Concentration Fluctuations and Capacitive Response in Dense Ionic Solutions.

Science.gov (United States)

Uralcan, Betul; Aksay, Ilhan A; Debenedetti, Pablo G; Limmer, David T

2016-07-07

We use molecular dynamics simulations in a constant potential ensemble to study the effects of solution composition on the electrochemical response of a double layer capacitor. We find that the capacitance first increases with ion concentration following its expected ideal solution behavior but decreases upon approaching a pure ionic liquid in agreement with recent experimental observations. The nonmonotonic behavior of the capacitance as a function of ion concentration results from the competition between the independent motion of solvated ions in the dilute regime and solvation fluctuations in the concentrated regime. Mirroring the capacitance, we find that the characteristic decay length of charge density correlations away from the electrode is also nonmonotonic. The correlation length first decreases with ion concentration as a result of better electrostatic screening but increases with ion concentration as a result of enhanced steric interactions. When charge fluctuations induced by correlated ion-solvent fluctuations are large relative to those induced by the pure ionic liquid, such capacitive behavior is expected to be generic.

Cardiovascular responses to the intracarotid injections of ionic contrast media and iohexol in the dog

International Nuclear Information System (INIS)

Hayakawa, K.; Morris, T.W.; Katzberg, R.W.; Fischer, H.W.

1986-01-01

Hypotension and bradycardia are the most significant cardiovascular responses resulting from intracarotid injections of hypertonic contrast media (CM). We have assessed both local and systemic vascular responses to the selective intracarotid injections of ionic and non-ionic CM in twelve pentobarbital anesthetized dogs. Alterations in blood pressure, heart rate, and femoral, renal and carotid blood flows were monitored following right common carotid artery injections of ionic contrast media (282-288 mg I/ml), isotonic saline, and iohexol (300 mg I/ml). Ionic CM led to early (0 to 10 s) decreases in blood pressure, heart rate and femoral vascular resistance. Isotonic saline induced no significant early changes in these same parameters while iohexol caused a decrease in heart rate. Our observations suggest that the early (0 to 10 s) decreases in femoral vascular resistance, heart rate and pressure that occur with the intracarotid injection of hypertonic CM are mediated via the autonomic nervous system and initiated from a site in the carotid circulation. During the 15 to 40 s period when the CM has reached the systemic circulation, iohexol produced smaller effects on systemic blood pressure and peripheral vascular resistances than did the ionic CM. During this 15 to 40 s period there were decreased vascular resistances in the carotid and renal vascular beds that probably result from local effects of the CM, however, the femoral resistance was actually increased. This later increase in femoral resistance probably represents the results of increased symphathetic nervous system activity working to offset the decrease in renal and carotid resistances and thus maintain pressure at baseline values. The vascular resistance changes observed demonstrate a complexity of responses to CM not previously appreciated. (orig.)

Ionic responses rapidly elicited by activation of protein kinase C in quiescent Swiss 3T3 cells

International Nuclear Information System (INIS)

Vara, F.; Schneider, J.A.; Rozengurt, E.

1985-01-01

Diacylglycerol and phorbol esters activate protein kinase C in intact cells. The authors report here that addition of the synthetic diacylglycerol 1-oleoyl-2-acetylglycerol (OAG) to quiescent cultures of Swiss 3T3 cells caused a marked increase in the rate of ouabain-sensitive 86 Rb + uptake, a measure of the activity of the Na + /K + pump. The effect was dose-dependent and could be detected after 1 min of exposure to the diacylglycerol. OAG stimulated Na + influx via an amiloride-sensitive pathway and increased intracellular pH by 0.15 pH unit. Phorbol 12,13-dibutyrate (PBt 2 ) also enhanced ouabain sensitive 86 Rb + uptake and amiloride-sensitive 22 Na + influx. Prolonged treatment (40 hr) of 3T3 cells with PBt 2 at a saturating dose, which reduces the number of PBt 2 binding sites and protein kinase C activity, abolished the ionic response of the cells to a subsequent addition of either OAG or PBt 2 . They suggest that activation of protein kinase C elicits, either directly or indirectly, enhanced Na + /H + antiport activity, which, in turn, leads to Na + influx, intracellular pH modulation, and stimulation of the Na + /K + pump

Comparative investigation on electrochemical behavior of hydroquinone at carbon ionic liquid electrode, ionic liquid modified carbon paste electrode and carbon paste electrode

International Nuclear Information System (INIS)

Zhang, Ya; Zheng, Jian Bin

2007-01-01

Ionic liquid, 1-heptyl-3-methylimidazolium hexafluorophosphate (HMIMPF 6 ), has been used to fabricate two new electrodes, carbon ionic liquid electrode (CILE) and ionic liquid modified carbon paste electrode (IL/CPE), using graphite powder mixed with HMIMPF 6 or the mixture of HMIMPF 6 /paraffin liquid as the binder, respectively. The electrochemical behaviors of hydroquinone at the CILE, the IL/CPE and the CPE were investigated in phosphate buffer solution. At all these electrodes, hydroquinone showed a pair of redox peaks. The order of the current response and the standard rate constant of hydroquinone at these electrodes were as follows: CILE > IL/CPE > CPE, while the peak-to-peak potential separation was in an opposite sequence: CILE < IL/CPE < CPE. The results show the superiority of CILE to IL/CPE and CPE, and IL/CPE to CPE in terms of promoting electron transfer, improving reversibility and enhancing sensitivity. The CILE was chosen as working electrode to determine hydroquinone by differential pulse voltammetry, which can be used for sensitive, simple and rapid determination of hydroquinone in medicated skin cosmetic cream

The shape-memory effect in ionic elastomers: fixation through ionic interactions.

Science.gov (United States)

González-Jiménez, Antonio; Malmierca, Marta A; Bernal-Ortega, Pilar; Posadas, Pilar; Pérez-Aparicio, Roberto; Marcos-Fernández, Ángel; Mather, Patrick T; Valentín, Juan L

2017-04-19

Shape-memory elastomers based on a commercial rubber cross-linked by both ionic and covalent bonds have been developed. The elastomeric matrix was a carboxylated nitrile rubber (XNBR) vulcanized with magnesium oxide (MgO) providing ionic interactions that form hierarchical structures. The so-named ionic transition is used as the unique thermal transition responsible for the shape-memory effect (SME) in these elastomers. These ionic interactions fix the temporary shape due to their behavior as dynamic cross-links with temperature changes. Covalent cross-links were incorporated with the addition of different proportions of dicumyl peroxide (DCP) to the ionic elastomer to establish and recover the permanent shape. In this article, the SME was modulated by modifying the degree of covalent cross-linking, while keeping the ionic contribution constant. In addition, different programming parameters, such as deformation temperature, heating/cooling rate, loading/unloading rate and percentage of tensile strain, were evaluated for their effects on shape-memory behavior.

CADDIS Volume 2. Sources, Stressors and Responses: Ionic Strength - Simple Conceptual Diagram

Science.gov (United States)

Introduction to the ionic strength module, when to list ionic strength as a candidate cause, ways to measure ionic strength, simple and detailed conceptual diagrams for ionic strength, ionic strength module references and literature reviews.

CADDIS Volume 2. Sources, Stressors and Responses: Ionic Strength - Detailed Conceptual Diagram

Science.gov (United States)

Introduction to the ionic strength module, when to list ionic strength as a candidate cause, ways to measure ionic strength, simple and detailed conceptual diagrams for ionic strength, ionic strength module references and literature reviews.

Vibrational Spectroscopy of Ionic Liquids.

Science.gov (United States)

Paschoal, Vitor H; Faria, Luiz F O; Ribeiro, Mauro C C

2017-05-24

Vibrational spectroscopy has continued use as a powerful tool to characterize ionic liquids since the literature on room temperature molten salts experienced the rapid increase in number of publications in the 1990's. In the past years, infrared (IR) and Raman spectroscopies have provided insights on ionic interactions and the resulting liquid structure in ionic liquids. A large body of information is now available concerning vibrational spectra of ionic liquids made of many different combinations of anions and cations, but reviews on this literature are scarce. This review is an attempt at filling this gap. Some basic care needed while recording IR or Raman spectra of ionic liquids is explained. We have reviewed the conceptual basis of theoretical frameworks which have been used to interpret vibrational spectra of ionic liquids, helping the reader to distinguish the scope of application of different methods of calculation. Vibrational frequencies observed in IR and Raman spectra of ionic liquids based on different anions and cations are discussed and eventual disagreements between different sources are critically reviewed. The aim is that the reader can use this information while assigning vibrational spectra of an ionic liquid containing another particular combination of anions and cations. Different applications of IR and Raman spectroscopies are given for both pure ionic liquids and solutions. Further issues addressed in this review are the intermolecular vibrations that are more directly probed by the low-frequency range of IR and Raman spectra and the applications of vibrational spectroscopy in studying phase transitions of ionic liquids.

Recent development of ionic liquid membranes

OpenAIRE

Wang, Junfeng; Luo, Jianquan; Feng, Shicao; Li, Haoran; Wan, Yinhua; Zhang, Xiangping

2016-01-01

The interest in ionic liquids (IL) is motivated by its unique properties, such as negligible vapor pressure, thermal stability, wide electrochemical stability window, and tunability of properties. ILs have been highlighted as solvents for liquidâliquid extraction and liquid membrane separation. To further expand its application in separation field, the ionic liquid membranes (ILMs) and its separation technology have been proposed and developed rapidly. This paper is to give a comprehensive ov...

Effective visualization assay for alcohol content sensing and methanol differentiation with solvent stimuli-responsive supramolecular ionic materials.

Science.gov (United States)

Zhang, Li; Qi, Hetong; Wang, Yuexiang; Yang, Lifen; Yu, Ping; Mao, Lanqun

2014-08-05

This study demonstrates a rapid visualization assay for on-spot sensing of alcohol content as well as for discriminating methanol-containing beverages with solvent stimuli-responsive supramolecular ionic material (SIM). The SIM is synthesized by ionic self-assembling of imidazolium-based dication C10(mim)2 and dianionic 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) in water and shows water stability, a solvent stimuli-responsive property, and adaptive encapsulation capability. The rationale for the visualization assay demonstrated here is based on the combined utilization of the unique properties of SIM, including its water stability, ethanol stimuli-responsive feature, and adaptive encapsulation capability toward optically active rhodamine 6G (Rh6G); the addition of ethanol into a stable aqueous dispersion of Rh6G-encapsulated SIM (Rh6G-SIM) destructs the Rh6G-SIM structure, resulting in the release of Rh6G from SIM into the solvent. Alcohol content can thus be visualized with the naked eyes through the color change of the dispersion caused by the addition of ethanol. Alcohol content can also be quantified by measuring the fluorescence line of Rh6G released from Rh6G-SIM on a thin-layer chromatography (TLC) plate in response to alcoholic beverages. By fixing the diffusion distance of the mobile phase, the fluorescence line of Rh6G shows a linear relationship with alcohol content (vol %) within a concentration range from 15% to 40%. We utilized this visualization assay for on-spot visualizing of the alcohol contents of three Chinese commercial spirits and discriminating methanol-containing counterfeit beverages. We found that addition of a trace amount of methanol leads to a large increase of the length of Rh6G on TLC plates, which provides a method to identify methanol adulterated beverages with labeled ethanol content. This study provides a simple yet effective assay for alcohol content sensing and methanol differentiation.

Recent development of ionic liquid membranes

Directory of Open Access Journals (Sweden)

Junfeng Wang

2016-04-01

Full Text Available The interest in ionic liquids (IL is motivated by its unique properties, such as negligible vapor pressure, thermal stability, wide electrochemical stability window, and tunability of properties. ILs have been highlighted as solvents for liquid–liquid extraction and liquid membrane separation. To further expand its application in separation field, the ionic liquid membranes (ILMs and its separation technology have been proposed and developed rapidly. This paper is to give a comprehensive overview on the recent applications of ILMs for the separation of various compounds, including organic compounds, mixed gases, and metal ions. Firstly, ILMs was classified into supported ionic liquid membranes (SILMs and quasi-solidified ionic liquid membranes (QSILMs according to the immobilization method of ILs. Then, preparation methods of ILMs, membrane stability as well as applications of ILMs in the separation of various mixtures were reviewed. Followed this, transport mechanisms of gaseous mixtures and organic compounds were elucidated in order to better understand the separation process of ILMs. This tutorial review intends to not only offer an overview on the development of ILMs but also provide a guide for ILMs preparations and applications. Keywords: Ionic liquid membrane, Supported ionic liquid membrane, Qusai-solidified ionic liquid membrane, Stability, Application

Picosecond radiolysis of ionic liquids

International Nuclear Information System (INIS)

Funston, A.M.; Wishart, J.F.; Neta, P.; Lall, S.I.; Engel, R.

2003-01-01

Ionic liquids (ILs) are a rapidly expanding family of condensed-phase media with important applications in nuclear fuel and waste processing, energy production, improving the efficiency and safety of industrial chemical processes, and pollution prevention. Ionic liquids are completely nonvolatile, noncombustible, highly conductive, recyclable and capable of dissolving a wide variety of materials. An understanding of the radiation chemistry of ionic liquids is important for development of their applications in radioactive material processing and for the application of pulse radiolysis techniques to the general study of chemical reactivity in ionic liquids. Kinetic studies with a picosecond electron accelerator, such as the BNL Laser-Electron Accelerator Facility (LEAF), allow one to observe primary radiation products and their reactions on short time scales. For example, the solvated electron lifetime in neat methyltributylammonium bis(trifluoromethylsulfonyl)imide is ∼300 ns and its absorption maximum is ∼1400 nm. Kinetic studies of primary radiolytic products and their reactivities will be described for several types of ionic liquids. Supported in part by the U.S. Department of Energy, Division of Chemical Sciences, Office of Basic Energy Sciences, under contract DE-AC02-98-CH1088

Reduction in Mortality Following Pediatric Rapid Response Team Implementation.

Science.gov (United States)

Kolovos, Nikoleta S; Gill, Jeff; Michelson, Peter H; Doctor, Allan; Hartman, Mary E

2018-05-01

To evaluate the effectiveness of a physician-led rapid response team program on morbidity and mortality following unplanned admission to the PICU. Before-after study. Single-center quaternary-referral PICU. All unplanned PICU admissions from the ward from 2005 to 2011. The dataset was divided into pre- and post-rapid response team groups for comparison. A Cox proportional hazards model was used to identify the patient characteristics associated with mortality following unplanned PICU admission. Following rapid response team implementation, Pediatric Risk of Mortality, version 3, illness severity was reduced (28.7%), PICU length of stay was less (19.0%), and mortality declined (22%). Relative risk of death following unplanned admission to the PICU after rapid response team implementation was 0.685. For children requiring unplanned admission to the PICU, rapid response team implementation is associated with reduced mortality, admission severity of illness, and length of stay. Rapid response team implementation led to more proximal capture and aggressive intervention in the trajectory of a decompensating pediatric ward patient.

Rapid Response in Psychological Treatments for Binge-Eating Disorder

Science.gov (United States)

Hilbert, Anja; Hildebrandt, Thomas; Agras, W. Stewart; Wilfley, Denise E.; Wilson, G. Terence

2015-01-01

Objective Analysis of short- and long-term effects of rapid response across three different treatments for binge-eating disorder (BED). Method In a randomized clinical study comparing interpersonal psychotherapy (IPT), cognitive-behavioral guided self-help (CBTgsh), and behavioral weight loss (BWL) treatment in 205 adults meeting DSM-IV criteria for BED, the predictive value of rapid response, defined as ≥ 70% reduction in binge-eating by week four, was determined for remission from binge-eating and global eating disorder psychopathology at posttreatment, 6-, 12-, 18-, and 24-month follow-up. Results Rapid responders in CBTgsh, but not in IPT or BWL, showed significantly greater rates of remission from binge-eating than non-rapid responders, which was sustained over the long term. Rapid and non-rapid responders in IPT and rapid responders in CBTgsh showed a greater remission from binge-eating than non-rapid responders in CBTgsh and BWL. Rapid responders in CBTgsh showed greater remission from binge-eating than rapid responders in BWL. Although rapid responders in all treatments had lower global eating disorder psychopathology than non-rapid responders in the short term, rapid responders in CBTgsh and IPT were more improved than those in BWL and non-rapid responders in each treatment. Rapid responders in BWL did not differ from non-rapid responders in CBTgsh and IPT. Conclusions Rapid response is a treatment-specific positive prognostic indicator of sustained remission from binge-eating in CBTgsh. Regarding an evidence-based stepped care model, IPT, equally efficacious for rapid and non-rapid responders, could be investigated as a second-line treatment in case of non-rapid response to first-line CBTgsh. PMID:25867446

Cellulose ionics: switching ionic diode responses by surface charge in reconstituted cellulose films.

Science.gov (United States)

Aaronson, Barak D B; Wigmore, David; Johns, Marcus A; Scott, Janet L; Polikarpov, Igor; Marken, Frank

2017-09-25

Cellulose films as well as chitosan-modified cellulose films of approximately 5 μm thickness, reconstituted from ionic liquid media onto a poly(ethylene-terephthalate) (PET, 6 μm thickness) film with a 5, 10, 20, or 40 μm diameter laser-drilled microhole, show significant current rectification in aqueous NaCl. Reconstituted α-cellulose films provide "cationic diodes" (due to predominant cation conductivity) whereas chitosan-doped cellulose shows "anionic diode" effects (due to predominant anion conductivity). The current rectification, or "ionic diode" behaviour, is investigated as a function of NaCl concentration, pH, microhole diameter, and molecular weight of the chitosan dopant. Future applications are envisaged exploiting the surface charge induced switching of diode currents for signal amplification in sensing.

Toxicity of ionic liquids: eco(cyto)activity as complicated, but unavoidable parameter for task-specific optimization.

Science.gov (United States)

Egorova, Ksenia S; Ananikov, Valentine P

2014-02-01

Rapid progress in the field of ionic liquids in recent decades led to the development of many outstanding energy-conversion processes, catalytic systems, synthetic procedures, and important practical applications. Task-specific optimization emerged as a sharpening stone for the fine-tuning of structure of ionic liquids, which resulted in unprecedented efficiency at the molecular level. Ionic-liquid systems showed promising opportunities in the development of green and sustainable technologies; however, the chemical nature of ionic liquids is not intrinsically green. Many ionic liquids were found to be toxic or even highly toxic towards cells and living organisms. In this Review, we show that biological activity and cytotoxicity of ionic liquids dramatically depend on the nature of a biological system. An ionic liquid may be not toxic for particular cells or organisms, but may demonstrate high toxicity towards another target present in the environment. Thus, a careful selection of biological activity data is a must for the correct assessment of chemical technologies involving ionic liquids. In addition to the direct biological activity (immediate response), several indirect effects and aftereffects are of primary importance. The following principal factors were revealed to modulate toxicity of ionic liquids: i) length of an alkyl chain in the cation; ii) degree of functionalization in the side chain of the cation; iii) anion nature; iv) cation nature; and v) mutual influence of anion and cation. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Influence of Ambient Humidity on the Voltage Response of Ionic Polymer-Metal Composite Sensor.

Science.gov (United States)

Zhu, Zicai; Horiuchi, Tetsuya; Kruusamäe, Karl; Chang, Longfei; Asaka, Kinji

2016-03-31

Electrical potential based on ion migration exists not only in natural systems but also in ionic polymer materials. In order to investigate the influence of ambient humidity on voltage response, classical Au-Nafion IPMC was chosen as the reference sample. Voltage response under a bending deformation was measured in two ways: first, continuous measurement of voltage response in the process of absorption and desorption of water to study the tendency of voltage variation at all water states; second, measurements at multiple fixed ambient humidity levels to characterize the process of voltage response quantitatively. Ambient humidity influences the voltage response mainly by varying water content in ionic polymer. Under a step bending, the amplitude of initial voltage peak first increases and then decreases as the ambient humidity and the inherent water content decrease. This tendency is explained semiquantitatively by mass storage capacity related to the stretchable state of the Nafion polymer network. Following the initial peak, the voltage shows a slow decay to a steady state, which is first characterized in this paper. The relative voltage decay during the steady state always decreases as the ambient humidity is lowered. It is ascribed to progressive increase of the ratio between the water molecules in the cation hydration shell to the free water. Under sinusoidal mechanical bending excitation in the range of 0.1-10 Hz, the voltage magnitude increases with frequency at high ambient humidity but decreases with frequency at low ambient humidity. The relationship is mainly controlled by the voltage decay effect and the response speed.

In-vitro investigations of a pH- and ionic-strength-responsive polyelectrolytic hydrogel using a piezoresistive microsensor

Science.gov (United States)

Schulz, Volker; Guenther, Margarita; Gerlach, Gerald; Magda, Jules J.; Tathireddy, Prashant; Rieth, Loren; Solzbacher, Florian

2010-01-01

Environmental responsive or smart hydrogels show a volume phase transition due to changes of external stimuli such as pH or ionic strength of an ambient solution. Thus, they are able to convert reversibly chemical energy into mechanical energy and therefore they are suitable as sensitive material for integration in biochemical microsensors and MEMS devices. In this work, micro-fabricated silicon pressure sensor chips with integrated piezoresistors were used as transducers for the conversion of mechanical work into an appropriate electrical output signal due to the deflection of a thin silicon bending plate. Within this work two different sensor designs have been studied. The biocompatible poly(hydroxypropyl methacrylate-N,N-dimethylaminoethyl methacrylate-tetra-ethyleneglycol dimethacrylate) (HPMA-DMA-TEGDMA) was used as an environmental sensitive element in piezoresistive biochemical sensors. This polyelectrolytic hydrogel shows a very sharp volume phase transition at pH values below about 7.4 which is in the range of the physiological pH. The sensor's characteristic response was measured in-vitro for changes in pH of PBS buffer solution at fixed ionic strength. The experimental data was applied to the Hill equation and the sensor sensitivity as a function of pH was calculated out of it. The time-dependent sensor response was measured for small changes in pH, whereas different time constants have been observed. The same sensor principal was used for sensing of ionic strength. The time-dependent electrical sensor signal of both sensors was measured for variations in ionic strength at fixed pH value using PBS buffer solution. Both sensor types showed an asymmetric swelling behavior between the swelling and the deswelling cycle as well as different time constants, which was attributed to the different nature of mechanical hydrogel-confinement inside the sensor. PMID:21152365

Synthesis of 5-(hydroxymethyl)furfural in Ionic Liquids - Paving the Way to Renewable Chemicals

DEFF Research Database (Denmark)

Ståhlberg, Tim; Fu, Wenjing; Woodley, John

2011-01-01

The synthesis of 5-(hydroxymethyl)furfural (HMF) in ionic liquids is a field that has grown rapidly in recent years. Unique dissolving properties for crude biomass in combination with a high selectivity for HMF formation from hexose sugars make ionic liquids attractive reaction media for the prod......The synthesis of 5-(hydroxymethyl)furfural (HMF) in ionic liquids is a field that has grown rapidly in recent years. Unique dissolving properties for crude biomass in combination with a high selectivity for HMF formation from hexose sugars make ionic liquids attractive reaction media...... for the production of chemicals from renewable resources. A wide range of new catalytic systems that are unique for the transformation of glucose and fructose to HMF in ionic liquids has been found. However, literature examples of scale-up and process development are still scarce, and future research needs...... directions in process technology....

Rapid response in psychological treatments for binge eating disorder.

Science.gov (United States)

Hilbert, Anja; Hildebrandt, Thomas; Agras, W Stewart; Wilfley, Denise E; Wilson, G Terence

2015-06-01

Analysis of short- and long-term effects of rapid response across 3 different treatments for binge eating disorder (BED). In a randomized clinical study comparing interpersonal psychotherapy (IPT), cognitive-behavioral therapy guided self-help (CBTgsh), and behavioral weight loss (BWL) treatment in 205 adults meeting Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; APA, 1994) criteria for BED, the predictive value of rapid response, defined as ≥70% reduction in binge eating by Week 4, was determined for remission from binge eating and global eating disorder psychopathology at posttreatment, 6-, 12-, 18-, and 24-month follow-ups. Rapid responders in CBTgsh, but not in IPT or BWL, showed significantly greater rates of remission from binge eating than nonrapid responders, which was sustained over the long term. Rapid and nonrapid responders in IPT and rapid responders in CBTgsh showed a greater remission from binge eating than nonrapid responders in CBTgsh and BWL. Rapid responders in CBTgsh showed greater remission from binge eating than rapid responders in BWL. Although rapid responders in all treatments had lower global eating disorder psychopathology than nonrapid responders in the short term, rapid responders in CBTgsh and IPT were more improved than those in BWL and nonrapid responders in each treatment. Rapid responders in BWL did not differ from nonrapid responders in CBTgsh and IPT. Rapid response is a treatment-specific positive prognostic indicator of sustained remission from binge eating in CBTgsh. Regarding an evidence-based, stepped-care model, IPT, equally efficacious for rapid and nonrapid responders, could be investigated as a second-line treatment in case of nonrapid response to first-line CBTgsh. (c) 2015 APA, all rights reserved).

Rapid analysis of ethanol and water in commercial products using ionic liquid capillary gas chromatography with thermal conductivity detection and/or barrier discharge ionization detection.

Science.gov (United States)

Weatherly, Choyce A; Woods, Ross M; Armstrong, Daniel W

2014-02-26

Analysis of ethanol and water in consumer products is important in a variety of processes and often is mandated by regulating agencies. A method for the simultaneous quantitation of ethanol and water that is simple, accurate, precise, rapid, and cost-effective is demonstrated. This approach requires no internal standard for the quantitation of both ethanol and water at any/all levels in commercial products. Ionic liquid based gas chromatography (GC) capillary columns are used to obtain a fast analysis with high selectivity and resolution of water and ethanol. Typical run times are just over 3 min. Examination of the response range of water and ethanol with GC, thermal conductivity detection (TCD), and barrier ionization detection (BID) is performed. Quantitation of both ethanol and water in consumer products is accomplished with both TCD and BID GC detectors using a nonlinear calibration. Validation of method accuracy is accomplished by using standard reference materials.

Computational modeling predicts the ionic mechanism of late-onset responses in Unipolar Brush Cells

Directory of Open Access Journals (Sweden)

Sathyaa eSubramaniyam

2014-08-01

Full Text Available Unipolar Brush Cells (UBCs have been suggested to have a strong impact on cerebellar granular layer functioning, yet the corresponding cellular mechanisms remain poorly understood. UBCs have recently been reported to generate, in addition to early-onset glutamatergic synaptic responses, a late-onset response (LOR composed of a slow depolarizing ramp followed by a spike burst (Locatelli et al., 2013. The LOR activates as a consequence of synaptic activity and involves an intracellular cascade modulating H- and TRP-current gating. In order to assess the LOR mechanisms, we have developed a UBC multi-compartmental model (including soma, dendrite, initial segment and axon incorporating biologically realistic representations of ionic currents and a generic coupling mechanism regulating TRP and H channel gating. The model finely reproduced UBC responses to current injection, including a low-threshold spike sustained by CaLVA currents, a persistent discharge sustained by CaHVA currents, and a rebound burst following hyperpolarization sustained by H- and CaLVA-currents. Moreover, the model predicted that H- and TRP-current regulation was necessary and sufficient to generate the LOR and its dependence on the intensity and duration of mossy fiber activity. Therefore, the model showed that, using a basic set of ionic channels, UBCs generate a rich repertoire of delayed bursts, which could take part to the formation of tunable delay-lines in the local microcircuit.

Computational modeling predicts the ionic mechanism of late-onset responses in unipolar brush cells.

Science.gov (United States)

Subramaniyam, Sathyaa; Solinas, Sergio; Perin, Paola; Locatelli, Francesca; Masetto, Sergio; D'Angelo, Egidio

2014-01-01

Unipolar Brush Cells (UBCs) have been suggested to play a critical role in cerebellar functioning, yet the corresponding cellular mechanisms remain poorly understood. UBCs have recently been reported to generate, in addition to early-onset glutamate receptor-dependent synaptic responses, a late-onset response (LOR) composed of a slow depolarizing ramp followed by a spike burst (Locatelli et al., 2013). The LOR activates as a consequence of synaptic activity and involves an intracellular cascade modulating H- and TRP-current gating. In order to assess the LOR mechanisms, we have developed a UBC multi-compartmental model (including soma, dendrite, initial segment, and axon) incorporating biologically realistic representations of ionic currents and a cytoplasmic coupling mechanism regulating TRP and H channel gating. The model finely reproduced UBC responses to current injection, including a burst triggered by a low-threshold spike (LTS) sustained by CaLVA currents, a persistent discharge sustained by CaHVA currents, and a rebound burst following hyperpolarization sustained by H- and CaLVA-currents. Moreover, the model predicted that H- and TRP-current regulation was necessary and sufficient to generate the LOR and its dependence on the intensity and duration of mossy fiber activity. Therefore, the model showed that, using a basic set of ionic channels, UBCs generate a rich repertoire of bursts, which could effectively implement tunable delay-lines in the local microcircuit.

Thermodynamics, electrostatics, and ionic current in nanochannels grafted with pH-responsive end-charged polyelectrolyte brushes.

Science.gov (United States)

Chen, Guang; Das, Siddhartha

2017-03-01

In this paper, we study the thermodynamics, electrostatics, and an external electric field driven ionic current in a pH-responsive, end-charged polyelectrolyte (PE) brush grafted nanochannel. By employing a mean field theory, we unravel a highly nonintuitive interplay of pH and electrolyte salt concentration in dictating the height of the end-charged PE brush. Larger pH or weak hydrogen ion concentration leads to maximum ionization of the charge-producing group-as a consequence, the resulting the electric double layer (EDL) energy get maximized causing a maximum deviation of the brush height from the value (d 0 ) of the uncharged brush. This deviation may result in enhancement or lowering of the brush height as compared to d 0 depending on whether the PE end locates lower or higher than h/2 (h is the nanochannel half height) and the salt concentration. Subsequently, we use this combined PE-brush-configuration-EDL-electrostatics framework to compute the ionic current in the nanochannel. We witness that the ionic current for smaller pH is much larger despite the corresponding magnitude of the EDL electrostatic potential being much smaller-this stems from the presence of a much larger concentration of H+ ions at small pH and the fact that H+ ions have very large mobilities. In fact, this ionic current shows a steep variation with pH that can be useful in exploring new designs for applications involving quantification and characterization of ionic current in PE-brush-grafted nanochannels. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Possibilities and limitations of ionic liquids in electrochemical and electroanalytical measurements (a review)

OpenAIRE

Weidlich, Tomáš; Stočes, Matěj; Švancara, Ivan

2010-01-01

A review (with 155 refs.) concerning the current achievements and typical trends in the chemistry of (room temperature) ionic liquids, (RT)ILs, with particular emphasis on their applicability in electrochemical and electroanalytical measurements. The latter is documented on a rapid progress of ionic liquid-modified carbon paste electrodes (IL-CPEs), the so-called carbon ionic liquid electrodes (CILEs), and related configurations in the last half-decade, within the period of 200...

Interactions in ion pairs of protic ionic liquids: Comparison with aprotic ionic liquids

International Nuclear Information System (INIS)

Tsuzuki, Seiji; Shinoda, Wataru; Miran, Md. Shah; Kinoshita, Hiroshi; Yasuda, Tomohiro; Watanabe, Masayoshi

2013-01-01

The stabilization energies for the formation (E form ) of 11 ion pairs of protic and aprotic ionic liquids were studied by MP2/6-311G ** level ab initio calculations to elucidate the difference between the interactions of ions in protic ionic liquids and those in aprotic ionic liquids. The interactions in the ion pairs of protic ionic liquids (diethylmethylammonium [dema] and dimethylpropylammonium [dmpa] based ionic liquids) are stronger than those of aprotic ionic liquids (ethyltrimethylammonium [etma] based ionic liquids). The E form for the [dema][CF 3 SO 3 ] and [dmpa][CF 3 SO 3 ] complexes (−95.6 and −96.4 kcal/mol, respectively) are significantly larger (more negative) than that for the [etma][CF 3 SO 3 ] complex (−81.0 kcal/mol). The same trend was observed for the calculations of ion pairs of the three cations with the Cl − , BF 4 − , TFSA − anions. The anion has contact with the N–H bond of the dema + or dmpa + cations in the most stable geometries of the dema + and dmpa + complexes. The optimized geometries, in which the anions locate on the counter side of the cations, are 11.0–18.0 kcal/mol less stable, which shows that the interactions in the ions pairs of protic ionic liquids have strong directionality. The E form for the less stable geometries for the dema + and dmpa + complexes are close to those for the most stable etma + complexes. The electrostatic interaction, which is the major source of the attraction in the ion pairs, is responsible for the directionality of the interactions and determining the magnitude of the interaction energy. Molecular dynamic simulations of the [dema][TFSA] and [dmpa][TFSA] ionic liquids show that the N–H bonds of the cations have contact with the negatively charged (oxygen and nitrogen) atoms of TFSA − anion, while the strong directionality of the interactions was not suggested from the simulation of the [etma][CF 3 SO 3 ] ionic liquid

Nanoconfinement-enhanced conformational response of single DNA molecules to changes in ionic environment

DEFF Research Database (Denmark)

Reisner, Walter; Beech, J. P.; Larsen, Niels Bent

2007-01-01

100×100 nm in dimension. Surprisingly, we find that the variation of the persistence length alone with ionic strength is not enough to explain our results. The effect is due mainly to increasing self-avoidance created by the reduced screening of electrostatic interactions at low ionic strength......We show that the ionic environment plays a critical role in determining the configurational properties of DNA confined in silica nanochannels. The extension of DNA in the nanochannels increases as the ionic strength is reduced, almost tripling over two decades in ionic strength for channels around....... To quantify the increase in self-avoidance, we introduce a new parameter into the de Gennes theory: an effective DNA width that gives the increase in the excluded volume due to electrostatic repulsion....

Ionic Liquid Mediated Dispersion and Support of Functional Molecules on Cellulose Fibers for Stimuli-Responsive Chromic Paper Devices.

Science.gov (United States)

Koga, Hirotaka; Nogi, Masaya; Isogai, Akira

2017-11-22

Functional molecules play a significant role in the development of high-performance composite materials. Functional molecules should be well dispersed (ideally dissolved) and supported within an easy-to-handle substrate to take full advantage of their functionality and ensure easy handling. However, simultaneously achieving the dissolution and support of functional molecules remains a challenge. Herein, we propose the combination of a nonvolatile ionic liquid and an easy-to-handle cellulose paper substrate for achieving this goal. First, the photochromic molecule, i.e., diarylethene, was dissolved in the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([bmim]NTf 2 ). Then, diarylethene/[bmim]NTf 2 was supported on cellulose fibers within the paper, through hydrogen bonding between [bmim] cations of the ionic liquid and the abundant hydroxyl groups of cellulose. The as-prepared paper composites exhibited reversible, rapid, uniform, and vivid coloration and bleaching upon ultraviolet and visible light irradiation. The photochromic performance was superior to that of the paper prepared in the absence of [bmim]NTf 2 . This concept could be applied to other functional molecules. For example, lithium perchlorate/[bmim] tetrafluoroborate supported within cellulose paper acted as a flexible electrolyte to provide a paper-based electrochromic device. These findings are expected to further the development of composite materials with high functionality and practicality.

Effectiveness Analysis of a Part-Time Rapid Response System During Operation Versus Nonoperation.

Science.gov (United States)

Kim, Youlim; Lee, Dong Seon; Min, Hyunju; Choi, Yun Young; Lee, Eun Young; Song, Inae; Park, Jong Sun; Cho, Young-Jae; Jo, You Hwan; Yoon, Ho Il; Lee, Jae Ho; Lee, Choon-Taek; Do, Sang Hwan; Lee, Yeon Joo

2017-06-01

To evaluate the effect of a part-time rapid response system on the occurrence rate of cardiopulmonary arrest by comparing the times of rapid response system operation versus nonoperation. Retrospective cohort study. A 1,360-bed tertiary care hospital. Adult patients admitted to the general ward were screened. Data were collected over 36 months from rapid response system implementation (October 2012 to September 2015) and more than 45 months before rapid response system implementation (January 2009 to September 2012). None. The rapid response system operates from 7 AM to 10 PM on weekdays and from 7 AM to 12 PM on Saturdays. Primary outcomes were the difference of cardiopulmonary arrest incidence between pre-rapid response system and post-rapid response system periods and whether the rapid response system operating time affects the cardiopulmonary arrest incidence. The overall cardiopulmonary arrest incidence (per 1,000 admissions) was 1.43. Although the number of admissions per month and case-mix index were increased (3,555.18 vs 4,564.72, p times (0.82 vs 0.49/1,000 admissions; p = 0.001) but remained similar during rapid response system nonoperating times (0.77 vs 0.73/1,000 admissions; p = 0.729). The implementation of a part-time rapid response system reduced the cardiopulmonary arrest incidence based on the reduction of cardiopulmonary arrest during rapid response system operating times. Further analysis of the cost effectiveness of part-time rapid response system is needed.

Long-term culture change related to rapid response system implementation.

Science.gov (United States)

Stevens, Jennifer; Johansson, Anna; Lennes, Inga; Hsu, Douglas; Tess, Anjala; Howell, Michael

2014-12-01

Increasing attention to patient safety in training hospitals may come at the expense of trainee autonomy and professional growth. This study sought to examine changes in medical trainees' self-reported behaviour after the institution-wide implementation of a rapid response system. We conducted a two-point cross-sectional survey of medical trainees in 2006, during the implementation of a rapid response system, and in 2010, in a single academic medical centre. A novel instrument was used to measure trainee likelihood of calling for supervisory assistance, perception of autonomy, and comfort in managing decompensating patients. Non-parametric tests to assess for change were used and year of training was evaluated as an effect modifier. Response rates were 38% in 2006 and 70% in 2010. After 5 years of the full implementation of the rapid response system, residents were significantly more likely to report calling their attending physicians for assistance (rising from 40% to 65% of relevant situations; p autonomy at 5 years after the implementation of the rapid response system. These changes were mirrored in the actual use of the rapid response system, which increased by 41% during the 5-year period after adjustment for patient volume (p < 0.0001). A primary team-focused implementation of a rapid response system was associated with durable changes in resident physicians' reported behaviour, including increased comfort with involving more experienced physicians and managing unstable patients. © 2014 John Wiley & Sons Ltd.

Rapid response teams: qualitative analysis of their effectiveness.

Science.gov (United States)

Leach, Linda Searle; Mayo, Ann M

2013-05-01

Multidisciplinary rapid response teams focus on patients' emergent needs and manage critical situations to prevent avoidable deaths. Although research has focused primarily on outcomes, studies of the actual team effectiveness within the teams from multiple perspectives have been limited. To describe effectiveness of rapid response teams in a large teaching hospital in California that had been using such teams for 5 years. The grounded-theory method was used to discover if substantive theory might emerge from interview and/or observational data. Purposeful sampling was used to conduct in-person semistructured interviews with 17 key informants. Convenience sampling was used for the 9 observed events that involved a rapid response team. Analysis involved use of a concept or indicator model to generate empirical results from the data. Data were coded, compared, and contrasted, and, when appropriate, relationships between concepts were formed. Results Dimensions of effective team performance included the concepts of organizational culture, team structure, expertise, communication, and teamwork. Professionals involved reported that rapid response teams functioned well in managing patients at risk or in crisis; however, unique challenges were identified. Teams were loosely coupled because of the inconsistency of team members from day to day. Team members had little opportunity to develop relationships or team skills. The need for team training may be greater than that among teams that work together regularly under less time pressure to perform. Communication between team members and managing a crisis were critical aspects of an effective response team.

Rapid Response Team activation for pediatric patients on the acute pain service.

Science.gov (United States)

Teets, Maxwell; Tumin, Dmitry; Walia, Hina; Stevens, Jenna; Wrona, Sharon; Martin, David; Bhalla, Tarun; Tobias, Joseph D

2017-11-01

Untreated pain or overly aggressive pain management may lead to adverse physiologic consequences and activation of the hospital's Rapid Response Team. This study is a quality improvement initiative that attempts to identify patient demographics and patterns associated with Rapid Response Team consultations for patients on the acute pain service. A retrospective review of all patients on the acute pain service from February 2011 until June 2015 was cross-referenced with inpatients requiring consultation from the Rapid Response Team. Two independent practitioners reviewed electronic medical records to determine which events were likely associated with pain management interventions. Over a 4-year period, 4872 patients were admitted to the acute pain service of whom 135 unique patients required Rapid Response Team consults. There were 159 unique Rapid Response Team activations among 6538 unique acute pain service consults. A subset of 27 pain management-related Rapid Response Team consultations was identified. The largest percentage of patients on the acute pain service were adolescents aged 12-17 (36%). Compared to this age group, the odds of Rapid Response Team activation were higher among infants Team consultations may help to identify patients at risk for clinical decompensation. © 2017 John Wiley & Sons Ltd.

Ionic polarization

International Nuclear Information System (INIS)

Mahan, G.D.

1992-01-01

Ferroelectricity occurs in many different kinds of materials. Many of the technologically important solids, which are ferroelectric, can be classified as ionic. Any microscopic theory of ferroelectricity must contain a description of local polarization forces. We have collaborated in the development of a theory of ionic polarization which is quite successful. Its basic assumption is that the polarization is derived from the properties of the individual ions. We have applied this theory successfully to diverse subjects as linear and nonlinear optical response, phonon dispersion, and piezoelectricity. We have developed numerical methods using the local Density approximation to calculate the multipole polarizabilities of ions when subject to various fields. We have also developed methods of calculating the nonlinear hyperpolarizability, and showed that it can be used to explain light scattering experiments. This paper elaborates on this polarization theory

Laser-induced microscopic phase-transition on an ionic liquid

International Nuclear Information System (INIS)

Iguchi, Natsuki; Datta, Alokmay; Yoshikawa, Kenichi; Ma Yue

2009-01-01

Nematic-isotropic transition is induced in a 5 μm 'droplet' within an oriented bulk of a mixture of a liquid crystalline material with a room-temperature ionic liquid, by a laser working at 532 nm with an output power of 200 mW and a beam diameter of 1 μm. No microscopic phase transition is observed either in absence of the ionic liquid or at the other wavelength of 1064 nm, available to the Nd-YAG laser. This indicates the essential role on a resonant transfer of energy to the ionic liquid from the laser radiation, which is subsequently transferred to the liquid crystal. Spectroscopy of the pure liquid crystal and ionic liquid samples confirms this concept. Spatio-temporal image of the droplet growth shows, however, that the phase transition remains confined within the microscopic domain for the first 50 s, and then spreads out rapidly. Since resonant, quantum transitions between molecular levels takes place in less than microseconds, the about seven orders of magnitude slowing down of energy transfer observed here suggests unique hierarchical dynamics including the coupling between the intra-molecular motions in the ionic liquid and the inter-molecular forces between ionic liquid and liquid crystal.

Continuum electrostatics for ionic solutions with non-uniform ionic sizes

International Nuclear Information System (INIS)

Li Bo

2009-01-01

This work concerns electrostatic properties of an ionic solution with multiple ionic species of possibly different ionic sizes. Such properties are described by the minimization of an electrostatic free-energy functional of ionic concentrations. Bounds are obtained for ionic concentrations with low electrostatic free energies. Such bounds are used to show that there exists a unique set of equilibrium ionic concentrations that minimizes the free-energy functional. The equilibrium ionic concentrations are found to depend sorely on the equilibrium electrostatic potential, resembling the classical Boltzmann distributions that relate the equilibrium ionic concentrations to the equilibrium electrostatic potential. Unless all the ionic and solvent molecular sizes are assumed to be the same, explicit formulae of such dependence are, however, not available in general. It is nevertheless proved that in equilibrium the ionic charge density is a decreasing function of the electrostatic potential. This determines a variational principle with a convex functional for the electrostatic potential

Theoretical and experimental studies on ionic currents in nanopore-based biosensors.

Science.gov (United States)

Liu, Lei; Li, Chu; Ma, Jian; Wu, Yingdong; Ni, Zhonghua; Chen, Yunfei

2014-12-01

Novel generation of analytical technology based on nanopores has provided possibilities to fabricate nanofluidic devices for low-cost DNA sequencing or rapid biosensing. In this paper, a simplified model was suggested to describe DNA molecule's translocation through a nanopore, and the internal potential, ion concentration, ionic flowing speed and ionic current in nanopores with different sizes were theoretically calculated and discussed on the basis of Poisson-Boltzmann equation, Navier-Stokes equation and Nernst-Planck equation by considering several important parameters, such as the applied voltage, the thickness and the electric potential distributions in nanopores. In this way, the basic ionic currents, the modulated ionic currents and the current drops induced by translocation were obtained, and the size effects of the nanopores were carefully compared and discussed based on the calculated results and experimental data, which indicated that nanopores with a size of 10 nm or so are more advantageous to achieve high quality ionic current signals in DNA sensing.

Ionic conductivity in oxide heterostructures: the role of interfaces

Directory of Open Access Journals (Sweden)

Emiliana Fabbri, Daniele Pergolesi and Enrico Traversa

2010-01-01

Full Text Available Rapidly growing attention is being directed to the investigation of ionic conductivity in oxide film heterostructures. The main reason for this interest arises from interfacial phenomena in these heterostructures and their applications. Recent results revealed that heterophase interfaces have faster ionic conduction pathways than the bulk or homophase interfaces. This finding can open attractive opportunities in the field of micro-ionic devices. The influence of the interfaces on the conduction properties of heterostructures is becoming increasingly important with the miniaturization of solid-state devices, which leads to an enhanced interface density at the expense of the bulk. This review aims to describe the main evidence of interfacial phenomena in ion-conducting film heterostructures, highlighting the fundamental and technological relevance and offering guidelines to understanding the interface conduction mechanisms in these structures.

Impurity effects on ionic-liquid-based supercapacitors

International Nuclear Information System (INIS)

Liu, Kun; Lian, Cheng; Henderson, Douglas; Wu, Jianzhong

2016-01-01

Small amounts of an impurity may affect the key properties of an ionic liquid and such effects can be dramatically amplified when the electrolyte is under confinement. Here the classical density functional theory is employed to investigate the impurity effects on the microscopic structure and the performance of ionic-liquid-based electrical double-layer capacitors, also known as supercapacitors. Using a primitive model for ionic species, we study the effects of an impurity on the double layer structure and the integral capacitance of a room temperature ionic liquid in model electrode pores and find that an impurity strongly binding to the surface of a porous electrode can significantly alter the electric double layer structure and dampen the oscillatory dependence of the capacitance with the pore size of the electrode. Meanwhile, a strong affinity of the impurity with the ionic species affects the dependence of the integral capacitance on the pore size. Up to 30% increase in the integral capacitance can be achieved even at a very low impurity bulk concentration. As a result, by comparing with an ionic liquid mixture containing modified ionic species, we find that the cooperative effect of the bounded impurities is mainly responsible for the significant enhancement of the supercapacitor performance.

Impurity effects on ionic-liquid-based supercapacitors

Science.gov (United States)

Liu, Kun; Lian, Cheng; Henderson, Douglas; Wu, Jianzhong

2017-02-01

Small amounts of an impurity may affect the key properties of an ionic liquid and such effects can be dramatically amplified when the electrolyte is under confinement. Here the classical density functional theory is employed to investigate the impurity effects on the microscopic structure and the performance of ionic-liquid-based electrical double-layer capacitors, also known as supercapacitors. Using a primitive model for ionic species, we study the effects of an impurity on the double layer structure and the integral capacitance of a room temperature ionic liquid in model electrode pores and find that an impurity strongly binding to the surface of a porous electrode can significantly alter the electric double layer structure and dampen the oscillatory dependence of the capacitance with the pore size of the electrode. Meanwhile, a strong affinity of the impurity with the ionic species affects the dependence of the integral capacitance on the pore size. Up to 30% increase in the integral capacitance can be achieved even at a very low impurity bulk concentration. By comparing with an ionic liquid mixture containing modified ionic species, we find that the cooperative effect of the bounded impurities is mainly responsible for the significant enhancement of the supercapacitor performance.

Screening of ionic cores in partially ionized plasmas within linear response

International Nuclear Information System (INIS)

Gericke, D. O.; Vorberger, J.; Wuensch, K.; Gregori, G.

2010-01-01

We employ a pseudopotential approach to investigate the screening of ionic cores in partially ionized plasmas. Here, the effect of the tightly bound electrons is condensed into an effective potential between the (free) valence electrons and the ionic cores. Even for weak electron-ion coupling, the corresponding screening clouds show strong modifications from the Debye result for elements heavier than helium. Modifications of the theoretically predicted x-ray scattering signal and implications on measurements are discussed.

Proteomic alterations induced by ionic liquids in Aspergillus nidulans and Neurospora crassa.

Science.gov (United States)

Martins, Isabel; Hartmann, Diego O; Alves, Paula C; Planchon, Sébastien; Renaut, Jenny; Leitão, M Cristina; Rebelo, Luís P N; Silva Pereira, Cristina

2013-12-06

This study constitutes the first attempt to understand at the proteomic level the fungal response to ionic liquid stress. Ascomycota are able to grow in media supplemented with high concentrations of an ionic liquid, which, in turn, lead to major alterations in the fungal metabolic footprint. Herein, we analysed the differential accumulation of mycelial proteins in Aspergillus nidulans and Neurospora crassa after their exposure to two of the most commonly used ionic liquids: 1-ethyl-3-methylimidazolium chloride or cholinium chloride. Data obtained showed that numerous stress-responsive proteins (e.g. anti-ROS defence proteins) as well as several critical biological processes and/or pathways were affected by either ionic liquid. Amongst other changes, these compounds altered developmental programmes in both fungi (e.g. promoting the development of Hülle cells or conidiation) and led to accumulation of osmolytes, some of which may play an important role in multiple stress responses. In particular, in N. crassa, both ionic liquids increased the levels of proteins which are likely involved in the biosynthesis of unusual metabolites. These data potentially open new perspectives on ionic liquid research, furthering their conscious design and their use to trigger production of targeted metabolites. The present study emphasises the importance of understanding ionic liquid's stress responses, crucial to further their safe large-scale usage. Knowledge of the alterations prompted at a cellular and biochemical level gives also fresh perspectives on how to employ these "novel" compounds to manipulate proteins or pathways of biotechnological value. The results presented here provide meaningful insights into the understanding of fungi stress and adaptation responses to anthropogenic chemicals used in industry. © 2013.

