of HMF esters can be synthesized. These HMF esters have found some promising applications, such as monomers, fuels, additives, surfactants, and fungicides, and thus several catalytic approaches for HMF (trans)esterifications have been reported. The intrinsic reactivity of HMF is challenging, forcing the use of mild reaction conditions to avoid by-product formation. This paper explores the lipase-catalyzed (trans)esterification of HMF with different acyl donors (carboxylic acids and methyl- and ethyl esters) mostly in solvent-free conditions. The results demonstrate that lipases may be promising alternatives for the synthesis of HMF esters-with high productivities and reactions at high substrate loadings-provided that robust systems for lipase immobilization are applied to assure an adequate reusability of the enzymes. Once (trans)esterifications have been conducted, the separation of unreacted HMF and HMF esters is performed by using deep-eutectic solvents (DES) as separation agents. DES are able to dissolve hydrogen-bond donors (e.g., HMF), whereas non-hydrogen-bond donors (in this case HMF esters) form a second phase. By using this approach, high ester purities (>99 %) and efficiencies (up to >90 % HMF ester recovery) in separations were obtained by using choline chloride-based DES. PMID:23456887

  15. Application of natural deep eutectic solvents to the extraction of anthocyanins from Catharanthus roseus with high extractability and stability replacing conventional organic solvents.

    PubMed

    Dai, Yuntao; Rozema, Evelien; Verpoorte, Robert; Choi, Young Hae

    2016-02-19

    Natural deep eutectic solvents (NADES) have attracted a great deal of attention in recent times as promising green media. They are generally composed of neutral, acidic or basic compounds that form liquids of high viscosity when mixed in certain molar ratio. Despite their potential, viscosity and acid or basic nature of some ingredients may affect the extraction capacity and stabilizing ability of the target compounds. To investigate these effects, extraction with a series of NADES was employed for the analysis of anthocyanins in flower petals of Catharanthus roseus in combination with HPLC-DAD-based metabolic profiling. Along with the extraction yields of anthocyanins their stability in NADES was also studied. Multivariate data analysis indicates that the lactic acid-glucose (LGH), and 1,2-propanediol-choline chloride (PCH) NADES present a similar extraction power for anthocyanins as conventional organic solvents. Furthermore, among the NADES employed, LGH exhibits an at least three times higher stabilizing capacity for cyanidins than acidified ethanol, which facilitates their extraction and analysis process. Comparing NADES to the conventional organic solvents, in addition to their reduced environmental impact, they proved to provide higher stability for anthocyanins, and therefore have a great potential as possible alternatives to those organic solvents in health related areas such as food, pharmaceuticals and cosmetics. PMID:26822320

  16. Improved solubility of DNA in recyclable and reusable bio-based deep eutectic solvents with long-term structural and chemical stability.

    PubMed

    Mondal, Dibyendu; Sharma, Mukesh; Mukesh, Chandrakant; Gupta, Vishal; Prasad, Kamalesh

    2013-10-25

    The solubility of DNA in bio-based deep eutectic solvents (DESs) consisting of mixtures of choline chloride with levulinic acid, glycerol, ethylene glycol, sorbitol and resorcinol was investigated. The macromolecule was found to be soluble and chemically and structurally stable in DESs consisting of mixtures containing glycerol and ethylene glycol. Furthermore recyclability of the DESs was demonstrated over three consecutive reuses in DNA dissolution. PMID:24022824

  17. The Effect of Temperature on Kinetics and Diffusion Coefficients of Metallocene Derivatives in Polyol-Based Deep Eutectic Solvents.

    PubMed

    Bahadori, Laleh; Chakrabarti, Mohammed Harun; Manan, Ninie Suhana Abdul; Hashim, Mohd Ali; Mjalli, Farouq Sabri; AlNashef, Inas Muen; Brandon, Nigel

    2015-01-01

    The temperature dependence of the density, dynamic viscosity and ionic conductivity of several deep eutectic solvents (DESs) containing ammonium-based salts and hydrogen bond donvnors (polyol type) are investigated. The temperature-dependent electrolyte viscosity as a function of molar conductivity is correlated by means of Walden's rule. The oxidation of ferrocene (Fc/Fc+) and reduction of cobaltocenium (Cc+/Cc) at different temperatures are studied by cyclic voltammetry and potential-step chronoamperometry in DESs. For most DESs, chronoamperometric transients are demonstrated to fit an Arrhenius-type relation to give activation energies for the diffusion of redox couples at different temperatures. The temperature dependence of the measured conductivities of DES1 and DES2 are better correlated with the Vogel-Tamman-Fulcher equation. The kinetics of the Fc/Fc+ and Cc+/Cc electrochemical systems have been investigated over a temperature range from 298 to 338 K. The heterogeneous electron transfer rate constant is then calculated at different temperatures by means of a logarithmic analysis. The glycerol-based DES (DES5) appears suitable for further testing in electrochemical energy storage devices. PMID:26642045

  18. The Effect of Temperature on Kinetics and Diffusion Coefficients of Metallocene Derivatives in Polyol-Based Deep Eutectic Solvents

    PubMed Central

    Bahadori, Laleh; Chakrabarti, Mohammed Harun; Manan, Ninie Suhana Abdul; Hashim, Mohd Ali; Mjalli, Farouq Sabri; AlNashef, Inas Muen; Brandon, Nigel

    2015-01-01

    The temperature dependence of the density, dynamic viscosity and ionic conductivity of several deep eutectic solvents (DESs) containing ammonium-based salts and hydrogen bond donvnors (polyol type) are investigated. The temperature-dependent electrolyte viscosity as a function of molar conductivity is correlated by means of Walden’s rule. The oxidation of ferrocene (Fc/Fc+) and reduction of cobaltocenium (Cc+/Cc) at different temperatures are studied by cyclic voltammetry and potential-step chronoamperometry in DESs. For most DESs, chronoamperometric transients are demonstrated to fit an Arrhenius-type relation to give activation energies for the diffusion of redox couples at different temperatures. The temperature dependence of the measured conductivities of DES1 and DES2 are better correlated with the Vogel-Tamman-Fulcher equation. The kinetics of the Fc/Fc+ and Cc+/Cc electrochemical systems have been investigated over a temperature range from 298 to 338 K. The heterogeneous electron transfer rate constant is then calculated at different temperatures by means of a logarithmic analysis. The glycerol-based DES (DES5) appears suitable for further testing in electrochemical energy storage devices. PMID:26642045

  19. Electro-codeposition of Ni-SiO2 nanocomposite coatings from deep eutectic solvent with improved corrosion resistance

    NASA Astrophysics Data System (ADS)

    Li, Ruiqian; Hou, Yuanyuan; Liang, Jun

    2016-03-01

    Electro-codeposition of nano-sized SiO2 particles into the metal matrix in aqueous solution is generally difficult. In this paper, the nano-sized SiO2 particles were successfully codeposited in the Ni matrix from a choline chloride (ChCl)/ethylene glycol (EG) based deep eutectic solvent (DES) by pulse electro-codeposition. The effects of nano-sized SiO2 particles on electrochemical behaviour of Ni(II) were investigated. The microstructure, composition and corrosion resistance of pure Ni and Ni-SiO2 nanocomposite coatings were explored. Results showed that the SiO2 nanoparticles exhibited excellent dispersion stability in ChCl:2EG DES without any stabilizing additives and the presence of SiO2 nanoparticles have significant effects on the nucleation mechanism of Ni. The maximum content of SiO2 nanoparticles in composite coatings can achieve 4.69 wt.%, which closes to the level of co-deposition micro-sized SiO2 particles from aqueous solution. The Ni-SiO2 nanocomposite coatings exhibit much better corrosion resistance than pure Ni coating, and the corrosion resistance performance increases with increasing SiO2 content in the composite coatings.

  20. In situ fabrication of electrochemically grown mesoporous metallic thin films by anodic dissolution in deep eutectic solvents.

    PubMed

    Renjith, Anu; Roy, Arun; Lakshminarayanan, V

    2014-07-15

    We describe here a simple electrodeposition process of forming thin films of noble metallic nanoparticles such as Au, Ag and Pd in deep eutectic solvents (DES). The method consists of anodic dissolution of the corresponding metal in DES followed by the deposition on the cathodic surface. The anodic dissolution process in DES overcomes the problems associated with copious hydrogen and oxygen evolution on the electrode surface when carried out in aqueous medium. The proposed method utilizes the inherent abilities of DES to act as a reducing medium while simultaneously stabilizing the nanoparticles that are formed. The mesoporous metal films were characterized by SEM, XRD and electrochemical techniques. Potential applications of these substrates in surface enhanced Raman spectroscopy and electrocatalysis have been investigated. A large enhancement of Raman signal of analyte was achieved on the mesoporous silver substrate after removing all the stabilizer molecules from the surface by calcination. The highly porous texture of the electrodeposited film provides superior electro catalytic performance for hydrogen evolution reaction (HER). The mechanisms of HER on the fabricated substrates were studied by Tafel analysis and electrochemical impedance spectroscopy (EIS). PMID:24863793

  1. Molecularly imprinted polymers combination with deep eutectic solvents for solid-phase extraction of caffeic acid from hawthorn.

    PubMed

    Li, Guizhen; Tang, Weiyang; Cao, Weimin; Wang, Qian; Zhu, Tao

    2015-08-01

    Molecularly imprinted polymers (MIPs) with caffeic acid as template and non-imprinted polymers (NIPs) materials were prepared in the same procedure. Field emission scanning electron microscopy (FE-SEM) and adsorption capacity test were used to evaluate characteristic of the new materials. MIPs, NIPs and C18 were used for rapid purification of caffeic acid from hawthorn with solid-phase extraction ( SPE) , and extract yields of caffeic acid with the proposed materials were 3.46 µg/g, 1.01 µg/g and 1.17 µg/g, respectively. To optimize the MIPs-SPE procedures, different kinds of elution solutions were studied. Deep eutectic solvents (DESs) were prepared by choline chloride (ChCl)-glycerol (1/2, n/n) and choline chloride-urea (1/ 2, n/n). Methanol was mixed with the two kinds of DESs (glycerol-based DESs, urea-based DESs) in different ratios (0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, v/v), and they were used to investigated as elution solutions in the above MIPs-SPE procedures. The results showed that MIPs were potential SPE materials, and methanol/ glycerol-based DESs (3 :1, v/v) had the best elution capability with the recovery of 82.32%. PMID:26749853

  2. Mechanical and barrier properties of starch-based films plasticized with two- or three component deep eutectic solvents.

    PubMed

    Zdanowicz, Magdalena; Johansson, Caisa

    2016-10-20

    The aim of this work was to prepare two- and three-components deep eutectic solvents (DES) and investigate their potential as starch plasticizers. Starch/DES films were prepared via casting method. Mechanical properties, water vapor- and oxygen transmission rates were measured; additionally contact angle and moisture sorption were determined and FTIR analysis was applied on the films. Native potato starch and hydroxypropylated and oxidized starch (HOPS) with common plasticizers (e.g. polyols, urea) and DES were studied. Moreover, influence of three methods of DES introduction and concentration of plasticizer on the films properties were compared. HOPS films were prepared by two methods: as non-cured and cured samples. Some of DESs containing citrate anion exhibited crosslinking ability of polysaccharide matrix. Non-cured HOPS/DES films exhibited more favourable mechanical and barrier properties than cured analogue films. Samples prepared with unmodified potato starch had higher mechanical and barrier properties than films made with HOPS. Starch-based films plasticized with novel DESs with parallel crosslinking activity exhibited satisfactory mechanical and barrier properties. PMID:27474548

  3. A new approach of microalgal biomass pretreatment using deep eutectic solvents for enhanced lipid recovery for biodiesel production.

    PubMed

    Lu, Weidong; Alam, Md Asraful; Pan, Ying; Wu, Jingcheng; Wang, Zhongming; Yuan, Zhenhong

    2016-10-01

    The biomass of Chlorella sp. was pretreated with three different aqueous deep eutectic solvents (aDESs), i.e. aqueous choline chloride-oxalic acid (aCh-O), aqueous choline chloride-ethylene glycol (aCh-EG) and aqueous urea-acetamide (aU-A). The effect of aDESs pretreatment of microalgae biomass was evaluated in terms of lipid recovery rate, total carbohydrate content, fatty acid composition, and thermal chemical behavior of biomass. Results indicated that, lipid recovery rate was increased from 52.03% of untreated biomass to 80.90%, 66.92%, and 75.26% of the biomass treated by aCh-O, aCh-EG and aU-A, respectively. However, there were no major changes observed in fatty acid profiles of both untreated and treated biomass, specifically palmitic acid, palmitoleic acid and stearic acid under various pretreatments. Furthermore, characterizations of untreated and treated biomass were carried out using Fourier transform infrared (FTIR), thermogravimetry analysis (TGA) and scanning electron microscope (SEM) to understand the enhanced lipids recovery. PMID:27359060

  4. Use of dilute hydrofluoric acid and deep eutectic solvent systems for back end of line cleaning in integrated circuit fabrication

    NASA Astrophysics Data System (ADS)

    Padmanabhan Ramalekshmi Thanu, Dinesh

    Fabrication of current generation integrated circuits involves the creation of multilevel copper/low-k dielectric structures during the back end of line processing. This is done by plasma etching of low-k dielectric layers to form vias and trenches, and this process typically leaves behind polymer-like post etch residues (PER) containing copper oxides, copper fluorides and fluoro carbons, on underlying copper and sidewalls of low-k dielectrics. Effective removal of PER is crucial for achieving good adhesion and low contact resistance in the interconnect structure, and this is accomplished using wet cleaning and rinsing steps. Currently, the removal of PER is carried out using semi-aqueous fluoride based formulations. To reduce the environmental burden and meet the semiconductor industry's environmental health and safety requirements, there is a desire to completely eliminate solvents in the cleaning formulations and explore the use of organic solvent-free formulations. The main objective of this work is to investigate the selective removal of PER over copper and low-k (Coral and Black DiamondRTM) dielectrics using all-aqueous dilute HF (DHF) solutions and choline chloride (CC) -- urea (U) based deep eutectic solvent (DES) system. Initial investigations were performed on plasma oxidized copper films. Copper oxide and copper fluoride based PER films representative of etch products were prepared by ashing g-line and deep UV photoresist films coated on copper in CF4/O2 plasma. PER removal process was characterized using scanning electron microscopy and X-ray photoelectron spectroscopy and verified using electrochemical impedance spectroscopy measurements. A PER removal rate of ~60 A/min was obtained using a 0.2 vol% HF (pH 2.8). Deaeration of DHF solutions improved the selectivity of PER over Cu mainly due to reduced Cu removal rate. A PER/Cu selectivity of ~20:1 was observed in a 0.05 vol% deaerated HF (pH 3). DES systems containing 2:1 U/CC removed PER at a rate of

  5. Deep eutectic solvent (DES) as a pretreatment for oil palm empty fruit bunch (OPEFB) in production of sugar

    NASA Astrophysics Data System (ADS)

    Nor, Nur Atikah Md; Mustapha, Wan Aida Wan; Hassan, Osman

    2015-09-01

    Oil Palm Empty Fruit Bunch (OPEFB) was pretreated using Deep Eutectic Solvent (DES) at different parameters to enable a highest yield of sugar. DES is a combination of two or more cheap and safe components to form a eutectic mixture through hydrogen bond interaction, which has a melting point lower than that of each component. DES can be used to replace ionic liquids (ILs), which are more expensive and toxic. In this study, OPEFB was pretreated with DES mixture of choline chloride: urea in 1:2 molar ratio. The pretreatment was performed at temperature 110°C and 80°C for 4 hours and 1 hour. Pretreatment A (110°C, 4 hours), B (110°C, 1 hour), C (80°C, 4 hours) and D (80°C, 1 hour). Enzymatic hydrolysis was done by using the combination of two enzymes, namely, Cellic Ctec2 and Cellic Htec2. The treated fiber is tested for crystallinity using XRD and functional group analysis using FTIR, to check the effect of the pretreatment on the fiber and compared it with the untreated fiber. From XRD analysis, DES successfully gave an effect towards degree of crystallinity of cellulose. Pretreatment A (110°C, 4 hours) and B (110°C, 1 hour) successfully reduce the percentage of crystallinity while pretreatment C (80°C, 4 hours) and D (80°C, 1 hour) increased the percentage of crystallinity. From FTIR analysis, DES cannot remove the functional group of lignin and hemicellulose but it is believed that DES can expose the structure of cellulose. Upon enzymatic hydrolysis, DES-treated fiber successfully produced sugar but not significantly when compared with raw. Pretreatment A (110°C, 4 hours), B (110°C, 1 hour), C (80°C, 4 hours) and D (80°C, 1 hour) produced glucose at the amount of 60.47 mg/ml, 66.33 mg/ml, 61.96 mg/ml and 59.12 mg/ml respectively. However, pretreatment C gave the highest xylose (70.01 mg/ml) production compared to other DES pretreatments.

  6. How a protein can remain stable in a solvent with high content of urea: insights from molecular dynamics simulation of Candida antarctica lipase B in urea : choline chloride deep eutectic solvent.

    PubMed

    Monhemi, Hassan; Housaindokht, Mohammad Reza; Moosavi-Movahedi, Ali Akbar; Bozorgmehr, Mohammad Reza

    2014-07-28

    Deep eutectic solvents (DESs) are utilized as green and inexpensive alternatives to classical ionic liquids. It has been known that some of DESs can be used as solvent in the enzymatic reactions to obtain very green chemical processes. DESs are quite poorly understood at the molecular level. Moreover, we do not know much about the enzyme microstructure in such systems. For example, how some hydrolase can remain active and stable in a deep eutectic solvent including 9 M of urea? In this study, the molecular dynamics of DESs as a liquid was simulated at the molecular level. Urea : choline chloride as a well-known eutectic mixture was chosen as a model DES. The behavior of the lipase as a biocatalyst was studied in this system. For comparison, the enzyme structure was also simulated in 8M urea. The thermal stability of the enzyme was also evaluated in DESs, water, and 8M urea. The enzyme showed very good conformational stability in the urea : choline chloride mixture with about 66% urea (9 M) even at high temperatures. The results are in good agreement with recent experimental observations. In contrast, complete enzyme denaturation occurred in 8M urea with only 12% urea in water. It was found that urea molecules denature the enzyme by interrupting the intra-chain hydrogen bonds in a "direct denaturation mechanism". However, in a urea : choline chloride deep eutectic solvent, as a result of hydrogen bonding with choline and chloride ions, urea molecules have a low diffusion coefficient and cannot reach the protein domains. Interestingly, urea, choline, and chloride ions form hydrogen bonds with the surface residues of the enzyme which, instead of lipase denaturation, leads to greater enzyme stability. To the best of our knowledge, this is the first study in which the microstructural properties of a macromolecule are examined in a deep eutectic solvent. PMID:24930496

  7. Electrochemistry and speciation of Au(+) in a deep eutectic solvent: growth and morphology of galvanic immersion coatings.