Ionic liquid based vortex assisted liquid-liquid microextraction combined with liquid chromatography mass spectrometry for the determination of bisphenols in thermal papers with the aid of response surface methodology.

Science.gov (United States)

Asati, Ankita; Satyanarayana, G N V; Panchal, Smita; Thakur, Ravindra Singh; Ansari, Nasreen G; Patel, Devendra K

2017-08-04

A sensitive, rapid and efficient ionic liquid-based vortex assisted liquid-liquid microextraction (IL-VALLME) with Liquid Chromatography Mass spectrometry (LC-MS/MS) method is proposed for the determination of bisphenols in thermal paper. Extraction factors were systematically optimized by response surface methodology. Experimental factors showing significant effects on the analytical responses were evaluated using design of experiment. The limit of detection for Bisphenol-A (BPA) and Bisphenol-S (BPS) in thermal paper were 1.25 and 0.93μgkg -1 respectively. The dynamic linearity range for BPA was between 4 and 100μgkg -1 and the determination of coefficient (R 2 ) was 0.996. The values of the same parameters were 3-100μgkg -1 and 0.998 for BPS. The extraction recoveries of BPA and BPS in thermal paper were 101% and 99%. Percent relative standard deviation (% RSD) for matrix effect and matrix match effects were not more than 10%, for both bisphenols. The proposed method uses a statistical approach for the analysis of bisphenols in environmental samples, and is easy, rapid, requires minimum organic solvents and efficient. Copyright © 2017 Elsevier B.V. All rights reserved.

Analysis of responsive characteristics of ionic-strength-sensitive hydrogel with consideration of effect of equilibrium constant by a chemo-electro-mechanical model.

Science.gov (United States)

Li, Hua; Lai, Fukun; Luo, Rongmo

2009-11-17

A multiphysics model is presented in this paper for analysis of the influence of various equilibrium constants on the smart hydrogel responsive to the ionic strength of environmental solution, and termed the multieffect-coupling ionic-strength stimulus (MECis) model. The model is characterized by a set of partial differential governing equations by consideration of the mass and momentum conservations of the system and coupled chemical, electrical, and mechanical multienergy domains. The Nernst-Planck equations are derived by the mass conservation of the ionic species in both the interstitial fluid of the hydrogel and the surrounding solution. The binding reaction between the fixed charge groups of the hydrogel and the mobile ions in the solution is described by the fixed charge equation, which is based on the Langmuir monolayer theory. As an important effect for the binding reaction, the equilibrium constant is incorporated into the fixed charge equation. The kinetics of the hydrogel swelling/deswelling is illustrated by the mechanical equation, based on the law of momentum conservation for the solid polymeric networks matrix within the hydrogel. The MECis model is examined by comparison of the numerical simulations and experiments from open literature. The analysis of the influence of different equilibrium constants on the responsive characteristics of the ionic-strength-sensitive hydrogel is carried out with detailed discussion.

Acidic Ionic Liquids.

Science.gov (United States)

Amarasekara, Ananda S

2016-05-25

Ionic liquid with acidic properties is an important branch in the wide ionic liquid field and the aim of this article is to cover all aspects of these acidic ionic liquids, especially focusing on the developments in the last four years. The structural diversity and synthesis of acidic ionic liquids are discussed in the introduction sections of this review. In addition, an unambiguous classification system for various types of acidic ionic liquids is presented in the introduction. The physical properties including acidity, thermo-physical properties, ionic conductivity, spectroscopy, and computational studies on acidic ionic liquids are covered in the next sections. The final section provides a comprehensive review on applications of acidic ionic liquids in a wide array of fields including catalysis, CO2 fixation, ionogel, electrolyte, fuel-cell, membrane, biomass processing, biodiesel synthesis, desulfurization of gasoline/diesel, metal processing, and metal electrodeposition.

Optimization of enzymatic esterification of dihydrocaffeic acid with hexanol in ionic liquid using response surface methodology.

Science.gov (United States)

Gholivand, Somayeh; Lasekan, Ola; Tan, Chin Ping; Abas, Faridah; Wei, Leong Sze

2017-05-26

Developing an efficient lipophilization reaction system for phenolic derivatives could enhance their applications in food processing. Low solubility of phenolic acids reduces the efficiency of phenolic derivatives in most benign enzyme solvents. The conversion of phenolic acids through esterification alters their solubility and enhances their use as food antioxidant additives as well as their application in cosmetics. This study has shown that lipase-catalyzed esterification of dihydrocaffeic acid with hexanol in ionic liquid (1-butyl-3-methylimidazoliumbis (trifluoromethylsulfonyl) imide) was the best approach for esterification reaction. In order to achieve the maximum yield, the process was optimized by response surface methodology (RSM) based on a five-level and four independent variables such as: dosage of enzyme; hexanol/dihydrocaffeic acid mole ratio; temperature and reaction time. The optimum esterification condition (Y = 84.4%) was predicted to be obtained at temperature of 39.4 °C, time of 77.5 h dosage of enzyme at 41.6% and hexanol/dihydrocaffeic acid mole ratio of 2.1. Finally, this study has produced an efficient enzymatic esterification method for the preparation of hexyl dihydrocaffeate in vitro using a lipase in an ionic liquid system. Concentration of hexanol was the most significant (p < 0.05) independent variable that influenced the yield of hexyl dihydrocaffeate. Graphical abstract Synthesis of different Hexyl dihydrocaffeates in ionic liquid.

Market design for rapid demand response

DEFF Research Database (Denmark)

Nielsen, Kurt; Tamirat, Tseganesh Wubale

We suggest a market design for rapid demand response in electricity markets. The solution consists of remotely controlled switches, meters, forecasting models as well as a flexible auction market to set prices and select endusers job by job. The auction market motivates truth-telling and makes...... it simple to involve the endusers in advance and to activate demand response immediately. The collective solution is analyzed and economic simulations are conducted for the case of Kenya. Kenya has been su ering from unreliable electricity supply for many years and companies and households have learned...... to adjust by investments in backup generators. We focus on turning the many private backup generators into a demand response system. The economic simulation focuses on possible distortion introduced by various ways of splitting the generated surplus from the demand response system. An auction run instantly...

Scanning thermo-ionic microscopy for probing local electrochemistry at the nanoscale

Energy Technology Data Exchange (ETDEWEB)

Eshghinejad, Ahmadreza; Nasr Esfahani, Ehsan; Wang, Peiqi; Li, Jiangyu, E-mail: jjli@uw.edu [Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195 (United States); Xie, Shuhong [Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education, School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, Hunan (China); Shenzhen Key Laboratory of Nanobiomechanics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, Guangdong (China); Geary, Timothy C.; Adler, Stuart B. [Department of Chemical Engineering, University of Washington, Seattle, Washington 98195 (United States)

2016-05-28

Conventional electrochemical characterization techniques based on voltage and current measurements only probe faradaic and capacitive rates in aggregate. In this work we develop a scanning thermo-ionic microscopy (STIM) to probe local electrochemistry at the nanoscale, based on imaging of Vegard strain induced by thermal oscillation. It is demonstrated from both theoretical analysis and experimental validation that the second harmonic response of thermally induced cantilever vibration, associated with thermal expansion, is present in all solids, whereas the fourth harmonic response, caused by local transport of mobile species, is only present in ionic materials. The origin of STIM response is further confirmed by its reduced amplitude with respect to increased contact force, due to the coupling of stress to concentration of ionic species and/or electronic defects. The technique has been applied to probe Sm-doped Ceria and LiFePO{sub 4}, both of which exhibit higher concentrations of mobile species near grain boundaries. The STIM gives us a powerful method to study local electrochemistry with high sensitivity and spatial resolution for a wide range of ionic systems, as well as ability to map local thermomechanical response.

Ionic and molecular transport in beta- and beta''-alumina

International Nuclear Information System (INIS)

Bates, J.B.

1984-03-01

Investigations of rapid transport of cations and water molecules in the β- and β''-alumina family of superionic conductors are reviewed. Particular topics that are discussed include the Haven ratio and mixed-ion effects in β-alumina, and the influence of superlattice ordering on ionic transport in β''-alumina

Ionic charging by local imbalance at interfaces in hybrid lead halide perovskites

Energy Technology Data Exchange (ETDEWEB)

Almora, Osbel; Guerrero, Antonio; Garcia-Belmonte, Germà, E-mail: garciag@uji.es [Institute of Advanced Materials (INAM), Universitat Jaume I, 12071 Castelló (Spain)

2016-01-25

Identification of specific operating mechanisms becomes particularly challenging when mixed ionic-electronic conductors are used in optoelectronic devices. Ionic effects in perovskite solar cells are believed to distort operation curves and possess serious doubts about their long term stability. Current hysteresis and switchable photovoltaic characteristics have been connected to the kinetics of ion migration. However, the nature of the specific ionic mechanism (or mechanisms) able to explain the operation distortions is still poorly understood. It is observed here that the local rearrangement of ions at the electrode interfaces gives rise to commonly observed capacitive effects. Charging transients in response to step voltage stimuli using thick CH{sub 3}NH{sub 3}PbI{sub 3} samples show two main polarization processes and reveal the structure of the ionic double-layer at the interface with the non-reacting contacts. It is observed that ionic charging, with a typical response time of 10 s, is a local effect confined in the vicinity of the electrode, which entails absence of net mobile ionic concentration (space-charge) in the material bulk.

Effect of plasticizer and fumed silica on ionic conductivity behaviour ...

Indian Academy of Sciences (India)

behaviour of proton conducting polymer electrolytes containing different concentrations of hexafluorophosphoric acid (HPF6) in polyethylene oxide ... Polymer electrolytes; ionic conductivity; polyethylene oxide; plasticizer; fumed silica. 1. Introduction ..... is a rapid weight loss which could be due to the degradation of polymer ...

Recent advances in electrohydrodynamic pumps operated by ionic winds: a review

Science.gov (United States)

Johnson, Michael J.; Go, David B.

2017-10-01

An ionic or electric wind is a bulk air movement induced by electrohydrodynamic (EHD) phenomena in a gas discharge. Because they are silent, low power, respond rapidly, and require no moving parts, ionic wind devices have been proposed for a wide range of applications, ranging from convection cooling and food drying to combustion management. The past several decades have seen the area grow tremendously leading to a number of new actuation strategies and devices that can be incorporated into various applications. In this review, we discuss the physics of ionic winds and recent developments of the past five years that have pushed the field forward, focusing on the development on bulk air-moving devices we term EHD pumps. We then highlight the ongoing challenges with transitioning ionic wind technologies to the market place, from issues that affect robustness to practical implementation, and point to areas where future research could have an impact on the field.

Response surface optimization of pH and ionic strength for emulsion characteristics of egg yolk.

Science.gov (United States)

Kurt, S; Zorba, O

2009-11-01

Effects of pH (3.5, 4.5, 6.0, 7.5, and 8.5) and ionic strength (0.05, 0.15, 0.30, 0.45, and 0.55 M NaCl) on emulsion capacity, emulsion stability (ES), apparent yield stress of emulsion (AYS), and emulsion density (ED) of egg yolk were studied by using a model system. Ionic strength and pH had significant (P emulsion characteristics of egg yolk. Their interaction effects also have been found significant on ES, AYS, and ED. Predicted solutions of ES, emulsion capacity, and ED were minimum. The critical point of ES was determined to be at pH 6.08 and an ionic strength of 0.49 (M NaCl). Predicted solution for AYS was a maximum, which was determined to be at pH 6.04 and an ionic strength of 0.29 (M NaCl). Optimum values of pH and ionic strenght were 4.61 to 7.43 and 0.10 to 0.47, respectively.

Low-lying Photoexcited States of a One-Dimensional Ionic Extended Hubbard Model

Science.gov (United States)

Yokoi, Kota; Maeshima, Nobuya; Hino, Ken-ichi

2017-10-01

We investigate the properties of low-lying photoexcited states of a one-dimensional (1D) ionic extended Hubbard model at half-filling. Numerical analysis by using the full and Lanczos diagonalization methods shows that, in the ionic phase, there exist low-lying photoexcited states below the charge transfer gap. As a result of comparison with numerical data for the 1D antiferromagnetic (AF) Heisenberg model, it was found that, for a small alternating potential Δ, these low-lying photoexcited states are spin excitations, which is consistent with a previous analytical study [Katsura et al., link ext-link-type="uri" xlink:href="https://doi.org/10.1103/PhysRevLett.103.177402" xlink:type="simple">Phys. Rev. Lett. 103, 177402 (2009)link>]. As Δ increases, the spectral intensity of the 1D ionic extended Hubbard model rapidly deviates from that of the 1D AF Heisenberg model and it is clarified that this deviation is due to the neutral-ionic domain wall, an elementary excitation near the neutral-ionic transition point.

Determination of triazine herbicides in juice samples by microwave-assisted ionic liquid/ionic liquid dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography.

Science.gov (United States)

Su, Rui; Li, Dan; Wu, Lijie; Han, Jing; Lian, Wenhui; Wang, Keren; Yang, Hongmei

2017-07-01

A novel microextraction method, termed microwave-assisted ionic liquid/ionic liquid dispersive liquid-liquid microextraction, has been developed for the rapid enrichment and analysis of triazine herbicides in fruit juice samples by high-performance liquid chromatography. Instead of using hazardous organic solvents, two kinds of ionic liquids, a hydrophobic ionic liquid (1-hexyl-3-methylimidazolium hexafluorophosphate) and a hydrophilic ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate), were used as the extraction solvent and dispersion agent, respectively, in this method. The extraction procedure was induced by the formation of cloudy solution, which was composed of fine drops of 1-hexyl-3-methylimidazolium hexafluorophosphate dispersed entirely into sample solution with the help of 1-butyl-3-methylimidazolium tetrafluoroborate. In addition, an ion-pairing agent (NH 4 PF 6 ) was introduced to improve recoveries of the ionic liquid phase. Several experimental parameters that might affect the extraction efficiency were investigated. Under the optimum experimental conditions, the linearity for determining the analytes was in the range of 5.00-250.00 μg/L, with the correlation coefficients of 0.9982-0.9997. The practical application of this effective and green method is demonstrated by the successful analysis of triazine herbicides in four juice samples, with satisfactory recoveries (76.7-105.7%) and relative standard deviations (lower than 6.6%). In general, this method is fast, effective, and robust to determine triazine herbicides in juice samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Canopy Dynamics in Nanoscale Ionic Materials

KAUST Repository

Jespersen, Michael L.

2010-07-27

Nanoscale ionic materials (NIMS) are organic - inorganic hybrids in which a core nanostructure is functionalized with a covalently attached corona and an ionically tethered organic canopy. NIMS are engineered to be liquids under ambient conditions in the absence of solvent and are of interest for a variety of applications. We have used nuclear magnetic resonance (NMR) relaxation and pulse-field gradient (PFG) diffusion experiments to measure the canopy dynamics of NIMS prepared from 18-nm silica cores modified by an alkylsilane monolayer possessing terminal sulfonic acid functionality, paired with an amine-terminated ethylene oxide/propylene oxide block copolymer canopy. Carbon NMR studies show that the block copolymer canopy is mobile both in the bulk and in the NIMS and that the fast (ns) dynamics are insensitive to the presence of the silica nanoparticles. Canopy diffusion in the NIMS is slowed relative to the neat canopy, but not to the degree predicted from the diffusion of hard-sphere particles. Canopy diffusion is not restricted to the surface of the nanoparticles and shows unexpected behavior upon addition of excess canopy. Taken together, these data indicate that the liquid-like behavior in NIMS is due to rapid exchange of the block copolymer canopy between the ionically modified nanoparticles. © 2010 American Chemical Society.

Canopy Dynamics in Nanoscale Ionic Materials

KAUST Repository

Jespersen, Michael L.; Mirau, Peter A.; Meerwall, Ernst von; Vaia, Richard A.; Rodriguez, Robert; Giannelis, Emmanuel P.

2010-01-01

Nanoscale ionic materials (NIMS) are organic - inorganic hybrids in which a core nanostructure is functionalized with a covalently attached corona and an ionically tethered organic canopy. NIMS are engineered to be liquids under ambient conditions in the absence of solvent and are of interest for a variety of applications. We have used nuclear magnetic resonance (NMR) relaxation and pulse-field gradient (PFG) diffusion experiments to measure the canopy dynamics of NIMS prepared from 18-nm silica cores modified by an alkylsilane monolayer possessing terminal sulfonic acid functionality, paired with an amine-terminated ethylene oxide/propylene oxide block copolymer canopy. Carbon NMR studies show that the block copolymer canopy is mobile both in the bulk and in the NIMS and that the fast (ns) dynamics are insensitive to the presence of the silica nanoparticles. Canopy diffusion in the NIMS is slowed relative to the neat canopy, but not to the degree predicted from the diffusion of hard-sphere particles. Canopy diffusion is not restricted to the surface of the nanoparticles and shows unexpected behavior upon addition of excess canopy. Taken together, these data indicate that the liquid-like behavior in NIMS is due to rapid exchange of the block copolymer canopy between the ionically modified nanoparticles. © 2010 American Chemical Society.

Correlates of rapid neuroleptic response in male patients with schizophrenia.

Science.gov (United States)

Petrie, E C; Faustman, W O; Moses, J A; Lombrozo, L; Csernansky, J G

1990-08-01

Correlates of neuroleptic response latency were assessed in 16 male schizophrenic inpatients during 4 weeks of fixed dose (20 mg/day) haloperidol treatment. Rapid responders showed a mean 40% reduction in Brief Psychiatric Rating Scale (BPRS) positive symptom scores by day 10 of treatment. Rapid responders had significantly lower plasma homovanillic acid (pHVA) concentrations compared to non-rapid responders during week 4 of haloperidol treatment. However, rapid versus non-rapid responders did not differ with respect to demographics, baseline positive or negative BPRS symptom scores, performance on tests of neuropsychological function, or mean plasma haloperidol concentrations.

Optical nose based on porous silicon photonic crystal infiltrated with ionic liquids

Energy Technology Data Exchange (ETDEWEB)

Zhang, Haijuan [Institute of Microanalytical System, Department of Chemistry, Zhejiang University, Hangzhou, 3100058 (China); Zhejiang Academy of Medical Sciences, Hangzhou, 310013 (China); Lin, Leimiao; Liu, Dong; Chen, Qiaofen [Institute of Microanalytical System, Department of Chemistry, Zhejiang University, Hangzhou, 3100058 (China); Wu, Jianmin, E-mail: wjm-st1@zju.edu.cn [Institute of Microanalytical System, Department of Chemistry, Zhejiang University, Hangzhou, 3100058 (China)

2017-02-08

A photonic-nose for the detection and discrimination of volatile organic compounds (VOCs) was constructed. Each sensing element on the photonic sensor array was formed by infiltrating a specific type of ionic liquid (IL) into the pore channel of a patterned porous silicon (PSi) chip. Upon exposure to VOC, the density of IL dramatically decreased due to the nano-confinement effect. As a result, the IL located in pore channel expanded its volume and protrude out of the pore channel, leading to the formation of microdroplets on the PSi surface. These VOC-stimulated microdroplets could scatter the light reflected from the PSi rugate filter, thereby producing an optical response to VOC. The intensity of the optical response produced by IL/PSi sensor mainly depends on the size and shape of microdroplets, which is related to the concentration of VOC and the physi-chemical propertied of ILs. For ethanol vapor, the optical response has linear relationship with its relative vapor pressure within 0–60%. The LOD of the IL/PSi sensor for ethanol detection is calculated to be 1.3 ppm. It takes around 30 s to reach a full optical response, while the time for recovery is less than 1 min. In addition, the sensor displayed good stability and reproducibility. Owing to the different molecular interaction between IL and VOC, the ILs/PSi sensor array can generate a unique cross-reactive “fingerprint” in response to a specific type of VOC analyte. With the assistance of image technologies and principle components analysis (PCA), rapid discrimination of VOC analyte could be achieved based on the pattern recognition of photonic sensor array. The technology established in this work allows monitoring in-door air pollution in a visualized way. - Highlights: • Ionic liquids confined in the pore channel of porous silicon (PSi) can form microdroplets on the PSi surface upon exposure to VOCs. • These VOC-stimulated microdroplets could scattered the light reflected from the PSi rugate

Holographic sensors for the determination of ionic strength

International Nuclear Information System (INIS)

Marshall, Alexander J.; Young, Duncan S.; Kabilan, Satyamoorthy; Hussain, Abid; Blyth, Jeff; Lowe, Christopher R.

2004-01-01

Holographic sensors for monitoring ionic strength have been fabricated from charged sulphonate and quaternary ammonium monomers, incorporated into thin, polymeric hydrogel films which were transformed into volume holograms. The diffraction wavelength or reflected colour of the holograms was used to characterise their swelling or de-swelling behaviour as a function of ionic strength in various media. The effects of co-monomer structure, buffer composition, ion composition, pH and temperature were evaluated, whilst the reversibility and reproducibility of the sensor was also assessed. An acrylamide-based hologram containing equal molar amounts of negatively and positively charged monomers was shown to be able to quantify ionic strength independent of the identity of the ionic species present in the test solution. The sensor was fully reversible, free of hysteresis and exhibited little response to pH between 3 and 9 and temperature within the range 20-45 deg. C. The system was successfully used to quantify the ionic strength of milk solutions, which contain a complex mixture of ions and biological components

Holographic sensors for the determination of ionic strength

Energy Technology Data Exchange (ETDEWEB)

Marshall, Alexander J. [Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT (United Kingdom)]. E-mail: ajm205@cam.ac.uk; Young, Duncan S. [Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT (United Kingdom); Kabilan, Satyamoorthy [Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT (United Kingdom); Hussain, Abid [Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT (United Kingdom); Blyth, Jeff [Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT (United Kingdom); Lowe, Christopher R. [Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT (United Kingdom)]. E-mail: crl1@biotech.cam.ac.uk

2004-11-29

Holographic sensors for monitoring ionic strength have been fabricated from charged sulphonate and quaternary ammonium monomers, incorporated into thin, polymeric hydrogel films which were transformed into volume holograms. The diffraction wavelength or reflected colour of the holograms was used to characterise their swelling or de-swelling behaviour as a function of ionic strength in various media. The effects of co-monomer structure, buffer composition, ion composition, pH and temperature were evaluated, whilst the reversibility and reproducibility of the sensor was also assessed. An acrylamide-based hologram containing equal molar amounts of negatively and positively charged monomers was shown to be able to quantify ionic strength independent of the identity of the ionic species present in the test solution. The sensor was fully reversible, free of hysteresis and exhibited little response to pH between 3 and 9 and temperature within the range 20-45 deg. C. The system was successfully used to quantify the ionic strength of milk solutions, which contain a complex mixture of ions and biological components.

Osmotic heat engine using thermally responsive ionic liquids

KAUST Repository

Zhong, Yujiang

2017-07-11

The osmotic heat engine (OHE) is a promising technology for converting low grade heat to electricity. Most of the existing studies have focused on thermolytic salt systems. Herein, for the first time, we proposed to use thermally responsive ionic liquids (TRIL) that have either an upper critical solution temperature (UCST) or lower critical solution temperature (LCST) type of phase behavior as novel thermolytic osmotic agents. Closed-loop TRIL-OHEs were designed based on these unique phase behaviors to convert low grade heat to work or electricity. Experimental studies using two UCST-type TRILs, protonated betaine bis(trifluoromethyl sulfonyl)imide ([Hbet][Tf2N]) and choline bis(trifluoromethylsulfonyl)imide ([Choline][Tf2N]) showed that (1) the specific energy of the TRIL-OHE system could reach as high as 4.0 times that of the seawater and river water system, (2) the power density measured from a commercial FO membrane reached up to 2.3 W/m2, and (3) the overall energy efficiency reached up to 2.6% or 18% of the Carnot efficiency at no heat recovery and up to 10.5% or 71% of the Carnet efficiency at 70% heat recovery. All of these results clearly demonstrated the great potential of using TRILs as novel osmotic agents to design high efficient OHEs for recovery of low grade thermal energy to work or electricity.

In-vitro investigations of a pH- and ionic-strength-responsive polyelectrolytic hydrogel using a piezoresistive microsensor

OpenAIRE

Schulz, Volker; Guenther, Margarita; Gerlach, Gerald; Magda, Jules J.; Tathireddy, Prashant; Rieth, Loren; Solzbacher, Florian

2009-01-01

Environmental responsive or smart hydrogels show a volume phase transition due to changes of external stimuli such as pH or ionic strength of an ambient solution. Thus, they are able to convert reversibly chemical energy into mechanical energy and therefore they are suitable as sensitive material for integration in biochemical microsensors and MEMS devices. In this work, micro-fabricated silicon pressure sensor chips with integrated piezoresistors were used as transducers for the conversion o...

Ionic liquids: solvents and sorbents in sample preparation.

Science.gov (United States)

Clark, Kevin D; Emaus, Miranda N; Varona, Marcelino; Bowers, Ashley N; Anderson, Jared L

2018-01-01

The applications of ionic liquids (ILs) and IL-derived sorbents are rapidly expanding. By careful selection of the cation and anion components, the physicochemical properties of ILs can be altered to meet the requirements of specific applications. Reports of IL solvents possessing high selectivity for specific analytes are numerous and continue to motivate the development of new IL-based sample preparation methods that are faster, more selective, and environmentally benign compared to conventional organic solvents. The advantages of ILs have also been exploited in solid/polymer formats in which ordinarily nonspecific sorbents are functionalized with IL moieties in order to impart selectivity for an analyte or analyte class. Furthermore, new ILs that incorporate a paramagnetic component into the IL structure, known as magnetic ionic liquids (MILs), have emerged as useful solvents for bioanalytical applications. In this rapidly changing field, this Review focuses on the applications of ILs and IL-based sorbents in sample preparation with a special emphasis on liquid phase extraction techniques using ILs and MILs, IL-based solid-phase extraction, ILs in mass spectrometry, and biological applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rapid Response Fault Drilling Past, Present, and Future

Directory of Open Access Journals (Sweden)

Demian M. Saffer

2009-09-01

Full Text Available New information about large earthquakes can be acquired by drilling into the fault zone quickly following a large seismic event. Specifically, we can learn about the levels of friction and strength of the fault which determine the dynamic rupture, monitor the healing process of the fault, record the stress changes that trigger aftershocks and capture important physical and chemical properties of the fault that control the rupture process. These scientific and associated technical issues were the focus of a three-day workshop on Rapid Response Fault Drilling: Past, Present, and Future, sponsored by the International Continental Scientific Drilling Program (ICDP and the Southern California Earthquake Center (SCEC. The meeting drewtogether forty-four scientists representing ten countries in Tokyo, Japan during November 2008. The group discussed the scientific problems and how they could be addressed through rapid response drilling. Focused talks presented previous work on drilling after large earthquakes and in fault zones in general, as well as the state of the art of experimental techniques and measurement strategies. Detailed discussion weighed the tradeoffs between rapid drilling andthe ability to satisfy a diverse range of scientific objectives. Plausible drilling sites and scenarios were evaluated. This is a shortened summary of the workshop report that discusses key scientific questions, measurement strategies, and recommendations. This report can provide a starting point for quickly mobilizing a drilling program following future large earthquakes. The full report can be seen at http://www.pmc.ucsc.edu/~rapid/.

Performance of the efferent limb of a rapid response system

DEFF Research Database (Denmark)

Sørensen, Emilie M; Petersen, Asger

2015-01-01

AIM: To determine the distribution of outcomes following a medical emergency team (MET) call using a modified version of the multidisciplinary audit and evaluation of outcomes of rapid response (MAELOR) tool, and to evaluate its usefulness in monitoring the performance of the efferent limb...... of the rapid response system (RRS) at our institution. METHOD: An observational study of prospectively collected data including all MET calls at our institution during the 36 weeks study period (23 December 2013 - 31 august 2014). Outcomes of MET calls were registered 24 h after the call occurred...

Ionic solution and nanoparticle assisted MALDI-MS as bacterial biosensors for rapid analysis of yogurt.

Science.gov (United States)

Lee, Chia-Hsun; Gopal, Judy; Wu, Hui-Fen

2012-01-15

Bacterial analysis from food samples is a highly challenging task because food samples contain intensive interferences from proteins and carbohydrates. Three different conditions of yogurt were analyzed: (1) the fresh yogurt immediately after purchasing, (2) the yogurt after expiry date stored in the refrigerator and (3) the yogurt left outside, without refrigeration. The shelf lives of both these yogurt was compared in terms of the decrease in bacterial signals. AB which initially contained 10(9) cells/mL drastically reduced to 10(7) cells/mL. However, Lin (Feng-Yin) yogurt which initially (fresh) had 10(8) cells/mL, even after two weeks beyond the expiry period showed no marked drop in bacterial count. Conventional MALDI-MS analysis showed limited sensitivity for analysis of yogurt bacteria amidst the complex milk proteins present in yogurt. A cost effective ionic solution, CrO(4)(2-) solution was used to enable the successful detection of bacterial signals (40-fold increased in sensitivity) selectively without the interference of the milk proteins. 0.035 mg of Ag nanoparticles (NPs) were also found to improve the detection of bacteria 2-6 times in yogurt samples. The current approach can be further applied as a rapid, sensitive and effective platform for bacterial analysis from food. Copyright © 2011 Elsevier B.V. All rights reserved.

Ionic diffusion in quartz studied by transport measurements, SIMS and atomistic simulations

International Nuclear Information System (INIS)

Sartbaeva, Asel; Wells, Stephen A; Redfern, Simon A T; Hinton, Richard W; Reed, Stephen J B

2005-01-01

Ionic diffusion in the quartz-β-eucryptite system is studied by DC transport measurements, SIMS and atomistic simulations. Transport data show a large transient increase in ionic current at the α-β phase transition of quartz (the Hedvall effect). The SIMS data indicate two diffusion processes, one involving rapid Li + motion and the other involving penetration of Al and Li atoms into quartz at the phase transition. Atomistic simulations explain why the fine microstructure of twin domain walls in quartz near the transition does not hinder Li + diffusion

Rapid conversion of sorbitol to isosorbide in hydrophobic ionic liquids under microwave irradiation.

Science.gov (United States)

Kamimura, Akio; Murata, Kengo; Tanaka, Yoshiki; Okagawa, Tomoki; Matsumoto, Hiroshi; Kaiso, Kouji; Yoshimoto, Makoto

2014-12-01

Sorbitol was effectively converted to isosorbide by treatment with [TMPA][NTf2 ] in the presence of catalytic amounts of TsOH under microwave heating at 180 °C. The reaction completed within 10 min and isosorbide was isolated to about 60%. Ionic liquids were readily recovered by an extraction treatment and reused several times. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Highly Elastic, Transparent, and Conductive 3D-Printed Ionic Composite Hydrogels

KAUST Repository

Odent, Jérémy

2017-07-17

Despite extensive progress to engineer hydrogels for a broad range of technologies, practical applications have remained elusive due to their (until recently) poor mechanical properties and lack of fabrication approaches, which constrain active structures to simple geometries. This study demonstrates a family of ionic composite hydrogels with excellent mechanical properties that can be rapidly 3D-printed at high resolution using commercial stereolithography technology. The new material design leverages the dynamic and reversible nature of ionic interactions present in the system with the reinforcement ability of nanoparticles. The composite hydrogels combine within a single platform tunable stiffness, toughness, extensibility, and resiliency behavior not reported previously in other engineered hydrogels. In addition to their excellent mechanical performance, the ionic composites exhibit fast gelling under near-UV exposure, remarkable conductivity, and fast osmotically driven actuation. The design of such ionic composites, which combine a range of tunable properties and can be readily 3D-printed into complex architectures, provides opportunities for a variety of practical applications such as artificial tissue, soft actuators, compliant conductors, and sensors for soft robotics.

Ionic liquids, electrolyte solutions including the ionic liquids, and energy storage devices including the ionic liquids

Science.gov (United States)

Gering, Kevin L.; Harrup, Mason K.; Rollins, Harry W.

2015-12-08

An ionic liquid including a phosphazene compound that has a plurality of phosphorus-nitrogen units and at least one pendant group bonded to each phosphorus atom of the plurality of phosphorus-nitrogen units. One pendant group of the at least one pendant group comprises a positively charged pendant group. Additional embodiments of ionic liquids are disclosed, as are electrolyte solutions and energy storage devices including the embodiments of the ionic liquid.

Fullerol ionic fluids

KAUST Repository

Fernandes, Nikhil; Dallas, Panagiotis; Rodriguez, Robert; Bourlinos, Athanasios B.; Georgakilas, Vasilios; Giannelis, Emmanuel P.

2010-01-01

®). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding

Dissociation of rapid response learning and facilitation in perceptual and conceptual networks of person recognition.

Science.gov (United States)

Valt, Christian; Klein, Christoph; Boehm, Stephan G

2015-08-01

Repetition priming is a prominent example of non-declarative memory, and it increases the accuracy and speed of responses to repeatedly processed stimuli. Major long-hold memory theories posit that repetition priming results from facilitation within perceptual and conceptual networks for stimulus recognition and categorization. Stimuli can also be bound to particular responses, and it has recently been suggested that this rapid response learning, not network facilitation, provides a sound theory of priming of object recognition. Here, we addressed the relevance of network facilitation and rapid response learning for priming of person recognition with a view to advance general theories of priming. In four experiments, participants performed conceptual decisions like occupation or nationality judgments for famous faces. The magnitude of rapid response learning varied across experiments, and rapid response learning co-occurred and interacted with facilitation in perceptual and conceptual networks. These findings indicate that rapid response learning and facilitation in perceptual and conceptual networks are complementary rather than competing theories of priming. Thus, future memory theories need to incorporate both rapid response learning and network facilitation as individual facets of priming. © 2014 The British Psychological Society.

Crosslinked ionic polysaccharides for stimuli-sensitive drug delivery.

Science.gov (United States)

Alvarez-Lorenzo, Carmen; Blanco-Fernandez, Barbara; Puga, Ana M; Concheiro, Angel

2013-08-01

Polysaccharides are gaining increasing attention as components of stimuli-responsive drug delivery systems, particularly since they can be obtained in a well characterized and reproducible way from the natural sources. Ionic polysaccharides can be readily crosslinked to render hydrogel networks sensitive to a variety of internal and external variables, and thus suitable for switching drug release on-off through diverse mechanisms. Hybrids, composites and grafted polymers can reinforce the responsiveness and widen the range of stimuli to which polysaccharide-based systems can respond. This review analyzes the state of the art of crosslinked ionic polysaccharides as components of delivery systems that can regulate drug release as a function of changes in pH, ion nature and concentration, electric and magnetic field intensity, light wavelength, temperature, redox potential, and certain molecules (enzymes, illness markers, and so on). Examples of specific applications are provided. The information compiled demonstrates that crosslinked networks of ionic polysaccharides are suitable building blocks for developing advanced externally activated and feed-back modulated drug delivery systems. Copyright © 2013 Elsevier B.V. All rights reserved.

Fullerol ionic fluids

KAUST Repository

Fernandes, Nikhil

2010-01-01

We report for the first time an ionic fluid based on hydroxylated fullerenes (fullerols). The ionic fluid was synthesized by neutralizing the fully protonated fullerol with an amine terminated polyethylene/polypropylene oxide oligomer (Jeffamine®). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding significantly perturbs the thermal transitions and melting/crystallization behavior of the amine. In contrast, both the normalized heat of fusion and crystallization of the amine in the control are similar to those of the neat amine consistent with a physical mixture of the fullerols/amine with minimal interactions. In addition to differences in thermal behavior, the fullerol ionic fluid exhibits a complex viscoelastic behavior intermediate between the neat Jeffamine® (liquid-like) and the control (solid-like). © 2010 The Royal Society of Chemistry.

Fullerol ionic fluids

Science.gov (United States)

Fernandes, Nikhil; Dallas, Panagiotis; Rodriguez, Robert; Bourlinos, Athanasios B.; Georgakilas, Vasilios; Giannelis, Emmanuel P.

2010-09-01

We report for the first time an ionic fluid based on hydroxylated fullerenes (fullerols). The ionic fluid was synthesized by neutralizing the fully protonated fullerol with an amine terminated polyethylene/polypropylene oxide oligomer (Jeffamine®). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding significantly perturbs the thermal transitions and melting/crystallization behavior of the amine. In contrast, both the normalized heat of fusion and crystallization of the amine in the control are similar to those of the neat amine consistent with a physical mixture of the fullerols/amine with minimal interactions. In addition to differences in thermal behavior, the fullerol ionic fluid exhibits a complex viscoelastic behavior intermediate between the neat Jeffamine® (liquid-like) and the control (solid-like).

Correlations between phase behaviors and ionic conductivities of (ionic liquid + alcohol) systems

International Nuclear Information System (INIS)

Park, Nam Ku; Bae, Young Chan

2010-01-01

To understand the basic properties of ionic liquids (ILs), we examined the phase behavior and ionic conductivity characteristics using various compositions of different ionic liquids (1-ethyl-3-methylimidazolium hexafluorophosphate [emim] [PF6] and 1-benzyl-3-methylimidazolium hexafluorophosphate [bzmim] [PF6]) in several different alcohols (ethanol, propanol, 1-butanol, 2-butanol, and hexanol). We conducted a systematic study of the impact of different factors on the phase behavior of imidazolium-based ionic liquids in alcohols. Using a new experimental method with a liquid electrolyte system, we observed that the ionic conductivity of the ionic liquid/alcohol was sensitive to the surrounding temperature. We employed Chang et al.'s thermodynamic model [Chang et al. (1997, 1998) ] based on the lattice model. The obtained co-ordinated unit parameter from this model was used to describe the phase behavior and ionic conductivities of the given system. Good agreement with experimental data of various alcohol and ILs systems was obtained in the range of interest.

Ionic liquids: radiation chemistry, solvation dynamics and reactivity patterns

International Nuclear Information System (INIS)

Wishart, J.F.; Funston, A.M.; Szreder, T.

2006-01-01

Ionic liquids (ILs) are a rapidly expanding family of condensed-phase media with important applications in energy production, nuclear fuel and waste processing, improving the efficiency and safety of industrial chemical processes, and pollution prevention. ILs are nonvolatile, noncombustible, highly conductive, recyclable and capable of dissolving a wide variety of materials. They are finding new uses in chemical synthesis, catalysis, separations chemistry, electrochemistry and other areas. Ionic liquids have dramatically different properties compared to conventional molecular solvents, and they provide a new and unusual environment to test our theoretical understanding of charge transfer and other reactions. We are interested in how IL properties influence physical and dynamical processes that determine the stability and lifetimes of reactive intermediates and thereby affect the courses of chemical reactions and product distributions. Successful use of ionic liquids in radiation-filled environments, where their safety advantages could be significant, requires an understanding of ionic liquid radiation chemistry. For example, characterizing the primary steps of IL radiolysis will reveal radiolytic degradation pathways and suggest ways to prevent them or mitigate their effects on the properties of the material. An understanding of ionic liquid radiation chemistry will also facilitate pulse radiolysis studies of general chemical reactivity in ILs, which will aid in the development of energy production, chemical industry and environmental applications. Pulse radiolysis of [R 4 N][NTf 2 ] [R 4 N][N(CN) 2 ], and [R 4 P][N(CN) 2 ] ionic liquids produces solvated electrons that absorb over a broad range in the near infrared and persisting for hundreds of nanoseconds. Systematic cation variation shows that solvated electron's spectroscopic properties depend strongly on the lattice structure of the ionic liquid. Very early in our radiolysis studies it became evident that

Adsorption of Chloroform by the Rapid Response System Filter

National Research Council Canada - National Science Library

Karwacki, Christopher

1997-01-01

Adsorption equilibria and dynamic breakthrough data were measured to determine the adsorption capacity and effect of purge air on the desorption of chloroform from activated carbon simulating the Rapid Response System (RRS) filter...

Clinical trial of non-ionic contrast media -comparison of efficacy and safety between non-ionic iopromide (Ultravist) and ionic contrast media-

International Nuclear Information System (INIS)

Lee, Ghi Jai; Kim, Seung Hyup; Park, Jae Hyung; Chang, Kee Hyun; Han, Man Chung; Kim, Chu Wan

1988-01-01

Non-ionic contrast media, iopromide (Ultravist) was compared with ioxitalamate (Telebrix) and/or ioxaglate (Hexabrix) for efficacy and safety in 203 patients undergoing cardiac angiography, neurovascular angiography, peripheral and visceral angiography and intravenous pyelography. In all patients, adverse symptoms and signs including heat sense, pain, nausea, vomiting, etc. were checked during and after the injection. In addition, EKG and LV pressure were monitored during the cardiac angiography. And also CBC, UA, BUN and creatinine were checked before and 24 hours after the cardiac angiography. Serious adverse effect did not occur in any case. Minor effects, such as nausea and abdominal pain, were less frequently caused by non-ionic contrast media than by ionic contrast media, especially in cardiac angiography and intravenous pyelography. There was no significant difference between ionic and non-ionic contrast media in regard to electrophysiologic parameters such as EKG and LV pressure. In case of intravenous pyelography, nonionic contrast media seemed to be superior to ionic contrast media in image quality. It is suggested that, in spite of higher cost, non-ionic contrast media be needed for the safety and image quality, particularly in those patients at high risk of adverse effects by ionic contrast media

Thermotropic Ionic Liquid Crystals

Science.gov (United States)

Axenov, Kirill V.; Laschat, Sabine

2011-01-01

The last five years’ achievements in the synthesis and investigation of thermotropic ionic liquid crystals are reviewed. The present review describes the mesomorphic properties displayed by organic, as well as metal-containing ionic mesogens. In addition, a short overview on the ionic polymer and self-assembled liquid crystals is given. Potential and actual applications of ionic mesogens are also discussed. PMID:28879986

Thermotropic Ionic Liquid Crystals

Directory of Open Access Journals (Sweden)

Sabine Laschat

2011-01-01

Full Text Available The last five years’ achievements in the synthesis and investigation of thermotropic ionic liquid crystals are reviewed. The present review describes the mesomorphic properties displayed by organic, as well as metal-containing ionic mesogens. In addition, a short overview on the ionic polymer and self-assembled liquid crystals is given. Potential and actual applications of ionic mesogens are also discussed.

Thermotropic Ionic Liquid Crystals.

Science.gov (United States)

Axenov, Kirill V; Laschat, Sabine

2011-01-14

The last five years' achievements in the synthesis and investigation of thermotropic ionic liquid crystals are reviewed. The present review describes the mesomorphic properties displayed by organic, as well as metal-containing ionic mesogens. In addition, a short overview on the ionic polymer and self-assembled liquid crystals is given. Potential and actual applications of ionic mesogens are also discussed.

Thermotropic Ionic Liquid Crystals

OpenAIRE

Axenov, Kirill V.; Laschat, Sabine

2011-01-01

The last five years’ achievements in the synthesis and investigation of thermotropic ionic liquid crystals are reviewed. The present review describes the mesomorphic properties displayed by organic, as well as metal-containing ionic mesogens. In addition, a short overview on the ionic polymer and self-assembled liquid crystals is given. Potential and actual applications of ionic mesogens are also discussed.

Density-viscosity product of small-volume ionic liquid samples using quartz crystal impedance analysis.

Science.gov (United States)

McHale, Glen; Hardacre, Chris; Ge, Rile; Doy, Nicola; Allen, Ray W K; MacInnes, Jordan M; Bown, Mark R; Newton, Michael I

2008-08-01

Quartz crystal impedance analysis has been developed as a technique to assess whether room-temperature ionic liquids are Newtonian fluids and as a small-volume method for determining the values of their viscosity-density product, rho eta. Changes in the impedance spectrum of a 5-MHz fundamental frequency quartz crystal induced by a water-miscible room-temperature ionic liquid, 1-butyl-3-methylimiclazolium trifluoromethylsulfonate ([C4mim][OTf]), were measured. From coupled frequency shift and bandwidth changes as the concentration was varied from 0 to 100% ionic liquid, it was determined that this liquid provided a Newtonian response. A second water-immiscible ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C4mim][NTf2], with concentration varied using methanol, was tested and also found to provide a Newtonian response. In both cases, the values of the square root of the viscosity-density product deduced from the small-volume quartz crystal technique were consistent with those measured using a viscometer and density meter. The third harmonic of the crystal was found to provide the closest agreement between the two measurement methods; the pure ionic liquids had the largest difference of approximately 10%. In addition, 18 pure ionic liquids were tested, and for 11 of these, good-quality frequency shift and bandwidth data were obtained; these 12 all had a Newtonian response. The frequency shift of the third harmonic was found to vary linearly with square root of viscosity-density product of the pure ionic liquids up to a value of square root(rho eta) approximately 18 kg m(-2) s(-1/2), but with a slope 10% smaller than that predicted by the Kanazawa and Gordon equation. It is envisaged that the quartz crystal technique could be used in a high-throughput microfluidic system for characterizing ionic liquids.

Lessons learned from Rapid Response Research on wildland fires

Science.gov (United States)

Leigh Lentile; Penny Morgan; Colin Hardy; Andrew Hudak; Robert Means; Roger Ottmar; Peter Robichaud; Elaine Sutherland; Frederick Way; Sarah Lewis

2007-01-01

In recent years, more researchers are collecting data either on active wildfires or immediately after wildfire occurrence. Known as Rapid Response Research, this important undertaking provides real-time information, useful data, and improved tools for managers.

Learning Ionic

CERN Document Server

Ravulavaru, Arvind

2015-01-01

This book is intended for those who want to learn how to build hybrid mobile applications using Ionic. It is also ideal for people who want to explore theming for Ionic apps. Prior knowledge of AngularJS is essential to complete this book successfully.

Nanoscale Ionic Liquids

Science.gov (United States)

2006-11-01

Technical Report 11 December 2005 - 30 November 2006 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Nanoscale Ionic Liquids 5b. GRANT NUMBER FA9550-06-1-0012...Title: Nanoscale Ionic Liquids Principal Investigator: Emmanuel P. Giannelis Address: Materials Science and Engineering, Bard Hall, Cornell University...based fluids exhibit high ionic conductivity. The NFs are typically synthesized by grafting a charged, oligomeric corona onto the nanoparticle cores

Scaling properties of fracture surfaces on glass strengthened by ionic exchange

International Nuclear Information System (INIS)

Garza-Mendez, F.J.; Hinojosa-Rivera, M.; Gomez, I.; Sanchez, E.M.

2007-01-01

In this work the results of the statistical topometric analysis of fracture surfaces of soda-lime-silica glass with and without ionic exchange treatment are reported. In this case, the mechanism of substitution is K + -Na + . atomic force microscopy (AFM) was employed to record the topometric data from the fracture surface. The roughness exponent (ζ) and the correlation length (ξ) were calculated by the variable bandwidth method. The analysis for both glasses (subjected and non-subjected to ionic exchange) for ζ shows a value ∼0.8, this value agrees well with that reported in the literature for rapid crack propagation in a variety of materials. The correlation length shows different values for each condition. These results, along with those of microhardness indentations suggest that the self-affine correlation length is influenced by the complex interactions of the stress field of microcracks with that resulting from the collective behavior of the point defects introduced by the strengthening mechanism of ionic exchange

Effect of eyestalk extirpation on haemolymph ionic concentration of Metapenaeus monoceros

Digital Repository Service at National Institute of Oceanography (India)

Venkitaraman, P.R.; Jayalakshmy, K.V.; Abhilash, K.R.

_________________________________________________________ Journal of Experimental Biology and Agricultural Sciences http://www.jebas.org KEYWORDS Metapenaeus monoceros Prawn Haemolymph Ionic concentration Eyestalk extirpation Osmoregulation ABSTRACT Metapenaeus monoceros in the size range 65... September 20, 2013. EFFECT OF EYESTALK EXTIRPATION ON HAEMOLYMPH IONIC CONCENTRATION OF Metapenaeus monoceros E-mail: kvjayaparam@yahoo.co.in (Jayalakshmy KV) Peer review under responsibility of Journal of Experimental Biology and Agricultural...

Rapid response predicts 12-month post-treatment outcomes in binge-eating disorder: theoretical and clinical implications

Science.gov (United States)

Grilo, C. M.; White, M. A.; Wilson, G. T.; Gueorguieva, R.; Masheb, R. M.

2011-01-01

Background We examined rapid response in obese patients with binge-eating disorder (BED) in a clinical trial testing cognitive behavioral therapy (CBT) and behavioral weight loss (BWL). Method Altogether, 90 participants were randomly assigned to CBT or BWL. Assessments were performed at baseline, throughout and post-treatment and at 6- and 12-month follow-ups. Rapid response, defined as ≥70% reduction in binge eating by week four, was determined by receiver operating characteristic curves and used to predict outcomes. Results Rapid response characterized 57% of participants (67% of CBT, 47% of BWL) and was unrelated to most baseline variables. Rapid response predicted greater improvements across outcomes but had different prognostic significance and distinct time courses for CBT versus BWL. Patients receiving CBT did comparably well regardless of rapid response in terms of reduced binge eating and eating disorder psychopathology but did not achieve weight loss. Among patients receiving BWL, those without rapid response failed to improve further. However, those with rapid response were significantly more likely to achieve binge-eating remission (62% v. 13%) and greater reductions in binge-eating frequency, eating disorder psychopathology and weight loss. Conclusions Rapid response to treatment in BED has prognostic significance through 12-month follow-up, provides evidence for treatment specificity and has clinical implications for stepped-care treatment models for BED. Rapid responders who receive BWL benefit in terms of both binge eating and short-term weight loss. Collectively, these findings suggest that BWL might be a candidate for initial intervention in stepped-care models with an evaluation of progress after 1 month to identify non-rapid responders who could be advised to consider a switch to a specialized treatment. PMID:21923964

Electrochemical Model for Ionic Liquid Electrolytes in Lithium Batteries

International Nuclear Information System (INIS)

Yoo, Kisoo; Deshpande, Anirudh; Banerjee, Soumik; Dutta, Prashanta

2015-01-01

ABSTRACT: Room temperature ionic liquids are considered as potential electrolytes for high performance and safe lithium batteries due to their very low vapor pressure and relatively wide electrochemical and thermal stability windows. Unlike organic electrolytes, ionic liquid electrolytes are molten salts at room temperature with dissociated cations and anions. These dissociated ions interfere with the transport of lithium ions in lithium battery. In this study, a mathematical model is developed for transport of ionic components to study the performance of ionic liquid based lithium batteries. The mathematical model is based on a univalent ternary electrolyte frequently encountered in ionic liquid electrolytes of lithium batteries. Owing to the very high concentration of components in ionic liquid, the transport of lithium ions is described by the mutual diffusion phenomena using Maxwell-Stefan diffusivities, which are obtained from atomistic simulation. The model is employed to study a lithium-ion battery where the electrolyte comprises ionic liquid with mppy + (N-methyl-N-propyl pyrrolidinium) cation and TFSI − (bis trifluoromethanesulfonyl imide) anion. For a moderate value of reaction rate constant, the electric performance results predicted by the model are in good agreement with experimental data. We also studied the effect of porosity and thickness of separator on the performance of lithium-ion battery using this model. Numerical results indicate that low rate of lithium ion transport causes lithium depleted zone in the porous cathode regions as the porosity decreases or the length of the separator increases. The lithium depleted region is responsible for lower specific capacity in lithium-ion cells. The model presented in this study can be used for design of optimal ionic liquid electrolytes for lithium-ion and lithium-air batteries

Acute renal response to rapid onset respiratory acidosis.

Science.gov (United States)

Ramadoss, Jayanth; Stewart, Randolph H; Cudd, Timothy A

2011-03-01

Renal strong ion compensation to chronic respiratory acidosis has been established, but the nature of the response to acute respiratory acidosis is not well defined. We hypothesized that the response to acute respiratory acidosis in sheep is a rapid increase in the difference in renal fractional excretions of chloride and sodium (Fe(Cl) - Fe(Na)). Inspired CO(2) concentrations were increased for 1 h to significantly alter P(a)CO(2) and pH(a) from 32 ± 1 mm Hg and 7.52 ± 0.02 to 74 ± 2 mm Hg and 7.22 ± 0.02, respectively. Fe(Cl) - Fe(Na) increased significantly from 0.372 ± 0.206 to 1.240 ± 0.217% and returned to baseline at 2 h when P(a)CO(2) and pH(a) were 37 ± 0.6 mm Hg and 7.49 ± 0.01, respectively. Arterial pH and Fe(Cl) - Fe(Na) were significantly correlated. We conclude that the kidney responds rapidly to acute respiratory acidosis, within 30 min of onset, by differential reabsorption of sodium and chloride.

Visual indication of enviromental humidity by using poly(ionic liquid) photonic crystals.

Science.gov (United States)

Huang, Jing; Tao, Cheng-an; An, Qi; Lin, Changxu; Li, Xuesong; Xu, Dan; Wu, Yiguang; Li, Xiaogang; Shen, Dezhong; Li, Guangtao

2010-06-21

The combination of poly (ionic liquid) and photonic structure affords a new class of self-reporting humidity sensory materials with excellent reversibility, which are able to rapidly, sensitively and visually indicate environmental humidity with colour change from blue to green, orange, and red, covering the whole visible range.

Ionic conduction in polyether-based lithium arylfluorosulfonimide ionic melt electrolytes

International Nuclear Information System (INIS)

Herath, Mahesha B.; Creager, Stephen E.; Rajagopal, Rama V.; Geiculescu, Olt E.; DesMarteau, Darryl D.

2009-01-01

We report synthesis, characterization and ion transport in polyether-based ionic melt electrolytes consisting of Li salts of low-basicity anions covalently attached to polyether oligomers. Purity of the materials was investigated by HPLC analysis and electrospray ionization mass spectrometry. The highest ionic conductivity of 7.1 x 10 -6 S/cm at 30 deg. C was obtained for the sample consisting of a lithium salt of an arylfluorosulfonimide anion attached to a polyether oligomer with an ethyleneoxide (EO) to lithium ratio of 12. The conductivity order of various ionic melts having different polyether chain lengths suggests that at higher EO:Li ratios the conductivity of the electrolytes at room temperature is determined in part by the amount of crystallization of the polyether portion of the ionic melt.

Rapid response of a hydrologic system to volcanic activity: Masaya volcano, Nicaragua

Science.gov (United States)

Pearson, S.C.P.; Connor, C.B.; Sanford, W.E.

2008-01-01

Hydrologic systems change in response to volcanic activity, and in turn may be sensitive indicators of volcanic activity. Here we investigate the coupled nature of magmatic and hydrologic systems using continuous multichannel time series of soil temperature collected on the flanks of Masaya volcano, Nicaragua, one of the most active volcanoes in Central America. The soil temperatures were measured in a low-temperature fumarole field located 3.5 km down the flanks of the volcano. Analysis of these time series reveals that they respond extremely rapidly, on a time scale of minutes, to changes in volcanic activity also manifested at the summit vent. These rapid temperature changes are caused by increased flow of water vapor through flank fumaroles during volcanism. The soil temperature response, ~5 °C, is repetitive and complex, with as many as 13 pulses during a single volcanic episode. Analysis of the frequency spectrum of these temperature time series shows that these anomalies are characterized by broad frequency content during volcanic activity. They are thus easily distinguished from seasonal trends, diurnal variations, or individual rainfall events, which triggered rapid transient increases in temperature during 5% of events. We suggest that the mechanism responsible for the distinctive temperature signals is rapid change in pore pressure in response to magmatism, a response that can be enhanced by meteoric water infiltration. Monitoring of distal fumaroles can therefore provide insight into coupled volcanic-hydrologic-meteorologic systems, and has potential as an inexpensive monitoring tool.

Ionic liquids in chemical engineering.

Science.gov (United States)

Werner, Sebastian; Haumann, Marco; Wasserscheid, Peter

2010-01-01

The development of engineering applications with ionic liquids stretches back to the mid-1990s when the first examples of continuous catalytic processes using ionic liquids and the first studies of ionic liquid-based extractions were published. Ever since, the use of ionic liquids has seen tremendous progress in many fields of chemistry and engineering, and the first commercial applications have been reported. The main driver for ionic liquid engineering applications is to make practical use of their unique property profiles, which are the result of a complex interplay of coulombic, hydrogen bonding and van der Waals interactions. Remarkably, many ionic liquid properties can be tuned in a wide range by structural modifications at their cation and anion. This review highlights specific examples of ionic liquid applications in catalysis and in separation technologies. Additionally, the application of ionic liquids as working fluids in process machines is introduced.

Ionic and viscoelastic mechanisms of a bucky-gel actuator

Science.gov (United States)

Kruusamäe, Karl; Sugino, Takushi; Asaka, Kinji

2015-07-01

Ionic electromechanically active polymers (IEAPs) are considered attractive candidates for soft, miniature, and lightweight actuators. The bucky-gel actuator is a carbonaceous subtype of IEAP that due to its structure (i.e. two highly porous electrodes sandwiching a thin ion-permeable electrolyte layer) and composition (i.e. being composed of soft porous polymer, carbon nanotubes, and ionic liquid) is very similar to an electric double-layer capacitor. In response to the voltage applied between the electrodes of a bucky-gel actuator, the laminar structure bends. The time domain behavior exhibits, however, a phenomenon called the back-relaxation, i.e., after some time the direction of bending is reversed even though voltage remains constant. In spite of the working mechanism of IEAP actuators being generally attributed to the transport of ions within the soft multilayer system, the specific details remain unclear. A so-called two-carrier model proposes that the bending and subsequent back-relaxation are caused by the relocation of two ionic species having different mobilities as they enter and exit the electrode layers. By adopting the two-carrier model for bucky-gel actuators, we see very good agreement between the mathematical representation and the experimental data of the electromechanical behavior. Furthermore, since the bucky-gel actuator is viscoelastic, we propose to use the time domain response of a blocking force as the key parameter related to the inner ionic mechanism. We also introduce a method to estimate the viscoelastic creep compliance function from the time domain responses for curvature and blocking force. This analysis includes four types of bucky-gel actuators of varying composition and structure.

Green Imidazolium Ionics-From Truly Sustainable Reagents to Highly Functional Ionic Liquids.

Science.gov (United States)

Tröger-Müller, Steffen; Brandt, Jessica; Antonietti, Markus; Liedel, Clemens

2017-09-04

We report the synthesis of task-specific imidazolium ionic compounds and ionic liquids with key functionalities of organic molecules from electro-, polymer-, and coordination chemistry. Such products are highly functional and potentially suitable for technology applications even though they are formed without elaborate reactions and from cheap and potentially green reagents. We further demonstrate the versatility of the used synthetic approach by introducing different functional and green counterions to the formed ionic liquids directly during the synthesis or after metathesis reactions. The influence of different cation structures and different anions on the thermal and electrochemical properties of the resulting ionic liquids is discussed. Our goal is to make progress towards economically competitive and sustainable task-specific ionic liquids. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ionic conductivity of ternary electrolyte containing sodium salt and ionic liquid

International Nuclear Information System (INIS)

Egashira, Minato; Asai, Takahito; Yoshimoto, Nobuko; Morita, Masayuki

2011-01-01

Highlights: ► Ternary electrolyte containing NaBF 4 , polyether and ionic liquid has been prepared. ► The conductivity of the electrolytes has been evaluated toward content of ionic liquid. ► The conductivity shows maximum 1.2 mS cm −1 and is varied in relation to solution structure. - Abstract: For the development of novel non-aqueous sodium ion conductor with safety of sodium secondary cell, non-flammable ionic liquid is attractive as electrolyte component. A preliminary study has been carried out for the purpose of constructing sodium ion conducting electrolyte based on ionic liquid. The solubility of sodium salt such as NaBF 4 in ionic liquid is poor, thus the ternary electrolyte has been prepared where NaBF 4 with poly(ethylene glycol) dimethyl ether (PEGDME) as coordination former is dissolved with ionic liquid diethyl methoxyethyl ammonium tetrafluoroborate (DEMEBF 4 ). The maximum conductivity among the prepared solutions, ca. 1.2 mS cm −1 at 25 °C, was obtained when the molar ratio (ethylene oxide unit in PEGDME):NaBF 4 :DEMEBF 4 was 8:1:2. The relationship between the conductivity of the ternary electrolyte and its solution structure has been discussed.

Disinfection of Spacecraft Potable Water Systems by Passivation with Ionic Silver

Science.gov (United States)

Birmele, Michele N.; McCoy, LaShelle e.; Roberts, Michael S.

2011-01-01

Microbial growth is common on wetted surfaces in spacecraft environmental control and life support systems despite the use of chemical and physical disinfection methods. Advanced control technologies are needed to limit microorganisms and increase the reliability of life support systems required for long-duration human missions. Silver ions and compounds are widely used as antimicrobial agents for medical applications and continue to be used as a residual biocide in some spacecraft water systems. The National Aeronautics and Space Administration (NASA) has identified silver fluoride for use in the potable water system on the next generation spacecraft. Due to ionic interactions between silver fluoride in solution and wetted metallic surfaces, ionic silver is rapidly depleted from solution and loses its antimicrobial efficacy over time. This report describes research to prolong the antimicrobial efficacy of ionic silver by maintaining its solubility. Three types of metal coupons (lnconel 718, Stainless Steel 316, and Titanium 6AI-4V) used in spacecraft potable water systems were exposed to either a continuous flow of water amended with 0.4 mg/L ionic silver fluoride or to a static, pre-treatment passivation in 50 mg/L ionic silver fluoride with or without a surface oxidation pre-treatment. Coupons were then challenged in a high-shear, CDC bioreactor (BioSurface Technologies) by exposure to six bacteria previously isolated from spacecraft potable water systems. Continuous exposure to 0.4 mg/L ionic silver over the course of 24 hours during the flow phase resulted in a >7-log reduction. The residual effect of a 24-hour passivation treatment in 50 mg/L of ionic silver resulted in a >3-log reduction, whereas a two-week treatment resulted in a >4-log reduction. Results indicate that 0.4 mg/L ionic silver is an effective biocide against many bacteria and that a prepassivation of metal surfaces with silver can provide additional microbial control.

Ecotoxicological characterization of polyoxyethylene glycerol ester non-ionic surfactants and their mixtures with anionic and non-ionic surfactants.

Science.gov (United States)

Ríos, Francisco; Fernández-Arteaga, Alejandro; Lechuga, Manuela; Fernández-Serrano, Mercedes

2017-04-01

This paper reports on a study that investigated the aquatic toxicity of new non-ionic surfactants derived from renewable raw materials, polyoxyethylene glycerol ester (PGE), and their binary mixtures with anionic and non-ionic surfactants. Toxicity of pure PGEs was determined using representative organisms from different trophic levels: luminescent bacteria (Vibrio fischeri), microalgae (Pseudokirchneriella subcapitata), and freshwater crustaceans (Daphnia magna). Relationships between toxicity and the structural parameters such as unit of ethylene oxide (EO) and hydrophilic-lipophilic balance (HLB) were evaluated. Critical micellar concentration (CMC) in the conditions of the toxicity test was also determined. It was found that the toxicity of the aqueous solutions of PGE decreased when the number of EO units in the molecule, HLB, and CMC increased. PGEs showed lower CMC in marine medium, and the toxicity to V. ficheri is lower when the CMC was higher. Given their non-polar nature, narcosis was expected to be the primary mode of toxic action of PGEs. For the mixture of surfactants, we observed that the mixtures with PGE that had the higher numbers of EO units were more toxic than the aqueous solutions of pure surfactants. Moreover, we found that concentration addition was the type of action more likely to occur for mixtures of PGE with lower numbers of EO units with non-ionic surfactants (alkylpolyglucoside and fatty alcohol ethoxylate), whereas for the mixture of PGE with lower EO units and anionic surfactant (ether carboxylic derivative), the most common response type was response addition. In case of mixtures involving amphoteric surfactants and PGEs with the higher numbers of EO units, no clear pattern with regard to the mixture toxicity response type could be observed.

Rapid and sensitive analysis of polychlorinated biphenyls and acrylamide in food samples using ionic liquid-based in situ dispersive liquid-liquid microextraction coupled to headspace gas chromatography.

Science.gov (United States)

Zhang, Cheng; Cagliero, Cecilia; Pierson, Stephen A; Anderson, Jared L

2017-01-20

A simple and rapid ionic liquid (IL)-based in situ dispersive liquid-liquid microextraction (DLLME) method was developed and coupled to headspace gas chromatography (HS-GC) employing electron capture (ECD) and mass spectrometry (MS) detection for the analysis of polychlorinated biphenyls (PCBs) and acrylamide at trace levels from milk and coffee samples. The chemical structures of the halide-based ILs were tailored by introducing various functional groups to the cations to evaluate the effect of different structural features on the extraction efficiency of the target analytes. Extraction parameters including the molar ratio of IL to metathesis reagent and IL mass were optimized. The effects of HS oven temperature and the HS sample vial volume on the analyte response were also evaluated. The optimized in situ DLLME method exhibited good analytical precision, good linearity, and provided detection limits down to the low ppt level for PCBs and the low ppb level for acrylamide in aqueous samples. The matrix-compatibility of the developed method was also established by quantifying acrylamide in brewed coffee samples. This method is much simpler and faster compared to previously reported GC-MS methods using solid-phase microextraction (SPME) for the extraction/preconcentration of PCBs and acrylamide from complex food samples. Copyright © 2016 Elsevier B.V. All rights reserved.

A reversible conductivity modulation of azobenzene-based ionic liquids in aqueous solutions using UV/vis light.

Science.gov (United States)

Li, Zhiyong; Yuan, Xiaoqing; Feng, Ying; Chen, Yongkui; Zhao, Yuling; Wang, Huiyong; Xu, Qingli; Wang, Jianji

2018-05-09

Photo-induced conductivity modulation of stimuli-responsive materials is of great importance from the viewpoint of fundamental research and technology. In this work, 5 new kinds of azobenzene-based photo-responsive ionic liquids were synthesized and characterized, and UV/vis light modulation of their conductivity was investigated in an aqueous solution. The factors affecting the conductivity modulation of the photo-responsive fluids, such as photo-isomerization efficiency, photo-regulation aggregation, concentration and chemical structure of the ionic liquids, were examined systematically. It was found that the conductivity of the ionic liquids in water exhibited a significant increase upon UV light irradiation and the ionic liquids with a shorter alkyl spacer in the cation showed a more remarkable photo-induced conductivity enhancement with a maximum increase of 150%. In addition, the solution conductivity was restored (or very close) to the initial value upon an alternative irradiation with visible light. Thus, the solution conductivity can be modulated using alternative irradiation with UV and visible light. Although the reversible photo-isomerization of the azobenzene group under UV/vis irradiation is the origin of the conductivity modulation, the photo-regulated aggregation of the ionic liquid in water is indispensable for the maximum degree of conductivity modulation because UV irradiation can weaken, even break the aggregated cis-isomers of the ionic liquids in an aqueous solution.

Ionic Liquids as Unforeseen Assets to Fight Life-Threatening Mycotic Diseases.

Science.gov (United States)

Hartmann, Diego O; Petkovic, Marija; Silva Pereira, Cristina

2016-01-01

Ionic liquids discovery has celebrated 100 years. They consist solely of ions, one of which is typically organic and asymmetrical. Remarkable physical and chemical properties stirred their use as alternative solvents in many chemical processes. The recent demonstration of their occurrence in nature might boost their interest in biological sciences. In the search of mechanistic understandings of ionic liquids' ecotoxicological impacts in fungi, we have analyzed the proteome, transcriptome, and metabolome responses to this chemical stress. Data illuminated new hypotheses that altered our research path - exploit ionic liquids as tools for the discovery of pathways and metabolites that may impact fungal development and pathogenicity. As we get closer to solve the primary effects of each ionic liquid family and their specific gene targets, the vision of developing antifungal ionic liquids and/or materials, by taking advantage of elegant progresses in this field, might become a reality. Task-designed formulations may improve the performance of conventional antifungal drugs, build functional coatings for reducing allergens production, or aid in the recovery of antifungal plant polymers. The frontier research in this cross-disciplinary field may provide us unforeseen means to address the global concern of mycotic diseases. Pathogenic and opportunistic fungi are responsible for numerous infections, killing annually nearly 1.5 million immunocompromised individuals worldwide, a similar rate to malaria or tuberculosis. This perspective will review our major findings and current hypotheses, contextualizing how they might bring us closer to efficient strategies to prevent and fight mycotic diseases.

Rapid Response Manufacturing (RRM). Final CRADA report

Energy Technology Data Exchange (ETDEWEB)

Cain, W.D. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States); Waddell, W.L. [National Centers for Manufacturing Sciences, Ann Arbor, MI (United States)

1997-08-28

A major accomplishment of the Rapid Response Manufacturing (RRM) project was the development of a broad-based generic framework for automating and integrating the design-to-manufacturing activities associated with machined part products. Key components of the framework are a manufacturing model that integrates product and process data in a consistent, minimally redundant manner, an advanced computer-aided engineering working environment, knowledge-based software systems for design, process planning, and manufacturing and new production technologies for making products directly from design application software.

Rapid continental-scale vegetation response to the Younger Dryas Cool Episode

Science.gov (United States)

Peros, M.; Gajewski, K.; Viau, A.

2006-12-01

The Younger Dryas Cool Episode had rapid and widespread effects on flora and fauna throughout the Americas. Fossil pollen records document how plant communities responded to this event, although such data are generally only representative of changes at local- to regional-scales. We use a new approach to provide insight into vegetation responses to the Younger Dryas at a continental-scale, by focusing on data extracted for a single taxon (Populus poplar, cottonwood, aspen) from pollen diagrams throughout North America. We show that Populus underwent a rapid and continent-wide decline as the climate rapidly cooled and dried. At the termination of the Younger Dryas, Populus underwent another widespread decline, this time in response to competition from boreal and temperate taxa as the climate abruptly warmed. Late glacial-early Holocene pollen assemblages with high quantities of Populus pollen often lack modern analogues and thus confound quantitative paleoclimatic reconstructions; our results provide a context to interpret these assemblages. Furthermore, while Populus may continue to expand in the future in response to human disturbance and increasing temperatures, its sensitivity to competition may eventually put it at risk as global warming accelerates.

Response selection difficulty modulates the behavioral impact of rapidly learnt action effects.

Directory of Open Access Journals (Sweden)

Uta eWolfensteller

2014-12-01

Full Text Available It is well established that we can pick up action effect associations when acting in a free-choice intentional mode. However, it is less clear whether and when action effect associations are learnt and actually affect behavior if we are acting in a forced-choice mode, applying a specific stimulus-response (S-R rule. In the present study, we investigated whether response selection difficulty imposed by S-R rules influences the initial rapid learning and the behavioral expression of previously learnt but weakly practiced action effect associations when those are re-activated by effect exposure. Experiment 1 showed that the rapid acquisition of action effect associations is not directly influenced by response selection difficulty. By contrast, the behavioral expression of re-activated action effect associations is prevented when actions are directly activated by highly over-learnt response cues and thus response selection difficulty is low. However, all three experiments showed that if response selection difficulty is sufficiently high during re-activation, the same action effect associations do influence behavior. Experiment 2 and 3 revealed that the effect of response selection difficulty cannot be fully reduced to giving action effects more time to prime an action, but seems to reflect competition during response selection. Finally, the present data suggest that when multiple novel rules are rapidly learnt in succession, which requires a lot of flexibility, action effect associations continue to influence behavior only if response selection difficulty is sufficiently high. Thus, response selection difficulty might modulate the impact of experiencing multiple learning episodes on action effect expression and learning, possibly via inducing different strategies.

Quantification of Ionic Diffusion in Lead Halide Perovskite Single Crystals

KAUST Repository

Peng, Wei

2018-05-25

Lead halide perovskites are mixed electronic/ionic semiconductors that have recently revolutionized the photovoltaics field. The physical characterization of the ionic conductivity has been rather elusive due to the highly intermixing of ionic and electronic current. In this work the synthesis of low defect density monocrystalline MAPbBr3 (MA=Methyl ammonium) solar cells free of hole transport layer (HTL) suppresses the effect of electronic current. Impedance spectroscopy reveals the characteristic signature of ionic diffusion (the Warburg element and transmission line equivalent circuit) and ion accumulation at the MAPbBr3/Au interface. Diffusion coefficients are calculated based on a good correlation between thickness of MAPbBr3 and characteristic diffusion transition frequency. In addition, reactive external interfaces are studied by comparison of polycrystalline MAPbBr3 devices prepared either with or without a HTL. The low frequency response in IS measurements is correlated with the chemical reactivity of moving ions with the external interfaces and diffusion into the HTL.

Ionic and secretory response of pancreatic islet cells to minoxidil sulfate

International Nuclear Information System (INIS)

Antoine, M.H.; Hermann, M.; Herchuelz, A.; Lebrun, P.

1991-01-01

Minoxidil sulfate is an antihypertensive agent belonging to the new class of vasodilators, the K+ channel openers. The present study was undertaken to characterize the effects of minoxidil sulfate on ionic and secretory events in rat pancreatic islets. The drug unexpectedly provoked a concentration-dependent decrease in 86Rb outflow. This inhibitory effect was reduced in a concentration-dependent manner by glucose and tolbutamide. Minoxidil sulfate did not affect 45Ca outflow from islets perfused in the presence of extracellular Ca++ and absence or presence of glucose. However, in islets exposed to a medium deprived of extracellular Ca++, the drug provoked a rise in 45Ca outflow. Whether in the absence or presence of extracellular Ca++, minoxidil sulfate increased the cytosolic free Ca++ concentration of islet cells. Lastly, minoxidil sulfate increased the release of insulin from glucose-stimulated pancreatic islets. These results suggest that minoxidil sulfate reduces the activity of the ATP-sensitive K+ channels and promotes an intracellular translocation of Ca++. The latter change might account for the effect of the drug on the insulin-releasing process. However, the secretory response to minoxidil sulfate could also be mediated, at least in part, by a modest Ca++ entry

Graphitic carbon nitride nanosheet electrode-based high-performance ionic actuator

Science.gov (United States)

Wu, Guan; Hu, Ying; Liu, Yang; Zhao, Jingjing; Chen, Xueli; Whoehling, Vincent; Plesse, Cédric; Nguyen, Giao T. M.; Vidal, Frédéric; Chen, Wei

2015-01-01

Ionic actuators have attracted attention due to their remarkably large strain under low-voltage stimulation. Because actuation performance is mainly dominated by the electrochemical and electromechanical processes of the electrode layer, the electrode material and structure are crucial. Here, we report a graphitic carbon nitride nanosheet electrode-based ionic actuator that displays high electrochemical activity and electromechanical conversion abilities, including large specific capacitance (259.4 F g−1) with ionic liquid as the electrolyte, fast actuation response (0.5±0.03% in 300 ms), large electromechanical strain (0.93±0.03%) and high actuation stability (100,000 cycles) under 3 V. The key to the high performance lies in the hierarchical pore structure with dominant size actuation performance. PMID:26028354

Degradation of 1-butyl-3-methylimidazolium chloride ionic liquid in a Fenton-like system

International Nuclear Information System (INIS)

Siedlecka, E.M.; Mrozik, W.; Kaczynski, Z.; Stepnowski, P.

2008-01-01

The study examined the usefulness of a Fenton-like system for the degradation of ionic liquid residues in water. The ionic liquid was oxidized in a dilute aqueous solution of 1-butyl-3-methylimidazolium chloride (bmimCl). The ionic liquid decomposes readily and rapidly in aqueous solution by chemical degradation in a Fenton-like system. Under chosen conditions the initial bmimCl solution was reduced by a factor of 0.973 within 90 min. Additional results showed that bmimCl degradations in a Fenton-like system in excess H 2 O 2 could be interpreted as a combined oxidation-reduction mechanism. Preliminary investigations of the mechanism of such degradations have indicated that initial OH· radicals can attack any one of the three carbon atoms on the imidazolium ring. The intermediates of this reaction may be mono- di- or amino- carboxylic acids

Architecture, Assembly, and Emerging Applications of Branched Functional Polyelectrolytes and Poly(ionic liquid)s.

Science.gov (United States)

Xu, Weinan; Ledin, Petr A; Shevchenko, Valery V; Tsukruk, Vladimir V

2015-06-17

Branched polyelectrolytes with cylindrical brush, dendritic, hyperbranched, grafted, and star architectures bearing ionizable functional groups possess complex and unique assembly behavior in solution at surfaces and interfaces as compared to their linear counterparts. This review summarizes the recent developments in the introduction of various architectures and understanding of the assembly behavior of branched polyelectrolytes with a focus on functional polyelectrolytes and poly(ionic liquid)s with responsive properties. The branched polyelectrolytes and poly(ionic liquid)s interact electrostatically with small molecules, linear polyelectrolytes, or other branched polyelectrolytes to form assemblies of hybrid nanoparticles, multilayer thin films, responsive microcapsules, and ion-conductive membranes. The branched structures lead to unconventional assemblies and complex hierarchical structures with responsive properties as summarized in this review. Finally, we discuss prospectives for emerging applications of branched polyelectrolytes and poly(ionic liquid)s for energy harvesting and storage, controlled delivery, chemical microreactors, adaptive surfaces, and ion-exchange membranes.

Ionic liquids as electrolytes

International Nuclear Information System (INIS)

Galinski, Maciej; Lewandowski, Andrzej; Stepniak, Izabela

2006-01-01

Salts having a low melting point are liquid at room temperature, or even below, and form a new class of liquids usually called room temperature ionic liquids (RTIL). Information about RTILs can be found in the literature with such key words as: room temperature molten salt, low-temperature molten salt, ambient-temperature molten salt, liquid organic salt or simply ionic liquid. Their physicochemical properties are the same as high temperature ionic liquids, but the practical aspects of their maintenance or handling are different enough to merit a distinction. The class of ionic liquids, based on tetraalkylammonium cation and chloroaluminate anion, has been extensively studied since late 1970s of the XX century, following the works of Osteryoung. Systematic research on the application of chloroaluminate ionic liquids as solvents was performed in 1980s. However, ionic liquids based on aluminium halides are moisture sensitive. During the last decade an increasing number of new ionic liquids have been prepared and used as solvents. The general aim of this paper was to review the physical and chemical properties of RTILs from the point of view of their possible application as electrolytes in electrochemical processes and devices. The following points are discussed: melting and freezing, conductivity, viscosity, temperature dependence of conductivity, transport and transference numbers, electrochemical stability, possible application in aluminium electroplating, lithium batteries and in electrochemical capacitors

Hydrogen bonding in ionic liquids.

Science.gov (United States)

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

2015-03-07

Ionic liquids (IL) and hydrogen bonding (H-bonding) are two diverse fields for which there is a developing recognition of significant overlap. Doubly ionic H-bonds occur when a H-bond forms between a cation and anion, and are a key feature of ILs. Doubly ionic H-bonds represent a wide area of H-bonding which has yet to be fully recognised, characterised or explored. H-bonds in ILs (both protic and aprotic) are bifurcated and chelating, and unlike many molecular liquids a significant variety of distinct H-bonds are formed between different types and numbers of donor and acceptor sites within a given IL. Traditional more neutral H-bonds can also be formed in functionalised ILs, adding a further level of complexity. Ab initio computed parameters; association energies, partial charges, density descriptors as encompassed by the QTAIM methodology (ρBCP), qualitative molecular orbital theory and NBO analysis provide established and robust mechanisms for understanding and interpreting traditional neutral and ionic H-bonds. In this review the applicability and extension of these parameters to describe and quantify the doubly ionic H-bond has been explored. Estimating the H-bonding energy is difficult because at a fundamental level the H-bond and ionic interaction are coupled. The NBO and QTAIM methodologies, unlike the total energy, are local descriptors and therefore can be used to directly compare neutral, ionic and doubly ionic H-bonds. The charged nature of the ions influences the ionic characteristics of the H-bond and vice versa, in addition the close association of the ions leads to enhanced orbital overlap and covalent contributions. The charge on the ions raises the energy of the Ylp and lowers the energy of the X-H σ* NBOs resulting in greater charge transfer, strengthening the H-bond. Using this range of parameters and comparing doubly ionic H-bonds to more traditional neutral and ionic H-bonds it is clear that doubly ionic H-bonds cover the full range of weak

Ionic Structure at Dielectric Interfaces

Science.gov (United States)

Jing, Yufei

The behavior of ions in liquids confined between macromolecules determines the outcome of many nanoscale assembly processes in synthetic and biological materials such as colloidal dispersions, emulsions, hydrogels, DNA, cell membranes, and proteins. Theoretically, the macromolecule-liquid boundary is often modeled as a dielectric interface and an important quantity of interest is the ionic structure in a liquid confined between two such interfaces. The knowledge gleaned from the study of ionic structure in such models can be useful in several industrial applications, such as biosensors, lithium-ion batteries double-layer supercapacitors for energy storage and seawater desalination. Electrostatics plays a critical role in the development of such functional materials. Many of the functions of these materials, result from charge and composition heterogeneities. There are great challenges in solving electrostatics problems in heterogeneous media with arbitrary shapes because electrostatic interactions remains unknown but depend on the particular density of charge distributions. Charged molecules in heterogeneous media affect the media's dielectric response and hence the interaction between the charges is unknown since it depends on the media and on the geometrical properties of the interfaces. To determine the properties of heterogeneous systems including crucial effects neglected in classical mean field models such as the hard core of the ions, the dielectric mismatch and interfaces with arbitrary shapes. The effect of hard core interactions accounts properly for short range interactions and the effect of local dielectric heterogeneities in the presence of ions and/or charged molecules for long-range interactions are both analyzed via an energy variational principle that enables to update charges and the medium's response in the same simulation time step. In particular, we compute the ionic structure in a model system of electrolyte confined by two planar dielectric

Sensitivities of ionic explosives

Science.gov (United States)

Politzer, Peter; Lane, Pat; Murray, Jane S.

2017-03-01

We have investigated the relevance for ionic explosive sensitivity of three factors that have been demonstrated to be related to the sensitivities of molecular explosives. These are (1) the maximum available heat of detonation, (2) the amount of free space per molecule (or per formula unit) in the crystal lattice and (3) specific features of the electrostatic potential on the molecular or ionic surface. We find that for ionic explosives, just as for molecular ones, there is an overall tendency for impact sensitivity to increase as the maximum detonation heat release is greater. This means that the usual emphasis upon designing explosives with large heats of detonation needs to be tempered somewhat. We also show that a moderate detonation heat release does not preclude a high level of detonation performance for ionic explosives, as was already demonstrated for molecular ones. Relating the free space per formula unit to sensitivity may require a modified procedure for ionic explosives; this will continue to be investigated. Finally, an encouraging start has been made in linking impact sensitivities to the electrostatic potentials on ionic surfaces, although limited so far to ammonium salts.

Determination of trihalomethanes in waters by ionic liquid-based single drop microextraction/gas chromatographic/mass spectrometry.

Science.gov (United States)

Aguilera-Herrador, Eva; Lucena, Rafael; Cárdenas, Soledad; Valcárcel, Miguel

2008-10-31

A simple, rapid, solventless method for the determination of trihalomethanes (THMs) (chloroform, bromodichloromethane, dibromochloromethane and bromoform) in water samples is presented. The analytes are extracted from the headspace of the aqueous matrix into a 2 microL drop of the ionic liquid 1-octyl-3-methyl-imidazolium hexafluorophosphate working at 30 degrees C for 30 min. The separation and detection of the target compounds is accomplished by gas chromatography/mass spectrometry owing to the use of an interface that efficiently transfers the analytes extracted in the ionic liquid drop to the gas chromatograph while preventing the ionic liquid from entering the column. The detection limits obtained are below the values compelled by the legislation, ranging from 0.5 microg L(-1) for chloroform and bromodichloromethane to 0.9 microg L(-1) for dibromochloromethane. The use of ionic liquid in the extraction procedure avoids the use of organic solvents and leads to relative standard deviations that range from 3.1% to 4.8%.

Ionic liquids as unforeseen assets to fight life-threatening mycotic diseases

Directory of Open Access Journals (Sweden)

Diego O. Hartmann

2016-02-01

Full Text Available Ionic liquids discovery has celebrated 100 years. They consist solely of ions, one of which is typically organic and asymmetrical. Remarkable physical and chemical properties stirred their use as alternative solvents in many chemical processes. The recent demonstration of their occurrence in nature might boost their interest in biological sciences. In the search of mechanistic understandings of ionic liquids’ ecotoxicological impacts in fungi, we have analyzed the proteome, transcriptome and metabolome responses to this chemical stress. Data illuminated new hypotheses that altered our research path – exploit ionic liquids as tools for the discovery of pathways and metabolites that may impact fungal development and pathogenicity. As we get closer to solve the primary effects of each ionic liquid family and their specific gene targets, the vision of developing antifungal ionic liquids and/or materials, by taking advantage of elegant progresses in this field, might become a reality. Task-designed formulations may improve the performance of conventional antifungal drugs, build functional coatings for reducing allergens production, or aid in the recovery of antifungal plant polymers. The frontier research in this cross-disciplinary field may provide us unforeseen means to address the global concern of mycotic diseases. Pathogenic and opportunistic fungi are responsible for numerous infections, killing annually nearly 1.5 million immunocompromised individuals worldwide, a similar rate to malaria or tuberculosis. This perspective will review our major findings and current hypotheses, contextualizing how they might bring us closer to efficient strategies to prevent and fight mycotic diseases.

Ionic Liquids as Unforeseen Assets to Fight Life-Threatening Mycotic Diseases

Science.gov (United States)

Hartmann, Diego O.; Petkovic, Marija; Silva Pereira, Cristina

2016-01-01

Ionic liquids discovery has celebrated 100 years. They consist solely of ions, one of which is typically organic and asymmetrical. Remarkable physical and chemical properties stirred their use as alternative solvents in many chemical processes. The recent demonstration of their occurrence in nature might boost their interest in biological sciences. In the search of mechanistic understandings of ionic liquids’ ecotoxicological impacts in fungi, we have analyzed the proteome, transcriptome, and metabolome responses to this chemical stress. Data illuminated new hypotheses that altered our research path – exploit ionic liquids as tools for the discovery of pathways and metabolites that may impact fungal development and pathogenicity. As we get closer to solve the primary effects of each ionic liquid family and their specific gene targets, the vision of developing antifungal ionic liquids and/or materials, by taking advantage of elegant progresses in this field, might become a reality. Task-designed formulations may improve the performance of conventional antifungal drugs, build functional coatings for reducing allergens production, or aid in the recovery of antifungal plant polymers. The frontier research in this cross-disciplinary field may provide us unforeseen means to address the global concern of mycotic diseases. Pathogenic and opportunistic fungi are responsible for numerous infections, killing annually nearly 1.5 million immunocompromised individuals worldwide, a similar rate to malaria or tuberculosis. This perspective will review our major findings and current hypotheses, contextualizing how they might bring us closer to efficient strategies to prevent and fight mycotic diseases. PMID:26903990

Graphene-ionic liquid composites

Energy Technology Data Exchange (ETDEWEB)

Aksay, Ilhan A.; Korkut, Sibel; Pope, Michael; Punckt, Christian

2016-11-01

Method of making a graphene-ionic liquid composite. The composite can be used to make elec-trodes for energy storage devices, such as batteries and supercapacitors. Dis-closed and claimed herein is method of making a graphene-ionic liquid com-posite, comprising combining a graphene source with at least one ionic liquid and heating the combination at a temperature of at least about 130 .degree. C.

Escherichia coli under Ionic Silver Stress: An Integrative Approach to Explore Transcriptional, Physiological and Biochemical Responses.

Directory of Open Access Journals (Sweden)

Claire Saulou-Bérion

Full Text Available For a better understanding of the systemic effect of sub-lethal micromolar concentrations of ionic silver on Escherichia coli, we performed a multi-level characterization of cells under Ag+-mediated stress using an integrative biology approach combining physiological, biochemical and transcriptomic data. Physiological parameters, namely bacterial growth and survival after Ag+ exposure, were first quantified and related to the accumulation of intracellular silver, probed for the first time by nano secondary ion mass spectroscopy at sub-micrometer lateral resolution. Modifications in E. coli biochemical composition were evaluated under Ag+-mediated stress by in situ synchrotron Fourier-transform infrared microspectroscopy and a comprehensive transcriptome response was also determined. Using multivariate statistics, correlations between the physiological parameters, the extracellular concentration of AgNO3 and the intracellular silver content, gene expression profiles and micro-spectroscopic data were investigated. We identified Ag+-dependent regulation of gene expression required for growth (e.g. transporter genes, transcriptional regulators, ribosomal proteins, for ionic silver transport and detoxification (e.g. copA, cueO, mgtA, nhaR and for coping with various types of stress (dnaK, pspA, metA,R, oxidoreductase genes. The silver-induced shortening of the acyl chain of fatty acids, mostly encountered in cell membrane, was highlighted by microspectroscopy and correlated with the down-regulated expression of genes involved in fatty acid transport (fadL and synthesis/modification of lipid A (lpxA and arnA. The increase in the disordered secondary structure of proteins in the presence of Ag+ was assessed through the conformational shift shown for amides I and II, and further correlated with the up-regulated expression of peptidase (hfq and chaperone (dnaJ, and regulation of transpeptidase expression (ycfS and ycbB. Interestingly, as these

Scaling and modeling in the analysis of dispersive relaxation of ionic materials

International Nuclear Information System (INIS)

Macdonald, J. Ross

2001-01-01

Problems with scaling of conductive-system experimental M dat # double p rime#(ω) and σ dat prime(ω) data are considered and resolved by dispersive-relaxation-model fitting and comparison. Scaling is attempted for both synthetic and experimental M # double p rime#(ω) data sets. A crucial element in all experimental frequency-response data is the influence of the high-frequency-limiting dipolar-and-vibronic dielectric constant var-epsilon D∞ , often designated var-epsilon ∞ , and not related to ionic transport. It is shown that var-epsilon D∞ precludes scaling of M dat # double p rime#(ω) for ionic materials when the mobile-charge concentration varies. When the effects of var-epsilon D∞ are properly removed from the data, however, such scaling is viable. Only the σprime(ω) and var-epsilon # double p rime#(ω) parts of immittance response are uninfluenced by var-epsilon D∞ . Thus, scaling is possible for experimental σprime(ω) data sets under concentration variation if the shape parameter of a well-fitting model remains constant and if any parts of the response not associated with bulk ionic transport are eliminated. Comparison between the predictions of the original-modulus-formalism (OMF) response model of 1972 - 1973 and a corrected version of it that takes proper account of var-epsilon D∞ , the corrected modulus formalism (CMF), demonstrates that the role played by var-epsilon D∞ (or var-epsilon ∞ ) in the OMF is incorrect. Detailed fitting of data for three different ionic glasses using a Kohlrausch - Williams - Watts response model, the KWW 1 , for OMF and CMF analysis clearly demonstrates that the OMF leads to inconsistent shape-parameter (β 1 ) estimates and the CMF does not. The CMF KWW 1 model is shown to subsume, correct, and generalize the recent disparate scaling/fitting approaches of Sidebottom, Leon, Roling, and Ngai. [copyright] 2001 American Institute of Physics

Ionic conductivity of polymer gels deriving from alkali metal ionic liquids and negatively charged polyelectrolytes

International Nuclear Information System (INIS)

Ogihara, Wataru; Sun Jiazeng; Forsyth, Maria; MacFarlane, Douglas R.; Yoshizawa, Masahiro; Ohno, Hiroyuki

2004-01-01

We have prepared polymer gel electrolytes with alkali metal ionic liquids (AMILs) that inherently contain alkali metal ions. The AMIL consisted of sulfate anion, imidazolium cation, and alkali metal cation. AMILs were mixed directly with poly(3-sulfopropyl acrylate) lithium salt or poly(2-acrylamido-2-methylpropanesulfonic acid) lithium salt to form polymer gels. The ionic conductivity of these gels decreased with increasing polymer fraction, as in general ionic liquid/polymer mixed systems. At low polymer concentrations, these gels displayed excellent ionic conductivity of 10 -4 to 10 -3 S cm -1 at room temperature. Gelation was found to cause little change in the 7 Li diffusion coefficient of the ionic liquid, as measured by pulse-field-gradient NMR. These data strongly suggest that the lithium cation migrates in successive pathways provided by the ionic liquids

Temperature and anion responsive self-assembly of ionic liquid block copolymers coating gold nanoparticles

Science.gov (United States)

Li, Junbo; Zhao, Jianlong; Wu, Wenlan; Liang, Ju; Guo, Jinwu; Zhou, Huiyun; Liang, Lijuan

2016-06-01

In this paper, double hydrophilic ionic liquid block copolymers (ILBCs), poly poly[1-methyl-3-(2-methacryloyloxy propylimidazolium bromine)]- block-(N-isopropylacrylamide) (PMMPImB- b-PNIPAAm) was first synthesized by reversible additionfragmentation chain transfer (RAFT) and then attached on the surface of gold nanoparticles (Au NPs) via a strong gold-sulfur bonding for preparing hybrid nanoparticles (PMMPImB- b-PNIPAAm-@-Au NPs). The hybrid NPs had a three layers micelle-like structure, including a gold core, thermo-responsive inner shell and anion responsive outer corona. The self-assembling behavior of thermal- and anion-response from shell and corona were respectively investigated by change of temperature and addition of (CF3SO2)2N-. The results showed the hybrid NPs retained a stable dispersion beyond the lower critical solution temperature (LCST) because of the space or electrostatic protecting by outer PMMPImB. However, with increasing concentration of (CF3SO2)2N-, the micellization of self-assembling PMMPImB- b-PNIPAAm-@-Au NPs was induced to form micellar structure containing the core with hydrophobic PMMPImB-(CF3SO2)2N- surrounded by composite shell of Au NPs-PNIPAAm via the anionresponsive properties of ILBCs. These results indicated that the block copolymers protected plasmonic nanoparticles remain self-assembling properties of block copolymers when phase transition from outer corona polymer.

High-throughput screening of ionic conductivity in polymer membranes

International Nuclear Information System (INIS)

Zapata, Pedro; Basak, Pratyay; Carson Meredith, J.

2009-01-01

Combinatorial and high-throughput techniques have been successfully used for efficient and rapid property screening in multiple fields. The use of these techniques can be an advantageous new approach to assay ionic conductivity and accelerate the development of novel materials in research areas such as fuel cells. A high-throughput ionic conductivity (HTC) apparatus is described and applied to screening candidate polymer electrolyte membranes for fuel cell applications. The device uses a miniature four-point probe for rapid, automated point-to-point AC electrochemical impedance measurements in both liquid and humid air environments. The conductivity of Nafion 112 HTC validation standards was within 1.8% of the manufacturer's specification. HTC screening of 40 novel Kynar poly(vinylidene fluoride) (PVDF)/acrylic polyelectrolyte (PE) membranes focused on varying the Kynar type (5x) and PE composition (8x) using reduced sample sizes. Two factors were found to be significant in determining the proton conducting capacity: (1) Kynar PVDF series: membranes containing a particular Kynar PVDF type exhibited statistically identical mean conductivity as other membranes containing different Kynar PVDF types that belong to the same series or family. (2) Maximum effective amount of polyelectrolyte: increments in polyelectrolyte content from 55 wt% to 60 wt% showed no statistically significant effect in increasing conductivity. In fact, some membranes experienced a reduction in conductivity.

Study of Thermally Responsive Ionic Liquids for Novel Water Desalination and Energy Conversion Applications

KAUST Repository

Zhong, Yujiang

2018-04-01

The rapidly expanding of the global population in the 21st-century forces people facing two serious problems: water scarcity and energy shortage. Enormous continuous studies focus on providing enough fresh water and energy in a sustainable way. This thesis aims at exploring novel membrane processes based on thermally responsive ionic liquids with the upper critical solution temperature (UCST ILs) for water desalination and energy conversion from low-grade heat energy to electricity. A UCST IL protonated betaine bis(trifluoromethylsulfonyl)imide ([Hbet][Tf2N]) was first experimentally studied as a novel draw solute in a thermal forward osmosis (FO). A 3.2 M [Hbet][Tf2N] solution can be obtained via spontaneous phase separation from an IL and water mixture at room temperature. By heating and maintaining the temperature above 56°C, this solution can draw water from high-salinity solution up to 3.0 M, 5 times salty as the sea water. The IL draw solution can be easily regenerated by phase separation. Conducting the FO process at higher temperatures can also increase the water flux. According to the different choices of the freshwater polishing step, the electric energy consumption in this novel process was estimated as 26.3% to 64.2% of conventional one-step sea water reverse osmosis. Two UCST ILs with better performance, [Hbet][Tf2N] and choline bis(trifluoromethylsulfonyl)imide ([Choline][Tf2N]), were selected as the agents in a novel closed-loop thermally responsive IL osmotic heat engine (TRIL-OHE) to convert low-grade thermal energy to electricity. The specific energies of the [Hbet][Tf2N] system and the [Choline][Tf2N] system are 2500 kJ/t and 3700 kJ/t, which are 2.7 and 4.0 times of the seawater and river water system, respectively. The maximum power density measured from a commercial FO membrane is 1.5 W/m2 for the [Hbet][Tf2N] system and 2.3 W/m2 for the [Choline][Tf2N] system, leaving a big room to improve if highly permeable membranes are used. Another

Rapid IV Versus Oral Rehydration: Responses to Subsequent Exercise Heat Stress

National Research Council Canada - National Science Library

Kenefick, Robert W; O'Moore, Kathleen M; Mahood, Nicholas V; Castellani, John W

2006-01-01

This study sought to determine the effect of rapid intravenous (IV) versus oral (ORAL) rehydration immediately after dehydration, on cardiovascular, thermoregulatory, and perceptual responses during subsequent exercise in the heat.

Functional ionic liquids

International Nuclear Information System (INIS)

Baecker, Tobias

2012-01-01

In the thesis at hand, new functional ionic liquids were investigated. Main focus was attended to their structure property relations and the structural features leading to a decrease of the melting point. New compounds of the type 1-butyl-3-methylimidazolium tris(N,Ndialkyldithiocarbamato) uranylate with variously substituated dithiocarbamato ligands were synthesized and characterized. Ligands with asymmetrical substitution pattern proved to be most suitable for ionic liquid formation. The single-crystal X-ray structures revealed the interactions in the solid state. Here, the first spectroscopic investigation of the U-S bond in sulfur donated uranyl complexes, up to now only observed in single-crystal X-ray structures, is presented, and the participation of the uranium f-orbitals is shown by theoretical calculations. Electrochemical investigations showed the accessibility of the respective U V O 2 + compounds. As well, ionic liquids with [FeCl 4 ] - and [Cl 3 FeOFeCl 3 ] 2- as anion were synthesized. Both of these anions contain high-spin Fe(III) centres in distorted tetrahedral environment, but exhibit different magnetic behaviour. The tetrachloroferrates show the usual paramagnetism, the m-oxobis(trichloroferrate) exhibits unexpectedly strong antiferromagnetic coupling, as was observed by NMR experiments and susceptibility measurements. To investigate structure-property relations in functionalized ionic liquids, a set of protic, primary alkylammonium and aprotic, quarternary trimethylalkylammonium based ionic liquids was synthesized, and characterized. The length of the alkyl chain was systematically varied, and all compounds were synthesized with and without hydroxyl group, as well as formate and bis(triflyl)amide salts, aiming at getting insight into the influence of the different structure parts on the respective ionic liquid's properties.

Cellulose-Supported Ionic Liquids for Low-Cost Pressure Swing CO{sub 2} Capture

Energy Technology Data Exchange (ETDEWEB)

Reed, Daniel G.; Dowson, George R. M.; Styring, Peter, E-mail: p.styring@sheffield.ac.uk [UK Centre for Carbon Dioxide Utilisation, Department of Chemical and Biological Engineering, The University of Sheffield, Sheffield (United Kingdom)

2017-07-07

Reducing the cost of capturing CO{sub 2} from point source emitters is a major challenge facing carbon capture, utilization, and storage. While solid ionic liquids (SoILs) have been shown to allow selective and rapid CO{sub 2} capture by pressure swing separation of flue gases, expectations of their high cost hinders their potential application. Cellulose is found to be a reliable, cheap, and sustainable support for a range of SoILs, reducing the total sorbent cost by improving the efficiency of the ionic liquid (IL) through increased ionic surface area that results from coating. It was also found that cellulose support imparts surface characteristics, which increased total sorbent uptake. Combined, these effects allowed a fourfold to eightfold improvement in uptake per gram of IL for SoILs that have previously shown high uptake and a 9- to 39-fold improvement for those with previously poor uptake. This offers the potential to drastically reduce the amount of IL required to separate a given gas volume. Furthermore, the fast kinetics are retained, with adsorb–desorb cycles taking place over a matter of seconds. This means that rapid cycling can be achieved, which results in high cumulative separation capacity relative to a conventional temperature swing process. The supported materials show an optimum at 75% cellulose:25% IL as a result of even coating of the cellulose surface. The projected reduction in plant size and operational costs represents a potentially ground-breaking step forward in carbon dioxide capture technologies.