    PubMed

    Ballantyne, Andrew D; Forrest, Gregory C H; Frisch, Gero; Hartley, Jennifer M; Ryder, Karl S

    2015-11-11

    In this study we compare the electrochemical and structural properties of three gold salts AuCl, AuCN and KAu(CN)2 in a Deep Eutectic Solvent (DES) electrolyte (Ethaline 200) in order to elucidate factors affecting the galvanic deposition of gold coatings on nickel substrates. A chemically reversible diffusion limited response was observed for AuCl, whereas AuCN and KAu(CN)2 showed much more complicated, kinetically limited responses. Galvanic exchange reactions were performed on nickel substrates from DES solutions of the three gold salts; the AuCN gave a bright gold coating, the KAu(CN)2 solution give a visibly thin coating, whilst the coating from AuCl was dull, friable and poorly adhesive. This behaviour was rationalised by the differing speciation for each of these compounds, as evidenced by EXAFS methods. Analysis of EXAFS data shows that AuCl forms the chlorido-complex [AuCl2](-), AuCN forms a mixed [AuCl(CN)](-) species, whereas KAu(CN)2 maintains its [Au(CN)2](-) structure. The more labile Cl(-) enables easier reduction of Au when compared to the tightly bound cyanide species, hence leading to slower kinetics of deposition and differing electrochemical behaviour. We conclude that metal speciation in DESs is a function of the initial metal salt and that this has a strong influence on the mechanism and rate of growth, as well as on the morphology of the metal deposit obtained. In addition, these coatings are also extremely promising from a technological perspective as Electroless Nickel Immersion Gold (ENIG) finishes in the printed circuit board (PCB) industry, where the elimination of acid in gold plating formulation could potentially lead to more reliable coatings. Consequently, these results are both significant and timely. PMID:26523806

  8. Deep eutectic solvents based on N-methylacetamide and a lithium salt as suitable electrolytes for lithium-ion batteries.

    PubMed

    Boisset, Aurélien; Menne, Sebastian; Jacquemin, Johan; Balducci, Andrea; Anouti, Mérièm

    2013-12-14

    In this work, we present a study on the physical and electrochemical properties of three new Deep Eutectic Solvents (DESs) based on N-methylacetamide (MAc) and a lithium salt (LiX, with X = bis[(trifluoromethyl)sulfonyl]imide, TFSI; hexafluorophosphate, PF6; or nitrate, NO3). Based on DSC measurements, it appears that these systems are liquid at room temperature for a lithium salt mole fraction ranging from 0.10 to 0.35. The temperature dependences of the ionic conductivity and the viscosity of these DESs are correctly described by using the Vogel-Tammann-Fulcher (VTF) type fitting equation, due to the strong interactions between Li(+), X(-) and MAc in solution. Furthermore, these electrolytes possess quite large electrochemical stability windows up to 4.7-5 V on Pt, and demonstrate also a passivating behavior toward the aluminum collector at room temperature. Based on these interesting electrochemical properties, these selected DESs can be classified as potential and promising electrolytes for lithium-ion batteries (LIBs). For this purpose, a test cell was then constructed and tested at 25 °C, 60 °C and 80 °C by using each selected DES as an electrolyte and LiFePO4 (LFP) material as a cathode. The results show a good compatibility between each DES and LFP electrode material. A capacity of up to 160 mA h g(-1) with a good efficiency (99%) is observed in the DES based on the LiNO3 salt at 60 °C despite the presence of residual water in the electrolyte. Finally preliminary tests using a LFP/DES/LTO (lithium titanate) full cell at room temperature clearly show that LiTFSI-based DES can be successfully introduced into LIBs. Considering the beneficial properties, especially, the cost of these electrolytes, such introduction could represent an important contribution for the realization of safer and environmentally friendly LIBs. PMID:24153449

  9. Magnetic graphene oxide modified with choline chloride-based deep eutectic solvent for the solid-phase extraction of protein.

    PubMed

    Huang, Yanhua; Wang, Yuzhi; Pan, Qi; Wang, Ying; Ding, Xueqin; Xu, Kaijia; Li, Na; Wen, Qian

    2015-06-01

    Four kinds of green deep eutectic solvents (DESs) based on choline chloride (ChCl) have been synthesized and coated on the surface of magnetic graphene oxide (Fe3O4@GO) to form Fe3O4@GO-DES for the magnetic solid-phase extraction of protein. X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA) were employed to characterize Fe3O4@GO-DES, and the results indicated the successful preparation of Fe3O4@GO-DES. The UV-vis spectrophotometer was used to measure the concentration of protein after extraction. Single factor experiments proved that the extraction amount was influenced by the types of DESs, solution temperature, solution ionic strength, extraction time, protein concentration and the amount of Fe3O4@GO-DES. Comparison of Fe3O4@GO and Fe3O4@GO-DES was carried out by extracting bovine serum albumin, ovalbumin, bovine hemoglobin and lysozyme. The experimental results showed that the proposed Fe3O4@GO-DES performs better than Fe3O4@GO in the extraction of acidic protein. Desorption of protein was carried out by eluting the solid extractant with 0.005 mol L(-1) Na2HPO4 contained 1 mol L(-1) NaCl. The obtained elution efficiency was about 90.9%. Attributed to the convenient magnetic separation, the solid extractant could be easily recycled. PMID:26002214

  10. Molecular and ionic diffusion in aqueous - deep eutectic solvent mixtures: probing inter-molecular interactions using PFG NMR.

    PubMed

    D'Agostino, Carmine; Gladden, Lynn F; Mantle, Mick D; Abbott, Andrew P; Ahmed, Essa I; Al-Murshedi, Azhar Y M; Harris, Robert C

    2015-06-21

    Pulsed field gradient (PFG) NMR has been used to probe self-diffusion of molecular and ionic species in aqueous mixtures of choline chloride (ChCl) based deep eutectic solvents (DESs), in order to elucidate the effect of water on motion and inter-molecular interactions between the different species in the mixtures, namely the Ch(+) cation and hydrogen bond donor (HBD). The results reveal an interesting and complex behaviour of such mixtures at a molecular level. In general, it is observed that the hydroxyl protons ((1)H) of Ch(+) and the hydrogen bond donor have diffusion coefficients significantly different from those measured for their parent molecules when water is added. This indicates a clear and significant change in inter-molecular interactions. In aqueous Ethaline, the hydroxyl species of Ch(+) and HBD show a stronger interaction with water as water is added to the system. In the case of Glyceline, water has little effect on both hydroxyl proton diffusion of Ch(+) and HBD. In Reline, it is likely that water allows the formation of small amounts of ammonium hydroxide. The most surprising observation is from the self-diffusion of water, which is considerably higher that expected from a homogeneous liquid. This leads to the conclusion that Reline and Glyceline form mixtures that are inhomogeneous at a microscopic level despite the hydrophilicity of the salt and HBD. This work shows that PFG NMR is a powerful tool to elucidate both molecular dynamics and inter-molecular interactions in complex liquid mixtures, such as the aqueous DES mixtures. PMID:25994171

  11. Ionic liquid and deep eutectic solvent-activated CelA2 variants generated by directed evolution.

    PubMed

    Lehmann, Christian; Bocola, Marco; Streit, Wolfgang R; Martinez, Ronny; Schwaneberg, Ulrich

    2014-06-01

    Chemoenzymatic cellulose degradation is one of the key steps for the production of biomass-based fuels under mild conditions. An effective cellulose degradation process requires diverse physico-chemical dissolution of the biomass prior to enzymatic degradation. In recent years, "green" solvents, such as ionic liquids and, more recently, deep eutectic liquids, have been proposed as suitable alternatives for biomass dissolution by homogenous catalysis. In this manuscript, a directed evolution campaign of an ionic liquid tolerant β-1,4-endoglucanase (CelA2) was performed in order to increase its performance in the presence of choline chloride/glycerol (ChCl:Gly) or 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), as a first step to identify residues which govern ionic strength resistance and obtaining insights for employing cellulases on the long run in homogenous catalysis of lignocellulose degradation. After mutant library screening, variant M4 (His288Phe, Ser300Arg) was identified, showing a dramatically reduced activity in potassium phosphate buffer and an increased activity in the presence of ChCl:Gly or [BMIM]Cl. Further characterization showed that the CelA2 variant M4 is activated in the presence of these solvents, representing a first report of an engineered enzyme with an ionic strength activity switch. Structural analysis revealed that Arg300 could be a key residue for the ionic strength activation through a salt bridge with the neighboring Asp287. Experimental and computational results suggest that the salt bridge Asp287-Arg300 generates a nearly inactive CelA2 variant and activity is regained when ChCl:Gly or [BMIM]Cl are supplemented (~5-fold increase from 0.64 to 3.37 μM 4-MU/h with the addition ChCl:Gly and ~23-fold increase from 3.84 to 89.21 μM 4-pNP/h with the addition of [BMIM]Cl). Molecular dynamic simulations further suggest that the salt bridge between Asp287 and Arg300 in variant M4 (His288Phe, Ser300Arg) modulates the observed salt

  12. Dynamic Solvent Control of a Reaction in Ionic Deep Eutectic Solvents: Time-Resolved Fluorescence Measurements of Reactive and Nonreactive Dynamics in (Choline Chloride + Urea) Melts.

    PubMed

    Das, Anuradha; Biswas, Ranjit

    2015-08-01

    Dynamic fluorescence anisotropy and Stokes shift measurements of [f choline chloride + (1 - f) urea)] deep eutectic solvents at f = 0.33 and 0.40 have been carried out using a dipolar solute, coumarin 153 (C153), in the temperature range 298 ≤ T ≤ 333 K. Subsequently, measured time-dependent solvent response is utilized to investigate the dynamic solvent control on the measured rates of photoexcited intramolecular charge transfer (ICT) reactions of two molecules, 4-(1-azetidinyl)benzonitrile (P4C) and 4-(1-pyrrolidinyl)benzonitrile (P5C), occurring in these media. Measured average reaction time scales (⟨τ(rxn)⟩) exhibit the following dependence on average solvation times scales (⟨τ(s)⟩): ⟨τ(rxn)⟩ ∝ ⟨τ(s)⟩(α) with α = 0.5 and 0.35 for P4C and P5C, respectively. Such a strong dynamic solvent control of ⟨τ(rxn)⟩, particularly for P4C, is different from earlier observations with these ICT molecules in conventional molecular solvents. Excitation wavelength-dependent fluorescence emissions of C153 and trans-2-[4-(dimethylamino)styryl]-benzothiazole (DMASBT), which differ widely in average fluorescence lifetimes (⟨τ(life)⟩), suggest the presence of substantial spatial heterogeneity in these systems. Dynamic heterogeneity is reflected via the following fractional viscosity (η) dependences of ⟨τ(s)⟩ and ⟨τ(r)⟩ (⟨τ(r)⟩ being solute's average rotation time): ⟨τx⟩ ∝ (η/T)(p) with 0.7 ≤ p ≤ 0.9. Different correlations between ⟨τ(s)⟩ and ⟨τ(r)⟩ emerge at different temperature regimes, indicating variable frictional coupling at low and high temperatures. Estimated dynamic Stokes shifts in these media vary between ∼1200 and ∼1600 cm(-1), more than 50% of which possess a time scale much faster than the temporal resolution (∼75 ps) employed in these measurements. Estimated activation energy for η is closer to that for ⟨τ(r)⟩ than that for ⟨τ(s)⟩, suggesting ⟨τ(s)⟩ being more decoupled

  13. Morphology-controlled preparation of lead powders by electrodeposition from different PbO-containing choline chloride-urea deep eutectic solvent

    NASA Astrophysics Data System (ADS)

    Ru, Juanjian; Hua, Yixin; Xu, Cunying; Li, Jian; Li, Yan; Wang, Ding; Qi, Cancan; Jie, Yafei

    2015-04-01

    Lead powders with different morphologies, including corals, rods, wires, needles, ferns and dendritic forms, are prepared by electrodeposition onto a stainless steel substrate from different PbO-containing (10-60 mM) choline chloride-urea deep eutectic solvent at cell voltage 2.5 V and 343 K for 2 h. The electrochemical behavior of the PbO dissolved in this solvent is investigated with cyclic voltammetry. It is demonstrated that the increasing of PbO concentration makes the reduction potential EPb(II)/Pb shift positively and facilitates the electrodeposition of lead from PbO in the deep eutectic solvent. According to the analysis of the morphological and crystallographic characteristics of lead powders, the predominant origin of the growth layers is turned away from centre type towards the edge and corner types with the increase in PbO concentration. Due to the large number of growth centres at higher PbO concentration, fine and irregular grains are observed on the surface of formed particles which results in the development of primary and secondary branches in dendrites.

  14. Preparation of a nitro-substituted tris(indolyl)methane modified silica in deep eutectic solvents for solid-phase extraction of organic acids.

    PubMed

    Wang, Na; Wang, Jiamin; Liao, Yuan; Shao, Shijun

    2016-05-01

    A new sorbent for solid-phase extraction was synthesized by chemical immobilization of nitro-substituted tris(indolyl)methane on silica in new and green deep eutectic solvents. Elemental analysis results indicated that deep eutectic solvents could be an alternative to the traditional solvents in preparing nitro-substituted tris(indolyl)methane modified silica. Coupled with high performance liquid chromatography, the extraction performance of the sorbent was evaluated by using four organic acids as model analytes. The rebinding experiments results showed that the nitro-substituted tris(indolyl)methane modified silica sorbent had a good adsorption capacity towards the selected organic acids. Under the appropriate experimental conditions, good precision and wide linear ranges with coefficient of determination (R(2)) of higher than 0.9957 were obtained, and the limits of detection were in the range of 0.50-2.0μgL(-1) for the organic acids tested. The developed solid-phase extraction-high performance liquid chromatography-diode array detection (SPE-HPLC-DAD) method was successfully applied for the determination of organic acids in two drinking samples with recoveries ranging from 76.7% to 110.0% and 67.7% to 104.0% for all the selected organic acids, respectively. PMID:26946003

  15. Preparation of porous lead from shape-controlled PbO bulk by in situ electrochemical reduction in ChCl-EG deep eutectic solvent

    NASA Astrophysics Data System (ADS)

    Ru, Juanjian; Hua, Yixin; Xu, Cunying; Li, Jian; Li, Yan; Wang, Ding; Zhou, Zhongren; Gong, Kai

    2015-12-01

    Porous lead with different shapes was firstly prepared from controlled geometries of solid PbO bulk by in situ electrochemical reduction in choline chloride-ethylene glycol deep eutectic solvents at cell voltage 2.5 V and 353 K. The electrochemical behavior of PbO powders on cavity microelectrode was investigated by cyclic voltammetry. It is indicated that solid PbO can be directly reduced to metal in the solvent and a nucleation loop is apparent. Constant voltage electrolysis demonstrates that PbO pellet can be completely converted to metal for 13 h, and the current efficiency and specific energy consumption are about 87.79% and 736.82 kWh t-1, respectively. With the electro-deoxidation progress on the pellet surface, the reduction rate reaches the fastest and decreases along the distance from surface to inner center. The morphologies of metallic products are porous and mainly consisted of uniform particles which connect with each other by finer strip-shaped grains to remain the geometry and macro size constant perfectly. In addition, an empirical model of the electro-deoxidation process from spherical PbO bulk to porous lead is also proposed. These findings provide a novel and simple route for the preparation of porous metals from oxide precursors in deep eutectic solvents at room temperature.

  16. Density relaxation and particle motion characteristics in a non-ionic deep eutectic solvent (acetamide + urea): Time-resolved fluorescence measurements and all-atom molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Das, Anuradha; Das, Suman; Biswas, Ranjit

    2015-01-01

    Temperature dependent relaxation dynamics, particle motion characteristics, and heterogeneity aspects of deep eutectic solvents (DESs) made of acetamide (CH3CONH2) and urea (NH2CONH2) have been investigated by employing time-resolved fluorescence measurements and all-atom molecular dynamics simulations. Three different compositions (f) for the mixture [fCH3CONH2 + (1 - f)NH2CONH2] have been studied in a temperature range of 328-353 K which is ˜120-145 K above the measured glass transition temperatures (˜207 K) of these DESs but much lower than the individual melting temperature of either of the constituents. Steady state fluorescence emission measurements using probe solutes with sharply different lifetimes do not indicate any dependence on excitation wavelength in these metastable molten systems. Time-resolved fluorescence anisotropy measurements reveal near-hydrodynamic coupling between medium viscosity and rotation of a dissolved dipolar solute. Stokes shift dynamics have been found to be too fast to be detected by the time-resolution (˜70 ps) employed, suggesting extremely rapid medium polarization relaxation. All-atom simulations reveal Gaussian distribution for particle displacements and van Hove correlations, and significant overlap between non-Gaussian (α2) and new non-Gaussian (γ) heterogeneity parameters. In addition, no stretched exponential relaxations have been detected in the simulated wavenumber dependent acetamide dynamic structure factors. All these results are in sharp contrast to earlier observations for ionic deep eutectics with acetamide [Guchhait et al., J. Chem. Phys. 140, 104514 (2014)] and suggest a fundamental difference in interaction and dynamics between ionic and non-ionic deep eutectic solvent systems.

  17. Density relaxation and particle motion characteristics in a non-ionic deep eutectic solvent (acetamide + urea): time-resolved fluorescence measurements and all-atom molecular dynamics simulations.