Structure, ionic Conductivity and mobile Carrier Density in Fast Ionic Conducting Chalcogenide Glasses

International Nuclear Information System (INIS)

Wenlong Yao

2006-01-01

This thesis consists of six sections. The first section gives the basic research background on the ionic conduction mechanism in glass, polarization in the glass, and the method of determining the mobile carrier density in glass. The proposed work is also included in this section. The second section is a paper that characterizes the structure of MI + M 2 S + (0.1 Ga 2 S 3 + 0.9 GeS 2 ) (M = Li, Na, K and Cs) glasses using Raman and IR spectroscopy. Since the ionic radius plays an important role in determining the ionic conductivity in glasses, the glass forming range for the addition of different alkalis into the basic glass forming system 0.1 Ga 2 S 3 + 0.9 GeS 2 was studied. The study found that the change of the alkali radius for the same nominal composition causes significant structure change to the glasses. The third section is a paper that investigates the ionic conductivity of MI + M 2 S + (0.1Ga 2 S 3 + 0.9 GeS 2 ) (M = Li, Na, K and Cs) glasses system. Corresponding to the compositional changes in these fast ionic conducting glasses, the ionic conductivity shows changes due to the induced structural changes. The ionic radius effect on the ionic conductivity in these glasses was investigated. The fourth section is a paper that examines the mobile carrier density based upon the measurements of space charge polarization. For the first time, the charge carrier number density in fast ionic conducting chalcogenide glasses was determined. The experimental impedance data were fitted using equivalent circuits and the obtained parameters were used to determine the mobile carrier density. The influence of mobile carrier density and mobility on the ionic conductivity was separated. The fifth section is a paper that studies the structures of low-alkali-content Na 2 S + B 2 S 3 (x (le) 0.2) glasses by neutron and synchrotron x-ray diffraction. Similar results were obtained both in neutron and synchrotron x-ray diffraction experiments. The results provide direct

Market Design for Rapid Demand Response - The Case of Kenya

OpenAIRE

Kurt Nielsen; Tseganesh Wubale Tamirat

2014-01-01

We suggest a market design for rapid demand response in electricity markets. The solution consists of remotely controlled switches, meters, forecasting models as well as a flexible auction market to set prices and select endusers job by job. The auction market motivates truth-telling and makes it simple to involve the endusers in advance and to activate demand response immediately. The collective solution is analyzed and economic simulations are conducted for the case of Kenya. Kenya has been...

Ionic and non-ionic contrast media used for contrast-enhanced computed tomography in experimental pancreatitis

International Nuclear Information System (INIS)

Kivisaari, L.; Nuutinen, P.; Lehtola, A.; Saari, A.; Pitkaeranta, P.; Standertskjoeld-Nordenstam, C.G.; Lempinen, M.; Schroeder, T.; Helsinki Univ. Central Hospital

1988-01-01

Contrast enhancement of the pancreas was studied in pigs using dynamic computed tomography in experimental oedematous and haemorrhagic/necrotizing pancreatitis during the first two minutes after injection of an intravenous bolus of non-ionic contrast medium (iohexol). The prospects of separating the two forms of the disease, known to be possible with ionic contrast media, were tested with a non-ionic contrast medium. In the oedematous form, contrast enhancement after 5 hours of the disease was significantly higher than in the haemorrhagic/necrotizing form. Contrast enhancement after 30 hours of disease tended to vary with the severity of the disease, showing that the course of oedematous pancreatitis is dynamic. Intermediate forms occur and follow-up studies are needed during the disease. A non-ionic contrast medium proved as good for separating the two forms of the disease in the early phase as were ionic contrast media. In severely ill patients, non-ionic contrast media should therefore be used. (orig.)

E-DECIDER Rapid Response to the M 6.0 South Napa Earthquake

Science.gov (United States)

Glasscoe, M. T.; Parker, J. W.; Pierce, M. E.; Wang, J.; Eguchi, R. T.; Huyck, C. K.; Hu, Z.; Chen, Z.; Yoder, M. R.; Rundle, J. B.; Rosinski, A.

2014-12-01

E-DECIDER initiated rapid response mode when the California Earthquake Clearinghouse was activated the morning following the M6 Napa earthquake. Data products, including: 1) rapid damage and loss estimates, 2) deformation magnitude and slope change maps, and 3) aftershock forecasts were provided to the Clearinghouse partners within 24 hours of the event via XchangeCore Web Service Data Orchestration sharing. NASA data products were provided to end-users via XchangeCore, EERI and Clearinghouse websites, and ArcGIS online for Napa response, reaching a wide response audience. The E-DECIDER team helped facilitate rapid delivery of NASA products to stakeholders and participated in Clearinghouse Napa earthquake briefings to update stakeholders on product information. Rapid response products from E-DECIDER can be used to help prioritize response efforts shortly after the event has occurred. InLET (Internet Loss Estimation Tool) post-event damage and casualty estimates were generated quickly after the Napa earthquake. InLET provides immediate post-event estimates of casualties and building damage by performing loss/impact simulations using USGS ground motion data and FEMA HAZUS damage estimation technology. These results were provided to E-DECIDER by their collaborators, ImageCat, Inc. and the Community Stakeholder Network (CSN). Strain magnitude and slope change maps were automatically generated when the Napa earthquake appeared on the USGS feed. These maps provide an early estimate of where the deformation has occurred and where damage may be localized. Using E-DECIDER critical infrastructure overlays with damage estimates, decision makers can direct response effort that can be verified later with field reconnaissance and remote sensing-based observations. Earthquake aftershock forecast maps were produced within hours of the event. These maps highlight areas where aftershocks are likely to occur and can also be coupled with infrastructure overlays to help direct response

Nanoparticles in ionic liquids: interactions and organization.

Science.gov (United States)

He, Zhiqi; Alexandridis, Paschalis

2015-07-28

Ionic liquids (ILs), defined as low-melting organic salts, are a novel class of compounds with unique properties and a combinatorially great chemical diversity. Ionic liquids are utilized as synthesis and dispersion media for nanoparticles as well as for surface functionalization. Ionic liquid and nanoparticle hybrid systems are governed by a combined effect of several intermolecular interactions between their constituents. For each interaction, including van der Waals, electrostatic, structural, solvophobic, steric, and hydrogen bonding, the characterization and quantitative calculation methods together with factors affecting these interactions are reviewed here. Various self-organized structures based on nanoparticles in ionic liquids are generated as a result of a balance of these intermolecular interactions. These structures, including colloidal glasses and gels, lyotropic liquid crystals, nanoparticle-stabilized ionic liquid-containing emulsions, ionic liquid surface-functionalized nanoparticles, and nanoscale ionic materials, possess properties of both ionic liquids and nanoparticles, which render them useful as novel materials especially in electrochemical and catalysis applications. This review of the interactions within nanoparticle dispersions in ionic liquids and of the structure of nanoparticle and ionic liquid hybrids provides guidance on the rational design of novel ionic liquid-based materials, enabling applications in broad areas.

Shape-Memory Behavior of Polylactide/Silica Ionic Hybrids

KAUST Repository

Odent, Jérémy

2017-03-27

Commercial polylactide (PLA) was converted and endowed with shape-memory properties by synthesizing ionic hybrids based on blends of PLA with imidazolium-terminated PLA and poly[ε-caprolactone-co-d,l-lactide] (P[CL-co-LA]) and surface-modified silica nanoparticles. The electrostatic interactions assist with the silica nanoparticle dispersion in the polymer matrix. Since nanoparticle dispersion in polymers is a perennial challenge and has prevented nanocomposites from reaching their full potential in terms of performance we expect this new design will be exploited in other polymers systems to synthesize well-dispersed nanocomposites. Rheological measurements of the ionic hybrids are consistent with the formation of a network. The ionic hybrids are also much more deformable compared to the neat PLA. More importantly, they exhibit shape-memory behavior with fixity ratio Rf ≈ 100% and recovery ratio Rr = 79%, for the blend containing 25 wt % im-PLA and 25 wt % im-P[CL-co-LA] and 5 wt % of SiO2–SO3Na. Dielectric spectroscopy and dynamic mechanical analysis show a second, low-frequency relaxation attributed to strongly immobilized polymer chains on silica due to electrostatic interactions. Creep compliance tests further suggest that the ionic interactions prevent permanent slippage in the hybrids which is most likely responsible for the significant shape-memory behavior observed.

Shape-Memory Behavior of Polylactide/Silica Ionic Hybrids

KAUST Repository

Odent, Jé ré my; Raquez, Jean-Marie; Samuel, Cé dric; Barrau, Sophie; Enotiadis, Apostolos; Dubois, Philippe; Giannelis, Emmanuel P.

2017-01-01

Commercial polylactide (PLA) was converted and endowed with shape-memory properties by synthesizing ionic hybrids based on blends of PLA with imidazolium-terminated PLA and poly[ε-caprolactone-co-d,l-lactide] (P[CL-co-LA]) and surface-modified silica nanoparticles. The electrostatic interactions assist with the silica nanoparticle dispersion in the polymer matrix. Since nanoparticle dispersion in polymers is a perennial challenge and has prevented nanocomposites from reaching their full potential in terms of performance we expect this new design will be exploited in other polymers systems to synthesize well-dispersed nanocomposites. Rheological measurements of the ionic hybrids are consistent with the formation of a network. The ionic hybrids are also much more deformable compared to the neat PLA. More importantly, they exhibit shape-memory behavior with fixity ratio Rf ≈ 100% and recovery ratio Rr = 79%, for the blend containing 25 wt % im-PLA and 25 wt % im-P[CL-co-LA] and 5 wt % of SiO2–SO3Na. Dielectric spectroscopy and dynamic mechanical analysis show a second, low-frequency relaxation attributed to strongly immobilized polymer chains on silica due to electrostatic interactions. Creep compliance tests further suggest that the ionic interactions prevent permanent slippage in the hybrids which is most likely responsible for the significant shape-memory behavior observed.

Near-infrared responsive PbS-sensitized photovoltaic photodetectors fabricated by the spin-assisted successive ionic layer adsorption and reaction method

International Nuclear Information System (INIS)

Im, Sang Hyuk; Kim, Hi-jung; Seok, Sang Il

2011-01-01

A PbS-sensitized photovoltaic photodetector responsive to near-infrared (NIR) light was fabricated by depositing monolayered PbS nanoparticles on a mesoporous TiO 2 (mp-TiO 2 ) film via the spin-assisted successive ionic layer adsorption and reaction (SILAR) method. By adjusting the size and morphology of the PbS nanoparticles through repeated spin-assisted SILAR cycles, the PbS-sensitized photovoltaic photodetector achieved an external quantum efficiency of 9.3% at 1140 nm wavelength and could process signals up to 1 kHz.

The Deployable Operations Group: A Model for a National Unified Interagency Rapid Response Command

National Research Council Canada - National Science Library

Cooper, Eric M

2008-01-01

.... Since the attacks, nationwide preparedness efforts have established numerous federal rapid response teams, which are coordinated during a federal interagency response under the National Incident Management System...

Effect of ionic strength on the kinetics of ionic and micellar reactions in aqueous solution

International Nuclear Information System (INIS)

Dung, M.H.; Kozak, J.J.

1982-01-01

The effect of electrostatic forces on the rate of reaction between ions in aqueous solutions of intermediate ionic strength is studied in this paper. We consider the kinetics of reactions involving simple ionic species (1--1 and 2--2 electrolyte systems) as well as kinetic processes mediated by the presence of micellar ions (or other charged organizates). In the regime of ionic strength considered, dielectric saturation of the solvent in the vicinity of the reacting ions must be taken into account and this is done by introducing several models to describe the recovery of the solvent from saturation to its continuum dielectric behavior. To explore the effects of ion size, charge number, and ionic strength on the overall rate constant for the process considered, we couple the traditional theory of ionic reactions in aqueous solution with calculations of the electrostatic potential obtained via solution of the nonlinear Poisson--Boltzmann equation. The great flexibility of the nonlinear Poisson--Boltzmann theory allows us to explore quantitatively the influence of each of these effects, and our simulations show that the short-range properties of the electrostatic potential affect primarily kinetically controlled processes (to varying degrees, depending on the ionic system considered) whereas the down-range properties of the potential play a (somewhat) greater role in influencing diffusion-controlled processes. A detailed examination is made of ionic strength effects over a broad range of ionic concentrations. In the regime of low ionic strength, the limiting slope and intercept of the curve describing the dependence of log k/sub D/ on I/sup 1/2//(1+I/sup 1/2/) may differ considerably from the usual Debye--Hueckel limiting relations, depending on the particular model chosen to describe local saturation effects

Comparative Investigation of the Ionicity of Aprotic and Protic Ionic Liquids in Molecular Solvents by using Conductometry and NMR Spectroscopy.

Science.gov (United States)

Thawarkar, Sachin; Khupse, Nageshwar D; Kumar, Anil

2016-04-04

Electrical conductivity (σ), viscosity (η), and self-diffusion coefficient (D) measurements of binary mixtures of aprotic and protic imidazolium-based ionic liquids with water, dimethyl sulfoxide, and ethylene glycol were measured from 293.15 to 323.15 K. The temperature dependence study reveals typical Arrhenius behavior. The ionicities of aprotic ionic liquids were observed to be higher than those of protic ionic liquids in these solvents. The aprotic ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate, [bmIm][BF4 ], displays 100 % ionicity in both water and ethylene glycol. The protic ionic liquids in both water and ethylene glycol are classed as good ionic candidates, whereas in DMSO they are classed as having a poor ionic nature. The solvation dynamics of the ionic species of the ionic liquids are illustrated on the basis of the (1) H NMR chemical shifts of the ionic liquids. The self-diffusion coefficients D of the cation and anion of [HmIm][CH3 COO] in D2 O and in [D6 ]DMSO are determined by using (1) H nuclei with pulsed field gradient spin-echo NMR spectroscopy. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structure, ionic conductivity and mobile carrier density in fast ionic conducting chalcogenide glasses

Energy Technology Data Exchange (ETDEWEB)

Yao, Wenlong [Iowa State Univ., Ames, IA (United States)

2006-01-01

This thesis consists of six sections. The first section gives the basic research background on the ionic conduction mechanism in glass, polarization in the glass, and the method of determining the mobile carrier density in glass. The proposed work is also included in this section. The second section is a paper that characterizes the structure of MI + M₂S + (0.1 Ga₂S₃ + 0.9 GeS₂) (M = Li, Na, K and Cs) glasses using Raman and IR spectroscopy. Since the ionic radius plays an important role in determining the ionic conductivity in glasses, the glass forming range for the addition of different alkalis into the basic glass forming system 0.1 Ga₂S₃ + 0.9 GeS₂ was studied. The study found that the change of the alkali radius for the same nominal composition causes significant structure change to the glasses. The third section is a paper that investigates the ionic conductivity of MI + M₂S + (0.1Ga₂S₃ + 0.9 GeS₂) (M = Li, Na, K and Cs) glasses system. Corresponding to the compositional changes in these fast ionic conducting glasses, the ionic conductivity shows changes due to the induced structural changes. The ionic radius effect on the ionic conductivity in these glasses was investigated. The fourth section is a paper that examines the mobile carrier density based upon the measurements of space charge polarization. For the first time, the charge carrier number density in fast ionic conducting chalcogenide glasses was determined. The experimental impedance data were fitted using equivalent circuits and the obtained parameters were used to determine the mobile carrier density. The influence of mobile carrier density and mobility on the ionic conductivity was separated. The fifth section is a paper that studies the structures of low-alkali-content Na₂S + B₂S₃ (x ≤ 0.2) glasses by neutron and synchrotron x-ray diffraction

Ionic Liquids: Radiation Chemistry, Solvation Dynamics and Reactivity Patterns

International Nuclear Information System (INIS)

Wishart, J.F.

2008-01-01

Ionic liquids (ILs) are a rapidly expanding family of condensed-phase media with important applications in energy production, nuclear fuel and waste processing, improving the efficiency and safety of industrial chemical processes, and pollution prevention. ILs are generally nonvolatile, noncombustible, highly conductive, recyclable and capable of dissolving a wide variety of materials. They are finding new uses in chemical synthesis, catalysis, separations chemistry, electrochemistry and other areas. Ionic liquids have dramatically different properties compared to conventional molecular solvents, and they provide a new and unusual environment to test our theoretical understanding of charge transfer and other reactions. We are interested in how IL properties influence physical and dynamical processes that determine the stability and lifetimes of reactive intermediates and thereby affect the courses of chemical reactions and product distributions. Successful use of ionic liquids in radiation-filled environments, where their safety advantages could be significant, requires an understanding of ionic liquid radiation chemistry. For example, characterizing the primary steps of IL radiolysis will reveal radiolytic degradation pathways and suggest ways to prevent them or mitigate their effects on the properties of the material. An understanding of ionic liquid radiation chemistry will also facilitate pulse radiolysis studies of general chemical reactivity in ILs, which will aid in the development of applications listed above. Very early in our radiolysis studies it became evident that slow solvation dynamics of the excess electron in ILs (which vary over a wide viscosity range) increases the importance of pre-solvated electron reactivity and consequently alters product distributions. Parallel studies of IL solvation phenomena using coumarin-153 dynamic Stokes shifts and polarization anisotropy decay rates are done to compare with electron solvation studies and to evaluate

Non-Critical-Care Nurses' Perceptions of Facilitators and Barriers to Rapid Response Team Activation.

Science.gov (United States)

Jenkins, Sheryl Henry; Astroth, Kim Schafer; Woith, Wendy Mann

2015-01-01

Rapid response teams can save lives but are only effective when activated. We surveyed 50 nurses for their perceptions of facilitators and barriers to activation. Findings showed that participants need more education on their role and when to activate the rapid response team. Nurses who comprise the team need help building their communication skills. We recommend nursing professional development specialists increase the frequency of offerings and expand the focus on roles, activation criteria, and communication skills.

Ionic Liquids in Tribology

Directory of Open Access Journals (Sweden)

Ichiro Minami

2009-06-01

Full Text Available Current research on room-temperature ionic liquids as lubricants is described. Ionic liquids possess excellent properties such as non-volatility, non-flammability, and thermo-oxidative stability. The potential use of ionic liquids as lubricants was first proposed in 2001 and approximately 70 articles pertaining to fundamental research on ionic liquids have been published through May 2009. A large majority of the cations examined in this area are derived from 1,3-dialkylimidazolium, with a higher alkyl group on the imidazolium cation being beneficial for good lubrication, while it reduces the thermo-oxidative stability. Hydrophobic anions provide both good lubricity and significant thermo-oxidative stability. The anions decompose through a tribochemical reaction to generate metal fluoride on the rubbed surface. Additive technology to improve lubricity is also explained. An introduction to tribology as an interdisciplinary field of lubrication is also provided.

Ionic liquids in tribology.

Science.gov (United States)

Minami, Ichiro

2009-06-24

Current research on room-temperature ionic liquids as lubricants is described. Ionic liquids possess excellent properties such as non-volatility, non-flammability, and thermo-oxidative stability. The potential use of ionic liquids as lubricants was first proposed in 2001 and approximately 70 articles pertaining to fundamental research on ionic liquids have been published through May 2009. A large majority of the cations examined in this area are derived from 1,3-dialkylimidazolium, with a higher alkyl group on the imidazolium cation being beneficial for good lubrication, while it reduces the thermo-oxidative stability. Hydrophobic anions provide both good lubricity and significant thermo-oxidative stability. The anions decompose through a tribochemical reaction to generate metal fluoride on the rubbed surface. Additive technology to improve lubricity is also explained. An introduction to tribology as an interdisciplinary field of lubrication is also provided.

Simulating chemical reactions in ionic liquids using QM/MM methodology.

Science.gov (United States)

Acevedo, Orlando

2014-12-18

The use of ionic liquids as a reaction medium for chemical reactions has dramatically increased in recent years due in large part to the numerous reported advances in catalysis and organic synthesis. In some extreme cases, ionic liquids have been shown to induce mechanistic changes relative to conventional solvents. Despite the large interest in the solvents, a clear understanding of the molecular factors behind their chemical impact is largely unknown. This feature article reviews our efforts developing and applying mixed quantum and molecular mechanical (QM/MM) methodology to elucidate the microscopic details of how these solvents operate to enhance rates and alter mechanisms for industrially and academically important reactions, e.g., Diels-Alder, Kemp eliminations, nucleophilic aromatic substitutions, and β-eliminations. Explicit solvent representation provided the medium dependence of the activation barriers and atomic-level characterization of the solute-solvent interactions responsible for the experimentally observed "ionic liquid effects". Technical advances are also discussed, including a linear-scaling pairwise electrostatic interaction alternative to Ewald sums, an efficient polynomial fitting method for modeling proton transfers, and the development of a custom ionic liquid OPLS-AA force field.

Alkaline ionic liquids applied in supported ionic liquid catalyst for selective hydrogenation of citral to citronellal

Directory of Open Access Journals (Sweden)

Eero eSalminen

2014-02-01

Full Text Available The challenge in preparation of ionic liquids containing a strong alkaline anion is to identify a suitable cation which can tolerate the harsh conditions induced by the anion. In this study, a commercial quaternary ammonium compound (quat benzalkonium [ADBA] (alkyldimethylbenzylammonium was used as a cation in the synthesis of different alkaline ionic liquids. In fact, the precursor, benzalkonium chloride, is a mixture of alkyldimethylbenzylammonium chlorides of various alkyl chain lengths and is commonly used in the formulation of various antiseptic products. The prepared ionic liquids were utilized as Supported Ionic Liquid Catalysts (SILCAs. Typically, a SILCA contains metal nanoparticles, enzymes or metal complexes in an ionic liquid layer which is immobilized on a solid carrier material such as an active carbon cloth (ACC. The catalysts were applied in the selective hydrogenation of citral to citronellal which is an important perfumery chemical. Interestingly, 70 % molar yield towards citronellal was achieved over a catalyst containing the alkaline ionic liquid benzalkonium methoxide.

Alkaline ionic liquids applied in supported ionic liquid catalyst for selective hydrogenation of citral to citronellal

Science.gov (United States)

Salminen, Eero; Virtanen, Pasi; Mikkola, Jyri-Pekka

2014-01-01

The challenge in preparation of ionic liquids containing a strong alkaline anion is to identify a suitable cation which can tolerate the harsh conditions induced by the anion. In this study, a commercial quaternary ammonium compound (quat) benzalkonium [ADBA] (alkyldimethylbenzylammonium) was used as a cation in the synthesis of different alkaline ionic liquids. In fact, the precursor, benzalkonium chloride, is a mixture of alkyldimethylbenzylammonium chlorides of various alkyl chain lengths and is commonly used in the formulation of various antiseptic products. The prepared ionic liquids were utilized as Supported Ionic Liquid Catalysts (SILCAs). Typically, a SILCA contains metal nanoparticles, enzymes, or metal complexes in an ionic liquid layer which is immobilized on a solid carrier material such as an active carbon cloth (ACC). The catalysts were applied in the selective hydrogenation of citral to citronellal which is an important perfumery chemical. Interestingly, 70% molar yield toward citronellal was achieved over a catalyst containing the alkaline ionic liquid benzalkonium methoxide. PMID:24790972

Fluctuating hydrodynamics for ionic liquids

Energy Technology Data Exchange (ETDEWEB)

Lazaridis, Konstantinos [Department of Mathematics and Statistics, Washington State University, Pullman, 99163 (United States); Wickham, Logan [Department of Computer Science, Washington State University, Richland, 99354 (United States); Voulgarakis, Nikolaos, E-mail: n.voulgarakis@wsu.edu [Department of Mathematics and Statistics, Washington State University, Pullman, 99163 (United States)

2017-04-25

We present a mean-field fluctuating hydrodynamics (FHD) method for studying the structural and transport properties of ionic liquids in bulk and near electrified surfaces. The free energy of the system consists of two competing terms: (1) a Landau–Lifshitz functional that models the spontaneous separation of the ionic groups, and (2) the standard mean-field electrostatic interaction between the ions in the liquid. The numerical approach used to solve the resulting FHD-Poisson equations is very efficient and models thermal fluctuations with remarkable accuracy. Such density fluctuations are sufficiently strong to excite the experimentally observed spontaneous formation of liquid nano-domains. Statistical analysis of our simulations provides quantitative information about the properties of ionic liquids, such as the mixing quality, stability, and the size of the nano-domains. Our model, thus, can be adequately parameterized by directly comparing our prediction with experimental measurements and all-atom simulations. Conclusively, this work can serve as a practical mathematical tool for testing various theories and designing more efficient mixtures of ionic liquids. - Highlights: • A new fluctuating hydrodynamics method for ionic liquids. • Description of ionic liquid morphology in bulk and near electrified surfaces. • Direct comparison with experimental measurements.

Application of Ionic Liquids in Hydrometallurgy

Science.gov (United States)

Park, Jesik; Jung, Yeojin; Kusumah, Priyandi; Lee, Jinyoung; Kwon, Kyungjung; Lee, Churl Kyoung

2014-01-01

Ionic liquids, low temperature molten salts, have various advantages manifesting themselves as durable and environmentally friendly solvents. Their application is expanding into various fields including hydrometallurgy due to their unique properties such as non-volatility, inflammability, low toxicity, good ionic conductivity, and wide electrochemical potential window. This paper reviews previous literatures and our recent results adopting ionic liquids in extraction, synthesis and processing of metals with an emphasis on the electrolysis of active/light, rare earth, and platinum group metals. Because the research and development of ionic liquids in this area are still emerging, various, more fundamental approaches are expected to popularize ionic liquids in the metal manufacturing industry. PMID:25177864

Rapid analysis of Fructus forsythiae essential oil by ionic liquids-assisted microwave distillation coupled with headspace single-drop microextraction followed by gas chromatography–mass spectrometry

International Nuclear Information System (INIS)

Jiao, Jiao; Ma, Dan-Hui; Gai, Qing-Yan; Wang, Wei; Luo, Meng; Fu, Yu-Jie; Ma, Wei

2013-01-01

Graphical abstract: -- Highlights: •A new ILAMD-HS-SDME method is developed for the microextraction of essential oil. •ILs used as destruction agent of plant cell walls and microwave absorption medium. •Parameters affecting the extraction efficiency are optimized by Box–Behnken design. •Procedure benefits: similar constituents, shorter duration and smaller sample amount. •ILAMD-HS-SDME followed by GC–MS is a promising technique in analytical fields. -- Abstract: A rapid, green and effective miniaturized sample preparation and analytical technique, i.e. ionic liquids-assisted microwave distillation coupled with headspace single-drop microextraction (ILAMD-HS-SDME) followed by gas chromatography–mass spectrometry (GC–MS) was developed for the analysis of essential oil (EO) in Fructus forsythiae. In this work, ionic liquids (ILs) were not only used as the absorption medium of microwave irradiation but also as the destruction agent of plant cell walls. 1-Ethyl-3-methylimidazolium acetate ([C 2 mim]OAc) was chosen as the optimal ILs. Moreover, n-heptadecane (2.0 μL) was selected as the appropriate suspended solvent for the extraction and concentration of EO. Extraction conditions of the proposed method were optimized using the relative peak area of EO constituents as the index, and the optimal operational parameters were obtained as follows: irradiation power (300 W), sample mass (0.7 g), mass ratio of ILs to sample (2.4), temperature (78 °C) and time (3.4 min). In comparison to previous reports, the proposed method was faster and required smaller sample amount but could equally monitor all EO constituents with no significant differences

Rapid analysis of Fructus forsythiae essential oil by ionic liquids-assisted microwave distillation coupled with headspace single-drop microextraction followed by gas chromatography–mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Jiao, Jiao [State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040 (China); Ma, Dan-Hui [College of Life Sciences, Northeast Forestry University, Harbin 150040 (China); Gai, Qing-Yan; Wang, Wei; Luo, Meng [State Engineering Laboratory of Bio-Resource Eco-Utilization, Northeast Forestry University, Harbin 150040 (China); Fu, Yu-Jie, E-mail: yujie_fu2002@yahoo.com [State Engineering Laboratory of Bio-Resource Eco-Utilization, Northeast Forestry University, Harbin 150040 (China); Ma, Wei, E-mail: mawei@hljucm.net [State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040 (China); School of Pharmaceutical, Heilongjiang University of Chinese Medicine, Harbin 150040 (China)

2013-12-04

Graphical abstract: -- Highlights: •A new ILAMD-HS-SDME method is developed for the microextraction of essential oil. •ILs used as destruction agent of plant cell walls and microwave absorption medium. •Parameters affecting the extraction efficiency are optimized by Box–Behnken design. •Procedure benefits: similar constituents, shorter duration and smaller sample amount. •ILAMD-HS-SDME followed by GC–MS is a promising technique in analytical fields. -- Abstract: A rapid, green and effective miniaturized sample preparation and analytical technique, i.e. ionic liquids-assisted microwave distillation coupled with headspace single-drop microextraction (ILAMD-HS-SDME) followed by gas chromatography–mass spectrometry (GC–MS) was developed for the analysis of essential oil (EO) in Fructus forsythiae. In this work, ionic liquids (ILs) were not only used as the absorption medium of microwave irradiation but also as the destruction agent of plant cell walls. 1-Ethyl-3-methylimidazolium acetate ([C{sub 2}mim]OAc) was chosen as the optimal ILs. Moreover, n-heptadecane (2.0 μL) was selected as the appropriate suspended solvent for the extraction and concentration of EO. Extraction conditions of the proposed method were optimized using the relative peak area of EO constituents as the index, and the optimal operational parameters were obtained as follows: irradiation power (300 W), sample mass (0.7 g), mass ratio of ILs to sample (2.4), temperature (78 °C) and time (3.4 min). In comparison to previous reports, the proposed method was faster and required smaller sample amount but could equally monitor all EO constituents with no significant differences.

Radiation Chemistry and Photochemistry of Ionic Liquids

International Nuclear Information System (INIS)

Wishart, J.F.; Takahaski, K.

2010-01-01

As our understanding of ionic liquids and their tunable properties has grown, it is possible to see many opportunities for ionic liquids to contribute to the sustainable use of energy. The potential safety and environmental benefits of ionic liquids, as compared to conventional solvents, have attracted interest in their use as processing media for the nuclear fuel cycle. Therefore, an understanding of the interactions of ionizing radiation and photons with ionic liquids is strongly needed. However, the radiation chemistry of ionic liquids is still a relatively unexplored topic although there has been a significant increase in the number of researchers in the field recently. This article provides a brief introduction to ionic liquids and their interesting properties, and recent advances in the radiation chemistry and photochemistry of ionic liquids. In this article, we will mainly focus on excess electron dynamics and radical reaction dynamics. Because solvation dynamics processes in ionic liquids are much slower than in molecular solvents, one of the distinguishing characteristics is that pre-solvated electrons play an important role in ionic liquid radiolysis. It will be also shown that the reaction dynamics of radical ions is significantly different from that observed in molecular solvents because of the Coulombic screening effects and electrostatic interactions in ionic liquids.

Rapid screening of aquatic toxicity of several metal-based nanoparticles using the MetPLATE™ bioassay

International Nuclear Information System (INIS)

Pokhrel, Lok R.; Silva, Thilini; Dubey, Brajesh; El Badawy, Amro M.; Tolaymat, Thabet M.; Scheuerman, Phillip R.

2012-01-01

Current understanding of potential toxicity of engineered nanomaterials to aquatic microorganisms is limited for risk assessment and management. Here we evaluate if the MetPLATE™ test can be used as an effective and rapid screening tool to test for potential aquatic toxicity of various metal-based nanoparticles (NPs). The MetPLATE bioassay is a heavy metal sensitive test based on β-galactosidase activity in Escherichia coli. Five different types of metal-based NPs were screened for toxicity: (1) citrate coated nAg (Citrate-nanosilver), (2) polyvinylpyrrolidone coated nAg (PVP-nAg), (3) uncoated nZnO, (4) uncoated nTiO 2 and (5) 1-Octadecylamine coated CdSe Quantum Dots (CdSe QDs); and compared with their corresponding ionic salt toxicity. Citrate-nAg was further fractionated into clean Citrate-nAg, unclean Citrate-nAg and permeate using a tangential flow filtration (TFF) system to eliminate residual ions and impurities from the stock Citrate-nAg suspension and also to differentiate between ionic- versus nano-specific toxicity. Our results showed that nAg, nZnO and CdSe QDs were less toxic than their corresponding ionic salts tested, while nano- or ionic form of TiO 2 was not toxic as high as 2.5 g L −1 to the MetPLATE™ bacteria. Although coating-dependent toxicity was noticeable between two types of Ag NPs evaluated, particle size and surface charge were not adequate to explain the observed toxicity; hence, the toxicity appeared to be material-specific. Overall, the toxicity followed the trend: CdCl 2 > AgNO 3 > PVP-nAg > unclean Citrate-nAg > clean Citrate-nAg > ZnSO 4 > nZnO > CdSe QDs > nTiO 2 /TiO 2 . These results indicate that an evaluation of β-galactosidase inhibition in MetPLATE™ E. coli can be an important consideration for rapid screening of metal-based NP toxicity, and should facilitate ecological risk assessment of these emerging contaminants. - Highlights: ► MetPLATE bioassay was evaluated as a rapid screening tool for nanotoxicity. �

In vivo relevance for photoprotection by the vitamin D rapid response pathway.

Science.gov (United States)

Dixon, K M; Deo, S S; Norman, A W; Bishop, J E; Halliday, G M; Reeve, V E; Mason, R S

2007-03-01

Vitamin D is produced by exposure of 7-dehydrocholesterol in the skin to UV irradiation (UVR) and further converted in the skin to the biologically active metabolite, 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) and other compounds. UVR also results in DNA damage producing cyclobutane pyrimidine dimers (CPD). We previously reported that 1,25(OH)(2)D(3) at picomolar concentrations, protects human skin cells from UVR-induced apoptosis, and decreases CPD in surviving cells. 1,25(OH)(2)D(3) has been shown to generate biological responses via two pathways-the classical steroid receptor/genomic pathway or a rapid, non-genomic pathway mediated by a putative membrane receptor. Whether the rapid response pathway is physiologically relevant is unclear. A cis-locked, rapid-acting agonist 1,25(OH)(2)lumisterol(3) (JN), entirely mimicked the actions of 1,25(OH)(2)D(3) to reduce fibroblast and keratinocyte loss and CPD damage after UVR. The effects of 1,25(OH)(2)D(3) were abolished by a rapid-acting antagonist, but not by a genomic antagonist. Skh:hr1 mice exposed to three times the minimal erythemal dose of solar-simulated UVR and treated topically with 1,25(OH)(2)D(3) or JN immediately after UVR showed reduction in UVR-induced UVR-induced sunburn cells (pphotoprotective effects via the rapid pathway and raise the possibility that other D compounds produced in skin may contribute to the photoprotective effects.

Electro-responsivity of ionic liquid boundary layers in a polar solvent revealed by neutron reflectance

Science.gov (United States)

Pilkington, Georgia A.; Harris, Kathryn; Bergendal, Erik; Reddy, Akepati Bhaskar; Palsson, Gunnar K.; Vorobiev, Alexei; Antzutkin, Oleg. N.; Glavatskih, Sergei; Rutland, Mark W.

2018-05-01

Using neutron reflectivity, the electro-responsive structuring of the non-halogenated ionic liquid (IL) trihexyl(tetradecyl)phosphonium-bis(mandelato)borate, [P6,6,6,14][BMB], has been studied at a gold electrode surface in a polar solvent. For a 20% w/w IL mixture, contrast matched to the gold surface, distinct Kiessig fringes were observed for all potentials studied, indicative of a boundary layer of different composition to that of the bulk IL-solvent mixture. With applied potential, the amplitudes of the fringes from the gold-boundary layer interface varied systematically. These changes are attributable to the differing ratios of cations and anions in the boundary layer, leading to a greater or diminished contrast with the gold electrode, depending on the individual ion scattering length densities. Such electro-responsive changes were also evident in the reflectivities measured for the pure IL and a less concentrated (5% w/w) IL-solvent mixture at the same applied potentials, but gave rise to less pronounced changes. These measurements, therefore, demonstrate the enhanced sensitivity achieved by contrast matching the bulk solution and that the structure of the IL boundary layers formed in mixtures is strongly influenced by the bulk concentration. Together these results represent an important step in characterising IL boundary layers in IL-solvent mixtures and provide clear evidence of electro-responsive structuring of IL ions in their solutions with applied potential.

Near-infrared responsive PbS-sensitized photovoltaic photodetectors fabricated by the spin-assisted successive ionic layer adsorption and reaction method

Energy Technology Data Exchange (ETDEWEB)

Im, Sang Hyuk; Kim, Hi-jung; Seok, Sang Il, E-mail: seoksi@krict.re.kr [KRICT-EPFL Global Research Laboratory, Advanced Materials Division, Korea Research Institute of Chemical Technology, 19 Sinseongno, Yuseong, Daejeon 305-600 (Korea, Republic of)

2011-09-30

A PbS-sensitized photovoltaic photodetector responsive to near-infrared (NIR) light was fabricated by depositing monolayered PbS nanoparticles on a mesoporous TiO{sub 2} (mp-TiO{sub 2}) film via the spin-assisted successive ionic layer adsorption and reaction (SILAR) method. By adjusting the size and morphology of the PbS nanoparticles through repeated spin-assisted SILAR cycles, the PbS-sensitized photovoltaic photodetector achieved an external quantum efficiency of 9.3% at 1140 nm wavelength and could process signals up to 1 kHz.

Frontiers in poly(ionic liquid)s: syntheses and applications.

Science.gov (United States)

Qian, Wenjing; Texter, John; Yan, Feng

2017-02-20

We review recent works on the synthesis and application of poly(ionic liquid)s (PILs). Novel chemical structures, different synthetic strategies and controllable morphologies are introduced as a supplement to PIL systems already reported. The primary properties determining applications, such as ionic conductivity, aqueous solubility, thermodynamic stability and electrochemical/chemical durability, are discussed. Furthermore, the near-term applications of PILs in multiple fields, such as their use in electrochemical energy materials, stimuli-responsive materials, carbon materials, and antimicrobial materials, in catalysis, in sensors, in absorption and in separation materials, as well as several special-interest applications, are described in detail. We also discuss the limitations of PIL applications, efforts to improve PIL physics, and likely future developments.

Ionic thermocurrents and ionic conductivity of solid solutions of SrF2 and YbF3

NARCIS (Netherlands)

Meuldijk, J.; Hartog, den H.W.

1983-01-01

We report dielectric [ionic thermocurrent (!TC)] experiments and ionic conductivity of cubic solid solutions of the type Sr1-xYbxF2+x. These combined experiments provide us with new information concerning the ionic conductivity mechanisms which play an important role in solid solutions Sr1-xRxF2+x

Application of Ionic Liquids in Hydrometallurgy

Directory of Open Access Journals (Sweden)

Jesik Park

2014-08-01

Full Text Available Ionic liquids, low temperature molten salts, have various advantages manifesting themselves as durable and environmentally friendly solvents. Their application is expanding into various fields including hydrometallurgy due to their unique properties such as non-volatility, inflammability, low toxicity, good ionic conductivity, and wide electrochemical potential window. This paper reviews previous literatures and our recent results adopting ionic liquids in extraction, synthesis and processing of metals with an emphasis on the electrolysis of active/light, rare earth, and platinum group metals. Because the research and development of ionic liquids in this area are still emerging, various, more fundamental approaches are expected to popularize ionic liquids in the metal manufacturing industry.

A rapid challenge protocol for determination of non-specific bronchial responsiveness

DEFF Research Database (Denmark)

Madsen, F; Nielsen, N H; Holstein-Rathlou, N H

1986-01-01

A rapid method for determination of non-specific bronchial hyperreactivity was developed. Resistance to breathing was determined by a modified expiratory airway interrupter technique and combined with a dosimeter-controlled nebulizer which made continuous determination of response possible during...... hyperreactivity since individual dose titration is easily performed, and the method could be valuable in epidemiological and occupational surveys as well.......A rapid method for determination of non-specific bronchial hyperreactivity was developed. Resistance to breathing was determined by a modified expiratory airway interrupter technique and combined with a dosimeter-controlled nebulizer which made continuous determination of response possible during...... challenge. The patients inhaled histamine chloride 8 mg/ml at every eighth breath until resistance to breathing (Rt) was increased by 60%. The number of inhalations (NI) or the provocative concentration (PC60-Rt) of histamine increasing Rt by 60% were determined in 68 patients. The new method correlated...

Ionic Liquid Crystals: Versatile Materials.

Science.gov (United States)

Goossens, Karel; Lava, Kathleen; Bielawski, Christopher W; Binnemans, Koen

2016-04-27

This Review covers the recent developments (2005-2015) in the design, synthesis, characterization, and application of thermotropic ionic liquid crystals. It was designed to give a comprehensive overview of the "state-of-the-art" in the field. The discussion is focused on low molar mass and dendrimeric thermotropic ionic mesogens, as well as selected metal-containing compounds (metallomesogens), but some references to polymeric and/or lyotropic ionic liquid crystals and particularly to ionic liquids will also be provided. Although zwitterionic and mesoionic mesogens are also treated to some extent, emphasis will be directed toward liquid-crystalline materials consisting of organic cations and organic/inorganic anions that are not covalently bound but interact via electrostatic and other noncovalent interactions.

Adaptive neuro-fuzzy control of ionic polymer metal composite actuators

International Nuclear Information System (INIS)

Thinh, Nguyen Truong; Yang, Young-Soo; Oh, Il-Kwon

2009-01-01

An adaptive neuro-fuzzy controller was newly designed to overcome the degradation of the actuation performance of ionic polymer metal composite actuators that show highly nonlinear responses such as a straightening-back problem under a step excitation. An adaptive control algorithm with the merits of fuzzy logic and neural networks was applied for controlling the tip displacement of the ionic polymer metal composite actuators. The reference and actual displacements and the change of the error with the electrical inputs were recorded to generate the training data. These data were used for training the adaptive neuro-fuzzy controller to find the membership functions in the fuzzy control algorithm. Software simulation and real-time experiments were conducted by using the Simulink and dSPACE environments. Present results show that the current adaptive neuro-fuzzy controller can be successfully applied to the reliable control of the ionic polymer metal composite actuator for which the performance degrades under long-time actuation

Screening in dense ionic fluids

International Nuclear Information System (INIS)

Tosi, M.P.

1991-01-01

There has been great progress in recent years in determining and understanding the structure of molten salts. I focus on molten alkali halides and discuss two main points concerning their liquid structure and its relationship with static electrical response in these dense ionic conductors. These are (i) the nature of screening and the related definitions and properties of the screening length and of the dielectric function, and (ii) developments in integral equations techniques for the evaluation of molten salt structure and static screening from given pair potentials. (author). 26 refs, 3 figs, 2 tabs

Scaling parallels in the non-Debye dielectric relaxation of ionic glasses and dipolar supercooled liquids

International Nuclear Information System (INIS)

Sidebottom, D.L.; Green, P.F.; Brow, R.K.

1997-01-01

We compare the dielectric response of ionic glasses and dipolar liquids near the glass transition. Our work is divided into two parts. In the first section we examine ionic glasses and the two prominent approaches to analyzing the dielectric response. The conductivity of ion-conducting glasses displays a power law dispersion σ(ω)∝ω n , where n∼0.67, but frequently the dielectric response is analyzed using the electrical modulus M * (ω)=1/var-epsilon * (ω), where var-epsilon * (ω)=var-epsilon(ω)-iσ(ω)/ω is the complex permittivity. We reexamine two specific examples where the shape of M * (ω) changes in response to changes in (a) temperature and (b) ion concentration, to suggest fundamental changes in ion dynamics are occurring. We show, however, that these changes in the shape of M * (ω) occur in the absence of changes in the scaling properties of σ(ω), for which n remains constant. In the second part, we examine the dielectric relaxation found in dipolar liquids, for which var-epsilon * (ω) likewise exhibits changes in shape on approach to the glass transition. Guided by similarities of M * (ω) in ionic glasses and var-epsilon * (ω) in dipolar liquids, we demonstrate that a recent scaling approach proposed by Dixon and co-workers for var-epsilon * (ω) of dipolar relaxation also appears valid for M * (ω) in the ionic case. While this suggests that the Dixon scaling approach is more universal than previously recognized, we demonstrate how the dielectric response can be scaled in a linear manner using an alternative data representation. copyright 1997 The American Physical Society

Non-ionic, thermo-responsive DEA/DMA nanogels: synthesis, characterization, and use for DNA separations by microchip electrophoresis.

Science.gov (United States)

Lu, Xihua; Sun, Mingyun; Barron, Annelise E

2011-05-15

Thermo-responsive polymer "nanogels" (crosslinked hydrogel particles with sub-100 nm diameters) are intriguing for many potential applications in biotechnology and medicine. There have been relatively few reports of electrostatically neutral, thermosensitive nanogels comprising a high fraction of hydrophilic co-monomer. Here we demonstrate the syntheses and characterization of novel, non-ionic nanogels based on random N,N-diethylacrylamide (DEA)/N,N-dimethylacrylamide (DMA) copolymers, made by free-radical, surfactant-free dispersion polymerization. The volume-phase transition temperatures of these DEA/DMA nanogels are strongly affected by co-monomer composition, providing a way to "tune" the phase transition temperature of these non-ionic nanogels. While DEA nanogels (comprising no DMA) can be obtained at 70 °C by standard emulsion precipitation, DEA/DMA random co-polymer nanogels can be obtained only in a particular range of temperatures, above the initial phase transition temperature and below the critical precipitation temperature of the DEA/DMA copolymer, controlled by co-monomer composition. Increasing percentages of DMA in the nanogels raises the phase transition temperature, and attenuates and broadens it as well. We find that concentrated DEA/DMA nanogel dispersions are optically clear at room temperature. This good optical clarity was exploited for their use in a novel DNA sieving matrix for microfluidic chip electrophoresis. An ultrafast, high-efficiency dsDNA separation was achieved in less than 120 s for dsDNA ranging from 75 bp to 15,000 bp. Copyright © 2011 Elsevier Inc. All rights reserved.

Ionic Conductivity of Polyelectrolyte Hydrogels.

Science.gov (United States)

Lee, Chen-Jung; Wu, Haiyan; Hu, Yang; Young, Megan; Wang, Huifeng; Lynch, Dylan; Xu, Fujian; Cong, Hongbo; Cheng, Gang

2018-02-14

Polyelectrolytes have many important functions in both living organisms and man-made applications. One key property of polyelectrolytes is the ionic conductivity due to their porous networks that allow the transport of water and small molecular solutes. Among polyelectrolytes, zwitterionic polymers have attracted huge attention for applications that involve ion transport in a polyelectrolyte matrix; however, it is still unclear how the functional groups of zwitterionic polymer side chains affect their ion transport and swelling properties. In this study, zwitterionic poly(carboxybetaine acrylamide), poly(2-methacryloyloxyethyl phosphorylcholine), and poly(sulfobetaine methacrylate) hydrogels were synthesized and their ionic conductivity was studied and compared to cationic, anionic, and nonionic hydrogels. The change of the ionic conductivity of zwitterionic and nonionic hydrogels in different saline solutions was investigated in detail. Zwitterionic hydrogels showed much higher ionic conductivity than that of the widely used nonionic poly(ethylene glycol) methyl ether methacrylate hydrogel in all tested solutions. For both cationic and anionic hydrogels, the presence of mobile counterions led to high ionic conductivity in low salt solutions; however, the ionic conductivity of zwitterionic hydrogels surpassed that of cationic and ionic hydrogels in high salt solutions. Cationic and anionic hydrogels showed much higher water content than that of zwitterionic hydrogels in deionized water; however, the cationic hydrogels shrank significantly with increasing saline concentration. This work provides insight into the effects of polyelectrolyte side chains on ion transport. This can guide us in choosing better polyelectrolytes for a broad spectrum of applications, including bioelectronics, neural implants, battery, and so on.

Supported Ionic Liquid Phase (SILP) catalysis

DEFF Research Database (Denmark)

Riisager, Anders; Fehrmann, Rasmus; Haumann, Marco

2006-01-01

Applications of ionic liquids to replace conventional solvents in homogeneous transition-metal catalysis have increased significantly during the last decade. Biphasic ionic liquid/organic liquid systems offer advantages with regard to product separation, catalyst stability, and recycling...... but utilise in the case of fast chemical reactions only a small amount of expensive ionic liquid and catalyst. The novel Supported Ionic Liquid Phase (SILP) catalysis concept overcomes these drawbacks and allows the use of fixed-bed reactors for continuous reactions. In this Microreview the SILP catalysis...

Hydrogen production from glucose in ionic liquids

Energy Technology Data Exchange (ETDEWEB)

Assenbaum, D.W.; Taccardi, N.; Berger, M.E.M.; Boesmann, A.; Enzenberger, F.; Woelfel, R.; Wasserscheid, P. [Erlangen-Nuernberg Univ. (Germany). Lehrstuhl fuer chemische Reaktionstechnik

2010-07-01

technologies suffer from the fact that the overall reaction rates are often restricted by mass and heat transport problems. Lastly, there are severe limitations concerning the feedstock selection as for some important substrates, such as e.g. glucose, the process can only be operated in very diluted systems to avoid rapid tar formation [22,23,24]. In this contribution we describe for the first time a catalytic reaction system producing hydrogen from glucose in astonishingly high selectivities using a single reaction step under very mild conditions. The catalytic reaction system is characterized by its homogeneous nature and comprises a Ru-complex catalyst dissolved and stabilized in an ionic liquid medium. Ionic liquids are salts of melting points below 100 C [25]. These liquid materials have attracted much interest in the last decade as solvents for catalytic reactions [26] and separation technologies (extraction, distillation) [27,28,29,30,31,32]. Besides, these liquids have found industrial applications as process fluids for mechanic [33] and electrochemical applications [34]. Finally, from the pioneering work of Rogers and co-workers, it is known that ionic liquids are able to dissolve significant amounts of water-insoluble biopolymers (such as e.g. cellulose and chitin)[35] and even complex biopolymer mixtures, such as e.g. wood, have been completely dissolved in some ionic liquids [36]. In our specific application, the role of the ionic liquid is threefold: a) the ionic liquid dissolves the carbohydrate starting material thus expanding the range of applicable carbohydrate to water insoluble polymers; b) the ionic liquid provides a medium to dissolve and stabilize the catalyst; c) the ionic liquid dissolves hydrogen at a very low level, so inhibiting any possible collateral hydrogen-consuming process (detailed investigation of the hydrogen solubility in ionic liquids have been reported by e.g. Brennecke and coworkers [37]). (orig.)