    PubMed

    Das, Anuradha; Das, Suman; Biswas, Ranjit

    2015-01-21

    Temperature dependent relaxation dynamics, particle motion characteristics, and heterogeneity aspects of deep eutectic solvents (DESs) made of acetamide (CH3CONH2) and urea (NH2CONH2) have been investigated by employing time-resolved fluorescence measurements and all-atom molecular dynamics simulations. Three different compositions (f) for the mixture [fCH3CONH2 + (1 - f)NH2CONH2] have been studied in a temperature range of 328-353 K which is ∼120-145 K above the measured glass transition temperatures (∼207 K) of these DESs but much lower than the individual melting temperature of either of the constituents. Steady state fluorescence emission measurements using probe solutes with sharply different lifetimes do not indicate any dependence on excitation wavelength in these metastable molten systems. Time-resolved fluorescence anisotropy measurements reveal near-hydrodynamic coupling between medium viscosity and rotation of a dissolved dipolar solute. Stokes shift dynamics have been found to be too fast to be detected by the time-resolution (∼70 ps) employed, suggesting extremely rapid medium polarization relaxation. All-atom simulations reveal Gaussian distribution for particle displacements and van Hove correlations, and significant overlap between non-Gaussian (α2) and new non-Gaussian (γ) heterogeneity parameters. In addition, no stretched exponential relaxations have been detected in the simulated wavenumber dependent acetamide dynamic structure factors. All these results are in sharp contrast to earlier observations for ionic deep eutectics with acetamide [Guchhait et al., J. Chem. Phys. 140, 104514 (2014)] and suggest a fundamental difference in interaction and dynamics between ionic and non-ionic deep eutectic solvent systems. PMID:25612718

  18. Density relaxation and particle motion characteristics in a non-ionic deep eutectic solvent (acetamide + urea): Time-resolved fluorescence measurements and all-atom molecular dynamics simulations

    SciTech Connect

    Das, Anuradha; Das, Suman; Biswas, Ranjit

    2015-01-21

    Temperature dependent relaxation dynamics, particle motion characteristics, and heterogeneity aspects of deep eutectic solvents (DESs) made of acetamide (CH{sub 3}CONH{sub 2}) and urea (NH{sub 2}CONH{sub 2}) have been investigated by employing time-resolved fluorescence measurements and all-atom molecular dynamics simulations. Three different compositions (f) for the mixture [fCH{sub 3}CONH{sub 2} + (1 − f)NH{sub 2}CONH{sub 2}] have been studied in a temperature range of 328-353 K which is ∼120-145 K above the measured glass transition temperatures (∼207 K) of these DESs but much lower than the individual melting temperature of either of the constituents. Steady state fluorescence emission measurements using probe solutes with sharply different lifetimes do not indicate any dependence on excitation wavelength in these metastable molten systems. Time-resolved fluorescence anisotropy measurements reveal near-hydrodynamic coupling between medium viscosity and rotation of a dissolved dipolar solute. Stokes shift dynamics have been found to be too fast to be detected by the time-resolution (∼70 ps) employed, suggesting extremely rapid medium polarization relaxation. All-atom simulations reveal Gaussian distribution for particle displacements and van Hove correlations, and significant overlap between non-Gaussian (α{sub 2}) and new non-Gaussian (γ) heterogeneity parameters. In addition, no stretched exponential relaxations have been detected in the simulated wavenumber dependent acetamide dynamic structure factors. All these results are in sharp contrast to earlier observations for ionic deep eutectics with acetamide [Guchhait et al., J. Chem. Phys. 140, 104514 (2014)] and suggest a fundamental difference in interaction and dynamics between ionic and non-ionic deep eutectic solvent systems.

  19. Choline and Geranate Deep Eutectic Solvent as a Broad-Spectrum Antiseptic Agent for Preventive and Therapeutic Applications.

    PubMed

    Zakrewsky, Michael; Banerjee, Amrita; Apte, Sanjana; Kern, Theresa L; Jones, Mattie R; Sesto, Rico E Del; Koppisch, Andrew T; Fox, David T; Mitragotri, Samir

    2016-06-01

    Antiseptic agents are the primary arsenal to disinfect skin and prevent pathogens spreading within the host as well as into the surroundings; however the Food and Drug Administration published a report in 2015 requiring additional validation of nearly all current antiseptic agents before their continued use can be allowed. This vulnerable position calls for urgent identification of novel antiseptic agents. Recently, the ability of a deep eutectic, Choline And Geranate (CAGE), to treat biofilms of Pseudomonas aeruginosa and Salmonella enterica was demonstrated. Here it is reported that CAGE exhibits broad-spectrum antimicrobial activity against a number of drug-resistant bacteria, fungi, and viruses including clinical isolates of Mycobacterium tuberculosis, Staphylococcus aureus, and Candida albicans as well as laboratory strains of Herpes Simplex Virus. Studies in human keratinocytes and mice show that CAGE affords negligible local or systemic toxicity, and an ≈180-14 000-fold improved efficacy/toxicity ratio over currently used antiseptic agents. Further, CAGE penetrates deep into the dermis and treats pathogens located in deep skin layers as confirmed by the ability of CAGE in vivo to treat Propionibacterium acnes infection. In combination, the results clearly demonstrate CAGE holds promise as a transformative platform antiseptic agent for preventive as well as therapeutic applications. PMID:26959835

  20. A detailed study of cholinium chloride and levulinic acid deep eutectic solvent system for CO2 capture via experimental and molecular simulation approaches.

    PubMed

    Ullah, Ruh; Atilhan, Mert; Anaya, Baraa; Khraisheh, Majeda; García, Gregorio; ElKhattat, Ahmed; Tariq, Mohammad; Aparicio, Santiago

    2015-08-28

    Choline chloride + levulinic acid deep eutectic solvent is studied as a suitable material for CO2 capturing purposes. The most relevant physicochemical properties of this solvent are reported together with the CO2 solubility as a function of temperature. The corrosivity of this solvent is studied showing better performance than amine-based solvents. A theoretical study using both density functional theory and molecular dynamics approaches is carried out to analyze the properties of this fluid from the nanoscopic viewpoint, and their relationship with the macroscopic behavior of the system and its ability for CO2 capturing. The behavior of the liquid-gas interface is also studied and its role on the CO2 absorption mechanism is analyzed. The reported combined experimental and theoretical approach leads to a complete picture of the behavior of this new sorbent with regard to CO2, which together with its low cost, and the suitable environmental and toxicological properties of this solvent, lead to a promising candidate for CO2 capturing technological applications. PMID:26214080

  1. Separation of the isomers of benzene poly(carboxylic acid)s by quaternary ammonium salt via formation of deep eutectic solvents.

    PubMed

    Hou, Yucui; Li, Jian; Ren, Shuhang; Niu, Muge; Wu, Weize

    2014-11-26

    Because of similar properties and very low volatility, isomers of benzene poly(carboxylic acid)s (BPCAs) are very difficult to separate. In this work, we found that isomers of BPCAs could be separated efficiently by quaternary ammonium salts (QASs) via formation of deep eutectic solvents (DESs). Three kinds of QASs were used to separate the isomers of BPCAs, including the isomers of benzene tricarboxylic acids (trimellitic acid, trimesic acid, and hemimellitic acid) and the isomers of benzene dicarboxylic acids (phthalic acid and isophthalic acid). Among the QASs, tetraethylammonium chloride was found to have the best performance, which could completely separate BPCA isomers in methyl ethyl ketone solutions. It was found that the hydrogen bond forming between QAS and BPCA results in the selective separation of BPCA isomers. QAS in DES was regenerated effectively by the antisolvent method, and the regenerated QAS was reused four times with the same high efficiency. PMID:25351281

  2. One-step synthesis of hematite nanospindles from choline chloride/urea deep eutectic solvent with highly powerful storage versus lithium

    NASA Astrophysics Data System (ADS)

    Xiong, Q. Q.; Tu, J. P.; Ge, X.; Wang, X. L.; Gu, C. D.

    2015-01-01

    Fe2O3 nanospindles assembled with nanoparticles as primary building blocks are directly synthesized by a versatile ionothermal strategy in the choline chloride/urea mixture-based deep eutectic solvent system. The proposed ionothermal protocol is attractive and environmental friendly because choline chloride and urea are both naturally biocompatible compounds. As an anode material for lithium-ion batteries, the resultant Fe2O3 nanospindles show high capacity and good cycle stability (921.7 mAh g-1 at a current density of 200 mA g-1 up to 50 cycles), as well as the excellent rate capability. The good electrochemical performance can be attributed to the nanospindle structure with high sufficient interfacial contact area between the active material and electrolyte, the short diffusion distance of Li ions. The environmentally benign strategy proposed in this study is expected to offer an attractive technique for the ionothermal synthesis of electrochemical energy storage materials.

  3. Introducing deep eutectic solvents to polar organometallic chemistry: chemoselective addition of organolithium and Grignard reagents to ketones in air.

    PubMed

    Vidal, Cristian; García-Álvarez, Joaquín; Hernán-Gómez, Alberto; Kennedy, Alan R; Hevia, Eva

    2014-06-01

    Despite their enormous synthetic relevance, the use of polar organolithium and Grignard reagents is greatly limited by their requirements of low temperatures in order to control their reactivity as well as the need of dry organic solvents and inert atmosphere protocols to avoid their fast decomposition. Breaking new ground on the applications of these commodity organometallics in synthesis under more environmentally friendly conditions, this work introduces deep eutetic solvents (DESs) as a green alternative media to carry out chemoselective additions of ketones in air at room temperature. Comparing their reactivities in DES with those observed in pure water suggest that a kinetic activation of the alkylating reagents is taking place, favoring nucleophilic addition over the competitive hydrolysis, which can be rationalized through formation of halide-rich magnesiate or lithiate species. PMID:24771680

  4. Electrochemical synthesis of copper nanoparticles using cuprous oxide as a precursor in choline chloride-urea deep eutectic solvent: nucleation and growth mechanism.

    PubMed

    Zhang, Q B; Hua, Y X

    2014-12-28

    The electrochemical nucleation and growth kinetics of copper nanoparticles on a Ni electrode have been studied with cyclic voltammetry and chronoamperometry in the choline chloride (ChCl)-urea based deep eutectic solvent (DES). The copper source was introduced into the solvent by the dissolution of Cu(I) oxide (Cu2O). Cyclic voltammetry indicates that the electroreduction of Cu(I) species in the DES is a diffusion-controlled quasi-reversible process. The analysis of the chronoamperometric transient behavior during electrodeposition suggests that the deposition of copper on the Ni electrode at low temperatures follows a progressive nucleation and three-dimensional growth controlled by diffusion. The effect of temperature on the diffusion coefficient of Cu(I) species that is present in the solvent and electron transfer rate constant obeys the Arrhenius law, according to which the activation energies are estimated to be 49.20 and 21.72 kJ mol(-1), respectively. The initial stage of morphological study demonstrates that both electrode potential and temperature play important roles in controlling the nucleation and growth kinetics of the nanocrystals during the electrodeposition process. Electrode potential is observed to affect mainly the nucleation process, whereas temperature makes a major contribution to the growth process. PMID:25387166

  5. Part I: Virtual laboratory versus traditional laboratory: Which is more effective for teaching electrochemistry? Part II: The green synthesis of aurones using a deep eutectic solvent

    NASA Astrophysics Data System (ADS)

    Hawkins, Ian C.

    The role of the teaching laboratory in science education has been debated over the last century. The goals and purposes of the laboratory are still debated and while most science educators consider laboratory a vital part of the education process, they differ widely on the purposes for laboratory and what methods should be used to teach laboratory. One method of instruction, virtual labs, has become popular among some as a possible way of capitalizing on the benefits of lab in a less costly and more time flexible format. The research regarding the use of virtual labs is limited and the few studies that have been done on General Chemistry labs do not use the virtual labs as a substitute for hands-on experiences, but rather as a supplement to a traditional laboratory program. This research seeks to determine the possible viability of a virtual simulation to replace a traditional hands-on electrochemistry lab in the General Chemistry II course sequence. The data indicate that for both content knowledge and the development of hands-on skills the virtual lab showed no significant difference in overall scores on the assessments, but that an individual item related to the physical set-up of a battery showed better scores for the hands-on labs over the virtual labs. Further research should be done to determine if these results are similar in other settings with the use of different virtual labs and how the virtual labs compare to other laboratories using different learning styles and learning goals. One often cited purpose of laboratory experiences in the context of preparing chemists is to simulate the experiences common in chemical research so graduate experience in a research laboratory was a necessary part of my education in the field of laboratory instruction. This research experience provided me the opportunity, to complete an organic synthesis of aurones using a deep eutectic solvent. These solvents show unique properties that make them a viable alternative to ionic

  6. Ultrasound assisted-deep eutectic solvent based on emulsification liquid phase microextraction combined with microsample injection flame atomic absorption spectrometry for valence speciation of chromium(III/VI) in environmental samples.

    PubMed

    Yilmaz, Erkan; Soylak, Mustafa

    2016-11-01

    A new type of deep eutectic solvents (DESs) have been prepared and used as extraction solvents for ultrasound assisted-deep eutectic solvent based emulsification liquid phase microextraction method (UA-DES-ELPME) for the determination and speciation of total chromium, chromium(III) and chromium(VI). The chromium concentration in DES rich phase (extraction phase) was determined by using microsample injection flame atomic absorption spectrometer (FAAS). The detection limit (LOD), the quantification limit (LOQ), preconcentration factor and relative standard deviation were found as 5.5µgL(-1), 18.2µgL(-1), 20 and 6%, respectively. The accuracy of the developed method was evaluated by the analysis of water the certified reference materials (TMDA-53.3 Fortified environmental water and TMDA-54.4 Fortified Lake Water) and addition-recovery tests for water samples. PMID:27591663

  7. Unexpected lateral-lithiation-induced alkylative ring opening of tetrahydrofurans in deep eutectic solvents: synthesis of functionalised primary alcohols.

    PubMed

    Sassone, Francesca C; Perna, Filippo M; Salomone, Antonio; Florio, Saverio; Capriati, Vito

    2015-06-11

    o-Tolyl-substituted tetrahydrofurans undergo highly regioselective ring opening with the concomitant formation of new C-C bonds as the result of a lateral lithiation reaction. This reaction provides a new method for the synthesis of functionalised primary alcohols and can be run directly in protic eutectic mixtures as benign reaction media at 0 °C and under air, competitively with protonolysis. PMID:25959580

  8. Ionothermal synthesis of two oxalate-bridged lanthanide(III) chains with slow magnetization relaxation by using a deep eutectic solvent.

    PubMed

    Meng, Yan; Liu, Jun-Liang; Zhang, Ze-Min; Lin, Wei-Quan; Lin, Zhuo-Jia; Tong, Ming-Liang

    2013-09-28

    Two novel isostructural oxalate-bridged lanthanide(III) chains, (choline)[Ln(ox)(H2O)3Cl]Cl·H2O (Ln = Dy/Er), were first obtained ionothermally by using a choline chloride-oxalic acid eutectic mixture as both solvent and structure-directing agent, both of which show field-induced slow relaxation of magnetization. PMID:23903323

  9. Glass transition dynamics and conductivity scaling in ionic deep eutectic solvents: The case of (acetamide + lithium nitrate/sodium thiocyanate) melts

    NASA Astrophysics Data System (ADS)

    Tripathy, Satya N.; Wojnarowska, Zaneta; Knapik, Justyna; Shirota, Hideaki; Biswas, Ranjit; Paluch, Marian

    2015-05-01

    A detailed investigation on the molecular dynamics of ionic deep eutectic solvents (acetamide + lithium nitrate/sodium thiocyanate) is reported. The study was carried out employing dielectric relaxation spectroscopy covering seven decades in frequency (10-1-106 Hz) and in a wide temperature range from 373 K down to 173 K, accessing the dynamic observables both in liquid and glassy state. The dielectric response of the ionic system has been presented in the dynamic window of modulus formalism to understand the conductivity relaxation and its possible connection to the origin of localized motion. Two secondary relaxation processes appear below glass transition temperature. Our findings provide suitable interpretation on the nature of secondary Johari-Goldstein process describing the ion translation and orientation of dipoles in a combined approach using Ngai's coupling model. A nearly constant loss feature is witnessed at shorter times/lower temperatures. We also discuss the ac conductivity scaling behavior using Summerfield approach and random free energy barrier model which establish the time-temperature superposition principle. These experimental observations have fundamental importance on theoretical elucidation of the conductivity relaxation and glass transition phenomena in molten ionic conductors.

  10. Infrared studies of polyacrylonitrile-based polymer electrolytes incorporated with lithium bis(trifluoromethane)sulfonimide and urea as deep eutectic solvent

    NASA Astrophysics Data System (ADS)

    Sim, L. N.; Yahya, R.; Arof, A. K.

    2016-06-01

    In this work, urea is introduced into polyacrylonitrile (PAN)-based polymer electrolyte containing lithium bis(trifluoromethane)sulfonimide (LiTFSI) to form a deep eutectic solvent with urea and LiTFSI in the mole ratio of 1:3. The ambient ionic conductivity of the polymer electrolyte film is enhanced from 2.54 × 10-4 S cm-1 to 3.82 × 10-3 S cm-1 with the addition of urea. Infrared studies has revealed that urea interacts with the LiTFSI through coordination of Li+ ions onto the carbonyl (Cdbnd O) group of urea, and hydrogen bonding possibly to the O atoms in the SO2 groups of TFSI- ions. Hydrogen bonding interactions of urea with DMF and PAN are also evident. The enhancement in conductivity is believed to be due to urea being involved in the dissociation of LiTFSI and its role as an additional ion conduction pathway through its carbonyl group.

  11. Intrinsic optical properties and divergent doping effects of manganese(II) on luminescence for tin(II) phosphite grown from a deep-eutectic solvent.

    PubMed

    Huang, Hui-Lin; Lai, Yei-Chen; Chiang, Yun-Wei; Wang, Sue-Lein

    2012-02-20

    This is the first study on the ionothermal synthesis, intrinsic photoluminescence (PL), and dopant effects for tin(II) phosphite, a stereochemically active 5s(2) lone-pair-electron-containing compound, the fundamental properties of which have rarely been explored before. In a new deep-eutectic solvent, single-phased products of SnHPO(3) (1) and Sn(1-x)Mn(x)HPO(3) (2) have been achieved in high yield. The crystalline powder of 1 is nonenantiomorphic, with an intense second-harmonic generation comparable to that of potassium dihydrogen phosphate. Under UV excitation, it unexpectedly emits white PL, an important intrinsic property never discovered in tin(II) oxysalts. Electron paramagnetic resonance hyperfine splitting characteristic of manganese has been detected on 2 and a three-pulse electron-spin-echo envelope modulation technique implemented to locate its corresponding location in the inorganic host. On the basis of temperature-dependent PL and lifetime measurements, the incorporated Mn(2+) uncommonly acts as a sensitizer in enhancing white emission until extremely low temperatures, in which it would resume its normal role as an activator to give out characteristic orange light. PMID:22288432

  12. Preparation of chlorocholine chloride/urea deep eutectic solvent-modified silica and an examination of the ion exchange properties of modified silica as a Lewis adduct.

    PubMed

    Tang, Baokun; Park, Ha Eun; Row, Kyung Ho

    2014-07-01

    Chlorocholine chloride/urea (ClChCl-urea), a deep eutectic solvent (DES), was applied successfully to the modification of silica. The resulting modified silica was characterized by Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller analysis, and elemental analysis. Based on the ClChCl-urea modification of silica, the ClChCl-urea-modified silica is a Lewis adduct with ion exchange properties, and ferulic acid was adsorbed on the ClChCl-urea-modified silica via an ion exchange process. The adsorbed percentage of ferulic acid increased with the increasing amount of modified silica, and a high adsorbed percentage of 89% could be obtained by the ion exchange process. The Freundlich isotherm used to describe the adsorption of ferulic acid on the modified silica by ion exchange showed a good correlation (R(2) = 0.93). Based on the characterization of the structure and the analysis of the ion exchange property of the ClChCl-urea-modified silica, the modified silica as a potential medium can be applied in some analytical technologies such as solid phase extraction, chromatography, and so on. PMID:24748453

  13. Combination of deep eutectic solvent and ionic liquid to improve biocatalytic reduction of 2-octanone with Acetobacter pasteurianus GIM1.158 cell.

    PubMed

    Xu, Pei; Du, Peng-Xuan; Zong, Min-Hua; Li, Ning; Lou, Wen-Yong

    2016-01-01

    The efficient anti-Prelog asymmetric reduction of 2-octanone with Acetobacter pasteurianus GIM1.158 cells was successfully performed in a biphasic system consisting of deep eutectic solvent (DES) and water-immiscible ionic liquid (IL). Various DESs exerted different effects on the synthesis of (R)-2-octanol. Choline chloride/ethylene glycol (ChCl/EG) exhibited good biocompatibility and could moderately increase the cell membrane permeability thus leading to the better results. Adding ChCl/EG increased the optimal substrate concentration from 40 mM to 60 mM and the product e.e. kept above 99.9%. To further improve the reaction efficiency, water-immiscible ILs were introduced to the reaction system and an enhanced substrate concentration (1.5 M) was observed with C4MIM·PF6. Additionally, the cells manifested good operational stability in the reaction system. Thus, the efficient biocatalytic process with ChCl/EG and C4MIM·PF6 was promising for efficient synthesis of (R)-2-octanol. PMID:27185089

  14. Preparation of bio-deep eutectic solvent triggered cephalopod shaped silver chloride-DNA hybrid material having antibacterial and bactericidal activity.

    PubMed

    Bhatt, Jitkumar; Mondal, Dibyendu; Bhojani, Gopal; Chatterjee, Shruti; Prasad, Kamalesh

    2015-11-01

    2.5% w/w DNA (Salmon testes) was solubilized in a bio-deep eutectic solvent [(bio-DES), obtained by the complexation of choline chloride and ethylene glycol at 1:2 molar ratio] containing 1% w/w of silver chloride (AgCl) to yield a AgCl decorated DNA based hybrid material. Concentration dependent formation of AgCl crystals in the DES was observed and upon interaction with DNA it gave formation of a cephalopod shaped hybrid material. DNA was found to maintain its chemical and structural stability in the material. Further, AgCl microstructures were found to have orderly self assembled on the DNA helices indicating the electrostatic interaction between Ag(+) and phosphate side chain of DNA as a driving force for the formation of the material with ordered microstructural distribution of AgCl. Furthermore, the functionalized material exhibited excellent antibacterial and bactericidal activity against both Gram negative and Gram positive pathogenic bacteria. PMID:26249573

  15. Glass transition dynamics and conductivity scaling in ionic deep eutectic solvents: The case of (acetamide + lithium nitrate/sodium thiocyanate) melts.

    PubMed

    Tripathy, Satya N; Wojnarowska, Zaneta; Knapik, Justyna; Shirota, Hideaki; Biswas, Ranjit; Paluch, Marian

    2015-05-14

    A detailed investigation on the molecular dynamics of ionic deep eutectic solvents (acetamide + lithium nitrate/sodium thiocyanate) is reported. The study was carried out employing dielectric relaxation spectroscopy covering seven decades in frequency (10(-1)-10(6) Hz) and in a wide temperature range from 373 K down to 173 K, accessing the dynamic observables both in liquid and glassy state. The dielectric response of the ionic system has been presented in the dynamic window of modulus formalism to understand the conductivity relaxation and its possible connection to the origin of localized motion. Two secondary relaxation processes appear below glass transition temperature. Our findings provide suitable interpretation on the nature of secondary Johari-Goldstein process describing the ion translation and orientation of dipoles in a combined approach using Ngai's coupling model. A nearly constant loss feature is witnessed at shorter times/lower temperatures. We also discuss the ac conductivity scaling behavior using Summerfield approach and random free energy barrier model which establish the time-temperature superposition principle. These experimental observations have fundamental importance on theoretical elucidation of the conductivity relaxation and glass transition phenomena in molten ionic conductors. PMID:25978897

  16. Glass transition dynamics and conductivity scaling in ionic deep eutectic solvents: The case of (acetamide + lithium nitrate/sodium thiocyanate) melts

    SciTech Connect

    Tripathy, Satya N. Wojnarowska, Zaneta; Knapik, Justyna; Paluch, Marian; Shirota, Hideaki; Biswas, Ranjit

    2015-05-14

    A detailed investigation on the molecular dynamics of ionic deep eutectic solvents (acetamide + lithium nitrate/sodium thiocyanate) is reported. The study was carried out employing dielectric relaxation spectroscopy covering seven decades in frequency (10{sup −1}-10{sup 6} Hz) and in a wide temperature range from 373 K down to 173 K, accessing the dynamic observables both in liquid and glassy state. The dielectric response of the ionic system has been presented in the dynamic window of modulus formalism to understand the conductivity relaxation and its possible connection to the origin of localized motion. Two secondary relaxation processes appear below glass transition temperature. Our findings provide suitable interpretation on the nature of secondary Johari-Goldstein process describing the ion translation and orientation of dipoles in a combined approach using Ngai’s coupling model. A nearly constant loss feature is witnessed at shorter times/lower temperatures. We also discuss the ac conductivity scaling behavior using Summerfield approach and random free energy barrier model which establish the time-temperature superposition principle. These experimental observations have fundamental importance on theoretical elucidation of the conductivity relaxation and glass transition phenomena in molten ionic conductors.

  17. Combination of deep eutectic solvent and ionic liquid to improve biocatalytic reduction of 2-octanone with Acetobacter pasteurianus GIM1.158 cell

    PubMed Central

    Xu, Pei; Du, Peng-Xuan; Zong, Min-Hua; Li, Ning; Lou, Wen-Yong

    2016-01-01

    The efficient anti-Prelog asymmetric reduction of 2-octanone with Acetobacter pasteurianus GIM1.158 cells was successfully performed in a biphasic system consisting of deep eutectic solvent (DES) and water-immiscible ionic liquid (IL). Various DESs exerted different effects on the synthesis of (R)-2-octanol. Choline chloride/ethylene glycol (ChCl/EG) exhibited good biocompatibility and could moderately increase the cell membrane permeability thus leading to the better results. Adding ChCl/EG increased the optimal substrate concentration from 40 mM to 60 mM and the product e.e. kept above 99.9%. To further improve the reaction efficiency, water-immiscible ILs were introduced to the reaction system and an enhanced substrate concentration (1.5 M) was observed with C4MIM·PF6. Additionally, the cells manifested good operational stability in the reaction system. Thus, the efficient biocatalytic process with ChCl/EG and C4MIM·PF6 was promising for efficient synthesis of (R)-2-octanol. PMID:27185089

  18. Molecular motion and ion diffusion in choline chloride based deep eutectic solvents studied by 1H pulsed field gradient NMR spectroscopy.

    PubMed

    D'Agostino, Carmine; Harris, Robert C; Abbott, Andrew P; Gladden, Lynn F; Mantle, Mick D

    2011-12-28

    Deep Eutectic Solvents (DESs) are a novel class of solvents with potential industrial applications in separation processes, chemical reactions, metal recovery and metal finishing processes such as electrodeposition and electropolishing. Macroscopic physical properties such as viscosity, conductivity, eutectic composition and surface tension are already available for several DESs, but the microscopic transport properties for this class of compounds are not well understood and the literature lacks experimental data that could give a better insight into the understanding of such properties. This paper presents the first pulsed field gradient nuclear magnetic resonance (PFG-NMR) study of DESs. Several choline chloride based DESs were chosen as experimental samples, each of them with a different associated hydrogen bond donor. The molecular equilibrium self-diffusion coefficient of both the choline cation and hydrogen bond donor was probed using a standard stimulated echo PFG-NMR pulse sequence. It is shown that the increasing temperature leads to a weaker interaction between the choline cation and the correspondent hydrogen bond donor. The self-diffusion coefficients of the samples obey an Arrhenius law temperature-dependence, with values of self-diffusivity in the range of [10(-10)-10(-13) m(2) s(-1)]. In addition, the results also highlight that the molecular structure of the hydrogen bond donor can greatly affect the mobility of the whole system. While for ethaline, glyceline and reline the choline cation diffuses slower than the associated hydrogen bond donor, reflecting the trend of molecular size and molecular weight, the opposite behaviour is observed for maline, in which the hydrogen bond donor, i.e. malonic acid, diffuses slower than the choline cation, with self-diffusion coefficients values of the order of 10(-13) m(2) s(-1) at room temperature, which are remarkably low values for a liquid. This is believed to be due to the formation of extensive dimer

  19. Deep eutectic liquid organic salt as a new solvent for liquid-phase microextraction and its application in ligandless extraction and preconcentraion of lead and cadmium in edible oils.

    PubMed

    Karimi, Mehdi; Dadfarnia, Shayessteh; Shabani, Ali Mohammad Haji; Tamaddon, Fatemeh; Azadi, Davood

    2015-11-01

    Deep eutectic liquid organic salt was used as the solvent and a liquid phase microextraction (DES-LPME) combined with electrothermal atomic absorption spectrometry (ETAAS) was developed for separation, preconcentration and determination of lead and cadmium in edible oils. A 4:1 mixture of deep eutectic solvent and 2% nitric acid (200 µL) was added to an oil sample. The mixture was vortexed and transferred into a water bath at 50 °C and stirred for 5 minutes. After the extraction was completed, the phases were separated by centrifugation, and the enriched analytes in the deep eutectic solvent phase were determined by ETAAS. Under optimized extraction conditions and for an oil sample of 28 g, enhancement factors of 198 and 195 and limits of detection (defined as 3 Sb/m) of 8 and 0. 2 ng kg(-1) were achieved for lead and cadmium respectively. The method was successfully applied to the determination of lead and cadmium in various edible oils. PMID:26452873

  20. Controlled electrodeposition of Cu-Ga from a deep eutectic solvent for low cost fabrication of CuGaSe2 thin film solar cells.

    PubMed

    Steichen, Marc; Thomassey, Matthieu; Siebentritt, Susanne; Dale, Phillip J

    2011-03-14

    The electrochemical deposition of Ga and Cu-Ga alloys from the deep eutectic solvent choline chloride/urea (Reline) is investigated to prepare CuGaSe(2) (CGS) semiconductors for their use in thin film solar cells. Ga electrodeposition is difficult from aqueous solution due to its low standard potential and the interfering hydrogen evolution reaction (HER). Ionic liquid electrolytes offer a better thermal stability and larger potential window and thus eliminate the interference of solvent breakdown reactions during Ga deposition. We demonstrate that metallic Ga can be electrodeposited from Reline without HER interference with high plating efficiency on Mo and Cu electrodes. A new low cost synthetic route for the preparation of CuGaSe(2) absorber thin films is presented and involves the one-step electrodeposition of Cu-Ga precursors from Reline followed by thermal annealing. Rotating disk electrode (RDE) cyclic voltammetry (CV) is used in combination with viscosity measurements to determine the diffusion coefficients of gallium and copper ions in Reline. The composition of the codeposited Cu-Ga precursor layers can be controlled to form Cu/Ga thin films with precise stoichiometry, which is important for achieving good optoelectronic properties of the final CuGaSe(2) absorbers. The morphology, the chemical composition and the crystal structure of the deposited thin films are analysed by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) and X-ray diffraction (XRD). Annealing of the Cu-Ga films in a selenium atmosphere allowed the formation of high quality CuGaSe(2) absorber layers. Completed CGS solar cells achieved a 4.1% total area power conversion efficiency. PMID:21249244

  1. Emulsification liquid-liquid microextraction based on deep eutectic solvent: An extraction method for the determination of benzene, toluene, ethylbenzene and seven polycyclic aromatic hydrocarbons from water samples.

    PubMed

    Khezeli, Tahere; Daneshfar, Ali; Sahraei, Reza

    2015-12-18

    In this study, for the first time, a simple, inexpensive and sensitive method named emulsification liquid-liquid microextraction based on deep eutectic solvent (ELLME-DES) was used for the extraction of benzene, toluene, ethylbenzene (BTE) and seven polycyclic aromatic hydrocarbons (PAHs) from water samples. In a typical experiment, 100μL of DES (as water-miscible extraction solvent) was added to 1.5mL of sample solution containing target analytes. A homogeneous solution was formed immediately. Injection of 100μL of THF (as emulsifier agent) into homogeneous solution provided a turbid state. After extraction, phase separation (aqueous phase/DES rich phase) was performed by centrifugation. DES rich phase was withdrawn by a micro-syringe and submitted to isocratic reverse-phase HPLC with UV detection. Under optimum conditions obtained by response surface methodology (RSM) and desirability function (DF), the calibration graphs were linear in the concentration range from 10 to 200μg/L for benzene, 10-400μg/L for toluene, 1-400μg/L for ethylbenzene, biphenyl, chrysene and fluorene, and 0.1-400μg/L for anthracene, benzo[a]pyrene, phenanthrene and pyrene. The coefficients of determination (r(2)) and limits of detection were 0.9924-0.9997 and 0.02-6.8μg/L, respectively. This procedure was successfully applied to the determination of target analytes in spiked water samples. The relative mean recoveries ranged from 93.1 to 103.3%. PMID:26614169

  2. Use of formulations based on choline chloride-malonic acid deep eutectic solvent for back end of line cleaning in integrated circuit fabrication

    NASA Astrophysics Data System (ADS)

    Taubert, Jenny

    Interconnection layers fabricated during back end of line processing in semiconductor manufacturing involve dry etching of a low-k material and deposition of copper and metal barriers to create copper/dielectric stacks. After plasma etching steps used to form the trenches and vias in the dielectric, post etch residues (PER) that consist of organic polymer, metal oxides and fluorides, form on top of copper and low-k dielectric sidewalls. Currently, most semiconductor companies use semi aqueous fluoride (SAF) based formulations containing organic solvent(s) for PER removal. Unfortunately, these formulations adversely impact the environmental health and safety (EHS) requirements of the semiconductor industry. Environmentally friendly "green" formulations, free of organic solvents, are preferred as alternatives to remove PER. In this work, a novel low temperature molten salt system, referred as deep eutectic solvent (DES) has been explored as a back end of line cleaning (BEOL) formulation. Specifically, the DES system comprised of two benign chemicals, malonic acid (MA) and choline chloride (CC), is a liquid at room temperature. In certain cases, the formulation was modified by the addition of glacial acetic acid (HAc). Using these formulations, selective removal of three types of PER generated by timed CF4/O2 etching of DUV PR films on Cu was achieved. Type I PER was mostly organic in character (fluorocarbon polymer type) and had a measured thickness of 160 nm. Type II PER was much thinner (25 nm) and consisted of a mixture of organic and inorganic compounds (copper fluorides). Further etching generated 17 nm thick Type III PER composed of copper fluorides and oxides. Experiments were also conducted on patterned structures. Cleaning was performed by immersing samples in a temperature controlled (30 or 40° C) double jacketed vessel for a time between 1 and 5 minutes. Effectiveness of cleaning was characterized using SEM, XPS and single frequency impedance measurements

  3. A novel digestion method based on a choline chloride-oxalic acid deep eutectic solvent for determining Cu, Fe, and Zn in fish samples.

    PubMed

    Habibi, Emadaldin; Ghanemi, Kamal; Fallah-Mehrjardi, Mehdi; Dadolahi-Sohrab, Ali

    2013-01-31

    A novel and efficient digestion method based on choline chloride-oxalic acid (ChCl-Ox) deep eutectic solvent (DES) was developed for flame atomic absorption spectrometry (FAAS) determination of Cu, Zn, and Fe in biological fish samples. Key parameters that influence analyte recovery were investigated and optimized, using the fish protein certified reference material (CRM, DORM-3) throughout the procedure. In this method, 100 mg of the sample was dissolved in ChCl-Ox (1:2, molar ratio) at 100°C for 45 min. Then, 5.0 mL HNO(3) (1.0 M) was added. After centrifugation, the supernatant solution was filtered, diluted to a known volume, and analyzed by FAAS. Under optimized conditions, an excellent agreement between the obtained results and the certified values was observed, using Student's t-test (P=0.05); the extraction recovery of the all elements was greater than 95.3%. The proposed method was successfully applied to the determination of analytes in different tissues (muscle, liver, and gills) having a broad concentration range in a marine fish sample. The reproducibility of the method was validated by analyzing all samples by our method in a different laboratory, using inductively coupled plasma optical emission spectrometry (ICP-OES). For comparison, a conventional acid digestion (CAD) method was also used for the determination of analytes in all studied samples. The simplicity of the proposed experimental procedure, high extraction efficiency, short analysis time, lack of concentrated acids and oxidizing agents, and the use of safe and inexpensive components demonstrate the high potential of ChCl-Ox (1:2) for routine trace metal analysis in biological samples. PMID:23327946

  4. Dielectric Relaxations of (Acetamide + Electrolyte) Deep Eutectic Solvents in the Frequency Window, 0.2 ≤ ν/GHz ≤ 50: Anion and Cation Dependence.

    PubMed

    Mukherjee, Kallol; Das, Anuradha; Choudhury, Samiran; Barman, Anjan; Biswas, Ranjit

    2015-06-25

    Dielectric relaxation (DR) measurements in the frequency range 0.2 ≤ ν/GHz ≤ 50 have been carried out for neat molten acetamide and six different (acetamide + electrolyte) deep eutectic solvents (DESs) for investigating ion effects on DR dynamics in these ionic DESs. Electrolytes used are lithium salts of bromide (LiBr), nitrate (LiNO3), and perchlorate (LiClO4); sodium salts of perchlorate (NaClO4) and thiocyante (NaSCN); and potassium thiocyanate (KSCN). With these electrolytes acetamide forms DESs approximately at an 80:20 mol ratio. Simultaneous fits to the measured permittivity (ε′) and loss (ε″) spectra of these DESs at ∼293 K require a sum of four Debye (4-D) processes with relaxation times spread over picosecond to nanosecond regime. In contrast, DR spectra for neat molten acetamide (∼354 K) depict 2-D relaxation with time constants ∼50 ps and ∼5 ps. For both the neat and ionic systems, the undetected dispersion, ε∞ – n(D)2, remains to be ∼3–4. Upon comparison, measured DR dynamics reveal pronounced anion and cation effects. Estimated static dielectric constants (ε0) from fits for these DESs cover the range 12 < ε0 < 30 and are remarkably lower than that (ε0 ∼ 64) measured for molten acetamide at ∼354 K. Hydrodynamic effective rotation volumes (Veff) estimated from the slowest DR relaxation time constants vary with ion identity and are much smaller than the molecular volume of acetamide. This decrease of ε0 and Veff is attributed respectively to the pinning of acetamide molecules by ions and orientation jumps and undetected portion to the limited frequency coverage employed in these measurements PMID:26012789

  5. Natural deep eutectic solvent mediated pretreatment of rice straw: bioanalytical characterization of lignin extract and enzymatic hydrolysis of pretreated biomass residue.