On the Chemical Stabilities of Ionic Liquids

Directory of Open Access Journals (Sweden)

Yen-Ho Chu

2009-09-01

Full Text Available Ionic liquids are novel solvents of interest as greener alternatives to conventional organic solvents aimed at facilitating sustainable chemistry. As a consequence of their unusual physical properties, reusability, and eco-friendly nature, ionic liquids have attracted the attention of organic chemists. Numerous reports have revealed that many catalysts and reagents were supported in the ionic liquid phase, resulting in enhanced reactivity and selectivity in various important reaction transformations. However, synthetic chemists cannot ignore the stability data and intermolecular interactions, or even reactions that are directly applicable to organic reactions in ionic liquids. It is becoming evident from the increasing number of reports on use of ionic liquids as solvents, catalysts, and reagents in organic synthesis that they are not totally inert under many reaction conditions. While in some cases, their unexpected reactivity has proven fortuitous and in others, it is imperative that when selecting an ionic liquid for a particular synthetic application, attention must be paid to its compatibility with the reaction conditions. Even though, more than 200 room temperature ionic liquids are known, only a few reports have commented their effects on reaction mechanisms or rate/stability. Therefore, rather than attempting to give a comprehensive overview of ionic liquid chemistry, this review focuses on the non-innocent nature of ionic liquids, with a decided emphasis to clearly illuminate the ability of ionic liquids to affect the mechanistic aspects of some organic reactions thereby affecting and promoting the yield and selectivity.

On the chemical stabilities of ionic liquids.

Science.gov (United States)

Sowmiah, Subbiah; Srinivasadesikan, Venkatesan; Tseng, Ming-Chung; Chu, Yen-Ho

2009-09-25

Ionic liquids are novel solvents of interest as greener alternatives to conventional organic solvents aimed at facilitating sustainable chemistry. As a consequence of their unusual physical properties, reusability, and eco-friendly nature, ionic liquids have attracted the attention of organic chemists. Numerous reports have revealed that many catalysts and reagents were supported in the ionic liquid phase, resulting in enhanced reactivity and selectivity in various important reaction transformations. However, synthetic chemists cannot ignore the stability data and intermolecular interactions, or even reactions that are directly applicable to organic reactions in ionic liquids. It is becoming evident from the increasing number of reports on use of ionic liquids as solvents, catalysts, and reagents in organic synthesis that they are not totally inert under many reaction conditions. While in some cases, their unexpected reactivity has proven fortuitously advantageous in others is has been a problem, it is imperative that when selecting an ionic liquid for a particular synthetic application, attention be paid to its compatibility with the reaction conditions. Even though, more than 200 room temperature ionic liquids are known, only a few reports have commented their effects on reaction mechanisms or rate/stability. Therefore, rather than attempting to give a comprehensive overview of ionic liquid chemistry, this review focuses on the non-innocent nature of ionic liquids, with a decided emphasis to clearly illuminate the ability of ionic liquids to affect the mechanistic aspects of some organic reactions thereby affecting and promoting the yield and selectivity.

Morphology, optical and ionic conductivity studies of electron beam irradiated polymer electrolyte film

Science.gov (United States)

Devendrappa, H.; Yesappa, L.; Niranjana, M.; Ashokkumar, S. P.; Vijeth, H.; Ganesh, S.

2018-04-01

The effects of electron beam (EB) irradiation on morphology, optical properties and ionic conductivity of (PVdF-co-HFP: LiClO4=90:10, PHL10) electrolyte films. The FESEM image reveal increasing porous morphology with increasing EB dose confirms the polymer degradation as result more amorphousity. The optical absorbance was found to be increase with red shift in UV region and direct optical band gaps was found decreased upon EB dose from 3.70 eV to 2.65 eV. The ionic conductivity increases slowly in lower frequency, whereas rapidly increases at the high frequency and found about 8.28×10-4 S/cm at 120 kGy dose. The obtained results suggest that the physical properties of polymer electrolytes can be changed using EB irradiation as requirement.

Ionic liquid-tolerant cellulase enzymes

Science.gov (United States)

Gladden, John; Park, Joshua; Singer, Steven; Simmons, Blake; Sale, Ken

2017-10-31

The present invention provides ionic liquid-tolerant cellulases and method of producing and using such cellulases. The cellulases of the invention are useful in saccharification reactions using ionic liquid treated biomass.

Stimuli responsive ion gels based on polysaccharides and other polymers prepared using ionic liquids and deep eutectic solvents.

Science.gov (United States)

Prasad, Kamalesh; Mondal, Dibyendu; Sharma, Mukesh; Freire, Mara G; Mukesh, Chandrakant; Bhatt, Jitkumar

2018-01-15

Ion gels and self-healing gels prepared using ionic liquids (ILs) and deep eutectic solvents (DESs) have been largely investigated in the past years due to their remarkable applications in different research areas. Herewith we provide an overview on the ILs and DESs used for the preparation of ion gels, highlight the preparation and physicochemical characteristics of stimuli responsive gel materials based on co-polymers and biopolymers, with special emphasis on polysaccharides and discuss their applications. Overall, this review summarizes the fundamentals and advances in ion gels with switchable properties prepared using ILs or DESs, as well as their potential applications in electrochemistry, in sensing devices and as drug delivery vehicles. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cellular and molecular responses of adult zebrafish after exposure to CuO nanoparticles or ionic copper.

Science.gov (United States)

Vicario-Parés, Unai; Lacave, Jose M; Reip, Paul; Cajaraville, Miren P; Orbea, Amaia

2018-01-01

Due to their antimicrobial, electrical and magnetic properties, copper nanoparticles (NPs) are suitable for a vast array of applications. Copper can be toxic to biota, making it necessary to assess the potential hazard of copper nanomaterials. Zebrafish (Danio rerio) were exposed to 10 µg Cu/L of CuO NPs of ≈100 nm (CuO-poly) or ionic copper to compare the effects provoked after 3 and 21 days of exposure and at 6 months post-exposure (mpe). At 21 days, significant copper accumulation was only detected in fish exposed to ionic copper. Exposure to both copper forms caused histopathological alterations that could reduce gill functionality, more markedly in the case of ionic copper. Nevertheless, at 6 mpe higher prevalences of gill lesions were detected in fish previously exposed to CuO-poly NPs. No relevant histological alterations were detected in liver, but the lysosomal membrane stability test showed significantly impaired general health status after exposure to both metal forms that lasted up to 6 mpe. 69 transcripts appeared regulated after 3 days of exposure to CuO-poly NPs, suggesting that NPs could produce oxidative stress and reduce metabolism and transport processes. Thirty transcripts were regulated after 21 days of exposure to ionic copper, indicating possible DNA damage. Genes of the circadian clock were identified as the key genes involved in time-dependent differences between the two copper forms. In conclusion, each copper form showed a distinct pattern of liver transcriptome regulation, but both caused gill histopathological alterations and long lasting impaired health status in adult zebrafish.

Rapid response manufacturing (RRM). Final CRADA report

Energy Technology Data Exchange (ETDEWEB)

Cain, W.D. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States); Waddell, W.L. [National Centers for Manufacturing Sciences, Ann Arbor, MI (United States)

1998-02-10

US industry is fighting to maintain its competitive edge in the global market place. Markets fluctuate rapidly. Companies have to be able to respond quickly with improved, high quality, cost efficient products. Because companies and their suppliers are geographically distributed, rapid product realization is dependent on the development of a secure integrated concurrent engineering environment operating across multiple business entities. The way products are developed and brought to market can be improved and made more efficient through the proper incorporation of emerging technologies implemented in a secure environment. This documents the work done under this CRADA to develop capabilities, which permit the effective application, incorporation, and use of advanced technologies in a secure environment to facilitate the product realization process. Lockheed Martin Energy Systems (LMES), through a CRADA with the National Center for Manufacturing Sciences (NCMS), worked within a consortium of major industrial firms--Ford, General Motors, Texas Instruments, United Technologies, and Eastman Kodak--and several small suppliers of advanced manufacturing technology--MacNeal-Schwendler Corp., Teknowledge Corp., Cimplex Corp., Concentra, Spatial Technology, and Structural Dynamics Research Corp. (SDRC)--to create infrastructure to support the development and implementation of secure engineering environments for Rapid Response Manufacturing. The major accomplishment achieved under this CRADA was the demonstration of a prototypical implementation of a broad-based generic framework for automating and integrating the design-to-manufacturing activities associated with machined parts in a secure NWC compliant environment. Specifically, methods needed to permit the effective application, incorporation, and use of advanced technologies in a secure environment to facilitate the product realization process were developed and demonstrated. An important aspect of this demonstration was

Lattice dynamics of ionic crystals

International Nuclear Information System (INIS)

Mahan, G.D.

1990-01-01

The theory of lattice dynamics for ionic and rare-gas crystals is derived in the harmonic approximation. We start from a Hamiltonian and average over electron coordinates in order to obtain an effective interaction between ion displacements. We assume that electronic excitations are localized on a single ion, which limits the theory to ionic crystals. The deformation-dipole model and the indirect-ionic-interaction model are derived. These two contributions are closely linked, and together provide an accurate description of short-range forces

Ionic conductivity studies of gel polyelectrolyte based on ionic liquid

Energy Technology Data Exchange (ETDEWEB)

Cha, E.H. [The Faculty of Liberal Arts (Chemistry), Hoseo University, Asan Choongnam 336-795 (Korea); Lim, S.A. [Functional Proteomics Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea); Park, J.H. [Department of Herbal Medicine, Hoseo University, Asan Choongnam 336-795 (Korea); Kim, D.W. [Department of Chemical Technology, Han Bat National University, Daejon 305-719 (Korea); Macfarlane, D.R. [School of Chemistry, Monash University, Clayton, Vic. 3800 (Australia)

2008-04-01

Novel lithium polyelectrolyte-ionic liquids have been prepared and characterized of their properties. Poly(lithium 2-acrylamido-2-methyl propanesulfonate) (PAMPSLi) and its copolymer with N-vinyl formamide (VF) also has been prepared as a copolymer. 1-Ethyl-3-methylimidazolium tricyanomethanide (emImTCM) and N,N-dimethyl-N-propyl-N-butyl ammonium tricyanomethanide (N{sub 1134}TCM) which are chosen because of the same with the anion of ionic liquid were prepared. The ionic conductivity of copolymer system (PAMPSLi/PVF/emImTCM: 5.43 x 10{sup -3} S cm{sup -1} at 25 C) exhibits about over four times higher than that of homopolymer system (PAMPSLi/emImTCM: 1.28 x 10{sup -3} S cm{sup -1} at 25 C). Introduction of vinyl formamide into the copolymer type can increase the dissociation of the lithium cations from the polymer backbone. The ionic conductivity of copolymer with emImTCM (PAMPSLi/PVF/emImTCM) exhibits the higher conductivity than that of PAMPSLi/PVF/N{sub 1134}TCM (2.48 x 10{sup -3} S cm{sup -1}). Because of using the polymerizable anion it is seen to maintain high flexibility of imidazolium cation effectively to exhibit the higher conductivity. And also the viscosity of emImTCM (19.56 cP) is lower than that of N{sub 1134}TCM (28.61 cP). Low viscosity leads to a fast rate of diffusion of redox species. (author)

Ionic conducting poly-benzimidazoles

International Nuclear Information System (INIS)

Jouanneau, J.

2006-11-01

Over the last years, many research works have been focused on new clean energy systems. Hydrogen fuel cell seems to be the most promising one. However, the large scale development of this technology is still limited by some key elements. One of them is the polymer electrolyte membrane 'Nafion' currently used, for which the ratio performance/cost is too low. The investigations we carried out during this thesis work are related to a new class of ionic conducting polymer, the sulfonated poly-benzimidazoles (sPBI). Poly-benzimidazoles (PBI) are aromatic heterocyclic polymers well-known for their excellent thermal and chemical stability. Ionic conduction properties are obtained by having strong acid groups (sulfonic acid SO 3 H) on the macromolecular structure. For that purpose, we first synthesized sulfonated monomers. Their poly-condensation with an appropriate non-sulfonated co-monomer yields to sPBI with sulfonation range from 0 to 100 per cent. Three different sPBI structures were obtained, and verified by appropriate analytical techniques. We also showed that the protocol used for the synthesis resulted in high molecular weights polymers. We prepared ionic conducting membrane by casting sPBI solutions on glass plates. Their properties of stability, water swelling and ionic conductivity were investigated. Surprisingly, the behaviour of sPBI was quite different from the other sulfonated aromatic polymers with same amount of SO 3 H, their stability was much higher, but their water swelling and ionic conductivity were quite low. We attributed these differences to strong ionic interactions between the sulfonic acid groups and the basic benzimidazole groups of our polymers. However, we managed to solve this problem synthesizing very highly sulfonated PBI, obtaining membranes with a good balance between all the properties necessary. (author)

77 FR 35962 - Utilizing Rapidly Deployable Aerial Communications Architecture in Response to an Emergency

Science.gov (United States)

2012-06-15

... Aerial Communications Architecture in Response to an Emergency AGENCY: Federal Communications Commission... deployable aerial communications architecture (DACA) in facilitating emergency response by rapidly restoring... copying during normal business hours in the FCC Reference Information Center, Portals II, 445 12th Street...

Swelling and Shrinking Properties of Thermo-Responsive Polymeric Ionic Liquid Hydrogels with Embedded Linear pNIPAAM

Directory of Open Access Journals (Sweden)

Simon Gallagher

2014-03-01

Full Text Available In this study, varying concentrations of linear pNIPAAM have been incorporated for the first time into a thermo-responsive polymeric ionic liquid (PIL hydrogel, namely tributyl-hexyl phosphonium 3-sulfopropylacrylate (P-SPA, to produce semi-interpenetrating polymer networks. The thermal properties of the resulting hydrogels have been investigated along with their thermo-induced shrinking and reswelling capabilities. The semi-interpenetrating networks (IPN hydrogels were found to have improved shrinking and reswelling properties compared with their PIL counterpart. At elevated temperatures (50–80 °C, it was found that the semi-IPN with the highest concentration of hydrophobic pNIPAAM exhibited the highest shrinking percentage of ~40% compared to the conventional P-SPA, (27%. This trend was also found to occur for the reswelling measurements, with semi-IPN hydrogels producing the highest reswelling percentage of ~67%, with respect to its contracted state. This was attributed to an increase in water affinity due to the presence of hydrophilic pNIPAAM. Moreover, the presence of linear pNIPAAM in the polymer matrix leads to improved shrinking and reswelling response compared to the equivalent PIL.

Ionic-Liquid-Tethered Nanoparticles: Hybrid Electrolytes

KAUST Repository

Moganty, Surya S.

2010-10-22

A new class of solventless electrolytes was created by tethering ionic liquids to hard inorganic ZrO2 nanostructures (see picture; NIM=nanoscale ionic material). These hybrid fluids exhibit exceptional redox stability windows, excellent thermal stability, good lithium transference numbers, long-term interfacial stability in the presence of a lithium anode and, when doped with lithium salt, reasonable ionic conductivities.

Electrode Materials for Ionic Liquid Based-Supercapacitors

OpenAIRE

Lazzari, Mariachiara

2010-01-01

The development of safe, high energy and power electrochemical energy-conversion systems can be a response to the worldwide demand for a clean and low-fuel-consuming transport. This thesis work, starting from a basic studies on the ionic liquid (IL) electrolytes and carbon electrodes and concluding with tests on large-size IL-based supercapacitor prototypes demonstrated that the IL-based asymmetric configuration (AEDLCs) is a powerful strategy to develop safe, high-energy supercapacitors that...

Thermochemistry of ionic liquid heat-transfer fluids

International Nuclear Information System (INIS)

Van Valkenburg, Michael E.; Vaughn, Robert L.; Williams, Margaret; Wilkes, John S.

2005-01-01

Large-scale solar energy collectors intended for electric power generation require a heat-transfer fluid with a set of properties not fully met by currently available commercial materials. Ionic liquids have thermophysical and chemical properties that may be suitable for heat transfer and short heat term storage in power plants using parabolic trough solar collectors. Ionic liquids are salts that are liquid at or near room temperature. Thermal properties important for heat transfer applications are melting point, boiling point, liquidus range, heat capacity, heat of fusion, vapor pressure, and thermal conductivity. Other properties needed to evaluate the usefulness of ionic liquids are density, viscosity and chemical compatibility with certain metals. Three ionic liquids were chosen for study based on their range of solvent properties. The solvent properties correlate with solubility of water in the ionic liquids. The thermal and chemical properties listed above were measured or compiled from the literature. Contamination of the ionic liquids by impurities such as water, halides, and metal ions often affect physical properties. The ionic liquids were analyzed for those impurities, and the impact of the contamination was evaluated by standard addition. The conclusion is that the ionic liquids have some very favorable thermal properties compared to targets established by the Department of Energy for solar collector applications

Toward protic ionic liquid and organic ionic plastic crystal electrolytes for fuel cells

International Nuclear Information System (INIS)

Rana, Usman Ali; Forsyth, Maria; MacFarlane, Douglas R.; Pringle, Jennifer M.

2012-01-01

Highlights: ► Polymer electrolyte membrane fuel cells that can operate above 120 °C, without humidification, would be much more commercially viable. ► Protic ionic liquids and organic ionic plastic crystals are showing increasing promise as anhydrous proton conductors in fuel cells. ► Here we review the recent progress in these two areas. - Abstract: There is increasing demand for the development of anhydrous proton conducting electrolytes, most notably to allow the development of fuel cells that can operate at temperatures above 120 °C, without the need for constant and controlled humidification. The emerging field of protic ionic liquids (PILs) represents a promising new direction for this research and the development of these materials has made significant progress in recent years. In a related but as yet little-explored avenue, proton conducting organic ionic plastic crystals offer the potential advantage of providing a solid state matrix for anhydrous proton conductivity. Here we discuss the recent progress in these areas and identify the key challenges for future research.

Early warning systems and rapid response to the deteriorating patient in hospital: A realist evaluation.

Science.gov (United States)

McGaughey, Jennifer; O'Halloran, Peter; Porter, Sam; Trinder, John; Blackwood, Bronagh

2017-12-01

To test the Rapid Response Systems programme theory against actual practice components of the Rapid Response Systems implemented to identify those contexts and mechanisms which have an impact on the successful achievement of desired outcomes in practice. Rapid Response Systems allow deteriorating patients to be recognized using Early Warning Systems, referred early via escalation protocols and managed at the bedside by competent staff. Realist evaluation. The research design was an embedded multiple case study approach of four wards in two hospitals in Northern Ireland which followed the principles of Realist Evaluation. We used various mixed methods including individual and focus group interviews, observation of nursing practice between June-November 2010 and document analysis of Early Warning Systems audit data between May-October 2010 and hospital acute care training records over 4.5 years from 2003-2008. Data were analysed using NiVivo8 and SPPS. A cross-case analysis highlighted similar patterns of factors which enabled or constrained successful recognition, referral and response to deteriorating patients in practice. Key enabling factors were the use of clinical judgement by experienced nurses and the empowerment of nurses as a result of organizational change associated with implementation of Early Warning System protocols. Key constraining factors were low staffing and inappropriate skill mix levels, rigid implementation of protocols and culturally embedded suboptimal communication processes. Successful implementation of Rapid Response Systems was dependent on adopting organizational and cultural changes that facilitated staff empowerment, flexible implementation of protocols and ongoing experiential learning. © 2017 John Wiley & Sons Ltd.

A model problem concerning ionic transport in microstructured solid electrolytes

Science.gov (United States)

Curto Sillamoni, Ignacio J.; Idiart, Martín I.

2015-11-01

We consider ionic transport by diffusion and migration through microstructured solid electrolytes. The assumed constitutive relations for the constituent phases follow from convex energy and dissipation potentials which guarantee thermodynamic consistency. The effective response is determined by homogenizing the relevant field equations via the notion ofmulti-scale convergence. The resulting homogenized response involves several effective tensors, but they all require the solution of just one standard conductivity problem over the representative volume element. A multi-scale model for semicrystalline polymer electrolytes with spherulitic morphologies is derived by applying the theory to a specific class of two-dimensional microgeometries for which the effective response can be computed exactly. An enriched model accounting for a random dispersion of filler particles with interphases is also derived. In both cases, explicit expressions for the effective material parameters are provided. The models are used to explore the effect of crystallinity and filler content on the overall response. Predictions support recent experimental observations on doped poly-ethylene-oxide systems which suggest that the anisotropic crystalline phase can actually support faster ion transport than the amorphous phase along certain directions dictated by the morphology of the polymeric chains. Predictions also support the viewpoint that ceramic fillers improve ionic conductivity and cation transport number via interphasial effects.

Thermophysical properties of ionic liquids.

Science.gov (United States)

Rooney, David; Jacquemin, Johan; Gardas, Ramesh

2010-01-01

Low melting point salts which are often classified as ionic liquids have received significant attention from research groups and industry for a range of novel applications. Many of these require a thorough knowledge of the thermophysical properties of the pure fluids and their mixtures. Despite this need, the necessary experimental data for many properties is scarce and often inconsistent between the various sources. By using accurate data, predictive physical models can be developed which are highly useful and some would consider essential if ionic liquids are to realize their full potential. This is particularly true if one can use them to design new ionic liquids which maximize key desired attributes. Therefore there is a growing interest in the ability to predict the physical properties and behavior of ionic liquids from simple structural information either by using group contribution methods or directly from computer simulations where recent advances in computational techniques are providing insight into physical processes within these fluids. Given the importance of these properties this review will discuss the recent advances in our understanding, prediction and correlation of selected ionic liquid physical properties.

Acoustic cavitation in 1-butyl-3-methylimidazolium bis(triflluoromethyl-sulfonyl)imide based ionic liquid.

Science.gov (United States)

Merouani, Slimane; Hamdaoui, Oualid; Haddad, Boumediene

2018-03-01

In this work, a comparison between the temperatures/pressures within acoustic cavitation bubble in an imidazolium-based room-temperature ionic liquid (RTIL), 1-butyl-3-methylimidazolium bis(triflluoromethyl-sulfonyl)imide ([BMIM][NTf 2 ]), and in water has been made for a wide range of cavitation parameters including frequency (140-1000kHz), acoustic intensity (0.5-1Wcm -2 ), liquid temperature (20-50°C) and external static pressure (0.7-1.5atm). The used cavitation model takes into account the liquid compressibility as well as the surface tension and the viscosity of the medium. It was found that the bubble temperatures and pressures were always much higher in the ionic liquid compared to those predicted in water. The valuable effect of [BMIM][NTf 2 ] on the bubble temperature was more pronounced at higher acoustic intensity and liquid temperature and lower frequency and external static pressure. However, confrontation between the predicted and the experimental estimated temperatures in ionic liquids showed an opposite trend as the temperatures measured in some pure ionic liquids are of the same order as those observed in water. The injection of liquid droplets into cavitation bubbles, the pyrolysis of ionic liquids at the bubble-solution interface as well as the lower number of collapsing bubbles in the ionic liquid may be the responsible for the lower measured bubble temperatures in ionic liquids, as compared with water. Copyright © 2017 Elsevier B.V. All rights reserved.

Membrane separation of ionic liquid solutions

Science.gov (United States)

Campos, Daniel; Feiring, Andrew Edward; Majumdar, Sudipto; Nemser, Stuart

2015-09-01

A membrane separation process using a highly fluorinated polymer membrane that selectively permeates water of an aqueous ionic liquid solution to provide dry ionic liquid. Preferably the polymer is a polymer that includes polymerized perfluoro-2,2-dimethyl-1,3-dioxole (PDD). The process is also capable of removing small molecular compounds such as organic solvents that can be present in the solution. This membrane separation process is suitable for drying the aqueous ionic liquid byproduct from precipitating solutions of biomass dissolved in ionic liquid, and is thus instrumental to providing usable lignocellulosic products for energy consumption and other industrial uses in an environmentally benign manner.

Extraction and Chromatographic Determination of Shikimic Acid in Chinese Conifer Needles with 1-Benzyl-3-methylimidazolium Bromide Ionic Liquid Aqueous Solutions

Science.gov (United States)

Chen, Fengli; Hou, Kexin; Li, Shuangyang; Zu, Yuangang; Yang, Lei

2014-01-01

An ionic liquids-based ultrasound-assisted extraction (ILUAE) method was successfully developed for extracting shikimic acid from conifer needles. Eleven 1-alkyl-3-methylimidazolium ionic liquids with different cations and anions were investigated and 1-benzyl-3-methylimidazolium bromide solution was selected as the solvent. The conditions for ILUAE, including the ionic liquid concentration, ultrasound power, ultrasound time, and liquid-solid ratio, were optimized. The proposed method had good recovery (99.37%–100.11%) and reproducibility (RSD, n = 6; 3.6%). ILUAE was an efficient, rapid, and simple sample preparation technique that showed high reproducibility. Based on the results, a number of plant species, namely, Picea koraiensis, Picea meyeri, Pinus elliottii, and Pinus banksiana, were identified as among the best resources of shikimic acid. PMID:24782942

Ionic liquid and nanoparticle hybrid systems: Emerging applications.

Science.gov (United States)

He, Zhiqi; Alexandridis, Paschalis

2017-06-01

Having novel electronic and optical properties that emanate from their nano-scale dimensions, nanoparticles are central to numerous applications. Ionic liquids can confer to nanoparticle chemical protection and physicochemical property enhancement through intermolecular interactions and can consequently improve the stability and reusability of nanoparticle for various operations. With an aim to combine the novel properties of nanoparticles and ionic liquids, different structures have been generated, based on a balance of several intermolecular interactions. Such ionic liquid and nanoparticle hybrids are showing great potential in diverse applications. In this review, we first introduce various types of ionic liquid and nanoparticle hybrids, including nanoparticle colloidal dispersions in ionic liquids, ionic liquid-grafted nanoparticles, and nanoparticle-stabilized ionic liquid-based emulsions. Such hybrid materials exhibit interesting synergisms. We then highlight representative applications of ionic liquid and nanoparticle hybrids in the catalysis, electrochemistry and separations fields. Such hybrids can attain better stability and higher efficiency under a broad range of conditions. Novel and enhanced performance can be achieved in these applications by combining desired properties of ionic liquids and of nanoparticles within an appropriate hybrid nanostructure. Copyright © 2016 Elsevier B.V. All rights reserved.

Fast Ignition and Sustained Combustion of Ionic Liquids

Science.gov (United States)

Joshi, Prakash B. (Inventor); Piper, Lawrence G. (Inventor); Oakes, David B. (Inventor); Sabourin, Justin L. (Inventor); Hicks, Adam J. (Inventor); Green, B. David (Inventor); Tsinberg, Anait (Inventor); Dokhan, Allan (Inventor)

2016-01-01

A catalyst free method of igniting an ionic liquid is provided. The method can include mixing a liquid hypergol with a HAN (Hydroxylammonium nitrate)-based ionic liquid to ignite the HAN-based ionic liquid in the absence of a catalyst. The HAN-based ionic liquid and the liquid hypergol can be injected into a combustion chamber. The HAN-based ionic liquid and the liquid hypergol can impinge upon a stagnation plate positioned at top portion of the combustion chamber.

Task-specific ionic liquids for solubilizing metal compounds

OpenAIRE

Thijs, Ben

2007-01-01

The main goal of this PhD thesis was to design new task-specific ionic liquids with the ability to dissolve metal compounds. Despite the large quantity of papers published on ionic liquids, not much is known about the mechanisms of dissolving metals in ionic liquids or about metal-containing ionic liquids. Additionally, many of the commercially available ionic liquids exhibit a very limited solubilizing power for metal compounds, although this is for many applications like electrodeposition a...

Supercritical fluids in ionic liquids

NARCIS (Netherlands)

Kroon, M.C.; Peters, C.J.; Plechkova, N.V.; Seddon, K.R.

2014-01-01

Ionic liquids and supercritical fluids are both alternative environmentally benign solvents, but their properties are very different. Ionic liquids are non-volatile but often considered highly polar compounds, whereas supercritical fluids are non-polar but highly volatile compounds. The combination

Comparison of soft tissue effects of conventional ionic, low osmolar ionic and nonionic iodine containing contrast material in experimental animals

International Nuclear Information System (INIS)

McAlister, W.H.; Kissane, J.M.

1990-01-01

Conventional, low osmolar, and non-ionic iodine containing contrast media and saline controls were placed in the paws, muscles, and subcutaneous tissues of Sprague-Dawley rat thighs. The paw injections were observed and photographed, while the thighs were examined histologically. Results showed that although the low osmolar and non-ionic agents did produce inflammatory reactions and focal necrosis in the soft tissues, they were much better tolerated than were the conventional ionic agents. A non-ionic or low osmolar ionic contrast agent should be strongly considered when a possibility for extravasation exists. (orig.)

Diffuse-charge dynamics of ionic liquids in electrochemical systems.

Science.gov (United States)

Zhao, Hui

2011-11-01

We employ a continuum theory of solvent-free ionic liquids accounting for both short-range electrostatic correlations and steric effects (finite ion size) [Bazant et al., Phys. Rev. Lett. 106, 046102 (2011)] to study the response of a model microelectrochemical cell to a step voltage. The model problem consists of a 1-1 symmetric ionic liquid between two parallel blocking electrodes, neglecting any transverse transport phenomena. Matched asymptotic expansions in the limit of thin double layers are applied to analyze the resulting one-dimensional equations and study the overall charge-time relation in the weakly nonlinear regime. One important conclusion is that our simple scaling analysis suggests that the length scale √(λ*(D)l*(c)) accurately characterizes the double-layer structure of ionic liquids with strong electrostatic correlations where l*(c) is the electrostatic correlation length (in contrast, the Debye screening length λ*(D) is the primary double-layer length for electrolytes) and the response time of λ(D)(*3/2)L*/(D*l(c)(1/2)) (not λ*(D)L*/D* that is the primary charging time of electrolytes) is the correct charging time scale of ionic liquids with strong electrostatic correlations where D* is the diffusivity and L* is the separation length of the cell. With these two new scales, data of both electric potential versus distance from the electrode and the total diffuse charge versus time collapse onto each individual master curve in the presence of strong electrostatic correlations. In addition, the dependance of the total diffuse charge on steric effects, short-range correlations, and driving voltages is thoroughly examined. The results from the asymptotic analysis are compared favorably with those from full numerical simulations. Finally, the absorption of excess salt by the double layer creates a depletion region outside the double layer. Such salt depletion may bring a correction to the leading order terms and break down the weakly nonlinear

Synthesis of hetero ionic compounds using dialkylcarbonate quaternization

Energy Technology Data Exchange (ETDEWEB)

Friesen, Cody A.; Wolfe, Derek; Johnson, Paul Bryan

2018-04-03

Methods of preparing hetero ionic complexes, and ionic liquids from bisulfate salts of heteroatomic compounds using dialkylcarbonates as a primary quaternizing reactant are disclosed. Also disclosed are methods of making electrochemical cells comprising the ionic liquids, and an electrochemical cell comprising an alkaline electrolyte and a hetero ionic complex additive.

Ionic Polymer Microactuator Activated by Photoresponsive Organic Proton Pumps

Directory of Open Access Journals (Sweden)

Khaled M. Al-Aribe

2015-10-01

Full Text Available An ionic polymer microactuator driven by an organic photoelectric proton pump transducer is described in this paper. The light responsive transducer is fabricated by using molecular self-assembly to immobilize oriented bacteriorhodopsin purple membrane (PM patches on a bio-functionalized porous anodic alumina (PAA substrate. When exposed to visible light, the PM proton pumps produce a unidirectional flow of ions through the structure’s nano-pores and alter the pH of the working solution in a microfluidic device. The change in pH is sufficient to generate an osmotic pressure difference across a hydroxyethyl methacrylate-acrylic acid (HEMA-AA actuator shell and induce volume expansion or contraction. Experiments show that the transducer can generate an ionic gradient of 2.5 μM and ionic potential of 25 mV, producing a pH increase of 0.42 in the working solution. The ΔpH is sufficient to increase the volume of the HEMA-AA microactuator by 80%. The volumetric transformation of the hydrogel can be used as a valve to close a fluid transport micro-channel or apply minute force to a mechanically flexible microcantilever beam.

Consumer participation in early detection of the deteriorating patient and call activation to rapid response systems: a literature review.

Science.gov (United States)

Vorwerk, Jane; King, Lindy

2016-01-01

This review investigated the impact of consumer participation in recognition of patient deterioration and response through call activation in rapid response systems. Nurses and doctors have taken the main role in recognition and response to patient deterioration through hospital rapid response systems. Yet patients and visitors (consumers) have appeared well placed to notice early signs of deterioration. In response, many hospitals have sought to partner health professionals with consumers in detection and response to early deterioration. However, to date, there have been no published research-based reviews to establish the impact of introducing consumer involvement into rapid response systems. A critical research-based review was undertaken. A comprehensive search of databases from 2006-2014 identified 11 studies. Critical appraisal of these studies was undertaken and thematic analysis of the findings revealed four major themes. Following implementation of the consumer activation programmes, the number of calls made by the consumers following detection of deterioration increased. Interestingly, the number of staff calls also increased. Importantly, mortality numbers were found to decrease in one major study following the introduction of consumer call activation. Consumer and staff knowledge and satisfaction with the new programmes indicated mixed results. Initial concerns of the staff over consumer involvement overwhelming the rapid response systems did not eventuate. Evaluation of successful consumer-activated programmes indicated the importance of: effective staff education and training; ongoing consumer education by nurses and clear educational materials. Findings indicated positive patient outcomes following introduction of consumer call activation programmes within rapid response systems. Effective consumer programmes included information that was readily accessible, easy-to-understand and available in a range of multimedia materials accompanied by the

Polyelectrolyte brushes in mixed ionic medium studied via intermolecular forces

Science.gov (United States)

Farina, Robert; Laugel, Nicolas; Pincus, Philip; Tirrell, Matthew

2011-03-01

The vast uses and applications of polyelectrolyte brushes make them an attractive field of research especially with the growing interest in responsive materials. Polymers which respond via changes in temperature, pH, and ionic strength are increasingly being used for applications in drug delivery, chemical gating, etc. When polyelectrolyte brushes are found in either nature (e.g., surfaces of cartilage and mammalian lung interiors) or commercially (e.g., skin care products, shampoo, and surfaces of medical devices) they are always surrounded by mixed ionic medium. This makes the study of these brushes in varying ionic environments extremely relevant for both current and future potential applications. The polyelectrolyte brushes in this work are diblock co-polymers of poly-styrene sulfonate (N=420) and poly-t-butyl styrene (N=20) which tethers to a hydrophobic surface allowing for a purely thermodynamic study of the polyelectrolyte chains. Intermolecular forces between two brushes are measured using the SFA. As multi-valent concentrations are increased, the brushes collapse internally and form strong adhesion between one another after contact (properties not seen in a purely mono-valent environment).

Solubilities of some gases in four immidazolium-based ionic liquids

International Nuclear Information System (INIS)

Afzal, Waheed; Liu, Xiangyang; Prausnitz, John M.

2013-01-01

Graphical abstract: Experimental apparatus based on the synthetic-volumetric method for measuring solubilities of gases in liquids. Highlights: • We constructed an apparatus for measuring solubilities of sparingly-soluble gases. • We measured solubilities of five gases in four immidazolium-based ionic liquids. • We calculated Henry’s constants for gases in the ionic liquids studied in this work. -- Abstract: The synthetic-volumetric method is used for rapidly measuring solubilities of sparingly-soluble gases in monoethylene glycol and in four ionic liquids. Known molar quantities of solute and solvent are charged into an equilibrium vessel. Measured quantities at equilibrium include: temperature, pressure, quantities of fluids, and volumes of the gas and liquid phases in the equilibrium vessel. These measurements enable calculation of equilibrium compositions using material balances. No sampling or chemical analyses are required. Solubilities are reported for carbon dioxide, krypton, oxygen, and hydrogen in monoethylene glycol, l-n-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4], l-n-butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF6], 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM][Tf 2 N], or 1-ethyl-3-methylimidazolium acetate [EMIM][AC]. Solubilities were measured over the temperature range (298 to 355) K and for pressures up to about 7 MPa using two different pieces of equipment, both based on the volumetric method: a low-pressure glass apparatus and a high-pressure stainless-steel apparatus. Special emphasis is given to experimental reliability to assure consistent data

Optimization of Ionic Liquid Based Simultaneous Ultrasonic- and Microwave-Assisted Extraction of Rutin and Quercetin from Leaves of Velvetleaf (Abutilon theophrasti by Response Surface Methodology

Directory of Open Access Journals (Sweden)

Chunjian Zhao

2014-01-01

Full Text Available An ionic liquids based simultaneous ultrasonic and microwave assisted extraction (ILs-UMAE method has been proposed for the extraction of rutin (RU, quercetin (QU, from velvetleaf leaves. The influential parameters of the ILs-UMAE were optimized by the single factor and the central composite design (CCD experiments. A 2.00 M 1-butyl-3-methylimidazolium bromide ([C4mim]Br was used as the experimental ionic liquid, extraction temperature 60°C, extraction time 12 min, liquid-solid ratio 32 mL/g, microwave power of 534 W, and a fixed ultrasonic power of 50 W. Compared to conventional heating reflux extraction (HRE, the RU and QU extraction yields obtained by ILs-UMAE were, respectively, 5.49 mg/g and 0.27 mg/g, which increased, respectively, 2.01-fold and 2.34-fold with the recoveries that were in the range of 97.62–102.36% for RU and 97.33–102.21% for QU with RSDs lower than 3.2% under the optimized UMAE conditions. In addition, the shorter extraction time was used in ILs-UMAE, compared with HRE. Therefore, ILs-UMAE was a rapid and an efficient method for the extraction of RU and QU from the leaves of velvetleaf.

Ionic liquid-nanoparticle hybrid electrolytes

KAUST Repository

Lu, Yingying

2012-01-01

We investigate physical and electrochemical properties of a family of organic-inorganic hybrid electrolytes based on the ionic liquid 1-methyl-3-propylimidazolium bis(trifluoromethanesulfone) imide covalently tethered to silica nanoparticles (SiO 2-IL-TFSI). The ionic conductivity exhibits a pronounced maximum versus LiTFSI composition, and in mixtures containing 13.4 wt% LiTFSI, the room-temperature ionic conductivity is enhanced by over 3 orders of magnitude relative to either of the mixture components, without compromising lithium transference number. The SiO 2-IL-TFSI/LiTFSI hybrid electrolytes are thermally stable up to 400°C and exhibit tunable mechanical properties and attractive (4.25V) electrochemical stability in the presence of metallic lithium. We explain these observations in terms of ionic coupling between counterion species in the mobile and immobile (particle-tethered) phases of the electrolytes. © 2012 The Royal Society of Chemistry.

Nanoparticle enhanced ionic liquid heat transfer fluids

Science.gov (United States)

Fox, Elise B.; Visser, Ann E.; Bridges, Nicholas J.; Gray, Joshua R.; Garcia-Diaz, Brenda L.

2014-08-12

A heat transfer fluid created from nanoparticles that are dispersed into an ionic liquid is provided. Small volumes of nanoparticles are created from e.g., metals or metal oxides and/or alloys of such materials are dispersed into ionic liquids to create a heat transfer fluid. The nanoparticles can be dispersed directly into the ionic liquid during nanoparticle formation or the nanoparticles can be formed and then, in a subsequent step, dispersed into the ionic liquid using e.g., agitation.

Probing Lipid Bilayers under Ionic Imbalance.

Science.gov (United States)

Lin, Jiaqi; Alexander-Katz, Alfredo

2016-12-06

Biological membranes are normally under a resting transmembrane potential (TMP), which originates from the ionic imbalance between extracellular fluids and cytosols, and serves as electric power storage for cells. In cell electroporation, the ionic imbalance builds up a high TMP, resulting in the poration of cell membranes. However, the relationship between ionic imbalance and TMP is not clearly understood, and little is known about the effect of ionic imbalance on the structure and dynamics of biological membranes. In this study, we used coarse-grained molecular dynamics to characterize a dipalmitoylphosphatidylcholine bilayer system under ionic imbalances ranging from 0 to ∼0.06 e charges per lipid (e/Lip). We found that the TMP displayed three distinct regimes: 1) a linear regime between 0 and 0.045 e/Lip, where the TMP increased linearly with ionic imbalance; 2) a yielding regime between ∼0.045 and 0.060 e/Lip, where the TMP displayed a plateau; and 3) a poration regime above ∼0.060 e/Lip, where we observed pore formation within the sampling time (80 ns). We found no structural changes in the linear regime, apart from a nonlinear increase in the area per lipid, whereas in the yielding regime the bilayer exhibited substantial thinning, leading to an excess of water and Na + within the bilayer, as well as significant misalignment of the lipid tails. In the poration regime, lipid molecules diffused slightly faster. We also found that the fluid-to-gel phase transition temperature of the bilayer dropped below the normal value with increased ionic imbalances. Our results show that a high ionic imbalance can substantially alter the essential properties of the bilayer, making the bilayer more fluid like, or conversely, depolarization of a cell could in principle lead to membrane stiffening. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Derivation of finite element formulation for electrochemical governing equations of ionic polymer actuators

International Nuclear Information System (INIS)

Kang, Sung Soo

2013-01-01

Ionic polymer actuators have recently attracted a great deal of interest as electroactive materials with potentials as soft actuators, sensors, artificial muscles, robotics, and microelectromechanical systems because of their numerous advantages, including low voltage requirement, high compliance, lightness, and flexibility. The platinum-plated Nafion, a perfluorosulfonic acid membrane made by Dupont, is commonly used as a polyelectrolyte in actuator applications. The bending of the ionic polymer actuators in an electric field is dominated by the electro-osmosis of hydrated ions and slow diffusion of free water molecules. The changes in hydration cause a local volumetric strain resulting in bending deformation, such as expansion and contraction. In this study, a two-dimensional finite element (FE) formulation based on the Galerkin method is derived for the governing equations describing these electrochemical responses. In addition, a three-dimensional FE deformation analysis is conducted on the bending behaviors of the platinum-plated ionic polymer actuators. Several numerical studies for ionic polymer actuators, such as plates with various electrode arrangements and disk models in electric field, are performed to confirm the validity of the proposed formulation.

Significant Improvement of Catalytic Efficiencies in Ionic Liquids

International Nuclear Information System (INIS)

Song, Choong Eui; Yoon, Mi Young; Choi, Doo Seong

2005-01-01

The use of ionic liquids as reaction media can confer many advantages upon catalytic reactions over reactions in organic solvents. In ionic liquids, catalysts having polar or ionic character can easily be immobilized without additional structural modification and thus the ionic solutions containing the catalyst can easily be separated from the reagents and reaction products, and then, be reused. More interestingly, switching from an organic solvent to an ionic liquid often results in a significant improvement in catalytic performance (e.g., rate acceleration, (enantio)selectivity improvement and an increase in catalyst stability). In this review, some recent interesting results which can nicely demonstrate these positive 'ionic liquid effect' on catalysis are discussed

Fluorescence recognition of chiral amino alcohols by using a novel ionic liquid sensor.

Science.gov (United States)

Cai, Pengfei; Wu, Datong; Zhao, Xiaoyong; Pan, Yuanjiang

2017-08-07

A novel task-specific ionic liquid derived from l-phenylalaninol was prepared as an enantioselective fluorescent sensor for the first time. Fluorescent chiral ionic liquid 1 (FCIL1) is found to exhibit highly enantioselective fluorescence enhancements toward both aromatic and non-aromatic chiral amino alcohols. When (S)-FCIL1 was treated with the enantiomers of phenylalaninol, a great fluorescence enhancement at 349 nm could be observed and the value of the enantiomeric fluorescence difference (ef) is 5.92. This demonstrated that the chiral sensor (S)-FCIL1 exhibited an excellent enantioselective response behaviour to d-phenylalaninol. Besides that, both the fluorescence intensity at 349 nm (I 349 ) and the ratio of I 349 to I 282 depend linearly on the concentration of amino alcohols. Both the concentration and the enantiomeric composition could be determined by using the chiral ionic liquid. Differently, the sensor treated with the enantiomers of 2-amino-1-butanol showed an opposite result: the fluorescence intensity of the S-enantiomer is higher than that of the R-enantiomer. Furthermore, the size of the substituents on the chiral carbon might be important for the enantioselective fluorescent response.

[Rapid Response obstetrics Team at Instituto Mexicano del Seguro Social,enabling factors].

Science.gov (United States)

Dávila-Torres, Javier; González-Izquierdo, José de Jesús; Ruíz-Rosas, Roberto Aguli; Cruz-Cruz, Polita Del Rocío; Hernández-Valencia, Marcelino

2015-01-01

There are barriers and enablers for the implementation of Rapid Response Teams in obstetric hospitals. The enabling factors were determined at Instituto Mexicano del Seguro Social (IMSS) MATERIAL AND METHODS: An observational, retrospective study was conducted by analysing the emergency obstetric reports sent by mobile technology and e-mail to the Medical Care Unit of the IMSS in 2013. Frequency and mean was obtained using the Excel 2010 program for descriptive statistics. A total of 164,250 emergency obstetric cases were reported, and there was a mean of 425 messages per day, of which 32.2% were true obstetric emergencies and required the Rapid Response team. By e-mail, there were 73,452 life threatening cases (a mean of 6 cases per day). A monthly simulation was performed in hospitals (480 in total). Enabling factors were messagés synchronisation among the participating personnel,the accurate record of the obstetrics, as well as the simulations performed by the operational staff. The most common emergency was pre-eclampsia-eclampsia with 3,351 reports, followed by obstetric haemorrhage with 2,982 cases. The enabling factors for the implementation of a rapid response team at IMSS were properly timed communication between the central delegation teams, as they allowed faster medical and administrative management and participation of hospital medical teams in the process. Mobile technology has increased the speed of medical and administrative management in emergency obstetric care. However, comparative studies are needed to determine the statistical significance. Published by Masson Doyma México S.A.

Irradiation response of rapidly solidified Path A type prime candidate alloys

International Nuclear Information System (INIS)

Imeson, E.; Tong, C.; Lee, M.; Vander Sande, J.B.; Harling, O.K.

1981-01-01

The objective of this study is to present a first assessment of the microstructural response to neutron irradiation shown by Path A alloys prepared by rapid solidification processing. To more fully demonstrate the potential of the method, alloys with increased titanium and carbon content have been used in addition to the Path A prime candidate alloy

New Pyrazolium Salts as a Support for Ionic Liquid Crystals and Ionic Conductors.

Science.gov (United States)

Pastor, María Jesús; Sánchez, Ignacio; Campo, José A; Schmidt, Rainer; Cano, Mercedes

2018-04-03

Ionic liquid crystals (ILCs) are a class of materials that combine the properties of liquid crystals (LCs) and ionic liquids (ILs). This type of materials is directed towards properties such as conductivity in ordered systems at different temperatures. In this work, we synthesize five new families of ILCs containing symmetrical and unsymmetrical substituted pyrazolium cations, with different alkyl long-chains, and anions such as Cl - , BF₄ - , ReO₄ - , p -CH₃-₆H₄SO₃ - (PTS) and CF₃SO₃ - (OTf). We study their thermal behavior by polarized light optical microscopy (POM) and differential scanning calorimetry (DSC). All of them, except those with OTf as counteranion, show thermotropic mesomorphism. The observations by POM reveal textures of lamellar mesophases. Those agree with the arrangement observed in the X-ray crystal structure of [H₂pz R(4),R(4) ][ReO₄]. The nature of the mesophases is also confirmed by variable temperature powder X-ray diffraction. On the other hand, the study of the dielectric properties at variable temperature in mesomorphic (Cl - and BF₄ - ) and non-mesomorphic (OTf) salts indicates that the supramolecular arrangement of the mesophase favors a greater ionic mobility and therefore ionic conductivity.

Many-electron electrochemical processes. Reactions in molten salts, room-temperature ionic liquids and ionic solutions

Energy Technology Data Exchange (ETDEWEB)

Andriiko, Aleksandr A. [National Technical Univ. Ukraine, Kyiv (Ukraine). Kyiv Polytechnic Inst.; Andriyko, Yuriy O. [CEST Centre of Electrochemical Surface Technology, Wiener Neustadt (Austria); Nauer, Gerhard E. [Vienna Univ. (Austria). Inst. of Physical Chemistry

2013-02-01

The authors provide a unified concept for understanding multi-electron processes in electrochemical systems such as molten salts, ionic liquids, or ionic solutions. A major advantage of this concept is its independence of assumptions like one-step many-electron transfers or 'discrete' discharge of complex species. This book contains the following main topics: 1. Many-electron electrochemical systems: Concepts and definitions. 2. Many-electron systems at equilibrium. 3. Phenomenology of electrochemical kinetics. 4. Electrode film systems: experimental evidences. 5. Dynamics of a non-equilibrium electrochemical system. 6. Electrochemistry of Ti(IV) in ionic liquids.

Self-consistent modelling of electrochemical strain microscopy in mixed ionic-electronic conductors: Nonlinear and dynamic regimes

Science.gov (United States)

Varenyk, O. V.; Silibin, M. V.; Kiselev, D. A.; Eliseev, E. A.; Kalinin, S. V.; Morozovska, A. N.