    PubMed

    Kumar, Adepu K; Parikh, Bhumika S; Pravakar, Mohanty

    2016-05-01

    The present investigation demonstrated pretreatment of lignocellulosic biomass rice straw using natural deep eutectic solvents (NADESs), and separation of high-quality lignin and holocellulose in a single step. Qualitative analysis of the NADES extract showed that the extracted lignin was of high purity (>90 %), and quantitative analysis showed that nearly 60 ± 5 % (w/w) of total lignin was separated from the lignocellulosic biomass. Addition of 5.0 % (v/v) water during pretreatment significantly enhanced the total lignin extraction, and nearly 22 ± 3 % more lignin was released from the residual biomass into the NADES extract. X-ray diffraction studies of the untreated and pretreated rice straw biomass showed that the crystallinity index ratio was marginally decreased from 46.4 to 44.3 %, indicating subtle structural alterations in the crystalline and amorphous regions of the cellulosic fractions. Thermogravimetric analysis of the pretreated biomass residue revealed a slightly higher T dcp (295 °C) compared to the T dcp (285 °C) of untreated biomass. Among the tested NADES reagents, lactic acid/choline chloride at molar ratio of 5:1 extracted maximum lignin of 68 ± 4 mg g(-1) from the rice straw biomass, and subsequent enzymatic hydrolysis of the residual holocellulose enriched biomass showed maximum reducing sugars of 333 ± 11 mg g(-1) with a saccharification efficiency of 36.0 ± 3.2 % in 24 h at 10 % solids loading. PMID:26032452

  6. Electropolishing of Re-melted SLM Stainless Steel 316L Parts Using Deep Eutectic Solvents: 3 × 3 Full Factorial Design

    NASA Astrophysics Data System (ADS)

    Alrbaey, K.; Wimpenny, D. I.; Al-Barzinjy, A. A.; Moroz, A.

    2016-07-01

    This three-level three-factor full factorial study describes the effects of electropolishing using deep eutectic solvents on the surface roughness of re-melted 316L stainless steel samples produced by the selective laser melting (SLM) powder bed fusion additive manufacturing method. An improvement in the surface finish of re-melted stainless steel 316L parts was achieved by optimizing the processing parameters for a relatively environmentally friendly (`green') electropolishing process using a Choline Chloride ionic electrolyte. The results show that further improvement of the response value-average surface roughness ( Ra) can be obtained by electropolishing after re-melting to yield a 75% improvement compared to the as-built Ra. The best Ra value was less than 0.5 μm, obtained with a potential of 4 V, maintained for 30 min at 40 °C. Electropolishing has been shown to be effective at removing the residual oxide film formed during the re-melting process. The material dissolution during the process is not homogenous and is directed preferentially toward the iron and nickel, leaving the surface rich in chromium with potentially enhanced properties. The re-melted and polished surface of the samples gave an approximately 20% improvement in fatigue life at low stresses (approximately 570 MPa). The results of the study demonstrate that a combination of re-melting and electropolishing provides a flexible method for surface texture improvement which is capable of delivering a significant improvement in surface finish while holding the dimensional accuracy of parts within an acceptable range.

  7. Tuning the gallium content of metal precursors for Cu(In,Ga)Se2 thin film solar cells by electrodeposition from a deep eutectic solvent.

    PubMed

    Malaquias, João C; Regesch, David; Dale, Phillip J; Steichen, Marc

    2014-02-14

    Controlling the Ga incorporation of Cu-In-Ga metal precursors for Cu(In,Ga)Se2 (CIGS) solar cells is one of the main challenges for low cost electrodeposition processes, mainly due to the difficulty in electrodepositing metallic Ga from aqueous electrolytes. In this work we use the deep eutectic solvent (DES) Choline Chloride : Urea (ChCl : U - 1 : 2) to efficiently codeposit In-Ga on Cu and Mo electrodes. We control the Ga/(Ga+In) (Ga/III) ratio of the films via the mass fluxes. The electrochemical behavior of ChCl : U containing GaCl3 and InCl3 is studied by rotating disk electrode cyclic voltammetry (CV) on Mo and Cu electrodes. CV revealed on both Mo and Cu electrodes that the electrochemical behavior of the ChCl : U-GaCl3-InCl3 system is the superposition of the individual In and Ga electrochemistry. On a Cu electrode the morphology, crystal structure and element distribution of the deposits were a function of the Ga/III ratio. We demonstrate the precise control of Ga incorporation over a large composition range from 0.1 ≤ Ga/III ≤ 0.9 and proved that ED from DES is a straightforward, robust and efficient process. First solar cells based on Mo/Cu/In-Ga metal stacks achieved efficiencies as high as 7.9% with a Voc of 520 mV. PMID:24382400

  8. Dissolution of biological samples in deep eutectic solvents: an approach for extraction of polycyclic aromatic hydrocarbons followed by liquid chromatography-fluorescence detection.

    PubMed

    Helalat-Nezhad, Zahra; Ghanemi, Kamal; Fallah-Mehrjardi, Mehdi

    2015-05-15

    A novel sample preparation method based on the complete dissolution of marine biological samples in choline chloride-oxalic acid (ChCl-Ox) deep eutectic solvent was developed for fast and efficient extraction of eight polycyclic aromatic hydrocarbons (PAHs) using minimum volumes of cyclohexane. The extracted PAHs were purified and then measured by high-performance liquid chromatography-fluorescence detection (HPLC-FL). The effect of key parameters on extraction recoveries and precision was investigated. At optimized conditions, the studied samples were dissolved under atmospheric pressure in ChCl-Ox (1:2) at 55°C for 30min, which is considerably lower than the temperature used in the classical and current methods. After dissolution, it took approximately 20min to quantitatively extract the PAHs from ChCl-Ox using 5mL cyclohexane. Depending on the analyte, the developed method was linear over the calibration range 1.0-250, 2.0-250, and 5.0-250ngg(-1), with r(2)>0.996. The detection limits of the method were between 0.50 and 3.08ngg(-1). The intra-day and inter-day precisions (based on the relative standard deviation, n=5) of the spiked PAHs at a concentration level of 50ngg(-1) were better than 12.6% and 13.3%, respectively. Individual PAH recoveries from spiked marine fish and macroalgae samples were in the range of 71.6% to 109.6%. For comparison, the spiked samples were also subjected to the Soxhlet extraction method. The simplicity of the procedure, high extraction efficiency, short analysis time, and use of safe and inexpensive components suggest the proposed method has a high potential for utilization in routine trace PAH analysis in biological samples. PMID:25857544

  9. Electropolishing of Re-melted SLM Stainless Steel 316L Parts Using Deep Eutectic Solvents: 3 × 3 Full Factorial Design

    NASA Astrophysics Data System (ADS)

    Alrbaey, K.; Wimpenny, D. I.; Al-Barzinjy, A. A.; Moroz, A.

    2016-05-01

    This three-level three-factor full factorial study describes the effects of electropolishing using deep eutectic solvents on the surface roughness of re-melted 316L stainless steel samples produced by the selective laser melting (SLM) powder bed fusion additive manufacturing method. An improvement in the surface finish of re-melted stainless steel 316L parts was achieved by optimizing the processing parameters for a relatively environmentally friendly (`green') electropolishing process using a Choline Chloride ionic electrolyte. The results show that further improvement of the response value-average surface roughness (Ra) can be obtained by electropolishing after re-melting to yield a 75% improvement compared to the as-built Ra. The best Ra value was less than 0.5 μm, obtained with a potential of 4 V, maintained for 30 min at 40 °C. Electropolishing has been shown to be effective at removing the residual oxide film formed during the re-melting process. The material dissolution during the process is not homogenous and is directed preferentially toward the iron and nickel, leaving the surface rich in chromium with potentially enhanced properties. The re-melted and polished surface of the samples gave an approximately 20% improvement in fatigue life at low stresses (approximately 570 MPa). The results of the study demonstrate that a combination of re-melting and electropolishing provides a flexible method for surface texture improvement which is capable of delivering a significant improvement in surface finish while holding the dimensional accuracy of parts within an acceptable range.

  10. Synthesis of monoclinic structured BiVO4 spindly microtubes in deep eutectic solvent and their application for dye degradation.

    PubMed

    Liu, Wei; Yu, Yaqin; Cao, Lixin; Su, Ge; Liu, Xiaoyun; Zhang, Lan; Wang, Yonggang

    2010-09-15

    Monoclinic structured spindly bismuth vanadate microtubes were fabricated on a large scale by a simple ionothermal treatment in the environment-friendly green solvent of urea/choline chloride. The as-prepared samples were characterized by XRD, SEM, TEM, IR and their photocatalytic activity was evaluated by photocatalytic decolorization of rhodamine B aqueous solution under visible-light irradiation. As-obtained BiVO(4) microtubes exhibit the spindly shape with a side length of ca. 800 nm and a wall thickness of ca. 100 nm. The opening of these microtubes presents a saw-toothed structure, which is seldom in other tube-shaped materials. The formation mechanism of the spindly microtubes is ascribed to the complex cooperation of the reaction-crystallization process controlled by BiOCl and the nucleation-growth process of nanosheets induced by solvent molecules attached on the surface of microtubes. Such spindly microtubes exhibit much higher visible-light photocatalytic activity than that of bulk BiVO(4) prepared by solid-state reaction, possibly resulting from their large surface area and improved crystallinity. PMID:20576353

  11. Low-frequency collective dynamics in deep eutectic solvents of acetamide and electrolytes: A femtosecond Raman-induced Kerr effect spectroscopic study

    NASA Astrophysics Data System (ADS)

    Biswas, Ranjit; Das, Anuradha; Shirota, Hideaki

    2014-10-01

    In this study, we have investigated the ion concentration dependent collective dynamics in two series of deep eutectic solvent (DES) systems by femtosecond Raman-induced Kerr effect spectroscopy, as well as some physical properties, e.g., shear viscosity (η), density (ρ), and surface tension (γ). The DES systems studied here are [0.75CH3CONH2 + 0.25{f KSCN + (1 - f )NaSCN}] and [0.78CH3CONH2 + 0.22{f LiBr + (1 - f )LiNO3}] with f = 0, 0.2, 0.4, 0.6, 0.8, and 1.0. γ of these DES systems shows near insensitivity to f, while ρ shows a moderate dependence on f. Interestingly, η exhibits a strong dependence on f. In the low-frequency Kerr spectra, obtained via the Fourier transform of the collected Kerr transients, a characteristic band at ˜70 cm-1 is clear in [0.78CH3CONH2 + 0.22{f LiBr + (1 - f )LiNO3}] DES especially at the larger f. The band is attributed to the intermolecular hydrogen bond of acetamide. Because of less depolarized Raman activities of intermolecular/interionic vibrational motions, which are mostly translational (collision-induced or interaction-induced) motions, of spherical ions, the intermolecular hydrogen-bonding band is clearly observed. In contrast, the intermolecular hydrogen-bonding band is buried in the other intermolecular/interionic vibrational motions, which includes translational and reorientational (librational) motions and their cross-terms, in [0.75CH3CONH2 + 0.25{f KSCN + (1 - f )NaSCN}] system. The first moment (M1) of the intermolecular/interionic vibrational band in these DES systems is much higher than that in typical neutral molecular liquids and shows a weak but contrasting dependence on the bulk parameter sqrt {γ /ρ }. The time constants for picosecond overdamped Kerr transients in both the DES systems, which are obtained on the basis of the analysis fitted by a triexponential function, are rather insensitive to f for both the DES systems, but all the three time constants (fast: ˜1-3 ps; intermediate: ˜7-20 ps; and

  12. A green ultrasonic-assisted liquid-liquid microextraction based on deep eutectic solvent for the HPLC-UV determination of ferulic, caffeic and cinnamic acid from olive, almond, sesame and cinnamon oil.

    PubMed

    Khezeli, Tahere; Daneshfar, Ali; Sahraei, Reza

    2016-04-01

    A simple, inexpensive and sensitive ultrasonic-assisted liquid-liquid microextraction method based on deep eutectic solvent (UALLME-DES) was used for the extraction of three phenolic acids (ferulic, caffeic and cinnamic) from vegetable oils. In a typical experiment, deep eutectic solvent as green extraction solvent was added to n-hexane (as a typical oil medium) containing target analytes. Subsequently, the extraction was accelerated by sonication. After the extraction, phase separation (DES rich phase/n-hexane phase) was performed by centrifugation. DES rich phase (lower phase) was withdrawn by a micro-syringe and submitted to isocratic reverse-phase HPLC with UV detection. Under optimum conditions obtained by response surface methodology (RSM) and desirability function (DF), the method has good linear calibration ranges (between 1.30 and 1000 µg L(-1)), coefficients of determination (r(2)>0.9949) and low limits of detection (between 0.39 and 0.63 µg L(-1)). This procedure was successfully applied to the determination of target analytes in olive, almond, sesame and cinnamon oil samples. The relative mean recoveries ranged from 94.7% to 104.6%. PMID:26838445

  13. Low-frequency collective dynamics in deep eutectic solvents of acetamide and electrolytes: a femtosecond Raman-induced Kerr effect spectroscopic study.

    PubMed

    Biswas, Ranjit; Das, Anuradha; Shirota, Hideaki

    2014-10-01

    In this study, we have investigated the ion concentration dependent collective dynamics in two series of deep eutectic solvent (DES) systems by femtosecond Raman-induced Kerr effect spectroscopy, as well as some physical properties, e.g., shear viscosity (η), density (ρ), and surface tension (γ). The DES systems studied here are [0.75CH3CONH2 + 0.25{f KSCN + (1 - f )NaSCN}] and [0.78CH3CONH2 + 0.22{f LiBr + (1 - f )LiNO3}] with f = 0, 0.2, 0.4, 0.6, 0.8, and 1.0. γ of these DES systems shows near insensitivity to f, while ρ shows a moderate dependence on f. Interestingly, η exhibits a strong dependence on f. In the low-frequency Kerr spectra, obtained via the Fourier transform of the collected Kerr transients, a characteristic band at ∼70 cm(-1) is clear in [0.78CH3CONH2 + 0.22{f LiBr + (1 - f )LiNO3}] DES especially at the larger f. The band is attributed to the intermolecular hydrogen bond of acetamide. Because of less depolarized Raman activities of intermolecular/interionic vibrational motions, which are mostly translational (collision-induced or interaction-induced) motions, of spherical ions, the intermolecular hydrogen-bonding band is clearly observed. In contrast, the intermolecular hydrogen-bonding band is buried in the other intermolecular/interionic vibrational motions, which includes translational and reorientational (librational) motions and their cross-terms, in [0.75CH3CONH2 + 0.25{f KSCN + (1 - f )NaSCN}] system. The first moment (M1) of the intermolecular/interionic vibrational band in these DES systems is much higher than that in typical neutral molecular liquids and shows a weak but contrasting dependence on the bulk parameter √γ/ρ. The time constants for picosecond overdamped Kerr transients in both the DES systems, which are obtained on the basis of the analysis fitted by a triexponential function, are rather insensitive to f for both the DES systems, but all the three time constants (fast: ∼1-3 ps; intermediate:

  14. Introducing deep eutectic solvents as biorenewable media for Au(I)-catalysed cycloisomerisation of γ-alkynoic acids: an unprecedented catalytic system.

    PubMed

    Rodríguez-Álvarez, María J; Vidal, Cristian; Díez, Josefina; García-Álvarez, Joaquín

    2014-11-01

    Cycloisomerisation of γ-alkynoic acids into cyclic enol-lactones was conveniently performed, for the first time, in the eutectic mixture 1ChCl/2Urea under standard bench experimental conditions (at room temperature, under air and in the absence of co-catalysts) by using a new iminophosphorane-Au(I) complex as the catalyst. Furthermore, the catalytic system could be recycled up to four runs. PMID:25215857

  15. Frontal polymerizations carried out in Deep-Eutectic mixtures providing both the monomers and the polymerization medium.

    PubMed

    Mota-Morales, Josué D; Gutiérrez, María C; Sanchez, Isaac C; Luna-Bárcenas, Gabriel; del Monte, Francisco

    2011-05-14

    Deep Eutectic Solvents (DESs) based upon mixtures of Acrylic Acid (AA) or Methacrylic Acid (MAA) and Choline Chloride (CCl) demonstrated superior performance than regular organic solvents and even ionic liquids for frontal polymerizations (FPs). Full recovering of CCl after FP provided an interesting green character to the process. PMID:21455538

  16. Structure Property Relationships in Imidazole-based Deep Eutectic Mixtures

    NASA Astrophysics Data System (ADS)

    Terheggen, Logan; Cosby, Tyler; Sangoro, Joshua

    2015-03-01

    Deep eutectic mixtures of levulinic acid with a systematic series of imidazoles are measured by broadband dielectric spectroscopy, differential scanning calorimetry, and Fourier transform infrared spectroscopy to investigate the impact of steric interactions on charge transport and structural dynamics. An enhancement of dc conductivity is found in each of the imidazoles upon the addition of levulinic acid. However, the extent of increase is dependent upon the alkyl substitution on the imidazole ring. These results highlight the importance of molecular structure on hydrogen bonding and charge transport in deep eutectic mixtures.

  17. Ambient temperature deposition of gallium nitride/gallium oxynitride from a deep eutectic electrolyte, under potential control.

    PubMed

    Sarkar, Sujoy; Sampath, S

    2016-05-11

    A ternary, ionically conducting, deep eutectic solvent based on acetamide, urea and gallium nitrate is reported for the electrodeposition of gallium nitride/gallium indium nitride under ambient conditions; blue and white light emitting photoluminescent deposits are obtained under potential control. PMID:27074315

  18. Charge Transport and Structural Dynamics in Deep Eutectic Mixtures

    NASA Astrophysics Data System (ADS)

    Cosby, Tyler; Holt, Adam; Terheggen, Logan; Griffin, Philip; Benson, Roberto; Sangoro, Joshua

    2015-03-01

    Charge transport and structural dynamics in a series of imidazole and carboxylic acid-based deep eutectic mixtures are investigated by broadband dielectric spectroscopy, dynamic light scattering, 1H nuclear magnetic resonance spectroscopy, calorimetry, and Fourier transform infrared spectroscopy. It is found that the extended hydrogen-bonded networks characteristic of imidazoles are broken down upon addition of carboxylic acids, resulting in an increase in dc conductivity of the mixtures. These results are discussed within the framework of recent theories of hydrogen bonding and proton transport.

  19. Transformation of eutectic emulsion to nanosuspension fabricating with solvent evaporation and ultrasonication technique

    PubMed Central

    Phaechamud, Thawatchai; Tuntarawongsa, Sarun

    2016-01-01

    Eutectic solvent can solubilize high amount of some therapeutic compounds. Volatile eutectic solvent is interesting to be used as solvent in the preparation of nanosuspension with emulsion solvent evaporation technique. The mechanism of transformation from the eutectic emulsion to nanosuspension was investigated in this study. The 30% w/w ibuprofen eutectic solution was used as the internal phase, and the external phase is composed of Tween 80 as emulsifier. Ibuprofen nanosuspension was prepared by eutectic emulsion solvent evaporating method followed with ultrasonication. During evaporation process, the ibuprofen concentration in emulsion droplets was increased leading to a drug supersaturation but did not immediately recrystallize because of low glass transition temperature (Tg) of ibuprofen. The contact angle of the internal phase on ibuprofen was apparently lower than that of the external phase at all times of evaporation, indicating that the ibuprofen crystals were preferentially wetted by the internal phase than the external phase. From calculated dewetting value ibuprofen crystallization occurred in the droplet. Crystallization of the drug was initiated with external mechanical force, and the particle size of the drug was larger due to Ostwald ripening. Cavitation force from ultrasonication minimized the ibuprofen crystals to the nanoscale. Particle size and zeta potential of formulated ibuprofen nanosuspension were 330.87±51.49 nm and −31.1±1.6 mV, respectively, and exhibited a fast dissolution. Therefore, the combination of eutectic emulsion solvent evaporation method with ultrasonication was favorable for fabricating an ibuprofen nanosuspension, and the transformation mechanism was attained successfully. PMID:27366064

  20. Transformation of eutectic emulsion to nanosuspension fabricating with solvent evaporation and ultrasonication technique.

    PubMed

    Phaechamud, Thawatchai; Tuntarawongsa, Sarun

    2016-01-01

    Eutectic solvent can solubilize high amount of some therapeutic compounds. Volatile eutectic solvent is interesting to be used as solvent in the preparation of nanosuspension with emulsion solvent evaporation technique. The mechanism of transformation from the eutectic emulsion to nanosuspension was investigated in this study. The 30% w/w ibuprofen eutectic solution was used as the internal phase, and the external phase is composed of Tween 80 as emulsifier. Ibuprofen nanosuspension was prepared by eutectic emulsion solvent evaporating method followed with ultrasonication. During evaporation process, the ibuprofen concentration in emulsion droplets was increased leading to a drug supersaturation but did not immediately recrystallize because of low glass transition temperature (T g) of ibuprofen. The contact angle of the internal phase on ibuprofen was apparently lower than that of the external phase at all times of evaporation, indicating that the ibuprofen crystals were preferentially wetted by the internal phase than the external phase. From calculated dewetting value ibuprofen crystallization occurred in the droplet. Crystallization of the drug was initiated with external mechanical force, and the particle size of the drug was larger due to Ostwald ripening. Cavitation force from ultrasonication minimized the ibuprofen crystals to the nanoscale. Particle size and zeta potential of formulated ibuprofen nanosuspension were 330.87±51.49 nm and -31.1±1.6 mV, respectively, and exhibited a fast dissolution. Therefore, the combination of eutectic emulsion solvent evaporation method with ultrasonication was favorable for fabricating an ibuprofen nanosuspension, and the transformation mechanism was attained successfully. PMID:27366064

  1. Dissolution enhancement of active pharmaceutical ingredients by therapeutic deep eutectic systems.

    PubMed

    Aroso, Ivo M; Silva, João C; Mano, Francisca; Ferreira, Ana S D; Dionísio, Madalena; Sá-Nogueira, Isabel; Barreiros, Susana; Reis, Rui L; Paiva, Alexandre; Duarte, Ana Rita C

    2016-01-01

    A therapeutic deep eutectic system (THEDES) is here defined as a deep eutectic solvent (DES) having an active pharmaceutical ingredient (API) as one of the components. In this work, THEDESs are proposed as enhanced transporters and delivery vehicles for bioactive molecules. THEDESs based on choline chloride (ChCl) or menthol conjugated with three different APIs, namely acetylsalicylic acid (AA), benzoic acid (BA) and phenylacetic acid (PA), were synthesized and characterized for thermal behaviour, structural features, dissolution rate and antibacterial activity. Differential scanning calorimetry and polarized optical microscopy showed that ChCl:PA (1:1), ChCl:AA (1:1), menthol:AA (3:1), menthol:BA (3:1), menthol:PA (2:1) and menthol:PA (3:1) were liquid at room temperature. Dissolution studies in PBS led to increased dissolution rates for the APIs when in the form of THEDES, compared to the API alone. The increase in dissolution rate was particularly noticeable for menthol-based THEDES. Antibacterial activity was assessed using both Gram-positive and Gram-negative model organisms. The results show that all the THEDESs retain the antibacterial activity of the API. Overall, our results highlight the great potential of THEDES as dissolution enhancers in the development of novel and more effective drug delivery systems. PMID:26586342

  2. A simple, efficient and environmentally benign synthetic protocol for the synthesis of spirooxindoles using choline chloride-oxalic acid eutectic mixture as catalyst/solvent system.

    PubMed

    Khandelwal, Sarita; Rajawat, Anshu; Tailor, Yogesh Kumar; Kumar, Mahendra

    2014-01-01

    An efficient and environmentally benign domino protocol has been presented for the synthesis of structurally diverse spirooxindoles spiroannulated with pyranopyridopyrimidines, indenopyridopyrimidines, and chromenopyridopyrimidines involving three-component reaction of aminouracils, isatins and cyclic carbonyl compounds in deep eutectic solvent (choline chloride-oxalic acid: 1:1) which acts as efficient catalyst and environmentally benign reaction medium. The present protocol offers several advantages such as operational simplicity with easy workup, shorter reaction times excellent yields with superior atom economy and environmentally benign reaction conditions with the use of cost-effective, recyclable, non-toxic and bio-degradable DES as catalyst/solvent. PMID:25329839

  3. Orientational Jumps in (Acetamide + Electrolyte) Deep Eutectics: Anion Dependence.

    PubMed

    Das, Suman; Biswas, Ranjit; Mukherjee, Biswaroop

    2015-08-27

    All-atom molecular dynamics simulations have been carried out to investigate orientation jumps of acetamide molecules in three different ionic deep eutectics made of acetamide (CH3CONH2) and lithium salts of bromide (Br(–)), nitrate (NO3(–)) and perchlorate (ClO4(–)) at approximately 80:20 mole ratio and 303 K. Orientational jumps have been dissected into acetamide–acetamide and acetamide–ion catagories. Simulated jump characteristics register a considerable dependence on the anion identity. For example, large angle jumps are relatively less frequent in the presence of NO3(–) than in the presence of the other two anions. Distribution of jump angles for rotation of acetamide molecules hydrogen bonded (H-bonded) to anions has been found to be bimodal in the presence of Br(–) and is qualitatively different from the other two cases. Estimated energy barrier for orientation jumps of these acetamide molecules (H-bonded to anions) differ by a factor of ∼2 between NO3(–) and ClO4(–), the barrier height for the latter being lower and ∼0.5kBT. Relative radial and angular displacements during jumps describe the sequence ClO(4)– > NO3(–) > Br(–) and follow a reverse viscosity trend. Jump barrier for acetamide–acetamide pairs reflects weak dependence on anion identity and remains closer to the magnitude (∼0.7kBT) found for orientation jumps in molten acetamide. Jump time distributions exhibit a power law dependence of the type, P(tjump) ∝ A(tjump/τ)(−β), with both β and τ showing substantial anion dependence. The latter suggests the presence of dynamic heterogeneity in these systems and supports earlier conclusions from time-resolved fluorescence measurements. PMID:26131593

  4. Ionic liquids and eutectic mixtures as solvent and template in synthesis of zeolite analogues.

    PubMed

    Cooper, Emily R; Andrews, Christopher D; Wheatley, Paul S; Webb, Paul B; Wormald, Philip; Morris, Russell E

    2004-08-26

    The challenges associated with synthesizing porous materials mean that new classes of zeolites (zeotypes)-such as aluminosilicate zeolites and zeolite analogues-together with new methods of preparing known zeotypes, continue to be of great importance. Normally these materials are prepared hydrothermally with water as the solvent in a sealed autoclave under autogenous pressure. The reaction mixture usually includes an organic template or 'structure-directing agent' that guides the synthesis pathway towards particular structures. Here we report the preparation of aluminophosphate zeolite analogues by using ionic liquids and eutectic mixtures. An imidazolium-based ionic liquid acts as both solvent and template, leading to four zeotype frameworks under different experimental conditions. The structural characteristics of the materials can be traced back to the solvent chemistry used. Because of the vanishingly low vapour pressure of ionic liquids, synthesis takes place at ambient pressure, eliminating safety concerns associated with high hydrothermal pressures. The ionic liquid can also be recycled for further use. A choline chloride/urea eutectic mixture is also used in the preparation of a new zeotype framework. PMID:15329717

  5. Innovative Poly(Ionic Liquid)s by the Polymerization of Deep Eutectic Monomers.

    PubMed

    Isik, Mehmet; Ruiperez, Fernando; Sardon, Haritz; Gonzalez, Alba; Zulfiqar, Sonia; Mecerreyes, David

    2016-07-01

    The incorporation of ionic liquid (IL) chemistry into functional polymers has extended the properties and applications of polyelectrolytes. However, ILs are expensive due to the presence of fluorinated anions or complicated synthetic steps which limit their technological viability. Here, we show a new family of poly(ionic liquid)s (PILs) which are based in cheap and renewable chemicals and involves facile synthetic approaches. Thus, deep eutectic monomers (DEMs) are prepared for the first time by using quaternary ammonium compounds and various hydrogen bond donors such as citric acid, terephthalic acid or an amidoxime. The deep eutectic formation is made through a simple mixing of the ingredients. Differential scanning calorimetry, nuclear magnetic resonance (NMR) and computational studies reveal the formation of the DEMs due to the ionic interactions. The resulting DEMs are liquid which facilitates their polymerization using mild photopolymerization or polycondensation strategies. Spectroscopic characterizations reveal the successful formation of the polymers. By this way, a new family of PILs can be synthesized which can be used for different applications. As an example, the polymers show promising performance as solid CO2 sorbents. Altogether the deep eutectic monomer route can lead to non-toxic, cheap and easy-to-prepare alternatives to current PILs for different applications. PMID:26954303

  6. Cellulosic ethanol production from green solvent-pretreated rice straw

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Natural deep eutectic solvents (NADES) are recently developed “green solvents” consisted of bio-based ionic liquids and deep eutectic solvents mainly from plant based metabolites. NADES are biodegradable, non-toxic and environment-friendly. Conventional chemically synthesized ionic liquids have be...

  7. Effects of solvents on deep hydrodesulfurization of benzothiophene and dibenzothiophene

    SciTech Connect

    Ishihara, Atsushi; Itoh, Tetsuro; Hino, Takuo; Nomura, Masatoshi; Pingyen Qi; Kabe, Toshiaki )

    1993-03-01

    Solvent effects on hydrodesulfurization (HDS) of benzothiophene (BT) and dibenzothiophene (DBT) catalyzed by Co-Mo/Al[sub 2]O[sub 3] were investigated under deep hydrodesulfurization conditions. Data for BT and DBT are arranged by the Langmuir-Hinshelwood equation. Activation energies of HDS of BT and DBT were approximately 21 and 24 kcal/mol respectively, in every solvent. Heats of adsorption of BT and DBT are both estimated to be 22 kcal/mol. Significant solvent effects were found under deep desulfurization conditions, and the values of heat of adsorption for various solvents were estimated from the K[sub sol] obtained. 14 refs., 3 figs., 3 tabs.

  8. Charge transport and structural dynamics in carboxylic-acid-based deep eutectic mixtures.

    PubMed

    Griffin, Philip J; Cosby, Tyler; Holt, Adam P; Benson, Roberto S; Sangoro, Joshua R

    2014-08-01

    Charge transport and structural dynamics in the 1:2 mol ratio mixture of lidocaine and decanoic acid (LID-DA), a model deep eutectic mixture (DEM), have been characterized over a wide temperature range using broad-band dielectric spectroscopy and depolarized dynamic light scattering. Additionally, Fourier transform infrared spectroscopy measurements were performed to assess the degree of proton transfer between the neutral parent molecules. From our detailed analysis of the dielectric spectra, we have determined that this carboxylic-acid-based DEM is approximately 25% ionic at room temperature. Furthermore, we have found that the characteristic diffusion rate of mobile charge carriers is practically identical to the rate of structural relaxation at all measured temperatures, indicating that fast proton transport does not occur in LID-DA. Our results demonstrate that while LID-DA exhibits the thermal characteristics of a DEM, its charge transport properties resemble those of a protic ionic liquid. PMID:25025600

  9. Recycling of electric arc furnace dust through dissolution in deep eutectic ionic liquids and electrowinning.

    PubMed

    Bakkar, Ashraf

    2014-09-15

    The dust waste formed during steelmaking in electric arc furnace (EAF) is rich in ferrous and nonferrous metals. Recycling of this dust as a raw material in iron or steel-making is hazardous and therefore it is mostly dumped. This paper demonstrates recycling of EAF dust through selective dissolution of metal oxides in a deep eutectic ionic liquid. It was found that about 60% of Zn and 39% of Pb could be dissolved from the dust when stirred for 48h in 1 choline chloride:2 urea ionic liquid at 60°C. The resultant electrolyte was subsequently fed to a conventional three-electrode cell where cyclic voltammetry (CV) measurements were conducted to describe its electrochemical behavior. Two deposition peaks were determined and ascribed to deposition of zinc and lead. Static potentials were successively applied to electrowin metallic zinc. SEM/EDX investigations showed that the zinc electrowon contained remarkable contents of lead. PMID:25156719

  10. High-performance dye-sensitized solar cells based on solvent-free electrolytes produced from eutectic melts.

    PubMed

    Bai, Yu; Cao, Yiming; Zhang, Jing; Wang, Mingkui; Li, Renzhi; Wang, Peng; Zakeeruddin, Shaik M; Grätzel, Michael

    2008-08-01

    Low-cost excitonic solar cells based on organic optoelectronic materials are receiving an ever-increasing amount of attention as potential alternatives to traditional inorganic photovoltaic devices. In this rapidly developing field, the dye-sensitized solar cell (DSC) has achieved so far the highest validated efficiency of 11.1% (ref. 2) and remarkable stability. However, the cells with the best performance use volatile solvents in their electrolytes, which may be prohibitive for outdoor solar panels in view of the need for robust encapsulation. Solvent-free room-temperature ionic liquids have been pursued as an attractive solution to this dilemma, and device efficiencies of over 7% were achieved by using some low-viscosity formulations containing 1-ethyl-3-methylimidazolium thiocyanate, selenocyanate, tricyanomethide or tetracyanoborate. Unfortunately, apart from tetracyanoborate, all of these low-viscosity melts proved to be unstable under prolonged thermal stress and light soaking. Here, we introduce the concept of using eutectic melts to produce solvent-free liquid redox electrolytes. Using a ternary melt in conjunction with a nanocrystalline titania film and the amphiphilic heteroleptic ruthenium complex Z907Na (ref. 10) as a sensitizer, we reach excellent stability and an unprecedented efficiency of 8.2% under air-mass 1.5 global illumination. Our results are of importance to realize large-scale outdoor applications of mesoscopic DSCs. PMID:18587401

  11. High-performance dye-sensitized solar cells based on solvent-free electrolytes produced from eutectic melts

    NASA Astrophysics Data System (ADS)

    Bai, Yu; Cao, Yiming; Zhang, Jing; Wang, Mingkui; Li, Renzhi; Wang, Peng; Zakeeruddin, Shaik M.; Grätzel, Michael

    2008-08-01

    Low-cost excitonic solar cells based on organic optoelectronic materials are receiving an ever-increasing amount of attention as potential alternatives to traditional inorganic photovoltaic devices. In this rapidly developing field, the dye-sensitized solar cell (DSC) has achieved so far the highest validated efficiency of 11.1% (ref. 2) and remarkable stability. However, the cells with the best performance use volatile solvents in their electrolytes, which may be prohibitive for outdoor solar panels in view of the need for robust encapsulation. Solvent-free room-temperature ionic liquids have been pursued as an attractive solution to this dilemma, and device efficiencies of over 7% were achieved by using some low-viscosity formulations containing 1-ethyl-3-methylimidazolium thiocyanate, selenocyanate, tricyanomethide or tetracyanoborate. Unfortunately, apart from tetracyanoborate, all of these low-viscosity melts proved to be unstable under prolonged thermal stress and light soaking. Here, we introduce the concept of using eutectic melts to produce solvent-free liquid redox electrolytes. Using a ternary melt in conjunction with a nanocrystalline titania film and the amphiphilic heteroleptic ruthenium complex Z907Na (ref. 10) as a sensitizer, we reach excellent stability and an unprecedented efficiency of 8.2% under air-mass 1.5 global illumination. Our results are of importance to realize large-scale outdoor applications of mesoscopic DSCs.

  12. Deep catalytic oxidative desulfurization (ODS) of dibenzothiophene (DBT) with oxalate-based deep eutectic solvents (DESs).

    PubMed

    Lü, Hongying; Li, Pengcheng; Deng, Changliang; Ren, Wanzhong; Wang, Shunan; Liu, Pan; Zhang, Han

    2015-07-01

    An oxalate-based DES with a tetrabutyl ammonium chloride and oxalate acid molar ratio of 1/2 (TBO1 : 2) exhibited high activity in oxidative desulfurization (ODS) of dibenzothiophene (DBT) under mild reaction conditions. It is potentially a promising and highly environmentally friendly approach for desulfurization of fuels. PMID:26051675

  13. Thermally conductive of nanofluid from surfactant doped polyaniline nanoparticle and deep eutectic ionic liquid

    NASA Astrophysics Data System (ADS)

    Siong, Chew Tze; Daik, Rusli; Hamid, Muhammad Azmi Abdul

    2014-09-01

    Nanofluid is a colloidal suspension of nano-size particles in a fluid. Spherical shape dodecylbenzenesulfonic acid doped polyaniline (DBSA-PANI) nanoparticles were synthesized via reverse micellar polymerization in isooctane with average size of 50 nm- 60 nm. The aim of study is to explore the possibility of using deep eutectic ionic liquid (DES) as a new base fluid in heat transfer application. DES was prepared by heating up choline chloride and urea with stirring. DES based nanofluids containing DBSA-PANI nanoparticles were prepared using two-step method. Thermal conductivity of nanofluids was measured using KD2 Pro Thermal Properties Analyzer. When incorporated with DBSA-PANI nanoparticles, DES with water was found to exhibit a bigger increase in thermal conductivity compared to that of the pure DES. The thermal conductivity of DES with water was increased by 4.67% when incorporated with 0.2 wt% of DBSA-PANI nanoparticles at 50°C. The enhancement in thermal conductivity of DES based nanofluids is possibly related to Brownian motion of nanoparticles as well as micro-convection of base fluids and also interaction between dopants and DES ions.