2015-08-01

The frequency dependent Electrochemical Strain Microscopy (ESM) response of mixed ionic-electronic conductors is analyzed within the framework of Fermi-Dirac statistics and the Vegard law, accounting for steric effects from mobile donors. The emergence of dynamic charge waves and nonlinear deformation of the surface in response to bias applied to the tip-surface junction is numerically explored. The 2D maps of the strain and concentration distributions across the mixed ionic-electronic conductor and bias-induced surface displacements are calculated. The obtained numerical results can be applied to quantify the ESM response of Li-based solid electrolytes, materials with resistive switching, and electroactive ferroelectric polymers, which are of potential interest for flexible and high-density non-volatile memory devices.

Self-consistent modelling of electrochemical strain microscopy in mixed ionic-electronic conductors: Nonlinear and dynamic regimes

Energy Technology Data Exchange (ETDEWEB)

Varenyk, O. V.; Morozovska, A. N., E-mail: sergei2@ornl.gov, E-mail: anna.n.morozovska@gmail.com [Institute of Physics, National Academy of Sciences of Ukraine, 46, pr. Nauky, 03028 Kyiv (Ukraine); Silibin, M. V. [National Research University of Electronic Technology “MIET,” 124498 Moscow (Russian Federation); Kiselev, D. A. [National University of Science and Technology “MISiS,” 119049 Moscow, Leninskiy pr. 4 (Russian Federation); Eliseev, E. A. [Institute for Problems of Materials Science, NAS of Ukraine, Krjijanovskogo 3, 03142 Kyiv (Ukraine); Kalinin, S. V., E-mail: sergei2@ornl.gov, E-mail: anna.n.morozovska@gmail.com [The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2015-08-21

The frequency dependent Electrochemical Strain Microscopy (ESM) response of mixed ionic-electronic conductors is analyzed within the framework of Fermi-Dirac statistics and the Vegard law, accounting for steric effects from mobile donors. The emergence of dynamic charge waves and nonlinear deformation of the surface in response to bias applied to the tip-surface junction is numerically explored. The 2D maps of the strain and concentration distributions across the mixed ionic-electronic conductor and bias-induced surface displacements are calculated. The obtained numerical results can be applied to quantify the ESM response of Li-based solid electrolytes, materials with resistive switching, and electroactive ferroelectric polymers, which are of potential interest for flexible and high-density non-volatile memory devices.

Ionic-Liquid-Infused Nanostructures as Repellent Surfaces.

Science.gov (United States)

Galvan, Yaraset; Phillips, Katherine R; Haumann, Marco; Wasserscheid, Peter; Zarraga, Ramon; Vogel, Nicolas

2018-02-02

In order to prepare lubricant-infused repellent coatings on silica nanostructures using low vapor pressure ionic liquids as lubricants, we study the wetting behavior of a set of imidazolium-based ionic liquids with different alkyl side chains as a function of the applied surface functionalities. We take advantage of the structural color of inverse opals prepared from a colloidal coassembly technique to study the infiltration of ionic liquids into these nanoporous structures. We find that the more hydrophobic ionic liquids with butyl and hexyl side chains can completely infiltrate inverse opals functionalized with mixed self-assembled monolayers composed of imidazole groups and aliphatic hydrocarbon chains, which we introduce via silane chemistry. These molecular species reflect the chemical nature of the ionic liquid, thereby increasing the affinity between the liquid and solid surface. The mixed surface chemistry provides sufficiently small contact angles with the ionic liquid to infiltrate the nanopores while maximizing the contact angle with water. As a result, the mixed monolayers enable the design of a stable ionic liquid/solid interface that is able to repel water as a test liquid. Our results underline the importance of matching chemical affinities to predict and control the wetting behavior in complex, multiphase systems.

[Advances of poly (ionic liquid) materials in separation science].

Science.gov (United States)

Liu, Cuicui; Guo, Ting; Su, Rina; Gu, Yuchen; Deng, Qiliang

2015-11-01

Ionic liquids, as novel ionization reagents, possess beneficial characteristics including good solubility, conductivity, thermal stability, biocompatibility, low volatility and non-flammability. Ionic liquids are attracting a mass of attention of analytical chemists. Poly (ionic liquid) materials have common performances of ionic liquids and polymers, and have been successfully applied in separation science area. In this paper, we discuss the interaction mechanisms between the poly(ionic liquid) materials and analytes including hydrophobic/hydrophilic interactions, hydrogen bond, ion exchange, π-π stacking and electrostatic interactions, and summarize the application advances of the poly(ionic liquid) materials in solid phase extraction, chromatographic separation and capillary electrophoresis. At last, we describe the future prospect of poly(ionic liquid) materials.

Minor Actinide Separations Using Ion Exchangers Or Ionic Liquids

International Nuclear Information System (INIS)

Hobbs, D.; Visser, A.; Bridges, N.

2011-01-01

This project seeks to determine if (1) inorganic-based ion exchange materials or (2) electrochemical methods in ionic liquids can be exploited to provide effective Am and Cm separations. Specifically, we seek to understand the fundamental structural and chemical factors responsible for the selectivity of inorganic-based ion-exchange materials for actinide and lanthanide ions. Furthermore, we seek to determine whether ionic liquids can serve as the electrolyte that would enable formation of higher oxidation states of Am and other actinides. Experiments indicated that pH, presence of complexants and Am oxidation state exhibit significant influence on the uptake of actinides and lanthanides by layered sodium titanate and hybrid zirconium and tin phosphonate ion exchangers. The affinity of the ion exchangers increased with increasing pH. Greater selectivity among Ln(III) ions with sodium titanate materials occurs at a pH close to the isoelectric potential of the ion exchanger. The addition of DTPA decreased uptake of Am and Ln, whereas the addition of TPEN generally increases uptake of Am and Ln ions by sodium titanate. Testing confirmed two different methods for producing Am(IV) by oxidation of Am(III) in ionic liquids (ILs). Experimental results suggest that the unique coordination environment of ionic liquids inhibits the direct electrochemical oxidation of Am(III). The non-coordinating environment increases the oxidation potential to a higher value, while making it difficult to remove the inner coordination of water. Both confirmed cases of Am(IV) were from the in-situ formation of strong chemical oxidizers.

Ionic liquids comprising heteraromatic anions

Energy Technology Data Exchange (ETDEWEB)

Schneider, William F.; Brennecke, Joan F.; Maginn, Edward J.; Mindrup, Elaine; Gurkan, Burcu; Price, Erica; Goodrich, Brett

2018-04-24

Some embodiments described herein relate to ionic liquids comprising an anion of a heteraromatic compound such as optionally substituted pyrrolide, optionally substituted pyrazolide, optionally substituted indolide, optionally substituted phospholide, or optionally substituted imidazolide. Methods and devices for gas separation or gas absorption related to these ionic liquids are also described herein.

Lewis Acidic Ionic Liquids.

Science.gov (United States)

Brown, Lucy C; Hogg, James M; Swadźba-Kwaśny, Małgorzata

2017-08-21

Until very recently, the term Lewis acidic ionic liquids (ILs) was nearly synonymous with halometallate ILs, with a strong focus on chloroaluminate(III) systems. The first part of this review covers the historical context in which these were developed, speciation of a range of halometallate ionic liquids, attempts to quantify their Lewis acidity, and selected recent applications: in industrial alkylation processes, in supported systems (SILPs/SCILLs) and in inorganic synthesis. In the last decade, interesting alternatives to halometallate ILs have emerged, which can be divided into two sub-sections: (1) liquid coordination complexes (LCCs), still based on halometallate species, but less expensive and more diverse than halometallate ionic liquids, and (2) ILs with main-group Lewis acidic cations. The two following sections cover these new liquid Lewis acids, also highlighting speciation studies, Lewis acidity measurements, and applications.

Forecasting wildlife response to rapid warming in the Alaskan Arctic

Science.gov (United States)

Van Hemert, Caroline R.; Flint, Paul L.; Udevitz, Mark S.; Koch, Joshua C.; Atwood, Todd C.; Oakley, Karen L.; Pearce, John M.

2015-01-01

Arctic wildlife species face a dynamic and increasingly novel environment because of climate warming and the associated increase in human activity. Both marine and terrestrial environments are undergoing rapid environmental shifts, including loss of sea ice, permafrost degradation, and altered biogeochemical fluxes. Forecasting wildlife responses to climate change can facilitate proactive decisions that balance stewardship with resource development. In this article, we discuss the primary and secondary responses to physical climate-related drivers in the Arctic, associated wildlife responses, and additional sources of complexity in forecasting wildlife population outcomes. Although the effects of warming on wildlife populations are becoming increasingly well documented in the scientific literature, clear mechanistic links are often difficult to establish. An integrated science approach and robust modeling tools are necessary to make predictions and determine resiliency to change. We provide a conceptual framework and introduce examples relevant for developing wildlife forecasts useful to management decisions.

Predictive modeling studies for the ecotoxicity of ionic liquids towards the green algae Scenedesmus vacuolatus.

Science.gov (United States)

Das, Rudra Narayan; Roy, Kunal

2014-06-01

Hazardous potential of ionic liquids is becoming an issue of high concern with increasing application of these compounds in various industrial processes. Predictive toxicological modeling on ionic liquids provides a rational assessment strategy and aids in developing suitable guidance for designing novel analogues. The present study attempts to explore the chemical features of ionic liquids responsible for their ecotoxicity towards the green algae Scenedesmus vacuolatus by developing mathematical models using extended topochemical atom (ETA) indices along with other categories of chemical descriptors. The entire study has been conducted with reference to the OECD guidelines for QSAR model development using predictive classification and regression modeling strategies. The best models from both the analyses showed that ecotoxicity of ionic liquids can be decreased by reducing chain length of cationic substituents and increasing hydrogen bond donor feature in cations, and replacing bulky unsaturated anions with simple saturated moiety having less lipophilic heteroatoms. Copyright © 2013 Elsevier Ltd. All rights reserved.

Glucose oxidase and graphene bionanocomposite bridged by ionic liquid unit for glucose biosensing application

DEFF Research Database (Denmark)

Jiang, Yuanyuan; Zhang, Qixian; Li, Fenghua

2012-01-01

activity towards the reduction of O2 and H2O2. Then negatively charged glucose oxidase (GOD) was immobilized onto the composite matrix simply by ionic exchange. The ionic liquid here could improve the dispersibility of graphene and provide a favorable conductive microenvironment for the immobilized GOD......, thus promote its direct electron transfer at the GC electrode. This novel IL-graphene–GOD bionanocomposite could act as a biosensor towards the detection of glucose with a linear response up to 16mM. In this report, the method for immobilizing GOD by ionic interaction is of universality and has...... widespread use, even in other biological systems, which brings a forceful combination between GOD and IL-graphene. Besides, the biosensor is easy to prepare, have good stability, and will have potential application in glucose detection....

Ionic dependence of sulphur mustard cytotoxicity

International Nuclear Information System (INIS)

Sawyer, Thomas W.; Nelson, Peggy; Bjarnason, Stephen; Vair, Cory; Shei Yimin; Tenn, Catherine; Lecavalier, Pierre; Burczyk, Andrew

2010-01-01

The effect of ionic environment on sulphur mustard (bis 2-chloroethyl sulphide; HD) toxicity was examined in CHO-K1 cells. Cultures were treated with HD in different ionic environments at constant osmolar conditions (320 mOsM, pH 7.4). The cultures were refed with fresh culture medium 1 h after HD exposure, and viability was assessed. Little toxicity was apparent when HD exposures were carried out in ion-free sucrose buffer compared to LC 50 values of ∼ 100-150 μM when the cultures were treated with HD in culture medium. Addition of NaCl to the buffer increased HD toxicity in a salt concentration-dependent manner to values similar to those obtained in culture medium. HD toxicity was dependent on both cationic and anionic species with anionic environment playing a much larger role in determining toxicity. Substitution of NaI for NaCl in the treatment buffers increased HD toxicity by over 1000%. The activity of the sodium hydrogen exchanger (NHE) in recovering from cytosolic acidification in salt-free and in different chloride salts did not correlate with the HD-induced toxicity in these buffers. However, the inhibition by HD of intracellular pH regulation correlated with its toxicity in NaCl, NaI and sucrose buffers. Analytical chemical studies and the toxicity of the iodine mustard derivative ruled out the role of chemical reactions yielding differentially toxic species as being responsible for the differences in HD toxicity observed. This work demonstrates that the early events that HD sets into motion to cause toxicity are dependent on ionic environment, possibly due to intracellular pH deregulation.

Key Developments in Ionic Liquid Crystals

OpenAIRE

Fernandez, A.A.; Kouwer, P.H.J.

2016-01-01

Ionic liquid crystals are materials that combine the classes of liquid crystals and ionic liquids. The first one is based on the multi-billion-dollar flat panel display industry, whilst the latter quickly developed in the past decades into a family of highly-tunable non-volatile solvents. The combination yields materials with a unique set of properties, but also with many challenges ahead. In this review, we provide an overview of the key concepts in ionic liquid crystals, particularly from a...

Thermally-responsive, nonflammable phosphonium ionic liquid electrolytes for lithium metal batteries: operating at 100 degrees celsius.

Science.gov (United States)

Lin, X; Kavian, R; Lu, Y; Hu, Q; Shao-Horn, Y; Grinstaff, M W

2015-11-13

Rechargeable batteries such as Li ion/Li metal batteries are widely used in the electronics market but the chemical instability of the electrolyte limits their use in more demanding environmental conditions such as in automotive, oil exploration, or mining applications. In this study, a series of alkyl phosphonium ionic liquid electrolyte are described with high thermal stability and solubility for LiTFSI. A lithium metal battery (LMB) containing a tailored phosphonium ionic liquid/LiTFSI electrolyte operates at 100 °C with good specific capacities and cycling stability. Substantial capacity is maintained during 70 cycles or 30 days. Instant on-off battery operation is realized via the significant temperature dependence of the electrolyte material, demonstrating the robustness and potential for use at high temperature.

Modeling electrokinetics in ionic liquids: General

Energy Technology Data Exchange (ETDEWEB)

Wang, Chao [Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA USA; Bao, Jie [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA USA; Pan, Wenxiao [Department of Mechanical Engineering, University of Wisconsin-Madison, Madison WI USA; Sun, Xin [Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA USA

2017-04-07

Using direct numerical simulations we provide a thorough study on the electrokinetics of ionic liquids. In particular, the modfied Poisson-Nernst-Planck (MPNP) equations are solved to capture the crowding and overscreening effects that are the characteristics of an ionic liquid. For modeling electrokinetic flows in an ionic liquid, the MPNP equations are coupled with the Navier-Stokes equations to study the coupling of ion transport, hydrodynamics, and electrostatic forces. Specifically, we consider the ion transport between two parallel plates, charging dynamics in a 2D straight-walled pore, electro-osmotic ow in a nano-channel, electroconvective instability on a plane ion-selective surface, and electroconvective ow on a curved ion-selective surface. We discuss how the crowding and overscreening effects and their interplay affect the electrokinetic behaviors of ionic liquids in these application problems.

Applications of ionic liquids in polymer science and technology

CERN Document Server

2015-01-01

This book summarizes the latest knowledge in the science and technology of ionic liquids and polymers in different areas. Ionic liquids (IL) are actively being investigated in polymer science and technology for a number of different applications. In the first part of the book the authors present the particular properties of ionic liquids as speciality solvents. The state-of-the art in the use of ionic liquids in polymer synthesis and modification reactions including polymer recycling is outlined. The second part focuses on the use of ionic liquids as speciality additives such as plasticizers or antistatic agents.  The third part examines the use of ionic liquids in the design of functional polymers (usually called polymeric ionic liquids (PIL) or poly(ionic liquids)). Many important applications in diverse scientific and industrial areas rely on these polymers, like polymer electrolytes in electrochemical devices, building blocks in materials science, nanocomposites, gas membranes, innovative anion sensitive...

Supported ionic liquids: versatile reaction and separation media

DEFF Research Database (Denmark)

Riisager, Anders; Fehrmann, Rasmus; Haumann, Marco

2006-01-01

The latest developments in supported ionic liquid phase (SILP) systems for catalysis and separation technology are surveyed. The SILP concept combines the advantages of homogeneous catalysis with heterogeneous process technology, and a variety of reactions have been studied where supported ionic ...... liquid catalysts proved to be more active and selective than common systems. In separation applications the use of supported ionic liquids can facilitate selective transport of substrates across membranes.......The latest developments in supported ionic liquid phase (SILP) systems for catalysis and separation technology are surveyed. The SILP concept combines the advantages of homogeneous catalysis with heterogeneous process technology, and a variety of reactions have been studied where supported ionic...

PEG-bis phosphonic acid based ionic supramolecular structures

DEFF Research Database (Denmark)

Gonzalez, Lidia; Skov, Anne Ladegaard; Hvilsted, Søren

2014-01-01

. The resulting ionic assemblies are very comprehensively characterized by ATR-FTIR, proton, and carbon-13 NMR spectroscopy that unequivocally demonstrate the ionic network formation through ammonium phophonates. The resulting salt and ionic networks are additionally analyzed by differential scanning calorimetry...... and thermogravimetric analysis. The conclusion is that mixing the virgin components at room temperature spontaneously form either a salt or ionic supramolecular networks. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim....

Ion pairing in ionic liquids

International Nuclear Information System (INIS)

Kirchner, Barbara; Malberg, Friedrich; Firaha, Dzmitry S; Hollóczki, Oldamur

2015-01-01

In the present article we briefly review the extensive discussion in literature about the presence or absence of ion pair-like aggregates in ionic liquids. While some experimental studies point towards the presence of neutral subunits in ionic liquids, many other experiments cannot confirm or even contradict their existence. Ion pairs can be detected directly in the gas phase, but no direct method is available to observe such association behavior in the liquid, and the corresponding indirect experimental proofs are based on such assumptions as unity charges at the ions. However, we have shown by calculating ionic liquid clusters of different sizes that assuming unity charges for ILs is erroneous, because a substantial charge transfer is taking place between the ionic liquid ions that reduce their total charge. Considering these effects might establish a bridge between the contradicting experimental results on this matter. Beside these results, according to molecular dynamics simulations the lifetimes of ion–ion contacts and their joint motions are far too short to verify the existence of neutral units in these materials. (topical review)

Nanoarchitecture Control Enabled by Ionic Liquids

Science.gov (United States)

Murdoch, Heather A.; Limmer, Krista R.; Labukas, Joseph P.

2017-04-01

Ionic liquids have many advantages over traditional aqueous electrosynthesis for fabrication of functional nanoarchitectures, including enabling the integration of nanoparticles into traditional coatings, superhydrophobicity, nanofoams, and other hierarchical structures. Shape and size control through ionic liquid selection and processing conditions can synthesize nanoparticles and nanoarchitectures without the use of capping agents, surfactants, or templates that are often deleterious to the functionality of the resultant system. Here we give a brief overview of some recent and interesting applications of ionic liquids to the synthesis of nanoparticles and nanoarchitectures.

A nationwide web-based automated system for early outbreak detection and rapid response in China

Directory of Open Access Journals (Sweden)

Yilan Liao

2011-03-01

Full Text Available Timely reporting, effective analyses and rapid distribution of surveillance data can assist in detecting the aberration of disease occurrence and further facilitate a timely response. In China, a new nationwide web-based automated system for outbreak detection and rapid response was developed in 2008. The China Infectious Disease Automated-alert and Response System (CIDARS was developed by the Chinese Center for Disease Control and Prevention based on the surveillance data from the existing electronic National Notifiable Infectious Diseases Reporting Information System (NIDRIS started in 2004. NIDRIS greatly improved the timeliness and completeness of data reporting with real time reporting information via the Internet. CIDARS further facilitates the data analysis, aberration detection, signal dissemination, signal response and information communication needed by public health departments across the country. In CIDARS, three aberration detection methods are used to detect the unusual occurrence of 28 notifiable infectious diseases at the county level and to transmit that information either in real-time or on a daily basis. The Internet, computers and mobile phones are used to accomplish rapid signal generation and dissemination, timely reporting and reviewing of the signal response results. CIDARS has been used nationwide since 2008; all Centers for Disease Control and Prevention (CDC in China at the county, prefecture, provincial and national levels are involved in the system. It assists with early outbreak detection at the local level and prompts reporting of unusual disease occurrences or potential outbreaks to CDCs throughout the country.

Ionic conductivity in irradiated KCL

International Nuclear Information System (INIS)

Vignolo Rubio, J.

1979-01-01

The ionic conductivity of X and gamma irradiated KCl single crystals has been studied between room temperature and 600 deg C. The radiation induced damage resulting in a decrease of the conductivity heals by thermal annealing in two steps which are at about 350 and 550 deg C respectively. It has been found that the radiation induced colour centres are not involved in the observed decrease of the ionic conductivity. Howewer, it has been observed that the effects of quenching and plastic deformation on the conductivity of the samples are very similar to the effect induced by irradiation. It is suggested that small radiation induced dislocation loops might cause the ionic conductivity decrease observed in irradiated samples. (auth)

Ionic conductivity in irradiated KCL

International Nuclear Information System (INIS)

Vignolo Rubio, J.

1979-01-01

The ionic conductivity of X and gamma irradiated KCL single crystals has been studied between room temperature and 600 degree centigree. the radiation induced damage resulting in a decrease of the conductivity heals by thermal annealing in two steps which are at about 350 and 550 degree centigree respectively. It has been found that the radiation induced colour centres are not involved in the observed decrease of the ionic conductivity. However. It has been observed that the effects of quenching and plastic deformation on the conductivity of the samples are very similar to the effect induced by irradiation. It is suggested that, samples radiation induced dislocation loops might cause the ionic conductivity decrease observed in irradiated samples. (Author)

A sol-gel derived pH-responsive bovine serum albumin molecularly imprinted poly(ionic liquids) on the surface of multiwall carbon nanotubes

International Nuclear Information System (INIS)

Liu, Mingming; Pi, Jiangyan; Wang, Xiaojie; Huang, Rong; Du, Yamei; Yu, Xiaoyang; Tan, Wenfeng; Liu, Fan; Shea, Kenneth J.

2016-01-01

A pH-responsive surface molecularly imprinted poly(ionic liquids) (MIPILs) was prepared on the surface of multiwall carbon nanotubes (MWCNTs) by a sol-gel technique. The material was synthesized using a 3-aminopropyl triethoxysilane modified multiwall carbon nanotube (MWCNT-APTES) as the substrate, bovine serum albumin (BSA) as the template molecule, an alkoxy-functionalized IL 1-(3-trimethoxysilyl propyl)-3-methyl imidazolium chloride ([TMSPMIM]Cl) as both the functional monomer and the sol-gel catalyst, and tetraethoxysilane (TEOS) as the crosslinking agent. The molecular interaction between BSA and [TMSPMIM]Cl was quantitatively evaluated by UV–vis spectroscopy prior to polymerization so as to identify an optimal template/monomer ratio and the most suitable pH value for the preparation of the MWCNTs@BSA-MIPILs. This strategy was found to be effective to overcome the problems of trial-and-error protocol in molecular imprinting. The optimum synthesis conditions were as follows: template/monomer ratio 7:20, crosslinking agent content 2.0–2.5 mL, temperature 4 °C and pH 8.9 Tris–HCl buffer. The influence of incubation pH on adsorption was also studied. The result showed that the imprinting effect and selectivity improved significantly with increasing incubation pH from 7.7 to 9.9. This is mainly because the non-specific binding from electrostatic and hydrogen bonding interactions decreased greatly with the increase of pH value, which made the specific binding affinity from shape selectivity strengthened instead. The polymers synthesized under the optimal conditions were then characterized by BET surface area measurement, FTIR, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The adsorption capacity, imprinting effect, selective recognition and reusability were also evaluated. The as-prepared MWCNTs@BSA-MIPILs were also found to have a number of advantages including high surface area (134.2 m"2 g"−"1), high adsorption capacity (55

A sol-gel derived pH-responsive bovine serum albumin molecularly imprinted poly(ionic liquids) on the surface of multiwall carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Liu, Mingming, E-mail: liumm@mail.hzau.edu.cn [Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China); Pi, Jiangyan; Wang, Xiaojie; Huang, Rong; Du, Yamei; Yu, Xiaoyang; Tan, Wenfeng; Liu, Fan [Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China); Shea, Kenneth J., E-mail: kjshea@uci.edu [Department of Chemistry, University of California-Irvine, Irvine, CA 92697 (United States)

2016-08-17

A pH-responsive surface molecularly imprinted poly(ionic liquids) (MIPILs) was prepared on the surface of multiwall carbon nanotubes (MWCNTs) by a sol-gel technique. The material was synthesized using a 3-aminopropyl triethoxysilane modified multiwall carbon nanotube (MWCNT-APTES) as the substrate, bovine serum albumin (BSA) as the template molecule, an alkoxy-functionalized IL 1-(3-trimethoxysilyl propyl)-3-methyl imidazolium chloride ([TMSPMIM]Cl) as both the functional monomer and the sol-gel catalyst, and tetraethoxysilane (TEOS) as the crosslinking agent. The molecular interaction between BSA and [TMSPMIM]Cl was quantitatively evaluated by UV–vis spectroscopy prior to polymerization so as to identify an optimal template/monomer ratio and the most suitable pH value for the preparation of the MWCNTs@BSA-MIPILs. This strategy was found to be effective to overcome the problems of trial-and-error protocol in molecular imprinting. The optimum synthesis conditions were as follows: template/monomer ratio 7:20, crosslinking agent content 2.0–2.5 mL, temperature 4 °C and pH 8.9 Tris–HCl buffer. The influence of incubation pH on adsorption was also studied. The result showed that the imprinting effect and selectivity improved significantly with increasing incubation pH from 7.7 to 9.9. This is mainly because the non-specific binding from electrostatic and hydrogen bonding interactions decreased greatly with the increase of pH value, which made the specific binding affinity from shape selectivity strengthened instead. The polymers synthesized under the optimal conditions were then characterized by BET surface area measurement, FTIR, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The adsorption capacity, imprinting effect, selective recognition and reusability were also evaluated. The as-prepared MWCNTs@BSA-MIPILs were also found to have a number of advantages including high surface area (134.2 m{sup 2} g{sup −1}), high adsorption

The Royal Australian College of Radiologists (RACR) survey of reactions to intravenous ionic and non-ionic contrast media

International Nuclear Information System (INIS)

Palmer, J.F.

1989-01-01

The Royal Australian College of Radiologists (RACR) expressed concern as to medico-legal implications of the continued use of conventional ionic contrast media in view of the availability of the new low-osmolar media. The new agents had demonstrated significant advantages and it was anticipated that their use would be associated with a lower incidence of undesirable reactions and deaths. However, these new media are significantly more expensive than conventional ionic media and complete changes to these agents has considerable implications for health budgets. Since it was the view of the RACR that there was insufficient information available of the incidence of reactions in clinical use to justify a complete change, a prospective survey of reations to intravenous contrast media injections was initiated. Particpants were issued a simple form, which required for each patient a record of the presence or absence of risk factors, wether ionic or non-ionic contrast media were used, and of the severity of eventual reactions. The results of about 170.000 patients were reported. The survey demonstrated the relative safety of non-ionic media for intravenous use. Despite the relative high cost of these media the continued use of conventional ionic media will become increasingly difficult to justify. (H.W.). 9 refs.; 4 tabs

Electrical double layer modulation of hybrid room temperature ionic liquid/aqueous buffer interface for enhanced sweat based biosensing.

Science.gov (United States)

Jagannath, Badrinath; Muthukumar, Sriram; Prasad, Shalini

2018-08-03

We have investigated the role of kosmotropic anionic moieties and chaotropic cationic moieties of room temperature hydrophilic ionic liquids in enhancing the biosensing performance of affinity based immunochemical biosensors in human sweat. Two ionic liquids, 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM[BF 4 ]) and choline dihydrogen phosphate (Choline[DHP]) were investigated in this study with Choline[DHP] being more kosmotropic in nature having a more protein stabilizing effect based on the hofmeister series. Non-faradaic interfacial charge transfer has been employed as the mechanism for evaluating the formation and the biosensing of capture probe antibodies in room temperature ionic liquids (RTILs)/aqueous human sweat interface. The charge of the ionic moieties were utilized to form compact electrical double layers around the antibodies for enhancing the stability of the antibody capture probes, which was evaluated through zeta potential measurements. The zeta potential measurements indicated stability of antibodies due to electrostatic repulsion of the RTIL charged moieties encompassing the antibodies, thus preventing any aggregation. Here, we report for the first time of non-faradaic electrochemical impedance spectroscopy equivalent circuit model analysis for analyzing and interpreting affinity based biosensing at hybrid electrode/ionic liquid-aqueous sweat buffer interface guided by the choice of the ionic liquid. Interleukin-6 (IL-6) and cortisol two commonly occurring biomarkers in human sweat were evaluated using this method. The limit of detection (LOD) obtained using both ionic liquids for IL-6 was 0.2 pg mL -1 with cross-reactivity studies indicating better performance of IL-6 detection using Choline[DHP] and no response to cross-reactive molecule. The LOD of 0.1 ng/mL was achieved for cortisol and the cross-reactivity studies indicated that cortisol antibody in BMIM[BF 4 ] did not show any signal response to cross-reactive molecules

Ionic liquids for addressing unmet needs in healthcare

Science.gov (United States)

Agatemor, Christian; Ibsen, Kelly N.; Tanner, Eden E. L.

2018-01-01

Abstract Advances in the field of ionic liquids have opened new applications beyond their traditional use as solvents into other fields especially healthcare. The broad chemical space, rich with structurally diverse ions, and coupled with the flexibility to form complementary ion pairs enables task‐specific optimization at the molecular level to design ionic liquids for envisioned functions. Consequently, ionic liquids now are tailored as innovative solutions to address many problems in medicine. To date, ionic liquids have been designed to promote dissolution of poorly soluble drugs and disrupt physiological barriers to transport drugs to targeted sites. Also, their antimicrobial activity has been demonstrated and could be exploited to prevent and treat infectious diseases. Metal‐containing ionic liquids have also been designed and offer unique features due to incorporation of metals. Here, we review application‐driven investigations of ionic liquids in medicine with respect to current status and future potential. PMID:29376130

Selective gas absorption by ionic liquids

DEFF Research Database (Denmark)

Shunmugavel, Saravanamurugan; Kegnæs, Søren; Due-Hansen, Johannes

2010-01-01

Reversible absorption performance for the flue gas components CO 2, NO and SO2 has been tested for several different ionic liquids (ILs) at different temperatures and flue gas compositions. Furthermore, different porous, high surface area carriers have been applied as supports for the ionic liquids...... to obtain Supported Ionic Liquid-Phase (SILP) absorber materials. The use of solid SILP absorbers with selected ILs were found to significantly improve the absorption capacity and sorption dynamics at low flue gas concentration, thus making the applicability of ILs viable in technical, continuous flow...... processes for flue gas cleaning. The results show that CO 2, NO and SO2 can be reversible and selective absorbed using different ILs and that Supported Ionic Liquid-Phase (SILP) absorbers are promising materials for industrial flue gas cleaning. Absorption/desorption dynamics can be tuned by temperatures...

Dynamic dielectrophoresis model of multi-phase ionic fluids.

Directory of Open Access Journals (Sweden)

Ying Yan

Full Text Available Ionic-based dielectrophoretic microchips have attracted significant attention due to their wide-ranging applications in electro kinetic and biological experiments. In this work, a numerical method is used to simulate the dynamic behaviors of ionic droplets in a microchannel under the effect of dielectrophoresis. When a discrete liquid dielectric is encompassed within a continuous fluid dielectric placed in an electric field, an electric force is produced due to the dielectrophoresis effect. If either or both of the fluids are ionic liquids, the magnitude and even the direction of the force will be changed because the net ionic charge induced by an electric field can affect the polarization degree of the dielectrics. However, using a dielectrophoresis model, assuming ideal dielectrics, results in significant errors. To avoid the inaccuracy caused by the model, this work incorporates the electrode kinetic equation and defines a relationship between the polarization charge and the net ionic charge. According to the simulation conditions presented herein, the electric force obtained in this work has an error exceeding 70% of the actual value if the false effect of net ionic charge is not accounted for, which would result in significant issues in the design and optimization of experimental parameters. Therefore, there is a clear motivation for developing a model adapted to ionic liquids to provide precise control for the dielectrophoresis of multi-phase ionic liquids.

Dynamic dielectrophoresis model of multi-phase ionic fluids.

Science.gov (United States)

Yan, Ying; Luo, Jing; Guo, Dan; Wen, Shizhu

2015-01-01

Ionic-based dielectrophoretic microchips have attracted significant attention due to their wide-ranging applications in electro kinetic and biological experiments. In this work, a numerical method is used to simulate the dynamic behaviors of ionic droplets in a microchannel under the effect of dielectrophoresis. When a discrete liquid dielectric is encompassed within a continuous fluid dielectric placed in an electric field, an electric force is produced due to the dielectrophoresis effect. If either or both of the fluids are ionic liquids, the magnitude and even the direction of the force will be changed because the net ionic charge induced by an electric field can affect the polarization degree of the dielectrics. However, using a dielectrophoresis model, assuming ideal dielectrics, results in significant errors. To avoid the inaccuracy caused by the model, this work incorporates the electrode kinetic equation and defines a relationship between the polarization charge and the net ionic charge. According to the simulation conditions presented herein, the electric force obtained in this work has an error exceeding 70% of the actual value if the false effect of net ionic charge is not accounted for, which would result in significant issues in the design and optimization of experimental parameters. Therefore, there is a clear motivation for developing a model adapted to ionic liquids to provide precise control for the dielectrophoresis of multi-phase ionic liquids.

Electrochemical behavior of ionically crosslinked polyampholytic gel electrolytes

International Nuclear Information System (INIS)

Chen Wanyu; Tang Haitao; Ou Ziwei; Wang Hong; Yang Yajiang

2007-01-01

An ionic complex of anionic and cationic monomers was obtained by protonation of (N,N-diethylamino)ethylmethacrylate (DEA) with acrylic acid (AAc). Free radical copolymerization of the ionic complex and acrylamide (AAm), yielded the ionically crosslinked polyampholytic gel electrolytes [poly(AAc-DEA-AAm), designated as PADA] using two types of organic solvents containing a lithium salt. The PADA gel electrolyte exhibited good thermal stability shown by the DSC thermogram. The impedance analysis at temperatures ranging from -30 to 75 deg. C indicated that the ionic conductivities of the PADA gel electrolytes were rather close to those of liquid electrolytes. The temperature dependence of the ionic conductivities was found to be in accord with the Arrhenius equation. Moreover, the ionic conductivities of PADA gel electrolytes increased with an increase of the molar ratios of cationic/anionic monomers. The ionic conductivities of PADA gels prepared in solvent mixtures of propylene carbonate, ethyl methyl ether and dioxolane (3:1:1, v/v) were higher than those of PADA gels prepared in propylene carbonate only. Significantly, the ionic conductivities of two kinds of PADA gel electrolytes were in the range of 10 -3 and 10 -4 S cm -1 even at -30 deg. C. The electrochemical windows of PADA gel electrolytes measured by cyclic voltammetry were in the range from -1 V to 4.5 V

Ionic liquids, tuneable solvents for intensifying reactions and separations

NARCIS (Netherlands)

Meindersma, G.W.; Kuipers, N.J.M.; Haan, de A.B.

2007-01-01

An Ionic Liquid (IL), or a Room Temperature Ionic Liquid (RTIL), is commonly defined as a liquid entirely composed of ions, which is a fluid below 100 °C. Due to the fact that an ionic liquid is a salt, it has a negligible vapour pressure. Therefore, ionic liquids are not volatile at ambient process

Ionic thermometers

International Nuclear Information System (INIS)

Strnad, M.

1975-01-01

An original method of temperature measurement based on conductivity changes near the phase transition point of ionic compounds and suitable for the range from 200 to 700 0 C according to the thermometric compound used, is given. By choosing between two approaches it is posible to evaluate either a discrete value of temperature or continuous measurement in a range to about 50 0 C below the phase transition point of thermometric compounds. The extreme nonlinearity of conductivity of the chosen group of ionic crystals used as well as the technical applications developed in the laboratories have not previously been published. The aim of the research is the application of this measuring method for temperature indication in nuclear reactors. Preliminary tests in radiation fields in an experimental reactor are yielding a real hope in this direction. (author)

Preliminary Testing For Anionic, Cationic and Non-ionic

Directory of Open Access Journals (Sweden)

Bokic, Lj.

2007-11-01

Full Text Available Detergents present a major environmental problem due to large quantities of surfactants released from laundries. For this reason, it is important to apply an appropriate analytical method for their determination. In this work, we propose two simple, fast and inexpensive analytical methods for anionic, cationic and non-ionic surfactant determination: thin layer chromatography (TLC separation for qualitative screening and quantitative potentiometric determination with ion-selective electrodes. These methods have been chosen because of their many advantages: rapidity, ease of operation, low cost of analysis and a wide variety of TLC application possibilities. The advantage of potentiometric titration is its very high degree of automation and very low detection limits obtained with different ion-selective electrodes applied for different surfactants.

Application of Ionic Liquids in Amperometric Gas Sensors.

Science.gov (United States)

Gębicki, Jacek; Kloskowski, Adam; Chrzanowski, Wojciech; Stepnowski, Piotr; Namiesnik, Jacek

2016-01-01

This article presents an analysis of available literature data on metrological parameters of the amperometric gas sensors containing ionic liquids as an electrolyte. Four mechanism types of signal generation in amperometric sensors with ionic liquid are described. Moreover, this article describes the influence of selected physico-chemical properties of the ionic liquids on the metrological parameters of these sensors. Some metrological parameters are also compared for amperometric sensors with GDE and SPE electrodes and with ionic liquids for selected analytes.

Ionic Liquids as Extraction Media for Metal Ions

Science.gov (United States)

Hirayama, Naoki

In solvent extraction separation of metal ions, recently, many researchers have investigated possible use of hydrophobic ionic liquids as extraction media instead of organic solvents. Ionic liquids are salts of liquid state around room temperature and can act not only as solvents but also as ion-exchangers. Therefore, the extraction mechanism of metal ions into ionic liquids is complicated. This review presents current overview and perspective on evaluation of nature of hydrophobic ionic liquids as extraction media for metal ions.

Recent applications of ionic liquids in the sol-gel process for polymer-silica nanocomposites with ionic interfaces

Czech Academy of Sciences Publication Activity Database

Donato, K. Z.; Matějka, Libor; Mauler, R. S.; Donato, R. K.

2017-01-01

Roč. 1, č. 1 (2017), s. 1-25, č. článku 5. E-ISSN 2504-5377 Institutional support: RVO:61389013 Keywords : ionic liquids * sol-gel * ionic interfaces Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science

Ionic liquid stationary phases for gas chromatography.

Science.gov (United States)

Poole, Colin F; Poole, Salwa K

2011-04-01

This article provides a summary of the development of ionic liquids as stationary phases for gas chromatography beginning with early work on packed columns that established details of the retention mechanism and established working methods to characterize selectivity differences compared with molecular stationary phases through the modern development of multi-centered cation and cross-linked ionic liquids for high-temperature applications in capillary gas chromatography. Since there are many reviews on ionic liquids dealing with all aspects of their chemical and physical properties, the emphasis in this article is placed on the role of gas chromatography played in the design of ionic liquids of low melting point, high thermal stability, high viscosity, and variable selectivity for separations. Ionic liquids provide unprecedented opportunities for extending the selectivity range and temperature-operating range of columns for gas chromatography, an area of separation science that has otherwise been almost stagnant for over a decade. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rapid screening of aquatic toxicity of several metal-based nanoparticles using the MetPLATE Trade-Mark-Sign bioassay

Energy Technology Data Exchange (ETDEWEB)

Pokhrel, Lok R.; Silva, Thilini [Department of Environmental Health, College of Public Health, East Tennessee State University, Johnson City, TN 37614 (United States); Dubey, Brajesh, E-mail: bdubey@uoguelph.ca [Environmental Engineering, School of Engineering, University of Guelph, 50 Stone Road East, Guelph, Ontario (Canada); El Badawy, Amro M. [Department of Civil and Environmental Engineering, University of Cincinnati, Cincinnati, OH (United States); Tolaymat, Thabet M. [USEPA, Office of Research and Development, National Risk Management Laboratory, 26 West Martin Luther King Drive, Cincinnati, OH 45224 (United States); Scheuerman, Phillip R. [Department of Environmental Health, College of Public Health, East Tennessee State University, Johnson City, TN 37614 (United States)

2012-06-01

Current understanding of potential toxicity of engineered nanomaterials to aquatic microorganisms is limited for risk assessment and management. Here we evaluate if the MetPLATE Trade-Mark-Sign test can be used as an effective and rapid screening tool to test for potential aquatic toxicity of various metal-based nanoparticles (NPs). The MetPLATE bioassay is a heavy metal sensitive test based on {beta}-galactosidase activity in Escherichia coli. Five different types of metal-based NPs were screened for toxicity: (1) citrate coated nAg (Citrate-nanosilver), (2) polyvinylpyrrolidone coated nAg (PVP-nAg), (3) uncoated nZnO, (4) uncoated nTiO{sub 2} and (5) 1-Octadecylamine coated CdSe Quantum Dots (CdSe QDs); and compared with their corresponding ionic salt toxicity. Citrate-nAg was further fractionated into clean Citrate-nAg, unclean Citrate-nAg and permeate using a tangential flow filtration (TFF) system to eliminate residual ions and impurities from the stock Citrate-nAg suspension and also to differentiate between ionic- versus nano-specific toxicity. Our results showed that nAg, nZnO and CdSe QDs were less toxic than their corresponding ionic salts tested, while nano- or ionic form of TiO{sub 2} was not toxic as high as 2.5 g L{sup -1} to the MetPLATE Trade-Mark-Sign bacteria. Although coating-dependent toxicity was noticeable between two types of Ag NPs evaluated, particle size and surface charge were not adequate to explain the observed toxicity; hence, the toxicity appeared to be material-specific. Overall, the toxicity followed the trend: CdCl{sub 2} > AgNO{sub 3} > PVP-nAg > unclean Citrate-nAg > clean Citrate-nAg > ZnSO{sub 4} > nZnO > CdSe QDs > nTiO{sub 2}/TiO{sub 2}. These results indicate that an evaluation of {beta}-galactosidase inhibition in MetPLATE Trade-Mark-Sign E. coli can be an important consideration for rapid screening of metal-based NP toxicity, and should facilitate ecological risk assessment of these emerging contaminants. - Highlights

High-performance supercapacitors based on poly(ionic liquid)-modified graphene electrodes.

Science.gov (United States)

Kim, Tae Young; Lee, Hyun Wook; Stoller, Meryl; Dreyer, Daniel R; Bielawski, Christopher W; Ruoff, Rodney S; Suh, Kwang S

2011-01-25

We report a high-performance supercapacitor incorporating a poly(ionic liquid)-modified reduced graphene oxide (PIL:RG-O) electrode and an ionic liquid (IL) electrolyte (specifically, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide or EMIM-NTf(2)). PIL:RG-O provides enhanced compatibility with the IL electrolyte, thereby increasing the effective electrode surface area accessible to electrolyte ions. The supercapacitor assembled with PIL:RG-O electrode and EMIM-NTf(2) electrolyte showed a stable electrochemical response up to 3.5 V operating voltage and was capable of yielding a maximum energy density of 6.5 W·h/kg with a power density of 2.4 kW/kg. These results demonstrate the potential of the PIL:RG-O material as an electrode in high-performance supercapacitors.

On the Chemical Stabilities of Ionic Liquids

OpenAIRE

Yen-Ho Chu; Ming-Chung Tseng; Venkatesan Srinivasadesikan; Subbiah Sowmiah

2009-01-01

Ionic liquids are novel solvents of interest as greener alternatives to conventional organic solvents aimed at facilitating sustainable chemistry. As a consequence of their unusual physical properties, reusability, and eco-friendly nature, ionic liquids have attracted the attention of organic chemists. Numerous reports have revealed that many catalysts and reagents were supported in the ionic liquid phase, resulting in enhanced reactivity and selectivity in various important reaction transfor...

High-pressure solubility of carbon dioxide in pyrrolidinium-based ionic liquids: [bmpyr][dca] and [bmpyr][Tf{sub 2}N

Energy Technology Data Exchange (ETDEWEB)

Lee, Byung-Chul; Nam, Sang Gyu [Hannam University, Daejeon (Korea, Republic of)

2015-03-15

Solubility data of carbon dioxide (CO{sub 2}) in two pyrrolidinium-based ionic liquids: 1-butyl-1-methylpyrrolidinium dicyanamide ([bmpyr][dca]) and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([bmpyr] [Tf{sub 2}N]) are presented at pressures up to about 30MPa and temperatures from 303..2 K to 343.2 K. The solubility was determined by measuring bubble or cloud point pressures of mixtures of CO{sub 2} and ionic liquid using a high-pressure equilibrium apparatus equipped with a variable-volume view cell. The CO{sub 2} solubility in the ionic liquid in terms of the mole fraction or the molality increased with the increase of the equilibrium pressure at a given temperature, but decreased with the increase of temperature at a given pressure. At a given temperature, the mole fraction of CO{sub 2} dissolved in the ionic liquid increased rapidly as pressure increased. CO{sub 2} solubility in the mole fraction almost reached saturation around 0.65 for [bmpyr][dca] and around 0..8 for [bmpyr][Tf{sub 2}N], respectively. The experimental data for the CO{sub 2}+ionic liquid systems were correlated using the Peng-Robinson equation of state (PR-EoS). The mixing rules of the Wong-Sandler type rather than the classical mixing rules of the van der Waals type were coupled with the PR-EoS. The resulting modeling approach proved to be able to correlate the CO{sub 2} solubilities in aforementioned ionic liquids over the aforementioned range of temperature and pressure within 5% average deviations.

Polypyrrole for Artificial Muscles: Ionic Mechanisms

DEFF Research Database (Denmark)

Skaarup, Steen

2006-01-01

the matrix of a polymer electrode – thereby causing volume expansion which can be converted into work. Solvent molecules are able to penetrate the polymer too. A precise description of the nature of these ionic and solvent movements is therefore important for understanding and improving the performance....... This work examines the influence of solvent, ionic species and electrolyte concentration on the fundamental question about the ionic mechanism involved: Is the actuation process driven by anion motion, cation motion, or a mixture of the two? In addition: What is the extent of solvent motion? The discussion...... is centered on polypyrrole (PPy), which is the material most used and studied. The tetraethyl ammonium cation (TEA) is shown to be able to move in and out of PPy(DBS) polymer films, in contrast to expectations. There is a switching between ionic mechanisms during cycling in TEACl electrolyte....

Transmitted/Founder Viruses Rapidly Escape from CD8+ T Cell Responses in Acute Hepatitis C Virus Infection.

Science.gov (United States)

Bull, Rowena A; Leung, Preston; Gaudieri, Silvana; Deshpande, Pooja; Cameron, Barbara; Walker, Melanie; Chopra, Abha; Lloyd, Andrew R; Luciani, Fabio

2015-05-01

The interaction between hepatitis C virus (HCV) and cellular immune responses during very early infection is critical for disease outcome. To date, the impact of antigen-specific cellular immune responses on the evolution of the viral population establishing infection and on potential escape has not been studied. Understanding these early host-virus dynamics is important for the development of a preventative vaccine. Three subjects who were followed longitudinally from the detection of viremia preseroconversion until disease outcome were analyzed. The evolution of transmitted/founder (T/F) viruses was undertaken using deep sequencing. CD8(+) T cell responses were measured via enzyme-linked immunosorbent spot (ELISpot) assay using HLA class I-restricted T/F epitopes. T/F viruses were rapidly extinguished in all subjects associated with either viral clearance (n = 1) or replacement with viral variants leading to establishment of chronic infection (n = 2). CD8(+) T cell responses against 11 T/F epitopes were detectable by 33 to 44 days postinfection, and 5 of these epitopes had not previously been reported. These responses declined rapidly in those who became chronically infected and were maintained in the subject who cleared infection. Higher-magnitude CD8(+) T cell responses were associated with rapid development of immune escape variants at a rate of up to 0.1 per day. Rapid escape from CD8(+) T cell responses has been quantified for the first time in the early phase of primary HCV infection. These rapid escape dynamics were associated with higher-magnitude CD8(+) T cell responses. These findings raise questions regarding optimal selection of immunogens for HCV vaccine development and suggest that detailed analysis of individual epitopes may be required. A major limitation in our detailed understanding of the role of immune response in HCV clearance has been the lack of data on very early primary infection when the transmitted viral variants successfully establish

The limitations in implementing and operating a rapid response system.

Science.gov (United States)

Subramaniam, A; Botha, J; Tiruvoipati, R

2016-10-01

Despite the widespread introduction of rapid response systems (RRS)/medical emergency teams (MET), there is still controversy regarding how effective they are. While there are some observational studies showing improved outcomes with RRS, there are no data from randomised controlled trials to support the effectiveness. Nevertheless, the MET system has become a standard of care in many healthcare organisations. In this review, we present an overview of the limitations in implementing and operating a RRS in modern healthcare. © 2016 Royal Australasian College of Physicians.

Thermoelectric Generators Based on Ionic Liquids

Science.gov (United States)

Laux, Edith; Uhl, Stefanie; Jeandupeux, Laure; López, Pilar Pérez; Sanglard, Pauline; Vanoli, Ennio; Marti, Roger; Keppner, Herbert

2018-06-01

Looking at energy harvesting using body or waste heat for portable electronic or on-board devices, Ionic liquids are interesting candidates as thermoactive materials in thermoelectric generators (TEGs) because of their outstanding properties. Two different kinds of ionic liquid, with alkylammonium and choline as cations, were studied, whereby different anions and redox couples were combined. This study focussed on the intention to find non-hazardous and environmentally friendly ionic liquids for TEGs to be selected among the thousands that can potentially be used. Seebeck coefficients (SEs) as high as - 15 mV/K were measured, in a particular case for an electrode temperature difference of 20 K. The bottleneck of our TEG device is still the abundance of negative SE liquids matching the internal resistance with the existing positive SE-liquids at series connections. In this paper, we show further progress in finding increased negative SE liquids. For current extraction from the TEG, the ionic liquid must be blended with a redox couple, allowing carrier exchange in a cyclic process under a voltage which is incuced by the asymmetry of the generator in terms of hot and cold electrodes. In our study, two types of redox pairs were tested. It was observed that a high SE of an ionic liquid/redox blend is not a sufficient condition for high power output. It appears that more complex effects between the ionic liquid and the electrode determine the magnitude of the final current/power output. The physico-chemical understanding of such a TEG cell is not yet available.