  14. Eutectic salt catalyzed environmentally benign and highly efficient Biginelli reaction.

    PubMed

    Azizi, Najmadin; Dezfuli, Sahar; Hahsemi, Mohmmad Mahmoodi

    2012-01-01

    A simple deep eutectic solvent based on tin (II) chloride was used as a dual catalyst and environmentally benign reaction medium for an efficient synthesis of 3,4-dihydropyrimidin-2(1H)-one derivatives, from aromatic and aliphatic aldehydes, 1,3-dicarbonyl compounds, and urea in good-to-excellent yields and short reaction time. This simple ammonium deep eutectic solvent, easily synthesized from choline chloride and tin chloride, is relatively inexpensive and recyclable, making it applicable for industrial applications. PMID:22649326

  15. Eutectic Salt Catalyzed Environmentally Benign and Highly Efficient Biginelli Reaction

    PubMed Central

    Azizi, Najmadin; Dezfuli, Sahar; Hahsemi, Mohmmad Mahmoodi

    2012-01-01

    A simple deep eutectic solvent based on tin (II) chloride was used as a dual catalyst and environmentally benign reaction medium for an efficient synthesis of 3,4-dihydropyrimidin-2(1H)-one derivatives, from aromatic and aliphatic aldehydes, 1,3-dicarbonyl compounds, and urea in good-to-excellent yields and short reaction time. This simple ammonium deep eutectic solvent, easily synthesized from choline chloride and tin chloride, is relatively inexpensive and recyclable, making it applicable for industrial applications. PMID:22649326

  16. Collective dynamic dipole moment and orientation fluctuations, cooperative hydrogen bond relaxations, and their connections to dielectric relaxation in ionic acetamide deep eutectics: Microscopic insight from simulations.

    PubMed

    Das, Suman; Biswas, Ranjit; Mukherjee, Biswaroop

    2016-08-28

    The paper reports a detailed simulation study on collective reorientational relaxation, cooperative hydrogen bond (H-bond) fluctuations, and their connections to dielectric relaxation (DR) in deep eutectic solvents made of acetamide and three uni-univalent electrolytes, lithium nitrate (LiNO3), lithium bromide (LiBr), and lithium perchlorate (LiClO4). Because cooperative H-bond fluctuations and ion migration complicate the straightforward interpretation of measured DR timescales in terms of molecular dipolar rotations for these conducting media which support extensive intra- and inter-species H-bonding, one needs to separate out the individual components from the overall relaxation for examining the microscopic origin of various timescales. The present study does so and finds that reorientation of ion-complexed acetamide molecules generates relaxation timescales that are in sub-nanosecond to nanosecond range. This explains in molecular terms the nanosecond timescales reported by recent giga-Hertz DR measurements. Interestingly, the simulated survival timescale for the acetamide-Li(+) complex has been found to be a few tens of nanosecond, suggesting such a cation-complexed species may be responsible for a similar timescale reported by mega-Hertz DR measurements of acetamide/potassium thiocyanate deep eutectics near room temperature. The issue of collective versus single particle relaxation is discussed, and jump waiting time distributions are determined. Dependence on anion-identity in each of the cases has been examined. In short, the present study demonstrates that assumption of nano-sized domain formation is not required for explaining the DR detected nanosecond and longer timescales in these media. PMID:27586932

  17. Deep Metastable Eutectic Nanometer-Scale Particles in the MgO-Al2O3-SiO2 System

    NASA Technical Reports Server (NTRS)

    Reitmeijer, Frans J. M.; Nash, J. A., III

    2011-01-01

    Laboratory vapor phase condensation experiments systematically yield amorphous, homogeneous, nanoparticles with unique deep metastable eutectic compositions. They formed during the nucleation stage in rapidly cooling vapor systems. These nanoparticles evidence the complexity of the nucleation stage. Similar complex behavior may occur during the nucleation stage in quenched-melt laboratory experiments. Because of the bulk size of the quenched system many of such deep metastable eutectic nanodomains will anneal and adjust to local equilibrium but some will persist metastably depending on the time-temperature regime and melt/glass transformation.

  18. Combined NMR and molecular dynamics modeling study of transport properties in sulfonamide based deep eutectic lithium electrolytes: LiTFSI based binary systems.

    PubMed

    Pauric, Allen D; Halalay, Ion C; Goward, Gillian R

    2016-03-01

    The trend toward Li-ion batteries operating at increased (>4.3 V vs. Li/Li(+)) voltages requires the development of novel classes of lithium electrolytes with electrochemical stability windows exceeding those of LiPF6/carbonate electrolyte solutions. Several new classes of electrolytes have been synthesized and investigated over the past decade, in the search for LIB electrolytes with improved properties (increased hydrolytic stability, improved thermal abuse tolerance, higher oxidation voltages, etc.) compared with the present state-of-the-art LiPF6 and organic carbonates-based formulations. Among these are deep eutectic electrolytes (DEEs), which share many beneficial characteristics with ionic liquids, such as low vapor pressure and large electrochemical stability windows, with the added advantage of a significantly higher lithium transference number. The present work presents the pulsed field gradient NMR characterization of the transport properties (diffusion coefficients and cation transport numbers) of binary DEEs consisting of a sulfonamide solvent and lithium bis(trifluoromethanesulfonyl)imide salt. Insights into the structural and dynamical properties, which enable one to rationalize the observed ionic conductivity behavior were obtained from a combination of NMR data and MD simulations. The insights thus gained should assist the formulation of novel DEEs with improved properties for LIB applications. PMID:26871506

  19. One-step fabrication of nanostructured Ni film with lotus effect from deep eutectic solvent.

    PubMed

    Gu, Changdong; Tu, Jiangping

    2011-08-16

    We report a procedure to fabricate nanostructured Ni films via programmed electrochemical deposition from a choline-chloride-based ionic liquid at a high temperature of 90 °C. Three electrodeposition modes using constant voltage, pulse voltage, and reverse pulse voltage produce a variety of nanostructured Ni films with micro/nanobinary surface architectures, such as nanosheets, aligned nanostrips, and hierarchical flowers. The nanostructured Ni films possess face-centered cubic crystal structure. Amazingly, it is found that the electrodeposited Ni films deliver the superhydrophobic surfaces without any further modifications by low surface-energy materials, which might be attributed to the vigorous micro/nanobinary architectures and the surface chemical composition. The electrochemical measurements reveal that the superhydrophobic Ni film exhibit an obvious passivation phenomenon, which could provide enhanced corrosion resistance for the substrate in the aqueous solutions. PMID:21739965

  20. Electroplated Fe-Co-Ni films prepared from deep-eutectic-solvent-based plating baths

    NASA Astrophysics Data System (ADS)

    Yanai, Takeshi; Shiraishi, Kotaro; Akiyoshi, Toshiki; Azuma, Keita; Watanabe, Yoshimasa; Ohgai, Takeshi; Morimura, Takao; Nakano, Masaki; Fukunaga, Hirotoshi

    2016-05-01

    We fabricated soft magnetic films from DES-based plating baths, and investigated magnetic properties of the plated films. The plating baths were obtained by stirring the mixture of choline chloride, ethylene glycol, FeCl2 ṡ 4H2O, NiCl2 ṡ 6H2O and CoCl2 ṡ 6H2O. The composition of the electroplated film depended on the amount of the reagent in the plating bath, and we consequently obtained the films with various composition. The current efficiency of the plating process shows high values (> 88 %) in the wide composition range. The soft magnetic films with low coercivity were obtained at the Fe compositions of ≈ 30 at.% and > 80 at.%, and we found that low coercivity could be realized by the control of the film composition. We also found that the Fe-rich films prepared from DES-based plating bath have some advantages as a soft magnetic phase for a nanocomposite magnet due to their high saturation magnetization and very fine crystal structure.

  1. Novel binary deep eutectic electrolytes for rechargeable Li-ion batteries based on mixtures of alkyl sulfonamides and lithium perfluoroalkylsulfonimide salts

    NASA Astrophysics Data System (ADS)

    Geiculescu, O. E.; DesMarteau, D. D.; Creager, S. E.; Haik, O.; Hirshberg, D.; Shilina, Y.; Zinigrad, E.; Levi, M. D.; Aurbach, D.; Halalay, I. C.

    2016-03-01

    Ionic liquids (IL's) were proposed for use in Li-ion batteries (LIBs), in order to mitigate some of the well-known drawbacks of LiPF6/mixed organic carbonates solutions. However, their large cations seriously decrease lithium transference numbers and block lithium insertion sites at electrode-electrolyte interfaces, leading to poor LIB rate performance. Deep eutectic electrolytes (DEEs) (which share some of the advantages of ILs but possess only one cation, Li+), were then proposed, in order to overcome the difficulties associated with ILs. We report herein on the preparation, thermal properties (melting, crystallization, and glass transition temperatures), transport properties (specific conductivity and viscosity) and thermal stability of binary DEEs based on mixtures of lithium bis(trifluoromethane)sulfonimide or lithium bis(fluoro)sulfonimide salts with an alkyl sulfonamide solvent. Promise for LIB applications is demonstrated by chronoamperometry on Al current collectors, and cycling behavior of negative and positive electrodes. Residual current densities of 12 and 45 nA cm-2 were observed at 5 V vs. Li/Li+ on aluminum, 1.5 and 16 nA cm-2 at 4.5 V vs. Li/Li+, respectively for LiFSI and LiTFSI based DEEs. Capacities of 220, 130, and 175 mAh· g-1 were observed at low (C/13 or C/10) rates, respectively for petroleum coke, LiMn1/3Ni1/3Co1/3O2 (a.k.a. NMC 111) and LiAl0.05Co0.15Ni0.8O2 (a.k.a. NCA).

  2. Interaction and dynamics of (alkylamide + electrolyte) deep eutectics: Dependence on alkyl chain-length, temperature, and anion identity

    NASA Astrophysics Data System (ADS)

    Guchhait, Biswajit; Das, Suman; Daschakraborty, Snehasis; Biswas, Ranjit

    2014-03-01

    Here we investigate the solute-medium interaction and solute-centered dynamics in (RCONH2 + LiX) deep eutectics (DEs) via carrying out time-resolved fluorescence measurements and all-atom molecular dynamics simulations at various temperatures. Alkylamides (RCONH2) considered are acetamide (CH3CONH2), propionamide (CH3CH2CONH2), and butyramide (CH3CH2CH2CONH2); the electrolytes (LiX) are lithium perchlorate (LiClO4), lithium bromide (LiBr), and lithium nitrate (LiNO3). Differential scanning calorimetric measurements reveal glass transition temperatures (Tg) of these DEs are ˜195 K and show a very weak dependence on alkyl chain-length and electrolyte identity. Time-resolved and steady state fluorescence measurements with these DEs have been carried out at six-to-nine different temperatures that are ˜100-150 K above their individual Tgs. Four different solute probes providing a good spread of fluorescence lifetimes have been employed in steady state measurements, revealing strong excitation wavelength dependence of probe fluorescence emission peak frequencies. Extent of this dependence, which shows sensitivity to anion identity, has been found to increase with increase of amide chain-length and decrease of probe lifetime. Time-resolved measurements reveal strong fractional power dependence of average rates for solute solvation and rotation with fraction power being relatively smaller (stronger viscosity decoupling) for DEs containing longer amide and larger (weaker decoupling) for DEs containing perchlorate anion. Representative all-atom molecular dynamics simulations of (CH3CONH2 + LiX) DEs at different temperatures reveal strongly stretched exponential relaxation of wavevector dependent acetamide self dynamic structure factor with time constants dependent both on ion identity and temperature, providing justification for explaining the fluorescence results in terms of temporal heterogeneity and amide clustering in these multi-component melts.

  3. Interaction and dynamics of (alkylamide + electrolyte) deep eutectics: dependence on alkyl chain-length, temperature, and anion identity.

    PubMed

    Guchhait, Biswajit; Das, Suman; Daschakraborty, Snehasis; Biswas, Ranjit

    2014-03-14

    Here we investigate the solute-medium interaction and solute-centered dynamics in (RCONH2 + LiX) deep eutectics (DEs) via carrying out time-resolved fluorescence measurements and all-atom molecular dynamics simulations at various temperatures. Alkylamides (RCONH2) considered are acetamide (CH3CONH2), propionamide (CH3CH2CONH2), and butyramide (CH3CH2CH2CONH2); the electrolytes (LiX) are lithium perchlorate (LiClO4), lithium bromide (LiBr), and lithium nitrate (LiNO3). Differential scanning calorimetric measurements reveal glass transition temperatures (T(g)) of these DEs are ~195 K and show a very weak dependence on alkyl chain-length and electrolyte identity. Time-resolved and steady state fluorescence measurements with these DEs have been carried out at six-to-nine different temperatures that are ~100-150 K above their individual T(g)s. Four different solute probes providing a good spread of fluorescence lifetimes have been employed in steady state measurements, revealing strong excitation wavelength dependence of probe fluorescence emission peak frequencies. Extent of this dependence, which shows sensitivity to anion identity, has been found to increase with increase of amide chain-length and decrease of probe lifetime. Time-resolved measurements reveal strong fractional power dependence of average rates for solute solvation and rotation with fraction power being relatively smaller (stronger viscosity decoupling) for DEs containing longer amide and larger (weaker decoupling) for DEs containing perchlorate anion. Representative all-atom molecular dynamics simulations of (CH3CONH2 + LiX) DEs at different temperatures reveal strongly stretched exponential relaxation of wavevector dependent acetamide self dynamic structure factor with time constants dependent both on ion identity and temperature, providing justification for explaining the fluorescence results in terms of temporal heterogeneity and amide clustering in these multi-component melts. PMID:24628189

  4. Deep desulfurization of light oil. 3. Effects of solvents on hydrodesulfurization of dibenzothiophene

    SciTech Connect

    Ishihara, Atsushi; Kabe, Toshiaki )

    1993-04-01

    Solvent effects on hydrodesulfurization (HDS) of dibenzothiophene (DBT) catalyzed by Co-Mo/Al[sub 2]O[sub 3] were investigated under deep hydrodesulfurization conditions. It was found that type of solvent affects HDS of DBT into biphenyl (BP). By contrast, the formation of cyclohexylbenzene (CHB) was scarcely affected by solvent such as xylene, decalin, tetralin, and n-hexadecane. From this result, it was suggested that desulfurization and hydrogenation proceed on different catalytic sites and that cyclohexylbenzene would be formed by hydrodesulfurization of hexahydrodibenzothiophene as well as hydrogenation of biphenyl.

  5. Interaction and dynamics of (alkylamide + electrolyte) deep eutectics: Dependence on alkyl chain-length, temperature, and anion identity

    SciTech Connect

    Guchhait, Biswajit; Das, Suman; Daschakraborty, Snehasis; Biswas, Ranjit

    2014-03-14

    Here we investigate the solute-medium interaction and solute-centered dynamics in (RCONH{sub 2} + LiX) deep eutectics (DEs) via carrying out time-resolved fluorescence measurements and all-atom molecular dynamics simulations at various temperatures. Alkylamides (RCONH{sub 2}) considered are acetamide (CH{sub 3}CONH{sub 2}), propionamide (CH{sub 3}CH{sub 2}CONH{sub 2}), and butyramide (CH{sub 3}CH{sub 2}CH{sub 2}CONH{sub 2}); the electrolytes (LiX) are lithium perchlorate (LiClO{sub 4}), lithium bromide (LiBr), and lithium nitrate (LiNO{sub 3}). Differential scanning calorimetric measurements reveal glass transition temperatures (T{sub g}) of these DEs are ∼195 K and show a very weak dependence on alkyl chain-length and electrolyte identity. Time-resolved and steady state fluorescence measurements with these DEs have been carried out at six-to-nine different temperatures that are ∼100–150 K above their individual T{sub g}s. Four different solute probes providing a good spread of fluorescence lifetimes have been employed in steady state measurements, revealing strong excitation wavelength dependence of probe fluorescence emission peak frequencies. Extent of this dependence, which shows sensitivity to anion identity, has been found to increase with increase of amide chain-length and decrease of probe lifetime. Time-resolved measurements reveal strong fractional power dependence of average rates for solute solvation and rotation with fraction power being relatively smaller (stronger viscosity decoupling) for DEs containing longer amide and larger (weaker decoupling) for DEs containing perchlorate anion. Representative all-atom molecular dynamics simulations of (CH{sub 3}CONH{sub 2} + LiX) DEs at different temperatures reveal strongly stretched exponential relaxation of wavevector dependent acetamide self dynamic structure factor with time constants dependent both on ion identity and temperature, providing justification for explaining the fluorescence results in

  6. Eutectic nucleation in hypoeutectic Al-Si alloys

    SciTech Connect

    Nafisi, S. Ghomashchi, R.; Vali, H.

    2008-10-15

    The nucleation mechanism of eutectic grains in hypoeutectic Al-Si foundry alloys has been investigated by examining deep etched specimens in high-resolution field emission gun scanning electron microscope (FEG-SEM) and by using in-situ Focused Ion Beam (FIB) milling and microscopy. Both unmodified and Sr-modified alloys were studied to characterize the nucleation mechanism of eutectic silicon flakes and fibers. It is proposed that following nucleation of eutectic Al on the primary {alpha}-Al dendrites, fine Si particles form at the solidification front upon which the eutectic Si flakes and fibers could develop. The formation of small Si particles is attributed to Si enrichment of the remaining melt due to the formation of eutectic Al (aluminum spikes) at the eutectic temperature. A hypothesis is then proposed to explain the mechanism of eutectic grains formation with main emphasis on the eutectic Si phase.

  7. Catalytic dehydration of carbohydrates suspended in organic solvents promoted by AlCl3 /SiO2 coated with choline chloride.

    PubMed

    Yang, Jie; De Oliveira Vigier, Karine; Gu, Yanlong; Jérôme, François

    2015-01-01

    We show that the coating of choline chloride on silica-supported AlCl3 allows the dehydration of carbohydrates to successfully proceed in low boiling point organic solvents. The concept is based on the in situ formation of a deep eutectic liquid phase on the catalyst surface, thus facilitating the interaction between the solid catalyst and insoluble carbohydrate. PMID:25404114

  8. Study of Eutectic Formation

    NASA Technical Reports Server (NTRS)

    Wilcox, W. R.

    1985-01-01

    The objectives of this program are to determine the influence of convection on the microstructure of eutectics and to develop a technique for revealing the longitudinal microstructure of the MnBi-Bi eutectic. Both objectives aim at trying to explain the observed influence of space processing on the microstructure of MnBi-Bi. A computer program was developed and used to determine the concentration field in front of a growing lamellar eutectic. From this the deviation of the interfacial concentration from the eutectic composition was calculated as a function of eutectic composition, freezing rate, convection, and lamellar spacing.

  9. Improving prediction of secondary structure, local backbone angles, and solvent accessible surface area of proteins by iterative deep learning

    PubMed Central

    Heffernan, Rhys; Paliwal, Kuldip; Lyons, James; Dehzangi, Abdollah; Sharma, Alok; Wang, Jihua; Sattar, Abdul; Yang, Yuedong; Zhou, Yaoqi

    2015-01-01

    Direct prediction of protein structure from sequence is a challenging problem. An effective approach is to break it up into independent sub-problems. These sub-problems such as prediction of protein secondary structure can then be solved independently. In a previous study, we found that an iterative use of predicted secondary structure and backbone torsion angles can further improve secondary structure and torsion angle prediction. In this study, we expand the iterative features to include solvent accessible surface area and backbone angles and dihedrals based on Cα atoms. By using a deep learning neural network in three iterations, we achieved 82% accuracy for secondary structure prediction, 0.76 for the correlation coefficient between predicted and actual solvent accessible surface area, 19° and 30° for mean absolute errors of backbone φ and ψ angles, respectively, and 8° and 32° for mean absolute errors of Cα-based θ and τ angles, respectively, for an independent test dataset of 1199 proteins. The accuracy of the method is slightly lower for 72 CASP 11 targets but much higher than those of model structures from current state-of-the-art techniques. This suggests the potentially beneficial use of these predicted properties for model assessment and ranking. PMID:26098304

  10. Low-transition-temperature mixtures (LTTMs): a new generation of designer solvents.

    PubMed

    Francisco, María; van den Bruinhorst, Adriaan; Kroon, Maaike C

    2013-03-11

    A new generation of designer solvents emerged in the last decade as promising green media for multiple applications, including separation processes: the low-transition-temperature mixtures (LTTMs). They can be prepared by mixing natural high-melting-point starting materials, which form a liquid by hydrogen-bond interactions. Among them, deep-eutectic solvents (DESs) were presented as promising alternatives to conventional ionic liquids (ILs). Some limitations of ILs are overcome by LTTMs, which are cheap and easy to prepare from natural and readily available starting materials, biodegradable, and renewable. PMID:23401138

  11. A simple model for examining composition effects in eutectic nucleation

    SciTech Connect

    Morris, James R; Jiang, Feng; Liaw, Peter K

    2007-01-01

    We present a simple thermodynamic calculation for a strongly partitioning eutectic system, to examine how the critical nucleus energy changes, depending upon assumptions of the chemical diffusion. The calculations show that for strongly partitioning systems, the maximum undercooling may occur at a composition significantly different than the eutectic composition, particularly if the rate of diffusion is slow in the undercooled state. These simple calculations emphasize the role that partitioning and composition may play in determining optimal compositions in metallic glass systems, which typically occur near (but not at) deep eutectic compositions.

  12. Part I: Virtual Laboratory versus Traditional Laboratory: Which Is More Effective for Teaching Electrochemistry? Part II: The Green Synthesis of Aurones Using a Deep Eutectic Solvent

    ERIC Educational Resources Information Center

    Hawkins, Ian C.

    2013-01-01

    The role of the teaching laboratory in science education has been debated over the last century. The goals and purposes of the laboratory are still debated and while most science educators consider laboratory a vital part of the education process, they differ widely on the purposes for laboratory and what methods should be used to teach…

  13. Study of eutectic formation

    NASA Technical Reports Server (NTRS)

    Wilcox, W. R.; Eisa, G. F.; Baskaran, V.; Richardson, D. C.

    1984-01-01

    A theory was developed for the influence of convection on the microstructure of lamellar eutectics. Convection is predicted to produce a coarser microstructure, especially at low freezing rates and large volume fractions of the minority phase. Similary convection is predicted to lower the interfacial undercooling, especially at low freezing rates. Experiments using spin-up/spin-down were performed on the Mn-Bi eutectic. This stirring had a dramatic effect on the microstructure, not only making it coarser but at low freezing rates also changing the morphology of the MnBi. The coarsering persisted to moderately high freezing rates. At the lowest freezing rate, vigorous stirring caused the MnBi to be concentrated at the periphery of the ingot and absent along the center. Progress was made on developing a technique for revealing the three-dimensional microstructure of the MnBi eutectic by time-lapse videotaping while etching.

  14. Eutectic-Alloy Morphology

    NASA Technical Reports Server (NTRS)

    Pirich, R. G.; Poit, W. J.

    1985-01-01

    Deviation in controlled-rod eutectic morphology anticipated for diffusion only crystal growth characterized at low solidification velocities. Naturally induced, gravity-related convective instabilities result in nonalined irregularly dispersed fibers or platelets. Lower solidification limit for controlled growth Bi/Mn alloys is 1 centimeter/ hour.

  15. Influence of convection of eutectic morphology

    NASA Technical Reports Server (NTRS)

    Curreri, P. A.; Larson, D. J.; Stefanescu, D. M.

    1988-01-01

    Experimental data are given for BiMn/Bi rod eutectic and Fe3C/Fe lamellar eutectic solidified in low gravity. Eutectic spacing is summarized for various alloy systems solidified in low gravity. On-eutectic and off-eutectic models are evaluated with respect to the low-gravity solidification data. The models examined are inadequate for quantitative prediction of phase spacing for on-eutectic solidification in low gravity.

  16. Template-Directed Directionally Solidified 3D Mesostructured AgCl-KCl Eutectic Photonic Crystals.

    PubMed

    Kim, Jinwoo; Aagesen, Larry K; Choi, Jun Hee; Choi, Jaewon; Kim, Ha Seong; Liu, Jinyun; Cho, Chae-Ryong; Kang, Jin Gu; Ramazani, Ali; Thornton, Katsuyo; Braun, Paul V

    2015-08-19

    3D mesostructured AgCl-KCl photonic crystals emerge from colloidal templating of eutectic solidification. Solvent removal of the KCl phase results in a mesostructured AgCl inverse opal. The 3D-template-induced confinement leads to the emergence of a complex microstructure. The 3D mesostructured eutectic photonic crystals have a large stop band ranging from the near-infrared to the visible tuned by the processing. PMID:26177830

  17. Coatings for directional eutectics

    NASA Technical Reports Server (NTRS)

    Rairden, J. R.; Jackson, M. R.

    1976-01-01

    Coatings developed to provide oxidation protection for the directionally-solidified eutectic alloy NiTaC-B (4.4 weight percent Cr) were evaluated. Of seven Co-, Fe- and Ni-base coatings that were initially investigated, best resistance to cyclic oxidation was demonstrated by duplex coatings fabricated by depositing a layer of NiCrAl(Y) by vacuum evaporation from an electron beam source followed by deposition of an Al overlayer using the pack cementation process. It was found that addition of carbon to the coating alloy substantially eliminated the problem of fiber denudation in TaC-type eutectic alloys. Burner rig cycled NiTaC-B samples coated with Ni-20Cr-5Al-0.1C-0.1Y+Al and rupture-tested at 1100 deg C performed as well as or better than uncoated, vacuum cycled and air-tested NiTaC-13; however, a slight degradation with respect to uncoated material was noted in air-stress rupture tests at 870 deg C for both cycled and uncycled samples.

  18. Composition formulas of binary eutectics

    NASA Astrophysics Data System (ADS)

    Ma, Y. P.; Dong, D. D.; Dong, C.; Luo, L. J.; Wang, Q.; Qiang, J. B.; Wang, Y. M.

    2015-12-01

    The present paper addresses the long-standing composition puzzle of eutectic points by introducing a new structural tool for the description of short-range-order structural unit, the cluster-plus-glue-atom model. In this model, any structure is dissociated into a 1st-neighbor cluster and a few glue atoms between the clusters, expressed by a cluster formula [cluster]gluex. This model is applied here to establish the structural model for eutectic liquids, assuming that a eutectic liquid consist of two subunits issued from the relevant eutectic phases, each being expressed by the cluster formula for ideal metallic glasses, i.e., [cluster](glue atom)1 or 3. A structural unit is then composed of two clusters from the relevant eutectic phases plus 2, 4, or 6 glue atoms. Such a dual cluster formulism is well validated in all boron-containing (except those located by the extreme phase diagram ends) and in some commonly-encountered binary eutectics, within accuracies below 1 at.%. The dual cluster formulas vary extensively and are rarely identical even for eutectics of close compositions. They are generally formed with two distinctly different cluster types, with special cluster matching rules such as cuboctahedron plus capped trigonal prism and rhombidodecahedron plus octahedral antiprism.

  19. Composition formulas of binary eutectics.

    PubMed

    Ma, Y P; Dong, D D; Dong, C; Luo, L J; Wang, Q; Qiang, J B; Wang, Y M

    2015-01-01

    The present paper addresses the long-standing composition puzzle of eutectic points by introducing a new structural tool for the description of short-range-order structural unit, the cluster-plus-glue-atom model. In this model, any structure is dissociated into a 1(st)-neighbor cluster and a few glue atoms between the clusters, expressed by a cluster formula [cluster]gluex. This model is applied here to establish the structural model for eutectic liquids, assuming that a eutectic liquid consist of two subunits issued from the relevant eutectic phases, each being expressed by the cluster formula for ideal metallic glasses, i.e., [cluster](glue atom)(1 or 3). A structural unit is then composed of two clusters from the relevant eutectic phases plus 2, 4, or 6 glue atoms. Such a dual cluster formulism is well validated in all boron-containing (except those located by the extreme phase diagram ends) and in some commonly-encountered binary eutectics, within accuracies below 1 at.%. The dual cluster formulas vary extensively and are rarely identical even for eutectics of close compositions. They are generally formed with two distinctly different cluster types, with special cluster matching rules such as cuboctahedron plus capped trigonal prism and rhombidodecahedron plus octahedral antiprism. PMID:26658618

  20. Composition formulas of binary eutectics

    PubMed Central

    Ma, Y. P.; Dong, D. D.; Dong, C.; Luo, L. J.; Wang, Q.; Qiang, J. B.; Wang, Y. M.

    2015-01-01

    The present paper addresses the long-standing composition puzzle of eutectic points by introducing a new structural tool for the description of short-range-order structural unit, the cluster-plus-glue-atom model. In this model, any structure is dissociated into a 1st-neighbor cluster and a few glue atoms between the clusters, expressed by a cluster formula [cluster]gluex. This model is applied here to establish the structural model for eutectic liquids, assuming that a eutectic liquid consist of two subunits issued from the relevant eutectic phases, each being expressed by the cluster formula for ideal metallic glasses, i.e., [cluster](glue atom)1 or 3. A structural unit is then composed of two clusters from the relevant eutectic phases plus 2, 4, or 6 glue atoms. Such a dual cluster formulism is well validated in all boron-containing (except those located by the extreme phase diagram ends) and in some commonly-encountered binary eutectics, within accuracies below 1 at.%. The dual cluster formulas vary extensively and are rarely identical even for eutectics of close compositions. They are generally formed with two distinctly different cluster types, with special cluster matching rules such as cuboctahedron plus capped trigonal prism and rhombidodecahedron plus octahedral antiprism. PMID:26658618

  1. Gravitational influence on eutectic solidification

    NASA Technical Reports Server (NTRS)

    Sokolowski, Robert S.; Glicksman, Martin E.

    1992-01-01

    The effect of gravity on eutectic solidification was investigated experimentally for Pb-Sn binary eutectic alloys. It is found that the separation of the primary crystals of the binary system from the coupled eutectic occurs over a wide range of cooling rates and gravitational fields (100-100,000 g). The separation is strongly influenced by the nucleation behavior of the particular alloy system. A mechanism for the strong phase separation is postulated on the basis of cloud convection models in atmospheric convection.

  2. Coatings for directional eutectics

    NASA Technical Reports Server (NTRS)

    Rairden, J. R.; Jackson, M. R.

    1976-01-01

    Significant advances have been made in the development of an environmentally stable coating for a very high strength, directionally solidified eutectic alloy designated NiTaC-13. Three duplex (two-layer) coatings survived 3,000 hours on a cyclic oxidation test (1,100 C to 90 C). These coatings were fabricated by first depositing a layer of NiCrAl(Y) by vacuum evaporation from an electron beam heated source, followed by depositing an aluminizing overlayer. The alloy after exposure with these coatings was denuded of carbide fibers at the substrate/coating interface. It was demonstrated that TaC fiber denudation can be greatly retarded by applying a carbon-bearing coating. The coating was applied by thermal spraying followed by aluminization. Specimens coated with NiCrAlCY+Al survived over 2,000 hours in the cyclic oxidation test with essentially no TaC denudation. Coating ductility was studied for coated and heat-treated bars, and stress rupture life at 871 C and 1,100 C was determined for coated and cycled bars.

  3. Directional Solidification of Eutectic Ceramics

    NASA Technical Reports Server (NTRS)

    Sayir, Ali

    2001-01-01

    Two major problems associated with structural ceramics are lack of damage tolerance and insufficient strength and creep resistance at very high temperatures of interest for aerospace application. This work demonstrated that the directionally solidified eutectics can have unique poly-phase microstructures and mechanical properties superior to either constituent alone. The constraining effect of unique eutectic microstructures result in higher resistance to slow crack growth and creep. Prospect of achieving superior properties through controlled solidification are presented and this technology can also be beneficial to produce new class of materials.

  4. A eutectic gold vapour laser

    NASA Astrophysics Data System (ADS)

    Tou, T. Y.; Cheak, K. E.; Low, K. S.

    This paper presents a eutectic gold vapour laser (EGVL) which uses the eutectic alloy of gold and silicon, Au/3.15Si, as the lasant. It was observed that, at low input power operation, the presence of the silicon vapour could increase the output of the 627.8 nm laser line by (50-60)% when compared with a gold vapour laser (GVL) which uses pure gold as the lasant. The improved laser output for the EGVL may be explained by an increased electron density, as a result of Penning ionization of silicon atoms. However, for higher input power operation, the EGVL showed a slower rate of increase in its laser output power and was overtaken by GVLs at a tube operating temperature of around 1650°C. This may be explained by a lowering of the electron temperature owing to increasing inelastic collisions between the electrons and silicon atoms which, although excited, may not produce additional electrons.

  5. A numerical model for eutectic spacing selection in the CBr 4C 2Cl 6 eutectic system

    NASA Astrophysics Data System (ADS)

    Liu, Jincheng; Elliott, R.

    1995-03-01

    It is well established that the lamellar eutectic structure exhibits a limited range of spacings rather than a unique spacing during steady state growth at a constant growth velocity. The minimum observed spacing corresponds to the extremum spacing predicted by the Jackson and Hunt analysis of eutectic growth. However, the maximum observed spacing is much less than the maximum spacing predicted by their analysis. The assumption of a planar interface by Jackson and Hunt is relaxed in this paper and a numerical model is developed which uses the boundary element method and an iterative technique to obtain the solute distribution for a selfconsistent curved interface shape. The maximum selfconsistent spacing, for which a selfconsistent interface exists, is determined for several growth velocities. The maximum selfconsistent spacings calculated in this way show good agreement with the maximum spacings observed in the CBr 4C 2Cl 6 eutectic system. The interface shape for the maximum selfconsistent spacings has a limiting slope which is far from vertical and the deepest point on the selfconsistent interface at the maximum spacing does not lie in a deep pocket.

  6. Metastability of Au-Ge liquid nanocatalysts: Ge vapor-liquid-solid nanowire growth far below the bulk eutectic temperature.

    PubMed

    Adhikari, Hemant; Marshall, Ann F; Goldthorpe, Irene A; Chidsey, Christopher E D; McIntyre, Paul C

    2007-12-01

    The vapor-liquid-solid mechanism of nanowire (NW) growth requires the presence of a liquid at one end of the wire; however, Au-catalyzed Ge nanowire growth by chemical vapor deposition can occur at approximately 100 degrees C below the bulk Au-Ge eutectic. In this paper, we investigate deep sub-eutectic stability of liquid Au-Ge catalysts on Ge NWs quantitatively, both theoretically and experimentally. We construct a binary Au-Ge phase diagram that is valid at the nanoscale and show that equilibrium arguments, based on capillarity, are inconsistent with stabilization of Au-Ge liquid at deep sub-eutectic temperatures, similar to those used in Ge NW growth. Hot-stage electron microscopy and X-ray diffraction are used to test the predictions of nanoscale phase equilibria. In addition to Ge supersaturation of the Au-Ge liquid droplet, which has recently been invoked as an explanation for deep sub-eutectic Ge NW growth, we find evidence of a substantial kinetic barrier to Au solidification during cooling below the nanoscale Au-Ge eutectic temperature. PMID:19206662

  7. New eutectic ionic liquids for lipase activation and enzymatic preparation of biodiesel†

    PubMed Central

    Zhao, Hua; Baker, Gary A.; Holmes, Shaletha

    2012-01-01

    The enzymatic preparation of biodiesel has been hampered by the lack of suitable solvents with desirable properties such as high lipase compatibility, low cost, low viscosity, high biodegradability, and ease of product separation. Recent interest in using ionic liquids (ILs) as advanced reaction media has led to fast reaction rates and high yields in the enzymatic synthesis of biodiesel. However, conventional (i.e., cation–anion paired) ILs based on imidazolium and other quaternary ammonium salts remain too expensive for wide application at industrial scales. In this study, we report on newly-synthesized eutectic ILs derived from choline acetate or choline chloride coupled with biocompatible hydrogen-bond donors, such as glycerol. These eutectic solvents have favorable properties including low viscosity, high biodegradability, and excellent compatibility with Novozym® 435, a commercial immobilized Candida antarctica lipase B. Furthermore, in a model biodiesel synthesis system, we demonstrate high reaction rates for the enzymatic transesterification of Miglyol® oil 812 with methanol, catalyzed by Novozym® 435 in choline acetate/glycerol (1 : 1.5 molar ratio). The high conversion (97%) of the triglyceride obtained within 3 h, under optimal conditions, suggests that these novel eutectic solvents warrant further exploration as potential media in the enzymatic production of biodiesel. PMID:21283901

  8. Eutectic Contact Inks for Solar Cells

    NASA Technical Reports Server (NTRS)

    Ross, B.

    1985-01-01

    Low-resistance electrical contacts formed on solar cells by melting powders of eutectic composition of semiconductor and dopant. Process improves cell performance without subjecting cell to processing temperatures high enough to degrade other characteristics.

  9. Eutectic bonding of sapphire to sapphire

    NASA Technical Reports Server (NTRS)

    Deluca, J. J.

    1973-01-01

    Eutectic mixture of aluminum oxide and zirconium oxide provides new bonding technique for sapphires and rubies. Technique effectively reduces possibility of contamination. Bonding material is aluminum oxide and zirconium oxide mixture that matches coefficient of thermal expansion of sapphire.

  10. Eutectic experiment development for space processing

    NASA Technical Reports Server (NTRS)

    Hopkins, R. H.

    1972-01-01

    A ground base test plan and a specimen evaluation scheme have been developed for the aluminum-copper eutectic solidification experiment to be run in the M518 multipurpose electric furnace during the Skylab mission. Besides thermal and solidification studies a detailed description is given of the quantitative metallographic technique which is appropriate for characterizing eutectic structures. This method should prove a key tool for evaluating specimen microstructure which is the most sensitive indicator of changes produced during solidification. It has been recommended that single grain pre-frozen eutectic specimens be used to simplify microstructural evaluation and to eliminate any porosity in the as-cast eutectic specimens. High purity (99.999%) materials from one supplier should be employed for all experiments. Laboratory studies indicate that porosity occurs in the MRC as-cast eutectic ingots but that this porosity can be eliminated by directional freezing. Chemical analysis shows that the MRC ingots are slightly Al rich and contain about .03% impurity. Because of the impurity content the lower cooldown rate (1.2 C/min) should be used for eutectic freezing if MRC material is used in the M518 furnace.