Low-Cost, Rapidly Responsive, Controllable, and Reversible Photochromic Hydrogel for Display and Storage.

Science.gov (United States)

Yang, Yongqi; Guan, Lin; Gao, Guanghui

2018-04-25

Traditional optoelectronic devices without stretchable performance could be limited for substrates with irregular shape. Therefore, it is urgent to explore a new generation of flexible, stretchable, and low-cost intelligent vehicles as visual display and storage devices, such as hydrogels. In the investigation, a novel photochromic hydrogel was developed by introducing the negatively charged ammonium molybdate as a photochromic unit into polyacrylamide via ionic and covalent cross-linking. The hydrogel exhibited excellent properties of low cost, easy preparation, stretchable deformation, fatigue resistance, high transparency, and second-order response to external signals. Moreover, the photochromic and fading process of hydrogels could be precisely controlled and repeated under the irradiation of UV light and exposure of oxygen at different time and temperature. The photochromic hydrogel could be considered applied for artificial intelligence system, wearable healthcare device, and flexible memory device. Therefore, the strategy for designing a soft photochromic material would open a new direction to manufacture flexible and stretchable devices.

Regio and stereoselectivity in ionic cycloadditions

Indian Academy of Sciences (India)

WINTEC

Though the reactions have both electrostatic control and frontier orbital control the former dominates in the initial stages of the reaction. Keywords. Stereoselectivity; ionic cycloaddition; density functional theory; acridizinium ion; methyl vinyl ether; 2,3-dimethylisoquinolinium ion. 1. Introduction. In polar or ionic cycloadditions ...

Rapid response and wide range neutronic power measuring systems for fast pulsed reactors

International Nuclear Information System (INIS)

Sumita, Kenji; Iida, Toshiyuki; Wakayama, Naoaki.

1976-01-01

This paper summarizes our investigation on design principles of the rapid, stable and wide range neutronic power measuring system for fast pulsed reactors. The picoammeter, the logarithmic amplifier, the reactivity meter and the neutron current chamber are the items of investigation. In order to get a rapid response, the method of compensation for the stray capacitance of the feedback circuits and the capacitance of signal cables is applied to the picoammeter, the logarithmic amplifier and the reactivity meter with consideration for the stability margin of a whole detecting system. The response of an ionization current chamber and the method for compensating the ion component of the chamber output to get optimum responses high pass filters are investigated. Statistical fluctuations of the current chamber output are also considered in those works. The optimum thickness of the surrounding moderator of the neutron detector is also discussed from the viewpoint of the pulse shape deformation and the neutron sensitivity increase. The experimental results are reported, which were observed in the pulse operations of the one shot fast pulsed reactor ''YAYOI'' and the one shot TRIGA ''NSRR'' with the measuring systems using those principles. (auth.)

Ionic liquid electrolytes for dye-sensitized solar cells.

Science.gov (United States)

Gorlov, Mikhail; Kloo, Lars

2008-05-28

The potential of room-temperature molten salts (ionic liquids) as solvents for electrolytes for dye-sensitized solar cells has been investigated during the last decade. The non-volatility, good solvent properties and high electrochemical stability of ionic liquids make them attractive solvents in contrast to volatile organic solvents. Despite this, the relatively high viscosity of ionic liquids leads to mass-transport limitations. Here we review recent developments in the application of different ionic liquids as solvents or components of liquid and quasi-solid electrolytes for dye-sensitized solar cells.

Active chemisorption sites in functionalized ionic liquids for carbon capture.

Science.gov (United States)

Cui, Guokai; Wang, Jianji; Zhang, Suojiang

2016-07-25

Development of novel technologies for the efficient and reversible capture of CO2 is highly desired. In the last decade, CO2 capture using ionic liquids has attracted intensive attention from both academia and industry, and has been recognized as a very promising technology. Recently, a new approach has been developed for highly efficient capture of CO2 by site-containing ionic liquids through chemical interaction. This perspective review focuses on the recent advances in the chemical absorption of CO2 using site-containing ionic liquids, such as amino-based ionic liquids, azolate ionic liquids, phenolate ionic liquids, dual-functionalized ionic liquids, pyridine-containing ionic liquids and so on. Other site-containing liquid absorbents such as amine-based solutions, switchable solvents, and functionalized ionic liquid-amine blends are also investigated. Strategies have been discussed for how to activate the existent reactive sites and develop novel reactive sites by physical and chemical methods to enhance CO2 absorption capacity and reduce absorption enthalpy. The carbon capture mechanisms of these site-containing liquid absorbents are also presented. Particular attention has been paid to the latest progress in CO2 capture in multiple-site interactions by amino-free anion-functionalized ionic liquids. In the last section, future directions and prospects for carbon capture by site-containing ionic liquids are outlined.

Ionic Liquid Epoxy Resin Monomers

Science.gov (United States)

Paley, Mark S. (Inventor)

2013-01-01

Ionic liquid epoxide monomers capable of reacting with cross-linking agents to form polymers with high tensile and adhesive strengths. Ionic liquid epoxide monomers comprising at least one bis(glycidyl) N-substituted nitrogen heterocyclic cation are made from nitrogen heterocycles corresponding to the bis(glycidyl) N-substituted nitrogen heterocyclic cations by a method involving a non-nucleophilic anion, an alkali metal cation, epichlorohydrin, and a strong base.

Studies in solid state ionics

International Nuclear Information System (INIS)

Jakes, D.; Rosenkranz, J.

1987-01-01

Studies performed over 10 years by the high temperature chemistry group are reviewed. Attention was paid to different aspects of ionic solids from the point of view of practical as well as theoretical needs of nuclear technology. Thus ceramic fuel compound like uranates, urania-thoria system, solid electrolytes based on oxides and ionics transformations were studied under reactor irradiation. (author) 13 figs., 3 tabs., 46 refs

Priors engaged in long-latency responses to mechanical perturbations suggest a rapid update in state estimation.

Directory of Open Access Journals (Sweden)

Frédéric Crevecoeur

Full Text Available In every motor task, our brain must handle external forces acting on the body. For example, riding a bike on cobblestones or skating on irregular surface requires us to appropriately respond to external perturbations. In these situations, motor predictions cannot help anticipate the motion of the body induced by external factors, and direct use of delayed sensory feedback will tend to generate instability. Here, we show that to solve this problem the motor system uses a rapid sensory prediction to correct the estimated state of the limb. We used a postural task with mechanical perturbations to address whether sensory predictions were engaged in upper-limb corrective movements. Subjects altered their initial motor response in ∼60 ms, depending on the expected perturbation profile, suggesting the use of an internal model, or prior, in this corrective process. Further, we found trial-to-trial changes in corrective responses indicating a rapid update of these perturbation priors. We used a computational model based on Kalman filtering to show that the response modulation was compatible with a rapid correction of the estimated state engaged in the feedback response. Such a process may allow us to handle external disturbances encountered in virtually every physical activity, which is likely an important feature of skilled motor behaviour.

SISGR: Physical Chemistry of Reaction Dynamics in Ionic Liquids

Energy Technology Data Exchange (ETDEWEB)

Blank, David [Univ. of Minnesota, Minneapolis, MN (United States)

2017-10-30

Room temperature ionic liquids (RTILs) are liquids made up of atomic and molecular ions. This is in contrast with more common liquids, such as water, that are made up of neutral molecules. The additional charges on the atoms and molecules can alter the properties of these liquids, for example they tend to have a very high vapor pressure and the ability to shield charge in electronic devices. For these and other reasons RTILs have recently been deployed in a number of applications that involve production of free electrons in the liquid, such as batteries, capacitors, nuclear power plants, and solar cells. Electrons tend to be very reactive, and understanding their behaviour in these liquids is important for the future design of ionic liquids to be employed in these environments. This study investigated the behavior of electrons generated in RTILs by pulses of ultraviolet light, including how long they survive, and how reactive they are with the both the surrounding liquid and impurities in the liquid. The ionic liquid studied was one of the most commonly used, called N-alkyl-N-methyl-pyrrolidinium bistriflimide. What the study revealed was that the majority of the electrons initially created, about 96%, had a very short lifetime of less than one picosecond (10-12 second) due to a process called geminate recombination. The study also demonstrated that the electrons are very reactive at the moment they are detached from the molecules in the liquid by light, but that they relax very quickly and lose almost all of their reactivity in much less than one picosecond. The short lifetime and rapid loss of reactivity both serve as important mechanisms that protect the liquid from radiolytic damage.

Ionic liquid syntheses via click chemistry: expeditious routes toward versatile functional materials.

Science.gov (United States)

Mirjafari, Arsalan

2018-03-25

Since the introduction of click chemistry by K. B. Sharpless in 2001, its exploration and exploitation has occurred in countless fields of materials sciences in both academic and industrial spheres. Click chemistry is defined as an efficient, robust, and orthogonal synthetic platform for the facile formation of new carbon-heteroatom bonds, using readily available starting materials. Premier examples of click reactions are copper(i)-catalyzed azide-alkyne Huisgen cycloaddition (CuAAC) and the thiol-X (X = ene and yne) coupling reactions to form C-N and C-S bonds, respectively. The emphasis of this review is centered on the rapidly expanding area of click chemistry-mediated synthesis of functional ionic liquids via CuAAC, thiol-X and oxime formation, and selected examples of nucleophilic ring-opening reactions, while offering some thoughts on emerging challenges, opportunities and ultimately the evolution of this field. Click chemistry offers tremendous opportunities, and introduces intriguing perspectives for efficient and robust generation of tailored task-specific ionic liquids - an important class of soft materials.

Ionic liquid gel materials: applications in green and sustainable chemistry

OpenAIRE

Marr, Patricia C.; Marr, Andrew C.

2016-01-01

Ionic liquid gel materials offer a way to further utilise ionic liquids in technological applications. Combining the controlled and directed assembly of gels, with the diverse applications of ionic liquids, enables the design of a heady combination of functional tailored materials, leading to the development of task specific / functional ionic liquid gels. This review introduces gels and gel classification, focusing on ionic liquid gels and their potential roles in a more sustainable future. ...

Notre Dame Geothermal Ionic Liquids Research: Ionic Liquids for Utilization of Geothermal Energy

Energy Technology Data Exchange (ETDEWEB)

Brennecke, Joan F. [Univ. of Notre Dame, IN (United States)

2017-03-07

The goal of this project was to develop ionic liquids for two geothermal energy related applications. The first goal was to design ionic liquids as high temperature heat transfer fluids. We identified appropriate compounds based on both experiments and molecular simulations. We synthesized the new ILs, and measured their thermal stability, measured storage density, viscosity, and thermal conductivity. We found that the most promising compounds for this application are aminopyridinium bis(trifluoromethylsulfonyl)imide based ILs. We also performed some measurements of thermal stability of IL mixtures and used molecular simulations to better understand the thermal conductivity of nanofluids (i.e., mixtures of ILs and nanoparticles). We found that the mixtures do not follow ideal mixture theories and that the addition of nanoparticles to ILs may well have a beneficial influence on the thermal and transport properties of IL-based heat transfer fluids. The second goal was to use ionic liquids in geothermally driven absorption refrigeration systems. We performed copious thermodynamic measurements and modeling of ionic liquid/water systems, including modeling of the absorption refrigeration systems and the resulting coefficients of performance. We explored some IL/organic solvent mixtures as candidates for this application, both with experimentation and molecular simulations. We found that the COPs of all of the IL/water systems were higher than the conventional system – LiBr/H2O. Thus, IL/water systems appear very attractive for absorption refrigeration applications.

Ionic liquids: an x-ray reflectivity study

International Nuclear Information System (INIS)

Sloutskin, E.; Deutsch, M.; Tamam, L.; Ocko, B.; Kuzmenko, I.; Gog, T.

2005-01-01

Full Text:Ionic liquids are non-volatile, non-flammable and thermally stable solvents, and as such are promising 'green' replacements for traditional volatile organic solvents. In the last years hundreds of Ionic liquids were synthesized. Due to the Ionic liquids great industrial potential, this number is growing at an exceedingly fast rate. Despite the great importance of the interfacial properties of materials for technological applications and basic science, the atomic-scale surface structure of the Ionic liquids has never been studied previously. In our study, synchrotron x-ray reflectivity and surface tensiometry were employed to obtain the surface structure and thermodynamics of two ionic liquids, based on the 1-alkyl-3-methylimidazolium cations. A molecular layer of a density ∼18% higher than that of the bulk is found to form at the free surface of these liquids. The excess concentration of the oppositely charged ions within the surface layer is determined by chemical substitution of the anion. Finally, the observed layering at the surface is contrasted with our measurements on the behavior of classical aqueous salt solutions

Importance of elastic finite-size effects: Neutral defects in ionic compounds

Science.gov (United States)

Burr, P. A.; Cooper, M. W. D.

2017-09-01

Small system sizes are a well-known source of error in density functional theory (DFT) calculations, yet computational constraints frequently dictate the use of small supercells, often as small as 96 atoms in oxides and compound semiconductors. In ionic compounds, electrostatic finite-size effects have been well characterized, but self-interaction of charge-neutral defects is often discounted or assumed to follow an asymptotic behavior and thus easily corrected with linear elastic theory. Here we show that elastic effects are also important in the description of defects in ionic compounds and can lead to qualitatively incorrect conclusions if inadequately small supercells are used; moreover, the spurious self-interaction does not follow the behavior predicted by linear elastic theory. Considering the exemplar cases of metal oxides with fluorite structure, we show that numerous previous studies, employing 96-atom supercells, misidentify the ground-state structure of (charge-neutral) Schottky defects. We show that the error is eliminated by employing larger cells (324, 768, and 1500 atoms), and careful analysis determines that elastic, not electrostatic, effects are responsible. The spurious self-interaction was also observed in nonoxide ionic compounds irrespective of the computational method used, thereby resolving long-standing discrepancies between DFT and force-field methods, previously attributed to the level of theory. The surprising magnitude of the elastic effects is a cautionary tale for defect calculations in ionic materials, particularly when employing computationally expensive methods (e.g., hybrid functionals) or when modeling large defect clusters. We propose two computationally practicable methods to test the magnitude of the elastic self-interaction in any ionic system. In commonly studied oxides, where electrostatic effects would be expected to be dominant, it is the elastic effects that dictate the need for larger supercells: greater than 96 atoms.

Glyphosate resistance in Ambrosia trifida: Part 1. Novel rapid cell death response to glyphosate.

Science.gov (United States)

Van Horn, Christopher R; Moretti, Marcelo L; Robertson, Renae R; Segobye, Kabelo; Weller, Stephen C; Young, Bryan G; Johnson, William G; Schulz, Burkhard; Green, Amanda C; Jeffery, Taylor; Lespérance, Mackenzie A; Tardif, François J; Sikkema, Peter H; Hall, J Christopher; McLean, Michael D; Lawton, Mark B; Sammons, R Douglas; Wang, Dafu; Westra, Philip; Gaines, Todd A

2018-05-01

Glyphosate-resistant (GR) Ambrosia trifida is now present in the midwestern United States and in southwestern Ontario, Canada. Two distinct GR phenotypes are known, including a rapid response (GR RR) phenotype, which exhibits cell death within hours after treatment, and a non-rapid response (GR NRR) phenotype. The mechanisms of resistance in both GR RR and GR NRR remain unknown. Here, we present a description of the RR phenotype and an investigation of target-site mechanisms on multiple A. trifida accessions. Glyphosate resistance was confirmed in several accessions, and whole-plant levels of resistance ranged from 2.3- to 7.5-fold compared with glyphosate-susceptible (GS) accessions. The two GR phenotypes displayed similar levels of resistance, despite having dramatically different phenotypic responses to glyphosate. Glyphosate resistance was not associated with mutations in EPSPS sequence, increased EPSPS copy number, EPSPS quantity, or EPSPS activity. These encompassing results suggest that resistance to glyphosate in these GR RR A. trifida accessions is not conferred by a target-site resistance mechanism. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Chemically synthesized PbS Nano particulate thin films for a rapid NO2 gas sensor

Directory of Open Access Journals (Sweden)

Burungale Vishal V.

2016-03-01

Full Text Available Rapid NO2 gas sensor has been developed based on PbS nanoparticulate thin films synthesized by Successive Ionic Layer Adsorption and Reaction (SILAR method at different precursor concentrations. The structural and morphological properties were investigated by means of X-ray diffraction and field emission scanning electron microscope. NO2 gas sensing properties of PbS thin films deposited at different concentrations were tested. PbS film with 0.25 M precursor concentration showed the highest sensitivity. In order to optimize the operating temperature, the sensitivity of the sensor to 50 ppm NO2 gas was measured at different operating temperatures, from 50 to 200 °C. The gas sensitivity increased with an increase in operating temperature and achieved the maximum value at 150 °C, followed by a decrease in sensitivity with further increase of the operating temperature. The sensitivity was about 35 % for 50 ppm NO2 at 150 °C with rapid response time of 6 s. T90 and T10 recovery time was 97 s at this gas concentration.

Measurement and Correlation of the Ionic Conductivity of Ionic Liquid-Molecular Solvent Solutions

Institute of Scientific and Technical Information of China (English)

LI,Wen-Jing; HAN,Bu-Xing; TAO,Ran-Ting; ZHANG,Zhao-Fu; ZHANG,Jian-Ling

2007-01-01

The ionic conductivity of the solutions formed from 1-n-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) or 1-n-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF6]) and different molecular solvents (MSs) were measured at 298.15 K. The molar conductivity of the ionic liquids (ILs) increased dramatically with increasing concentration of the MSs. It was found that the molar conductivity of the IL in the solutions studied in this work could be well correlated by the molar conductivity of the neat ILs and the dielectric constant and molar volume of the MSs.

Excimer Formation Dynamics of Dipyrenyldecane in Structurally Different Ionic Liquids.

Science.gov (United States)

Yadav, Anita; Pandey, Siddharth

2017-12-07

Ionic liquids, being composed of ions alone, may offer alternative pathways for molecular aggregation. These pathways could be controlled by the chemical structure of the cation and the anion of the ionic liquids. Intramolecular excimer formation dynamics of a bifluorophoric probe, 1,3-bis(1-pyrenyl)decane [1Py(10)1Py], where the fluorophoric pyrene moieties are separated by a long decyl chain, is investigated in seven different ionic liquids in 10-90 °C temperature range. The long alkyl separator allows for ample interaction with the solubilizing milieu prior to the formation of the excimer. The ionic liquids are composed of two sets, one having four ionic liquids of 1-butyl-3-methylimidazolium cation ([bmim + ]) with different anions and the other having four ionic liquids of bis(trifluoromethylsulfonyl)imide anion ([Tf 2 N - ]) with different cations. The excimer-to-monomer emission intensity ratio (I E /I M ) is found to increase with increasing temperature in sigmoidal fashion. Chemical structure of the ionic liquid controls the excimer formation efficiency, as I E /I M values within ionic liquids with the same viscosities are found to be significantly different. The excited-state intensity decay kinetics of 1Py(10)1Py in ionic liquids do not adhere to a simplistic Birk's scheme, where only one excimer conformer forms after excitation. The apparent rate constants of excimer formation (k a ) in highly viscous ionic liquids are an order of magnitude lower than those reported in organic solvents. In general, the higher the viscosity of the ionic liquid, the more sensitive is the k a to the temperature with higher activation energy, E a . The trend in E a is found to be similar to that for activation energy of the viscous flow (E a,η ). Stokes-Einstein relationship is not followed in [bmim + ] ionic liquids; however, with the exception of [choline][Tf 2 N], it is found to be followed in [Tf 2 N - ] ionic liquids suggesting the cyclization dynamics of 1Py(10)1Py

Ionic liquids behave as dilute electrolyte solutions

Science.gov (United States)

Gebbie, Matthew A.; Valtiner, Markus; Banquy, Xavier; Fox, Eric T.; Henderson, Wesley A.; Israelachvili, Jacob N.

2013-01-01

We combine direct surface force measurements with thermodynamic arguments to demonstrate that pure ionic liquids are expected to behave as dilute weak electrolyte solutions, with typical effective dissociated ion concentrations of less than 0.1% at room temperature. We performed equilibrium force–distance measurements across the common ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2]) using a surface forces apparatus with in situ electrochemical control and quantitatively modeled these measurements using the van der Waals and electrostatic double-layer forces of the Derjaguin–Landau–Verwey–Overbeek theory with an additive repulsive steric (entropic) ion–surface binding force. Our results indicate that ionic liquids screen charged surfaces through the formation of both bound (Stern) and diffuse electric double layers, where the diffuse double layer is comprised of effectively dissociated ionic liquid ions. Additionally, we used the energetics of thermally dissociating ions in a dielectric medium to quantitatively predict the equilibrium for the effective dissociation reaction of [C4mim][NTf2] ions, in excellent agreement with the measured Debye length. Our results clearly demonstrate that, outside of the bound double layer, most of the ions in [C4mim][NTf2] are not effectively dissociated and thus do not contribute to electrostatic screening. We also provide a general, molecular-scale framework for designing ionic liquids with significantly increased dissociated charge densities via judiciously balancing ion pair interactions with bulk dielectric properties. Our results clear up several inconsistencies that have hampered scientific progress in this important area and guide the rational design of unique, high–free-ion density ionic liquids and ionic liquid blends. PMID:23716690

Course on Ionic Channels

CERN Document Server

1986-01-01

This book is based on a series of lectures for a course on ionic channels held in Santiago, Chile, on November 17-20, 1984. It is intended as a tutorial guide on the properties, function, modulation, and reconstitution of ionic channels, and it should be accessible to graduate students taking their first steps in this field. In the presentation there has been a deliberate emphasis on the spe­ cific methodologies used toward the understanding of the workings and function of channels. Thus, in the first section, we learn to "read" single­ channel records: how to interpret them in the theoretical frame of kinetic models, which information can be extracted from gating currents in re­ lation to the closing and opening processes, and how ion transport through an open channel can be explained in terms of fluctuating energy barriers. The importance of assessing unequivocally the origin and purity of mem­ brane preparations and the use of membrane vesicles and optical tech­ niques in the stUGY of ionic channels a...

Numerical modeling of ultrasonic cavitation in ionic liquids

Science.gov (United States)

Calvisi, Michael L.; Elder, Ross M.

2017-11-01

Ionic liquids have favorable properties for sonochemistry applications in which the high temperatures and pressures achieved by cavitation bubbles are important drivers of chemical processes. Two different numerical models are presented to simulate ultrasonic cavitation in ionic liquids, each with different capabilities and physical assumptions. A model based on a compressible form of the Rayleigh-Plesset equation (RPE) simulates ultrasonic cavitation of a spherical bubble with a homogeneous interior, incorporating evaporation and condensation at the bubble surface, and temperature-varying thermodynamic properties in the interior. A second, more computationally intensive model of a spherical bubble uses the finite element method (FEM) and accounts for spatial variations in pressure and temperature throughout the flow domain. This model provides insight into heat transfer across the bubble surface and throughout the bubble interior and exterior. Parametric studies are presented for sonochemistry applications involving ionic liquids as a solvent, examining a range of realistic ionic liquid properties and initial conditions to determine their effect on temperature and pressure. Results from the two models are presented for parametric variations including viscosity, thermal conductivity, water content of the ionic liquid solvent, acoustic frequency, and initial bubble pressure. An additional study performed with the FEM model examines thermal penetration into the surrounding ionic liquid during bubble oscillation. The results suggest the prospect of tuning ionic liquid properties for specific applications.

Printable polymer actuators from ionic liquid, soluble polyimide, and ubiquitous carbon materials.

Science.gov (United States)

Imaizumi, Satoru; Ohtsuki, Yuto; Yasuda, Tomohiro; Kokubo, Hisashi; Watanabe, Masayoshi

2013-07-10

We present here printable high-performance polymer actuators comprising ionic liquid (IL), soluble polyimide, and ubiquitous carbon materials. Polymer electrolytes with high ionic conductivity and reliable mechanical strength are required for high-performance polymer actuators. The developed polymer electrolytes comprised a soluble sulfonated polyimide (SPI) and IL, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([C2mim][NTf2]), and they exhibited acceptable ionic conductivity up to 1 × 10(-3) S cm(-1) and favorable mechanical properties (elastic modulus >1 × 10(7) Pa). Polymer actuators based on SPI/[C2mim][NTf2] electrolytes were prepared using inexpensive activated carbon (AC) together with highly electron-conducting carbon such as acetylene black (AB), vapor grown carbon fiber (VGCF), and Ketjen black (KB). The resulting polymer actuators have a trilaminar electric double-layer capacitor structure, consisting of a polymer electrolyte layer sandwiched between carbon electrode layers. Displacement, response speed, and durability of the actuators depended on the combination of carbons. Especially the actuators with mixed AC/KB carbon electrodes exhibited relatively large displacement and high-speed response, and they kept 80% of the initial displacement even after more than 5000 cycles. The generated force of the actuators correlated with the elastic modulus of SPI/[C2mim][NTf2] electrolytes. The displacement of the actuators was proportional to the accumulated electric charge in the electrodes, regardless of carbon materials, and agreed well with the previously proposed displacement model.

Rapid response to syphilis outbreak among female sex workers

Directory of Open Access Journals (Sweden)

Shaily B Surti

2017-01-01

Full Text Available Background: Outbreak of syphilis, i.e., 16 cases of rapid plasma reagin (RPR reactive cases of syphilis was reported in Community Based Organization (CBO Sahyog of Surat, India, from April to August 2014. The aim of the study was to find risk factors and take immediate actions to prevent spread. Materials and Methods: Outbreak investigation of 16 Female Sex Workers of CBO Sahyog in Surat who were found Rapid Plasma Reagin (RPR and Treponema Pallidum Hemagglutination Assay (TPHA positive from April to August 2014; was carried out. Clinico-epidemiological and laboratory-based evidence for different sexually transmitted infections (STIs conducted at Government Medical College, New Civil Hospital, Surat. Root cause analysis (RCA of index case was carried out. Results: Desk review for the past 3 years data of STI revealed total STI cases as 88 (2011, 95 (2012, and 130 (2013, of which 4, 2, and 2 found RPR reactive, respectively. Data from April to August 2014 revealed 16 RPR reactive cases and confirmed by TPHA. On examination, one had ulcerative cervical lesion, rest did not have any symptoms of syphilis. Eleven had vaginal/cervical discharge, 11 had lower abdominal pain. A total of 11 had unprotected sex, 7 encountered condom tear in the past 6 months, and 5 reported sexual violence. Seven had sexual activity under influence of alcohol. Laboratory investigation revealed two as HIV-positive. RPR reactivity reported highest (9 out of 16 from same area of hotspot. RCA of probable index case revealed factors responsible as violence and nonuse of condoms. Conclusions: Outbreak investigation revealed one probable index case. All 16 treated with injection Penidure. Violence or condom tear is responsible for the spread. Crisis management team should be strengthened.

Ionic liquid containing hydroxamate and N-alkyl sulfamate ions

Science.gov (United States)

Friesen, Cody A.; Wolfe, Derek; Johnson, Paul Bryan

2016-03-15

Embodiments of the invention are related to ionic liquids and more specifically to ionic liquids used in electrochemical metal-air cells in which the ionic liquid includes a cation and an anion selected from hydroxamate and/or N-alkyl sulfamate anions.

Thioimidazolium Ionic Liquids as Tunable Alkylating Agents.

Science.gov (United States)

Guterman, Ryan; Miao, Han; Antonietti, Markus

2018-01-19

Alkylating ionic liquids based on the thioimidazolium structure combine the conventional properties of ionic liquids, including low melting point and nonvolatility, with the alkylating function. Alkyl transfer occurs exclusively from the S-alkyl position, thus allowing for easy derivatization of the structure without compromising specificity. We apply this feature to tune the electrophilicty of the cation to profoundly affect the reactivity of these alkylating ionic liquids, with a caffeine-derived compound possessing the highest reactivity. Anion choice was found to affect reaction rates, with iodide anions assisting in the alkylation reaction through a "shuttling" process. The ability to tune the properties of the alkylating agent using the toolbox of ionic liquid chemistry highlights the modular nature of these compounds as a platform for alkylating agent design and integration in to future systems.

Ionomer design for augmented charge transport in novel ionic polymer transducers

International Nuclear Information System (INIS)

Duncan, Andrew J; Akle, Barbar J; Long, Timothy E; Leo, Donald J

2009-01-01

Ionic polymer transducers are devices that display electromechanical transduction and are projected to have extensive applications as actuators and sensors. This study employs novel, highly branched sulfonated polysulfones (sBPS) as part of an investigation into the contribution of polymer topology to electromechanical transduction. Specifically, the ionomers are combined with an ionic liquid to determine the optimal ratio and method for maximizing ionic conductivity, where charge transport is essential to device performance. Two uptake methods are assessed for introduction of ionic liquid into the central ionomeric membrane. The effects of casting membranes in the presence of ionic liquid and swelling preformed membranes in ionic liquid on film stability and ionic conductivity are examined. Membranes cast from a solution of the ionomer and ionic liquid allow for direct targeting of the component ratio and a single-step process for membrane formation. Swelling conditions for preformed neat membranes combine time, temperature, and the presence of organic co-diluents to achieve the maximum stable uptake of ionic liquid. Comparison of optimal conditions for the various methods reveals that swelling with co-diluents achieves ionic conductivity of the imbibed membrane per uptake higher than the levels achieved with the casting process for highly sulfonated sBPS. However, for less sulfonated sBPS the casting process successfully produced membranes with ionic conductivities unreachable with the co-diluent process. Both methods will enable the production of high performance ionic polymer transducers constructed from novel sBPS ionomers and ionic liquids

Optical nose based on porous silicon photonic crystal infiltrated with ionic liquids.

Science.gov (United States)

Zhang, Haijuan; Lin, Leimiao; Liu, Dong; Chen, Qiaofen; Wu, Jianmin

2017-02-08

A photonic-nose for the detection and discrimination of volatile organic compounds (VOCs) was constructed. Each sensing element on the photonic sensor array was formed by infiltrating a specific type of ionic liquid (IL) into the pore channel of a patterned porous silicon (PSi) chip. Upon exposure to VOC, the density of IL dramatically decreased due to the nano-confinement effect. As a result, the IL located in pore channel expanded its volume and protrude out of the pore channel, leading to the formation of microdroplets on the PSi surface. These VOC-stimulated microdroplets could scatter the light reflected from the PSi rugate filter, thereby producing an optical response to VOC. The intensity of the optical response produced by IL/PSi sensor mainly depends on the size and shape of microdroplets, which is related to the concentration of VOC and the physi-chemical propertied of ILs. For ethanol vapor, the optical response has linear relationship with its relative vapor pressure within 0-60%. The LOD of the IL/PSi sensor for ethanol detection is calculated to be 1.3 ppm. It takes around 30 s to reach a full optical response, while the time for recovery is less than 1 min. In addition, the sensor displayed good stability and reproducibility. Owing to the different molecular interaction between IL and VOC, the ILs/PSi sensor array can generate a unique cross-reactive "fingerprint" in response to a specific type of VOC analyte. With the assistance of image technologies and principle components analysis (PCA), rapid discrimination of VOC analyte could be achieved based on the pattern recognition of photonic sensor array. The technology established in this work allows monitoring in-door air pollution in a visualized way. Copyright © 2016 Elsevier B.V. All rights reserved.

A method for the rapid generation of nonsequential light-response curves of chlorophyll fluorescence.

Science.gov (United States)

Serôdio, João; Ezequiel, João; Frommlet, Jörg; Laviale, Martin; Lavaud, Johann

2013-11-01

Light-response curves (LCs) of chlorophyll fluorescence are widely used in plant physiology. Most commonly, LCs are generated sequentially, exposing the same sample to a sequence of distinct actinic light intensities. These measurements are not independent, as the response to each new light level is affected by the light exposure history experienced during previous steps of the LC, an issue particularly relevant in the case of the popular rapid light curves. In this work, we demonstrate the proof of concept of a new method for the rapid generation of LCs from nonsequential, temporally independent fluorescence measurements. The method is based on the combined use of sample illumination with digitally controlled, spatially separated beams of actinic light and a fluorescence imaging system. It allows the generation of a whole LC, including a large number of actinic light steps and adequate replication, within the time required for a single measurement (and therefore named "single-pulse light curve"). This method is illustrated for the generation of LCs of photosystem II quantum yield, relative electron transport rate, and nonphotochemical quenching on intact plant leaves exhibiting distinct light responses. This approach makes it also possible to easily characterize the integrated dynamic light response of a sample by combining the measurement of LCs (actinic light intensity is varied while measuring time is fixed) with induction/relaxation kinetics (actinic light intensity is fixed and the response is followed over time), describing both how the response to light varies with time and how the response kinetics varies with light intensity.

Comparative Experimental Study on Ionic Polymer Mental Composite based on Nafion and Aquivion Membrane as Actuators

Science.gov (United States)

Luo, B.; Chen, Z.

2017-11-01

Most ionic polymer mental composites employ Nafion as the polymer matrix, Aquivion can also manufactured as ionic polymer mental composite while research was little. This paper researched on two kinds of ionic polymer mental composite based on Aquivion and Nafion matrix with palladium electrode called Aquivion-IPMC and Nafion-IPMC. The samples were fabricated by the same preparation process. The current and deformation responses of the samples were measured at voltage to characterize the mechano-electrical properties. The experimental observations revealed that shorter flexible side chains in Aquivion-IPMC provide a larger force than Nafion-IPMC, while the displacement properties were similar in two different samples. The results also showed that Aquivion membrane can also replace Nafion to reproduce IPMC application in soft robots, MEMS, and so on.

Effect of Ionic Strength on Settling of Activated Sludge

OpenAIRE

M Ahmadi Moghadam, M Soheili, MM Esfahani

2005-01-01

Structural properties of activated sludge flocs were found to be sensitive to small changes in ionic strength. This study investigates the effect of ionic strength on settling of activated sludge. Samples were taken from activated sludge process of Ghazvin Sasan soft drink wastewater treatment plant, then treated with different ionic strengths of KCl and CaCl2 solution, after that the turbidity of supernatant was measured. The results indicated that low ionic strength resulted in a steeper sl...

Applying Bayesian belief networks in rapid response situations

Energy Technology Data Exchange (ETDEWEB)

Gibson, William L [Los Alamos National Laboratory; Deborah, Leishman, A. [Los Alamos National Laboratory; Van Eeckhout, Edward [Los Alamos National Laboratory

2008-01-01

The authors have developed an enhanced Bayesian analysis tool called the Integrated Knowledge Engine (IKE) for monitoring and surveillance. The enhancements are suited for Rapid Response Situations where decisions must be made based on uncertain and incomplete evidence from many diverse and heterogeneous sources. The enhancements extend the probabilistic results of the traditional Bayesian analysis by (1) better quantifying uncertainty arising from model parameter uncertainty and uncertain evidence, (2) optimizing the collection of evidence to reach conclusions more quickly, and (3) allowing the analyst to determine the influence of the remaining evidence that cannot be obtained in the time allowed. These extended features give the analyst and decision maker a better comprehension of the adequacy of the acquired evidence and hence the quality of the hurried decisions. They also describe two example systems where the above features are highlighted.

Ionic liquids based simultaneous ultrasonic and microwave assisted extraction of phenolic compounds from burdock leaves

International Nuclear Information System (INIS)

Lou Zaixiang; Wang Hongxin; Zhu Song; Chen Shangwei; Zhang Ming; Wang Zhouping

2012-01-01

The ionic liquids based simultaneous ultrasonic and microwave assisted extraction (IL-UMAE) technique was first proposed and applied to isolate compounds. The ionic liquids comprising a range of four anions, five 1-alkyl-3-methylimidazolium derivatives were designed and prepared. The results suggested that varying the anion and cation both had apparent effects on the extraction of phenolics. The results also showed that irradiation power, time and solid–liquid ratio significantly affected the yields. The yields of caffeic acid and quercetin obtained by IL-UMAE were higher than those by regular UMAE. Compared with conventional heat-reflux extraction (HRE), the proposed approach exhibited higher efficiency (8–17% enhanced) and shorter extraction time (from 5 h to 30 s). The results indicated ILUMAE to be a fast and efficient extraction technique. Moreover, the proposed method was validated by the reproducibility and recovery experiments. The ILUMAE method provided good recoveries (from 96.1% to 105.3%) with RSD lower than 5.2%, which indicated that the proposed method was credible. Based on the designable nature of ionic liquids, and the rapid and highly efficient performance of the proposed approach, ILUMAE provided a new alternative for preparation of various useful substances from solid samples.

Functional ionic liquids; Funktionelle ionische Fluessigkeiten

Energy Technology Data Exchange (ETDEWEB)

Baecker, Tobias

2012-07-01

In the thesis at hand, new functional ionic liquids were investigated. Main focus was attended to their structure property relations and the structural features leading to a decrease of the melting point. New compounds of the type 1-butyl-3-methylimidazolium tris(N,Ndialkyldithiocarbamato) uranylate with variously substituated dithiocarbamato ligands were synthesized and characterized. Ligands with asymmetrical substitution pattern proved to be most suitable for ionic liquid formation. The single-crystal X-ray structures revealed the interactions in the solid state. Here, the first spectroscopic investigation of the U-S bond in sulfur donated uranyl complexes, up to now only observed in single-crystal X-ray structures, is presented, and the participation of the uranium f-orbitals is shown by theoretical calculations. Electrochemical investigations showed the accessibility of the respective U{sup V}O{sub 2}{sup +} compounds. As well, ionic liquids with [FeCl{sub 4}]{sup -} and [Cl{sub 3}FeOFeCl{sub 3}]{sup 2-} as anion were synthesized. Both of these anions contain high-spin Fe(III) centres in distorted tetrahedral environment, but exhibit different magnetic behaviour. The tetrachloroferrates show the usual paramagnetism, the m-oxobis(trichloroferrate) exhibits unexpectedly strong antiferromagnetic coupling, as was observed by NMR experiments and susceptibility measurements. To investigate structure-property relations in functionalized ionic liquids, a set of protic, primary alkylammonium and aprotic, quarternary trimethylalkylammonium based ionic liquids was synthesized, and characterized. The length of the alkyl chain was systematically varied, and all compounds were synthesized with and without hydroxyl group, as well as formate and bis(triflyl)amide salts, aiming at getting insight into the influence of the different structure parts on the respective ionic liquid's properties.

Condition Help: A Patient- and Family-Initiated Rapid Response System.

Science.gov (United States)

Eden, Elizabeth L; Rack, Laurie L; Chen, Ling-Wan; Bump, Gregory M

2017-03-01

Rapid response teams (RRTs) help in delivering safe, timely care. Typically they are activated by clinicians using specific parameters. Allowing patients and families to activate RRTs is a novel intervention. The University of Pittsburgh Medical Center developed and implemented a patient- and family-initiated rapid response system called Condition Help (CH). When the CH system is activated, a patient care liaison or an on-duty administrator meets bedside with the unit charge nurse to address the patient's concerns. In this study, we collected demographic data, call reasons, call designations (safety or nonsafety), and outcome information for all CH calls made during the period January 2012 through June 2015. Two hundred forty patients/family members made 367 CH calls during the study period. Most calls were made by patients (76.8%) rather than family members (21.8%). Of the 240 patients, 43 (18%) made multiple calls; their calls accounted for 46.3% of all calls (170/367). Inadequate pain control was the reason for the call in most cases (48.2%), followed by dissatisfaction with staff (12.5%). The majority of calls involved nonsafety issues (83.4%) rather than safety issues (11.4%). In 41.4% of cases, a change in care was made. Patient- and family-initiated RRTs are designed to engage patients and families in providing safer care. In the CH system, safety issues are identified, but the majority of calls involve nonsafety issues. Journal of Hospital Medicine 2017;12:157-161. © 2017 Society of Hospital Medicine

Solid ionic: these unusual materials applications in high-energy-density

International Nuclear Information System (INIS)

Shriver, D.F.; Farrington, G.C.

1985-01-01

The idea that ions can diffuse as rapidly in a solid as in an aqueous salt solution may seem strange to many chemists. But a variety of solids with high ionic conductivities are known. Compounds have been discovered that conduct anions (including F - and O 2- ) and cations (including monovalent, divalent, and trivalent cations). These substances range from hard, refractory materials, such as sodium β-alumina, through softer compounds, such as silver iodide (AgI) to the very soft polymer electrolytes. They include compounds that are stoichiometric (AgI), nonstoichiometric (sodium β-alumina), or doped (calcia-stabilized zirconia). A variety of names have been applied to these materials: among them, solid electrolytes, superionic conductors, and fast-ion conductors. Fast-ion transport in solids is a lively area of study in solid-state chemistry and physics. High-conductivity solid electrolytes have revolutionized conventional concepts of ionic compounds, and their potential uses range from high-energy-density battery and fuel-cell electrolytes to chemical sensors and from lasers to phosphors. Devices using solid electrolytes are already available commercially-oxygen detectors for automotive pollution-control systems employ solid O 2- electrolytes, and solid-state batteries using solid electrolytes are employed in heart pacemakers

Early Detection Rapid Response Program Targets New Noxious Weed Species in Washington State

Science.gov (United States)

Andreas, Jennifer E.; Halpern, Alison D.; DesCamp, Wendy C.; Miller, Timothy W.

2015-01-01

Early detection, rapid response is a critical component of invasive plant management. It can be challenging, however, to detect new invaders before they become established if landowners cannot identify species of concern. In order to increase awareness, eye-catching postcards were developed in Washington State as part of a noxious weed educational…

Key Developments in Ionic Liquid Crystals.

Science.gov (United States)

Alvarez Fernandez, Alexandra; Kouwer, Paul H J

2016-05-16

Ionic liquid crystals are materials that combine the classes of liquid crystals and ionic liquids. The first one is based on the multi-billion-dollar flat panel display industry, whilst the latter quickly developed in the past decades into a family of highly-tunable non-volatile solvents. The combination yields materials with a unique set of properties, but also with many challenges ahead. In this review, we provide an overview of the key concepts in ionic liquid crystals, particularly from a molecular perspective. What are the important molecular parameters that determine the phase behavior? How should they be introduced into the molecules? Finally, which other tools does one have to realize specific properties in the material?

Key Developments in Ionic Liquid Crystals

Directory of Open Access Journals (Sweden)

Alexandra Alvarez Fernandez

2016-05-01

Full Text Available Ionic liquid crystals are materials that combine the classes of liquid crystals and ionic liquids. The first one is based on the multi-billion-dollar flat panel display industry, whilst the latter quickly developed in the past decades into a family of highly-tunable non-volatile solvents. The combination yields materials with a unique set of properties, but also with many challenges ahead. In this review, we provide an overview of the key concepts in ionic liquid crystals, particularly from a molecular perspective. What are the important molecular parameters that determine the phase behavior? How should they be introduced into the molecules? Finally, which other tools does one have to realize specific properties in the material?

Physicochemical properties of fatty acid based ionic liquids

International Nuclear Information System (INIS)

Rocha, Marisa A.A.; Bruinhorst, Adriaan van den; Schröer, Wolffram; Rathke, Bernd; Kroon, Maaike C.

2016-01-01

Highlights: • Effects of a branched anion and a mono-unsaturated anion on the physicochemical properties have been explored. • Fatty acid based ionic liquids were synthesized and characterized. • Densities and viscosities at different temperatures have been measured. • The thermal operating window and thermal phase behavior have been evaluated. - Abstract: In this work a series of fatty acid based ionic liquids has been synthesized and characterized. Densities and viscosities at different temperatures have been measured in the temperature range from (293.15 to 363.15) K. The thermal operating window and thermal phase behavior have been evaluated. The effects of a branched anion and a mono-unsaturated anion on the physicochemical properties have been explored. It has been observed that the density (T = 298.15 K) decreases with the following sequence: methyltrioctylammonium 4-ethyloctanoate > methyltrioctylammonium oleate ≈ tetrahexylammonium oleate > tetraoctylammonium oleate, with no detectable dependency of the thermal expansion coefficients on the total number of carbons in the ionic liquid. An almost linear correlation between the molar volumes and the total number of carbons of the alkanes together with the studied ionic liquids was found. The experimental viscosity data were correlated using the Vogel–Fulcher–Tammann (VFT) equation, where a maximum relative deviation of 1.4% was achieved. The ionic liquid with branched alkyl chains on the anion presents the highest viscosity, and methyltrioctylammonium oleate has the highest viscosity compared to the rest of the oleate based ionic liquids. The short and long-term stability were evaluated for all ionic liquids, their long-term decomposition temperatures were found to be significantly lower than their short-term decomposition temperatures. From the long-term thermal analysis was concluded that the highest temperature at which these ionic liquids can be kept is 363 K. In addition, the thermal

Synthetic Organic Electrochemistry in Ionic Liquids: The Viscosity Question

Directory of Open Access Journals (Sweden)

Scott T. Handy

2011-07-01

Full Text Available Ionic liquids are obvious candidates for use in electrochemical applications due to their ionic character. Nevertheless, relatively little has been done to explore their application in electrosynthesis. We have studied the Shono oxidation of arylamines and carbamates using ionic liquids as recyclable solvents and have noted that the viscosity of the medium is a major problem, although with the addition of sufficient co-solvent, good results and excellent recovery and recycling of the ionic liquid can be achieved.

Self-consistent field theory of polymer-ionic molecule complexation

OpenAIRE

Nakamura, Issei; Shi, An-Chang

2010-01-01

A self-consistent field theory is developed for polymers that are capable of binding small ionic molecules (adsorbates). The polymer-ionic molecule association is described by Ising-like binding variables, C_(i)^(a)(kΔ)(= 0 or 1), whose average determines the number of adsorbed molecules, nBI. Polymer gelation can occur through polymer-ionic molecule complexation in our model. For polymer-polymer cross-links through the ionic molecules, three types of solutions for nBI are obtained, depending...

NIR responsive liposomal system for rapid release of drugs in cancer therapy

Directory of Open Access Journals (Sweden)

Chen MM

2017-06-01

Full Text Available Ming-Mao Chen,1 Yuan-Yuan Liu,1 Guang-Hao Su,2 Fei-Fei Song,1 Yan Liu,3 Qi-Qing Zhang1,4 1Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou, 2Institute of Pediatric Research, Children’s Hospital of Soochow University, Suzhou, 3State Key Lab of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 4Key Laboratory of Biomedical Material of Tianjin, Institute of Biomedical Engineering, Chinese Academy of Medical Science & Peking Union Medical College, Tianjin, People’s Republic of China Abstract: To design a rapid release liposomal system for cancer therapy, a NIR responsive bubble-generating thermosensitive liposome (BTSL system combined with photothermal agent (Cypate, doxorubicin (DOX, and NH4HCO3 was developed. Cypate/DOX-BTSL exhibited a good aqueous stability, photostability, and photothermal effect. In vitro release suggested that the amounts of DOX released from BTSL were obviously higher than that of (NH42SO4 liposomes at 42°C. After NIR irradiation, the hyperthermic temperature induced by Cypate led to the decomposition of NH4HCO3 and the generation of a large number of CO2 bubbles, triggering a rapid release of drugs. Confocal laser scanning microscope and acridine orange staining indicated that Cypate/DOX-BTSL upon irradiation could facilitate to disrupt the lysosomal membranes and realize endolysosomal escape into cytosol, improving the intracellular uptake of DOX clearly. MTT and trypan blue staining implied that the cell damage of Cypate/DOX-BTSL with NIR irradiation was more severe than that in the groups without irradiation. In vivo results indicated that Cypate/DOX-BTSL with irradiation could dramatically increase the accumulation of DOX in tumor, inhibit tumor growth, and reduce systemic side effects of DOX. These data demonstrated that Cypate/DOX-BTSL has the potential to be used as a NIR responsive liposomal system for a rapid

Understanding the impact of the central atom on the ionic liquid behavior: Phosphonium vs ammonium cations

International Nuclear Information System (INIS)

Carvalho, Pedro J.; Ventura, Sónia P. M.; Batista, Marta L. S.; Schröder, Bernd; Coutinho, João A. P.; Gonçalves, Fernando; Esperança, José; Mutelet, Fabrice

2014-01-01

The influence of the cation's central atom in the behavior of pairs of ammonium- and phosphonium-based ionic liquids was investigated through the measurement of densities, viscosities, melting temperatures, activity coefficients at infinite dilution, refractive indices, and toxicity against Vibrio fischeri. All the properties investigated are affected by the cation's central atom nature, with ammonium-based ionic liquids presenting higher densities, viscosities, melting temperatures, and enthalpies. Activity coefficients at infinite dilution show the ammonium-based ionic liquids to present slightly higher infinite dilution activity coefficients for non-polar solvents, becoming slightly lower for polar solvents, suggesting that the ammonium-based ionic liquids present somewhat higher polarities. In good agreement these compounds present lower toxicities than the phosphonium congeners. To explain this behavior quantum chemical gas phase DFT calculations were performed on isolated ion pairs at the BP-TZVP level of theory. Electronic density results were used to derive electrostatic potentials of the identified minimum conformers. Electrostatic potential-derived CHelpG and Natural Population Analysis charges show the P atom of the tetraalkylphosphonium-based ionic liquids cation to be more positively charged than the N atom in the tetraalkylammonium-based analogous IL cation, and a noticeable charge delocalization occurring in the tetraalkylammonium cation, when compared with the respective phosphonium congener. It is argued that this charge delocalization is responsible for the enhanced polarity observed on the ammonium based ionic liquids explaining the changes in the thermophysical properties observed

Rapid response to Ebola outbreaks in remote areas - Liberia, July-November 2014.

Science.gov (United States)

Kateh, Francis; Nagbe, Thomas; Kieta, Abraham; Barskey, Albert; Gasasira, Alex Ntale; Driscoll, Anne; Tucker, Anthony; Christie, Athalia; Karmo, Ben; Scott, Colleen; Bowah, Collin; Barradas, Danielle; Blackley, David; Dweh, Emmanuel; Warren, Felicia; Mahoney, Frank; Kassay, Gabriel; Calvert, Geoffrey M; Castro, Georgina; Logan, Gorbee; Appiah, Grace; Kirking, Hannah; Koon, Hawa; Papowitz, Heather; Walke, Henry; Cole, Isaac B; Montgomery, Joel; Neatherlin, John; Tappero, Jordan W; Hagan, Jose E; Forrester, Joseph; Woodring, Joseph; Mott, Joshua; Attfield, Kathleen; DeCock, Kevin; Lindblade, Kim A; Powell, Krista; Yeoman, Kristin; Adams, Laura; Broyles, Laura N; Slutsker, Laurence; Larway, Lawrence; Belcher, Lisa; Cooper, Lorraine; Santos, Marjorie; Westercamp, Matthew; Weinberg, Meghan Pearce; Massoudi, Mehran; Dea, Monica; Patel, Monita; Hennessey, Morgan; Fomba, Moses; Lubogo, Mutaawe; Maxwell, Nikki; Moonan, Patrick; Arzoaquoi, Sampson; Gee, Samuel; Zayzay, Samuel; Pillai, Satish; Williams, Seymour; Zarecki, Shauna Mettee; Yett, Sheldon; James, Stephen; Grube, Steven; Gupta, Sundeep; Nelson, Thelma; Malibiche, Theophil; Frank, Wilmont; Smith, Wilmot; Nyenswah, Tolbert

2015-02-27

West Africa is experiencing its first epidemic of Ebola virus disease (Ebola). As of February 9, Liberia has reported 8,864 Ebola cases, of which 3,147 were laboratory-confirmed. Beginning in August 2014, the Liberia Ministry of Health and Social Welfare (MOHSW), supported by CDC, the World Health Organization (WHO), and others, began systematically investigating and responding to Ebola outbreaks in remote areas. Because many of these areas lacked mobile telephone service, easy road access, and basic infrastructure, flexible and targeted interventions often were required. Development of a national strategy for the Rapid Isolation and Treatment of Ebola (RITE) began in early October. The strategy focuses on enhancing capacity of county health teams (CHT) to investigate outbreaks in remote areas and lead tailored responses through effective and efficient coordination of technical and operational assistance from the MOHSW central level and international partners. To measure improvements in response indicators and outcomes over time, data from investigations of 12 of 15 outbreaks in remote areas with illness onset dates of index cases during July 16-November 20, 2014, were analyzed. The times to initial outbreak alerts and durations of the outbreaks declined over that period while the proportions of patients who were isolated and treated increased. At the same time, the case-fatality rate in each outbreak declined. Implementation of strategies, such as RITE, to rapidly respond to rural outbreaks of Ebola through coordinated and tailored responses can successfully reduce transmission and improve outcomes.

Ionic conductivity and complexation in liquid dielectrics

International Nuclear Information System (INIS)

Zhakin, Anatolii I

2003-01-01

Electronic and ionic conductivity in nonpolar liquids is reviewed. Theoretical results on ionic complexation (formation of ion pairs and triplets, dipole-dipole chains, ion-dipole clusters) in liquid dielectrics in an intense external electric field are considered, and the relation between the complexation process and ionic conductivity is discussed. Experimental results supporting the possibility of complexation are presented and compared with theoretical calculations. Onsager's theory about the effect of an intense external electric field on ion-pair dissociation is corrected for the finite size of ions. (reviews of topical problems)

Dye-sensitized solar cells using ionic liquids as redox mediator

Science.gov (United States)

Denizalti, Serpil; Ali, Abdulrahman Khalaf; Ela, Çağatay; Ekmekci, Mesut; Erten-Ela, Sule

2018-01-01

In this research, the influence of ionic liquid on the conversion efficiency, incident photons to converted electrons (IPCE) and performance of fabricated solar cell was investigated using various ionic liquids. Ionic liquids with different substituents and ions were prepared and used as redox mediators in dye-sensitized solar cells (DSSCs). Ionic liquids were characterized 1H and 13C NMR spectra. We practically investigated the performance of ionic liquid salts were used as the mobile ions and found that the efficiencies of DSSCs were increased up to 40% comparing commercial electrolyte system. The ionic liquid compounds were incorporated in DSSCs to obtain an efficient charge transfer, solving the corrosion problem of platinum layer in counter electrode compared to commercial electrolyte.

Visualization of ionic wind in laminar jet flames

KAUST Repository

Park, Daegeun

2017-07-03

Electric field, when it is applied to hydrocarbon flames, generates ionic wind due to the electric body force on charge carrying species. Ionic wind has been shown to influence soot emission, propagation speed, and stability of flames; however, a detailed behavior of ionic wind and its effects on flames is still not clear. Here, we investigated the dynamic behaviors of flames and ionic wind in the presence of direct current (DC) and alternating current (AC) electric fields in nonpremixed and premixed jet flames with a jet nozzle placed between two parallel electrodes. We observed a skewed flame toward a lower potential electrode with DC and lower frequency AC (e.g., 10Hz) and a steady flame with higher frequencies AC (1000Hz), while we found that the ionic wind blew toward both the anode and cathode regardless of flame type (nonpremixed or premixed) or the source of the electric field (DC and AC).

Counterion-induced swelling of ionic microgels

Science.gov (United States)

Denton, Alan R.; Tang, Qiyun

2016-10-01

Ionic microgel particles, when dispersed in a solvent, swell to equilibrium sizes that are governed by a balance between electrostatic and elastic forces. Tuning of particle size by varying external stimuli, such as pH, salt concentration, and temperature, has relevance for drug delivery, microfluidics, and filtration. To model swelling of ionic microgels, we derive a statistical mechanical theorem, which proves exact within the cell model, for the electrostatic contribution to the osmotic pressure inside a permeable colloidal macroion. Applying the theorem, we demonstrate how the distribution of counterions within an ionic microgel determines the internal osmotic pressure. By combining the electrostatic pressure, which we compute via both Poisson-Boltzmann theory and molecular dynamics simulation, with the elastic pressure, modeled via the Flory-Rehner theory of swollen polymer networks, we show how deswelling of ionic microgels with increasing concentration of particles can result from a redistribution of counterions that reduces electrostatic pressure. A linearized approximation for the electrostatic pressure, which proves remarkably accurate, provides physical insight and greatly eases numerical calculations for practical applications. Comparing with experiments, we explain why soft particles in deionized suspensions deswell upon increasing concentration and why this effect may be suppressed at higher ionic strength. The failure of the uniform ideal-gas approximation to adequately account for counterion-induced deswelling below close packing of microgels is attributed to neglect of spatial variation of the counterion density profile and the electrostatic pressure of incompletely neutralized macroions.

Solid state ionics: a Japan perspective

Science.gov (United States)

Yamamoto, Osamu

2017-12-01

The 70-year history of scientific endeavor of solid state ionics research in Japan is reviewed to show the contribution of Japanese scientists to the basic science of solid state ionics and its applications. The term 'solid state ionics' was defined by Takehiko Takahashi of Nagoya University, Japan: it refers to ions in solids, especially solids that exhibit high ionic conductivity at a fairly low temperature below their melting points. During the last few decades of exploration, many ion conducting solids have been discovered in Japan such as the copper-ion conductor Rb4Cu16I7Cl13, proton conductor SrCe1-xYxO3, oxide-ion conductor La0.9Sr0.9Ga0.9Mg0.1O3, and lithium-ion conductor Li10GeP2S12. Rb4Cu16I7Cl13 has a conductivity of 0.33 S cm-1 at 25 °C, which is the highest of all room temperature ion conductive solid electrolytes reported to date, and Li10GeP2S12 has a conductivity of 0.012 S cm-1 at 25 °C, which is the highest among lithium-ion conductors reported to date. Research on high-temperature proton conducting ceramics began in Japan. The history, the discovery of novel ionic conductors and the story behind them are summarized along with basic science and technology.

Ionic liquid marbles.

Science.gov (United States)

Gao, Lichao; McCarthy, Thomas J

2007-10-09

Liquid marbles have been reported during this decade and have been argued to be potentially useful for microfluidic and lab-on-a-chip applications. The liquid marbles described to date have been composed of either water or glycerol as the liquid and hydrophobized lycopodium or silica as the stabilizing particles. Both of these components are potentially reactive and do not permit the use of organic chemistry; the liquids are volatile. We report the use of perfluoroalkyl particles (oligomeric (OTFE) and polymeric (PTFE) tetrafluoroethylene, which are unreactive) to support/stabilize a range of ionic liquid marbles. Ionic liquids are not volatile and have been demonstrated to be versatile solvents for chemical transformations. Water marbles prepared with OTFE are much more robust than those prepared with hydrophobized lycopodium or silica.

Effect of ionic and non-ionic contrast media on whole blood viscosity, plasma viscosity and hematocrit in vitro

International Nuclear Information System (INIS)

Aspelin, P.

1978-01-01

The effect of the ionic contrast media diatrizoate, iocarmate and metrizoate and the non-ionic metrizamide on whole blood viscosity, plasma viscosity and hematocrit was investigated. All the contrast media increased whole blood and plasma viscosity and reduced the hematocrit. The whole blood viscosity increased with increasing osmolality of the contrast medium solutions, whereas the plasma viscosity increased with increasing viscosity of the contrast medium solutions. The higher the osmolality of the contrast media, the lower the hematocrit became. The normal shear-thinning (decreasing viscosity with increasing shear rate) property of blood was reduced when contrast medium was added to the blood. At 50 per cent volume ratio (contrast medium to blood), the ionic contrast media converted the blood into a shear-thickening (increasing viscosity with increasing shear rate) suspension, indicating a marked rigidification of the single red cell, while the non-ionic contrast medium still produced shear-thinning, indicating less rigidification of the red cell (p<0.01). (Auth.)

Rapid Response Teams: Is it Time to Reframe the Questions of Rapid Response Team Measurement?

Science.gov (United States)

Salvatierra, Gail G; Bindler, Ruth C; Daratha, Kenn B

2016-11-01

The purpose of this article is to present an overview of rapid response team (RRT) history in the United States, provide a review of prior RRT effectiveness research, and propose the reframing of four new questions of RRT measurement that are designed to better understand RRTs in the context of contemporary nursing practice as well as patient outcomes. RRTs were adopted in the United States because of their intuitive appeal, and despite a lack of evidence for their effectiveness. Subsequent studies used mortality and cardiac arrest rates to measure whether or not RRTs "work." Few studies have thoroughly examined the effect of RRTs on nurses and on nursing practice. An extensive literature review provided the background. Suppositions and four critical, unanswered questions arising from the literature are suggested. The results of RRT effectiveness, which have focused on patient-oriented outcomes, have been ambiguous, contradictory, and difficult to interpret. Additionally, they have not taken into account the multiple ways in which these teams have impacted nurses and nursing practice as well as patient outcomes. What happens in terms of RRT process and utilization is likely to have a major impact on nurses and nursing care on general medical and surgical wards. What that impact will be depends on what we can learn from measuring with an expanded yardstick, in order to answer the question, "Do RRTs work?" Evidence for the benefits of RRTs depends on proper framing of questions relating to their effectiveness, including the multiple ways RRTs contribute to nursing efficacy. © 2016 Sigma Theta Tau International.

Predicting meaningful outcomes to medication and self-help treatments for binge-eating disorder in primary care: The significance of early rapid response.

Science.gov (United States)

Grilo, Carlos M; White, Marney A; Masheb, Robin M; Gueorguieva, Ralitza

2015-04-01

We examined rapid response among obese patients with binge-eating disorder (BED) in a randomized clinical trial testing antiobesity medication and self-help cognitive-behavioral therapy (shCBT), alone and in combination, in primary-care settings. One hundred four obese patients with BED were randomly assigned to 1 of 4 treatments: sibutramine, placebo, shCBT + sibutramine, or shCBT + placebo. Treatments were delivered by generalist primary-care physicians and the medications were given double-blind. Independent assessments were performed by trained and monitored doctoral research clinicians monthly throughout treatment, posttreatment (4 months), and at 6- and 12-month follow-ups (i.e., 16 months after randomization). Rapid response, defined as ≥65% reduction in binge eating by the fourth treatment week, was used to predict outcomes. Rapid response characterized 47% of patients, was unrelated to demographic and baseline clinical characteristics, and was significantly associated, prospectively, with remission from binge eating at posttreatment (51% vs. 9% for nonrapid responders), 6-month (53% vs. 23.6%), and 12-month (46.9% vs. 23.6%) follow-ups. Mixed-effects model analyses revealed that rapid response was significantly associated with greater decreases in binge-eating or eating-disorder psychopathology, depression, and percent weight loss. Our findings, based on a diverse obese patient group receiving medication and shCBT for BED in primary-care settings, indicate that patients who have a rapid response achieve good clinical outcomes through 12-month follow-ups after ending treatment. Rapid response represents a strong prognostic indicator of clinically meaningful outcomes, even in low-intensity medication and self-help interventions. Rapid response has important clinical implications for stepped-care treatment models for BED. clinicaltrials.gov: NCT00537810 (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Synergistic extraction of europium(III) in ammonium ionic liquid

International Nuclear Information System (INIS)

Rout, Alok; Venkatesan, K.A.; Antony, M.P.

2016-01-01

Room temperature ionic liquids have been receiving increased attention for possible applications in the area of nuclear fuel reprocessing and waste management due to their fascinating properties such as good ionicity, high solvation capability, properties tunable etc. Most of the studies in the literature on the extraction of metal ions with molecular extractants dissolved in ionic liquid diluents are making use of the hydrophobic ionic liquids containing imidazolium cations such as the 1-alkyl-3-methylimidazolium ion. From an environmental point of view, such ionic liquids are not suitable as the primary mode of the metal extraction is by cation exchange mechanism wherein ionic liquid cation is lost to the aqueous phase leading to aqueous contamination and issue of recyclability of organic phase. However, there are some hydrophobic ionic liquids such as trioctylmethylammonium chloride ((N 1888 )(Cl)), and trihexyl(tetradecyl)phoshonium chloride (Cyphos IL 101) that exhibit no cation exchange in the aqueous phase during extraction. In this context, the extraction behavior of europium(III) using a neutral extractant, octyl, phenyl-N.N-diisobutylmethylcarbamoylphophinoxide (CMPO) and/or an acidic extractant bis(ethylhexyl)phosphoric acid (D2EHPA) dissolved in the ammonium ionic liquid diluent, trioctylmethylammonium bis(trifluoromethanesulfonyl)imide, (N 1888 )(NTf 2 ). The extraction behavior of CMPO (or D2EHPA)/(N 1888 )((Tf 2 ) system was investigated as a function of different extraction parameters such as feed acidity, extractant concentration, equilibration time etc.

Preparation and transport properties of novel lithium ionic liquids

International Nuclear Information System (INIS)

Shobukawa, Hitoshi; Tokuda, Hiroyuki; Tabata, Sei-Ichiro; Watanabe, Masayoshi

2004-01-01

Novel lithium salts of borates having two electron-withdrawing groups (either 1,1,1,3,3,3-hexafluoro-2-propoxy or pentafluorophenoxy group) and two methoxy-oligo(ethylene oxide) groups (number of repeating unit: n = 3, 4, 7.2) were prepared by successive substitution-reactions from LiBH 4 . The obtained lithium salts were clear and colorless liquids at room temperature. The density, thermal property, viscosity, and ionic conductivity were measured for the lithium ionic liquids. The pulsed-gradient spin-echo NMR (PGSE-NMR) method was used to independently determine self-diffusion coefficients of the lithium cation ( 7 Li NMR) and the anion ( 19 F NMR) in the bulk. The ionic conductivity of the new lithium salts was 10 -5 to 10 -4 S cm -1 at 30 deg. C, which was lower than that of typical ionic liquids by two orders of magnitude. However, the degree of self-dissociation of the lithium ionic liquids; the ratio of the molar conductivity determined by the complex impedance method to that calculated from the self-diffusion coefficients and the Nernst-Einstein equation, ranged from 0.1 to 0.4, which are comparable values to those of a highly dissociable salt in an aprotic polar solvent and of typical ionic liquids. The main reason for the meager conductivity was high viscosities of the lithium ionic liquids. It should be noted that the lithium ionic liquids have self-dissociation ability and conduct the ions in the absence of organic solvents

Aqueous solutions of ionic liquids: microscopic assembly

NARCIS (Netherlands)

Vicent-Luna, J.M.; Dubbeldam, D.; Gómez-Álvarez, P.; Calero, S.

2016-01-01

Aqueous solutions of ionic liquids are of special interest, due to the distinctive properties of ionic liquids, in particular, their amphiphilic character. A better understanding of the structure-property relationships of such systems is hence desirable. One of the crucial molecular-level

Ionic Liquid Catalyzed Electrolyte for Electrochemical Polyaniline Supercapacitors

Science.gov (United States)

Inamdar, A. I.; Im, Hyunsik; Jung, Woong; Kim, Hyungsang; Kim, Byungchul; Yu, Kook-Hyun; Kim, Jin-Sang; Hwang, Sung-Min

2013-05-01

The effect of different wt.% of ionic liquid "1,6-bis (trimethylammonium-1-yl) hexane tetrafluoroborate" in 0.5 M LiClO4+PC electrolyte on the supercapacitor properties of polyaniline (PANI) thin film are investigated. The PANI film is synthesized using electropolymerization of aniline in the presence of sulfuric acid. The electrochemical properties of the PANI thin film are studied by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS) measurements. The optimum amount of the ionic liquid is found to be 2 wt.% which provides better ionic conductivity of the electrolyte. The highest specific capacitance of 259 F/g is obtained using the 2 wt.% electrolyte. This capacitance remains at up to 208 F/g (80% capacity retention) after 1000 charge-discharge cycles at a current density of 0.5 mA/g. The PANI film in the 2 wt.% ionic liquid catalyzed 0.5 M LiClO4+PC electrolyte shows small electrochemical resistance, better rate performance and higher cyclability. The increased ionic conductivity of the 2 wt.% ionic liquid catalyzed electrolyte causes a reduction in resistance at the electrode/electrolyte interface, which can be useful in electrochemically-preferred power devices for better applicability.

Ionic liquid-based microwave-assisted dispersive liquid-liquid microextraction and derivatization of sulfonamides in river water, honey, milk, and animal plasma

Energy Technology Data Exchange (ETDEWEB)

Xu Xu; Su Rui; Zhao Xin; Liu Zhuang; Zhang Yupu; Li Dan; Li Xueyuan; Zhang Hanqi [College of Chemistry, Jilin University, Changchun 130012 (China); Wang Ziming, E-mail: analchem@jlu.edu.cn [College of Chemistry, Jilin University, Changchun 130012 (China)

2011-11-30

Graphical abstract: The extraction and derivatization efficiency of SAs is dependent on type and volume of extraction solvent, type and volume of disperser, microwave power and irradiation time, volume of derivatization reagent, pH of sample solution as well as ionic strength. Highlights: Black-Right-Pointing-Pointer A new, rapid and sensitive method for determining sulfonamides (SAs) was proposed. Black-Right-Pointing-Pointer Derivatization, extraction and preconcentration of SAs were performed in one step. Black-Right-Pointing-Pointer IL-based MADLLME and derivatization were first applied for the determination of SAs. Black-Right-Pointing-Pointer Trace SAs in river water, honey, milk, and pig plasma were determined. - Abstract: The ionic liquid-based microwave-assisted dispersive liquid-liquid microextraction (IL-based MADLLME) and derivatization was applied for the pretreatment of six sulfonamides (SAs) prior to the determination by high-performance liquid chromatography (HPLC). By adding methanol (disperser), fluorescamine solution (derivatization reagent) and ionic liquid (extraction solvent) into sample, extraction, derivatization, and preconcentration were continuously performed. Several experimental parameters, such as the type and volume of extraction solvent, the type and volume of disperser, amount of derivatization reagent, microwave power, microwave irradiation time, pH of sample solution, and ionic strength were investigated and optimized. When the microwave power was 240 W, the analytes could be derivatized and extracted simultaneously within 90 s. The proposed method was applied to the analysis of river water, honey, milk, and pig plasma samples, and the recoveries of analytes obtained were in the range of 95.0-110.8, 95.4-106.3, 95.0-108.3, and 95.7-107.7, respectively. The relative standard deviations varied between 1.5% and 7.3% (n = 5). The results showed that the proposed method was a rapid, convenient and feasible method for the determination

Ionic liquid-based microwave-assisted dispersive liquid–liquid microextraction and derivatization of sulfonamides in river water, honey, milk, and animal plasma

International Nuclear Information System (INIS)

Xu Xu; Su Rui; Zhao Xin; Liu Zhuang; Zhang Yupu; Li Dan; Li Xueyuan; Zhang Hanqi; Wang Ziming

2011-01-01

Graphical abstract: The extraction and derivatization efficiency of SAs is dependent on type and volume of extraction solvent, type and volume of disperser, microwave power and irradiation time, volume of derivatization reagent, pH of sample solution as well as ionic strength. Highlights: ► A new, rapid and sensitive method for determining sulfonamides (SAs) was proposed. ► Derivatization, extraction and preconcentration of SAs were performed in one step. ► IL-based MADLLME and derivatization were first applied for the determination of SAs. ► Trace SAs in river water, honey, milk, and pig plasma were determined. - Abstract: The ionic liquid-based microwave-assisted dispersive liquid–liquid microextraction (IL-based MADLLME) and derivatization was applied for the pretreatment of six sulfonamides (SAs) prior to the determination by high-performance liquid chromatography (HPLC). By adding methanol (disperser), fluorescamine solution (derivatization reagent) and ionic liquid (extraction solvent) into sample, extraction, derivatization, and preconcentration were continuously performed. Several experimental parameters, such as the type and volume of extraction solvent, the type and volume of disperser, amount of derivatization reagent, microwave power, microwave irradiation time, pH of sample solution, and ionic strength were investigated and optimized. When the microwave power was 240 W, the analytes could be derivatized and extracted simultaneously within 90 s. The proposed method was applied to the analysis of river water, honey, milk, and pig plasma samples, and the recoveries of analytes obtained were in the range of 95.0–110.8, 95.4–106.3, 95.0–108.3, and 95.7–107.7, respectively. The relative standard deviations varied between 1.5% and 7.3% (n = 5). The results showed that the proposed method was a rapid, convenient and feasible method for the determination of SAs in liquid samples.

Information needs for the rapid response team electronic clinical tool.

Science.gov (United States)

Barwise, Amelia; Caples, Sean; Jensen, Jeffrey; Pickering, Brian; Herasevich, Vitaly

2017-10-02

Information overload in healthcare is dangerous. It can lead to critical errors and delays. During Rapid Response Team (RRT) activations providers must make decisions quickly to rescue patients from physiological deterioration. In order to understand the clinical data required and how best to present that information in electronic systems we aimed to better assess the data needs of providers on the RRT when they respond to an event. A web based survey to evaluate clinical data requirements was created and distributed to all RRT providers at our institution. Participants were asked to rate the importance of each data item in guiding clinical decisions during a RRT event response. There were 96 surveys completed (24.5% response rate) with fairly even distribution throughout all clinical roles on the RRT. Physiological data including heart rate, respiratory rate, and blood pressure were ranked by more than 80% of responders as being critical information. Resuscitation status was also considered critically useful by more than 85% of providers. There is a limited dataset that is considered important during an RRT. The data is widely available in EMR. The findings from this study could be used to improve user-centered EMR interfaces.

Method for enhancing the thermal stability of ionic compounds

DEFF Research Database (Denmark)

2013-01-01

This invention relates to a method for enhancing the thermal stability of ionic compounds including ionic liquids, by immobilization on porous solid support materials having a pore diameter of between about 20-200 AA, wherein the solid support does not have a pore size of 90 AA.......This invention relates to a method for enhancing the thermal stability of ionic compounds including ionic liquids, by immobilization on porous solid support materials having a pore diameter of between about 20-200 AA, wherein the solid support does not have a pore size of 90 AA....

Ionic systems in materials research : new materials and processes based on ionic polymerizations and/or ionic liquids

NARCIS (Netherlands)

Guerrero-Sanchez, C.A.

2007-01-01

Systems based on ionic interactions are usually related to reversible processes and/or transitory chemical states and, nowadays, they are believed to be key factors for the understanding and for the development of processes in several branches of chemistry and materials research. During the last

Decolorization of Ionic Dyes from Synthesized Textile Wastewater by Nanofiltration Using Response Surface Methodology

Directory of Open Access Journals (Sweden)

Mehrdad Farhadian

2015-07-01

Full Text Available Decolorization of aqueous solutions containing ionic dyes (Reactive Blue 19 and Acid Black 172 by a TFC commercial polyamide nanofilter (NF in a spiral wound configuration was studied. The effect of operating parameters including feed concentration (60-180 mg/l, pressure (0.5-1.1 MPa and pH (6-10 on dye removal efficiency was evaluated. The response surface method (RSM was utilized for the experimental design and statistical analysis to identify the impact of each factor. The results showed that an increase in the dye concentration and pH can significantly enhance the removal efficiency from 88% and 87% up to 95% and 93% for Reactive and Acid dye, respectively. The effect of pressure on the removal efficiency showed different behavior such that by the raise of pressure from 0.5 to 0.8 MPa, the removal efficiency increased to its maximum, then reduction in removal efficiency was observed by further increases in pressure above the optimum range. The maximum dye removal efficiencies which were predicted at the optimum conditions by Design Expert software were 97 % and 94 % for Reactive Blue 19 and Acid Black 172, respectively. According to the results of this study, NF processes can be used at a significantly lower pressure and fouling issue for reuse applications as an alternative to the widely used RO process.

Soft ionization of thermally evaporated hypergolic ionic liquid aerosols

Energy Technology Data Exchange (ETDEWEB)

University of California; ERC, Incorporated, Edwards Air Force Base; Air Force Research Laboratory, Edwards Air Force Base; National Synchrotron Radiation Research Center (NSRRC); Institute of Chemistry, Hebrew University; Koh, Christine J.; Liu, Chen-Lin; Harmon, Christopher W.; Strasser, Daniel; Golan, Amir; Kostko, Oleg; Chambreau, Steven D.; Vaghjiani, Ghanshyam L.; Leone, Stephen R.

2011-07-19

Isolated ion pairs of a conventional ionic liquid, 1-Ethyl-3-Methyl-Imidazolium Bis(trifluoromethylsulfonyl)imide ([Emim+][Tf2N?]), and a reactive hypergolic ionic liquid, 1-Butyl-3-Methyl-Imidazolium Dicyanamide ([Bmim+][Dca?]), are generated by vaporizing ionic liquid submicron aerosol particles for the first time; the vaporized species are investigated by dissociative ionization with tunable vacuum ultraviolet (VUV) light, exhibiting clear intact cations, Emim+ and Bmim+, presumably originating from intact ion pairs. Mass spectra of ion pair vapor from an effusive source of the hypergolic ionic liquid show substantial reactive decomposition due to the internal energy of the molecules emanating from the source. Photoionization efficiency curves in the near threshold ionization region of isolated ion pairs of [Emim+][Tf2N?]ionic liquid vapor are compared for an aerosol source and an effusive source, revealing changes in the appearance energy due to the amount of internal energy in the ion pairs. The aerosol source has a shift to higher threshold energy (~;;0.3 eV), attributed to reduced internal energy of the isolated ion pairs. The method of ionic liquid submicron aerosol particle vaporization, for reactive ionic liquids such as hypergolic species, is a convenient, thermally ?cooler? source of isolated intact ion pairs in the gas phase compared to effusive sources.

Lattice mechanics of ionic crystals - unified study

International Nuclear Information System (INIS)

Sengupta, S.; Roy, D.; Basu, A.N.

1979-01-01

The up-to-date situation in the understanding of the mechanical properties of ionic solids is reviewed. These properties are determined by the Born-Oppenheimer (B-O) potential energy function. For ionic crystals this potential energy function can be written down with some precision. To keep the expression tractable, the dominant electron deformation, the dipolar deformation, is treated as an adiabatic variable and the energy then becomes a function of both the nuclear coordinates and the ionic dipole moments. All the well known models for ionic crystals are discussed in terms of the energy expression they imply. This makes the comparison straight forward and brings out the essential difference between the models clearly. Next various quantum mechanical treatments for ionic crystals are reviewed. An attempt is made to obtain the B-O potential energy expression using a Heitler-London approach. By comparing the various models one can arrive at some definitive conclusions about the degree of validity and the assumptions underlying these models. Finally a comprehensive review of the results of actual computation on various ionic crystals done by different authors is undertaken. The crucial quantitative results are examined and the success and shortcoming of each calculation are critically analysed. The guiding principle in this part is the unified approach. i.e. to see how far a model with a given set of parameters accounts for both the dynamic and static properties. The discussion is divided in three sections for crystals with sodium chloride, cesium chloride and zinc sulfide structures. Outstanding problems and difficulties in the present understanding are pointed out. (auth.)

Aerobic, catalytic oxidation of alcohols in ionic liquids

Directory of Open Access Journals (Sweden)

Souza Roberto F. de

2006-01-01

Full Text Available An efficient and simple catalytic system based on RuCl3 dissolved in ionic liquids has been developed for the oxidation of alcohols into aldehydes and ketones under mild conditions. A new fluorinated ionic liquid, 1-n-butyl-3-methylimidazolium pentadecafluorooctanoate, was synthesized and demonstrated better performance that the other ionic liquids employed. Moreover this catalytic system utilizes molecular oxygen as an oxidizing agent, producing water as the only by-product.

Simultaneous Design of Ionic Liquids and Azeotropic Separation Processes

DEFF Research Database (Denmark)

Roughton, Brock C.; White, John; Camarda, Kyle V.

2011-01-01

A methodology for the design of azeotrope separation processes using ionic liquids as entrainers is outlined. A Hildebrand solubility parameter group contribution model has been developed to screen for or design an ionic liquid entrainer that is soluble with the azeotropic components. Using the b...... % [BMPy][BF4] added. The driving force concept is used to design an extractive distillation process that minimizes energy inputs. The methodology given can be expanded to the use of ionic liquids as entrainers in any azeotropic system of interest.......A methodology for the design of azeotrope separation processes using ionic liquids as entrainers is outlined. A Hildebrand solubility parameter group contribution model has been developed to screen for or design an ionic liquid entrainer that is soluble with the azeotropic components. Using...

Protic Cationic Oligomeric Ionic Liquids of the Urethane Type

DEFF Research Database (Denmark)

Shevchenko, V. V.; Stryutsky, A. V.; Klymenko, N. S.

2014-01-01

Protic oligomeric cationic ionic liquids of the oligo(ether urethane) type are synthesized via the reaction of an isocyanate prepolymer based on oligo(oxy ethylene)glycol with M = 1000 with hexamethylene-diisocyanate followed by blocking of the terminal isocyanate groups with the use of amine...... derivatives of imidazole, pyridine, and 3-methylpyridine and neutralization of heterocycles with ethanesulfonic acid and p-toluenesulfonic acid. The structures and properties of the synthesized oligomeric ionic liquids substantially depend on the structures of the ionic groups. They are amorphous at room...... temperature, but ethanesulfonate imidazolium and pyridinium oligomeric ionic liquids form a low melting crystalline phase. The proton conductivities of the oligomeric ionic liquids are determined by the type of cation in the temperature range 80-120 degrees C under anhydrous conditions and vary within five...

Fast Conversion of Ionic Liquids and Poly(Ionic Liquid)s into Porous Nitrogen-Doped Carbons in Air.

Science.gov (United States)

Men, Yongjun; Ambrogi, Martina; Han, Baohang; Yuan, Jiayin

2016-04-08

Ionic liquids and poly(ionic liquid)s have been successfully converted into nitrogen-doped porous carbons with tunable surface area up to 1200 m²/g at high temperatures in air. Compared to conventional carbonization process conducted under inert gas to produce nitrogen-doped carbons, the new production method was completed in a rather shorter time without noble gas protection.

Ionic polymer metal composites with polypyrrole-silver electrodes

Science.gov (United States)

Cellini, F.; Grillo, A.; Porfiri, M.

2015-03-01

Ionic polymer metal composites (IPMCs) are a class of soft active materials that are finding increasing application in robotics, environmental sensing, and energy harvesting. In this letter, we demonstrate the fabrication of IPMCs via in-situ photoinduced polymerization of polypyrrole-silver electrodes on an ionomeric membrane. The composition, morphology, and sheet resistance of the electrodes are extensively characterized through a range of experimental techniques. We experimentally investigate IPMC electrochemistry through electrochemical impedance spectroscopy, and we propose a modified Randle's model to interpret the impedance spectrum. Finally, we demonstrate in-air dynamic actuation and sensing and assess IPMC performance against more established fabrication methods. Given the simplicity of the process and the short time required for the formation of the electrodes, we envision the application of our technique in the development of a rapid prototyping technology for IPMCs.

Rapid Field Response to a Cluster of Illnesses and Deaths - Sinoe County, Liberia, April-May, 2017.

Science.gov (United States)

Doedeh, John; Frimpong, Joseph Asamoah; Yealue, Kwuakuan D M; Wilson, Himiede W; Konway, Youhn; Wiah, Samson Q; Doedeh, Vivian; Bao, Umaru; Seneh, George; Gorwor, Lawrence; Toe, Sylvester; Ghartey, Emmanuel; Larway, Lawrence; Gweh, Dedesco; Gonotee, Philemon; Paasewe, Thomas; Tamatai, George; Yarkeh, James; Smith, Samuel; Brima-Davis, Annette; Dauda, George; Monger, Thomas; Gornor-Pewu, Leleh W; Lombeh, Siafa; Naiene, Jeremias; Dovillie, Nathaniel; Korvayan, Mark; George, Geraldine; Kerwillain, Garrison; Jetoh, Ralph; Friesen, Suzanne; Kinkade, Carl; Katawera, Victoria; Amo-Addae, Maame; George, Roseline N; Gbanya, Miatta Z; Dokubo, E Kainne

2017-10-27

On April 25, 2017, the Sinoe County Health Team (CHT) notified the Liberia Ministry of Health (MoH) and the National Public Health Institute of Liberia of an unknown illness among 14 persons that resulted in eight deaths in Sinoe County. On April 26, the National Rapid Response Team and epidemiologists from CDC, the World Health Organization (WHO) and the African Field Epidemiology Network (AFENET) in Liberia were deployed to support the county-led response. Measures were immediately implemented to identify all cases, ascertain the cause of illness, and control the outbreak. Illness was associated with attendance at a funeral event, and laboratory testing confirmed Neisseria meningitidis in biologic specimens from cases. The 2014-2015 Ebola virus disease (Ebola) outbreak in West Africa devastated Liberia's already fragile health system, and it took many months for the country to mount an effective response to control the outbreak. Substantial efforts have been made to strengthen Liberia's health system to prevent, detect, and respond to health threats. The rapid and efficient field response to this outbreak of N. meningitidis resulted in implementation of appropriate steps to prevent a widespread outbreak and reflects improved public health and outbreak response capacity in Liberia.

Response time distributions in rapid chess: A large-scale decision making experiment

Directory of Open Access Journals (Sweden)

Mariano Sigman

2010-10-01

Full Text Available Rapid chess provides an unparalleled laboratory to understand decision making in a natural environment. In a chess game, players choose consecutively around 40 moves in a finite time budget. The goodness of each choice can be determined quantitatively since current chess algorithms estimate precisely the value of a position. Web-based chess produces vast amounts of data, millions of decisions per day, incommensurable with traditional psychological experiments. We generated a database of response times and position value in rapid chess games. We measured robust emergent statistical observables: 1 Response time (RT distributions are long-tailed and show qualitatively distinct forms at different stages of the game, 2 RT of successive moves are highly correlated both for intra- and inter-player moves. These findings have theoretical implications since they deny two basic assumptions of sequential decision making algorithms: RTs are not stationary and can not be generated by a state function. Our results also have practical implications. First, we characterized the capacity of blunders and score fluctuations to predict a player strength, which is yet an open problem in chess softwares. Second, we show that the winning likelihood can be reliably estimated from a weighted combination of remaining times and position evaluation.

Magnetic Solid-phase Extraction with Fe₃O₄/Molecularly Imprinted Polymers Modified by Deep Eutectic Solvents and Ionic Liquids for the Rapid Purification of Alkaloid Isomers (Theobromine and Theophylline) from Green Tea.

Science.gov (United States)

Li, Guizhen; Wang, Xiaoqin; Row, Kyung Ho

2017-06-25

Different kinds of deep eutectic solvents (DES) based on choline chloride (ChCl) and ionic liquids (ILs) based on 1-methylimidazole were used to modify Fe3O4/molecularly imprinted polymers (Fe3O4/MIPs), and the resulting materials were applied for the rapid purification of alkaloid isomers (theobromine and theophylline) from green tea with magnetic solid-phase extraction (M-SPE). The M-SPE procedure was optimized using the response surface methodology (RSM) to analyze the maximum conditions. The materials were characterized by Fourier transform infrared spectroscopy (FI-IR) and field emission scanning electron microscopy (FE-SEM). Compared to the ILs-Fe3O4/MIPs, the DESs-Fe3O4/MIPs were developed for the stronger recognition and higher recoveries of the isomers (theophylline and theobromine) from green tea, particularly DES-7-Fe3O4/MIPs. With RSM, the optimal recovery condition for theobromine and theophylline in the M-SPE were observed with ratio of methanol (80%) as the washing solution, methanol/acetic acid (HAc) (8:2) as the eluent at pH 3, and an eluent volume of 4 mL. The practical recoveries of theobromine and theophylline in green tea were 92.27% and 87.51%, respectively, with a corresponding actual extraction amount of 4.87 mg•g-1 and 5.07 mg•g-1. Overall, the proposed approach with the high affinity of Fe3O4/MIPs might offer a novel method for the purification of complex isomer samples.

"Identifying the hospitalised patient in crisis"--a consensus conference on the afferent limb of rapid response systems

DEFF Research Database (Denmark)

DeVita, Michael A; Smith, Gary B; Adam, Sheila K

2010-01-01

Most reports of Rapid Response Systems (RRS) focus on the efferent, response component of the system, although evidence suggests that improved vital sign monitoring and recognition of a clinical crisis may have outcome benefits. There is no consensus regarding how best to detect patient deteriora...

Improved ionic model of liquid uranium dioxide

NARCIS (Netherlands)

Gryaznov, [No Value; Iosilevski, [No Value; Yakub, E; Fortov, [No Value; Hyland, GJ; Ronchi, C

The paper presents a model for liquid uranium dioxide, obtained by improving a simplified ionic model, previously adopted to describe the equation of state of this substance [1]. A "chemical picture" is used for liquid UO2 of stoichiometric and non-stoichiometric composition. Several ionic species

Conductivity-Relaxation Relations in Nanocomposite Polymer Electrolytes Containing Ionic Liquid.

Science.gov (United States)

Shojaatalhosseini, Mansoureh; Elamin, Khalid; Swenson, Jan

2017-10-19

In this study, we have used nanocomposite polymer electrolytes, consisting of poly(ethylene oxide) (PEO), δ-Al 2 O 3 nanoparticles, and lithium bis(trifluoromethanesolfonyl)imide (LiTFSI) salt (with 4 wt % δ-Al 2 O 3 and PEO:Li ratios of 16:1 and 8:1), and added different amounts of the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesolfonyl)imide (BMITFSI). The aim was to elucidate whether the ionic liquid is able to dissociate the Li-ions from the ether oxygens and thereby decouple the ionic conductivity from the segmental polymer dynamics. The results from DSC and dielectric spectroscopy show that the ionic liquid speeds up both the segmental polymer dynamics and the motion of the Li + ions. However, a close comparison between the structural (α) relaxation process, given by the segmental polymer dynamics, and the ionic conductivity shows that the motion of the Li + ions decouples from the segmental polymer dynamics at higher concentrations of the ionic liquid (≥20 wt %) and instead becomes more related to the viscosity of the ionic liquid. This decoupling increases with decreasing temperature. In addition to the structural α-relaxation, two more local relaxation processes, denoted β and γ, are observed. The β-relaxation becomes slightly faster at the highest concentration of the ionic liquid (at least for the lower salt concentration), whereas the γ-relaxation is unaffected by the ionic liquid, over the whole concentration range 0-40 wt %.

Local fields in ionic crystals

International Nuclear Information System (INIS)

Claro, F.

1981-08-01

Local fields arising from the electronic distortion in perfect ionic crystals are described in terms of multipolar excitations. Field factors for the alkali halides and chalcogenide ions are found to differ significantly from the Lorentz value of 4π/3, the correction size following an exponential dependence on the difference in ionic radii. Local fields are only slightly modified by these corrections however, and together with the Clausius-Mossotti relation may be regarded as accurate to within 2% if the Lorentz value is adopted. (author)

Rapid screening of radioactivity in food for emergency response.

Science.gov (United States)

Bari, A; Khan, A J; Semkow, T M; Syed, U-F; Roselan, A; Haines, D K; Roth, G; West, L; Arndt, M

2011-06-01

This paper describes the development of methods for the rapid screening of gross alpha (GA) and gross beta (GB) radioactivity in liquid foods, specifically, Tang drink mix, apple juice, and milk, as well as screening of GA, GB, and gamma radioactivity from surface deposition on apples. Detailed procedures were developed for spiking of matrices with (241)Am (alpha radioactivity), (90)Sr/(90)Y (beta radioactivity), and (60)Co, (137)Cs, and (241)Am (gamma radioactivity). Matrix stability studies were performed for 43 days after spiking. The method for liquid foods is based upon rapid digestion, evaporation, and flaming, followed by gas proportional (GP) counting. For the apple matrix, surface radioactivity was acid-leached, followed by GP counting and/or gamma spectrometry. The average leaching recoveries from four different apple brands were between 63% and 96%, and have been interpreted on the basis of ion transport through the apple cuticle. The minimum detectable concentrations (MDCs) were calculated from either the background or method-blank (MB) measurements. They were found to satisfy the required U.S. FDA's Derived Intervention Levels (DILs) in all but one case. The newly developed methods can perform radioactivity screening in foods within a few hours and have the potential to capacity with further automation. They are especially applicable to emergency response following accidental or intentional contamination of food with radioactivity. Published by Elsevier Ltd.

Rapid screening of radioactivity in food for emergency response

International Nuclear Information System (INIS)

Bari, A.; Khan, A.J.; Semkow, T.M.; Syed, U.-F.; Roselan, A.; Haines, D.K.; Roth, G.; West, L.; Arndt, M.

2011-01-01

This paper describes the development of methods for the rapid screening of gross alpha (GA) and gross beta (GB) radioactivity in liquid foods, specifically, Tang drink mix, apple juice, and milk, as well as screening of GA, GB, and gamma radioactivity from surface deposition on apples. Detailed procedures were developed for spiking of matrices with 241 Am (alpha radioactivity), 90 Sr/ 90 Y (beta radioactivity), and 60 Co, 137 Cs, and 241 Am (gamma radioactivity). Matrix stability studies were performed for 43 days after spiking. The method for liquid foods is based upon rapid digestion, evaporation, and flaming, followed by gas proportional (GP) counting. For the apple matrix, surface radioactivity was acid-leached, followed by GP counting and/or gamma spectrometry. The average leaching recoveries from four different apple brands were between 63% and 96%, and have been interpreted on the basis of ion transport through the apple cuticle. The minimum detectable concentrations (MDCs) were calculated from either the background or method-blank (MB) measurements. They were found to satisfy the required U.S. FDA's Derived Intervention Levels (DILs) in all but one case. The newly developed methods can perform radioactivity screening in foods within a few hours and have the potential to capacity with further automation. They are especially applicable to emergency response following accidental or intentional contamination of food with radioactivity.

Symmetric Imidazolium-Based Paramagnetic Ionic Liquids

Science.gov (United States)

2017-11-29

Charts N/A Unclassified Unclassified Unclassified SAR 14 Kamran Ghiassi N/A 1 Symmetric Imidazolium-Based Paramagnetic Ionic Liquids Kevin T. Greeson...NUMBER (Include area code) 29 November 2017 Briefing Charts 01 November 2017 - 30 November 2017 Symmetric Imidazolium-Based Paramagnetic Ionic ... Liquids K. Greeson, K. Ghiassi, J. Alston, N. Redeker, J. Marcischak, L. Gilmore, A. Guenthner Air Force Research Laboratory (AFMC) AFRL/RQRP 9 Antares

The Solubility Parameters of Ionic Liquids

Science.gov (United States)

Marciniak, Andrzej

2010-01-01

The Hildebrand’s solubility parameters have been calculated for 18 ionic liquids from the inverse gas chromatography measurements of the activity coefficients at infinite dilution. Retention data were used for the calculation. The solubility parameters are helpful for the prediction of the solubility in the binary solvent mixtures. From the solubility parameters, the standard enthalpies of vaporization of ionic liquids were estimated. PMID:20559495

The Solubility Parameters of Ionic Liquids

Directory of Open Access Journals (Sweden)

Andrzej Marciniak

2010-04-01

Full Text Available The Hildebrand’s solubility parameters have been calculated for 18 ionic liquids from the inverse gas chromatography measurements of the activity coefficients at infinite dilution. Retention data were used for the calculation. The solubility parameters are helpful for the prediction of the solubility in the binary solvent mixtures. From the solubility parameters, the standard enthalpies of vaporization of ionic liquids were estimated.

Lead-Salt Quantum-Dot Ionic Liquids

KAUST Repository

Sun, Liangfeng

2010-03-08

PbS quantum dots (QDs) are functionalized using ionic liquids with thiol moieties as capping ligands. The resulting amphiphilic QD ionic liquids exhibit fluidlike behavior at room temperature, even in the absence of solvents. The photostability of the QDs is dramatically improved compared to the as-synthesized oleic acid-capped QDs dispersed in toluene. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Phase Behavior of Mixtures of Ionic Liquids and Organic Solvents

DEFF Research Database (Denmark)

Abildskov, Jens; Ellegaard, Martin Dela; O’Connell, J.P.

2010-01-01

A corresponding-states form of the generalized van der Waals equation, previously developed for mixtures of an ionic liquid and a supercritical solute, is here extended to mixtures including an ionic liquid and a solvent (water or organic). Group contributions to characteristic parameters...... are implemented, leading to an entirely predictive method for densities of mixed compressed ionic liquids. Quantitative agreement with experimental data is obtained over wide ranges of conditions. Previously, the method has been applied to solubilities of sparingly soluble gases in ionic liquids and in organic...... solvents. Here we show results for heavier and more-than-sparingly solutes such as carbon dioxide and propane in ionic liquids....

Single component, reversible ionic liquids for energy applications

Energy Technology Data Exchange (ETDEWEB)

Vittoria Blasucci; Ryan Hart; Veronica Llopis Mestre; Dominique Julia Hahne; Melissa Burlager; Hillary Huttenhower; Beng Joo Reginald Thio; Pamela Pollet; Charles L. Liotta; Charles A. Eckert [Georgia Institute of Technology, Atlanta, GA (United States). Chemical & Biomolecular Engineering

2010-06-15

Single component, reversible ionic liquids have excellent potential as novel solvents for a variety of energy applications. Our energy industry is faced with many new challenges including increased energy consumption, depleting oil reserves, and increased environmental awareness. We report the use of reversible ionic liquids to solve two energy challenges: extraction of hydrocarbons from contaminated crude oil and carbon capture from power plant flue gas streams. Our reversible solvents are derived from silylated amine molecular liquids which react with carbon dioxide reversibly to form ionic liquids. Here we compare the properties of various silylated amine precursors and their corresponding ionic liquids. We show how the property changes are advantageous in the two aforementioned energy applications. In the case of hydrocarbon purification, we take advantage of the polarity switch between precursor and ionic liquid to enable separations. In carbon capture, our solvents act as dual physical and chemical capture agents for carbon dioxide. Finally, we show the potential economics of scale-up for both processes. 20 refs., 1 fig., 3 tabs.

Direct current dielectrophoretic manipulation of the ionic liquid droplets in water.

Science.gov (United States)

Zhao, Kai; Li, Dongqing

2018-07-13

The ionic liquids (ILs) as the environmentally benign solvents show great potentials in microemulsion carrier systems and have been widely used in the biochemical and pharmaceutical fields. In the work, the ionic liquid-in-water microemulsions were fabricated by using two kinds of hydrophobic ionic liquid, 1-Butyl-3-methylimidazolium hexafluorophosphate [Bmim][PF 6 ] and 1-Hexyl-3-methylimidazolium hexafluorophosphate [Hmim][PF 6 ] with Tween 20. The ionic liquid droplets in water experience the dielectrophoretic (DEP) forces induced by applying electrical field via a nano-orifice and a micron orifice on the opposite channel walls of a microchannel. The dielectrophoretic behaviors of the ionic liquid-in-water emulsion droplets were investigated under direct current (DC) electric field. The positive and negative DEP behaviors of the ionic liquid-in-water droplets varying with the electrical conductivity of the suspending medium were investigated and two kinds of the ionic liquid droplets of similar sizes were separated by their different DEP behaviors. In addition, the separation of the ionic liquid-in-water droplets by size was conducted. This paper, for the first time to our knowledge, presents the DC-DEP manipulation of the ionic liquid-in-water emulsion droplets by size and by type. This method provides a platform to manipulate the ionic liquid droplets individually. Copyright © 2018 Elsevier B.V. All rights reserved.

Absorption and oxidation of nitrogen oxide in ionic liquids

DEFF Research Database (Denmark)

Kunov-Kruse, Andreas Jonas; Thomassen, Peter Langelund; Riisager, Anders

2016-01-01

A new strategy for capturing nitrogen oxide, NO, from the gas phase is presented. Dilute NO gas is removed from the gas phase by ionic liquids under ambient conditions. The nitrate anion of the ionic liquid catalyzes the oxidation of NO to nitric acid by atmospheric oxygen in the presence of water....... The nitric acid is absorbed in the ionic liquid up to approximately one mole HNO3 per mole of the ionic liquid due to the formation of hydrogen bonds. The nitric acid can be desorbed by heating, thereby regenerating the ionic liquid with excellent reproducibility. Here, time-resolved in-situ spectroscopic...... investigations of the reaction and products are presented. The procedure reveals a new vision for removing the pollutant NO by absorption into a non-volatile liquid and converting it into a useful bulk chemical, that is, HNO3....

Ion irradiation effects on ionic liquids interfaced with rf discharge plasmas

International Nuclear Information System (INIS)

Baba, K.; Kaneko, T.; Hatakeyama, R.

2007-01-01

The availability of plasma ion irradiation toward a gas-liquid interface is investigated in a rf discharge system incorporating an ionic liquid. The introduction of the ionic liquid to the plasma causes the formation of a sheath electric field on the ionic liquid surface, resulting in the acceleration of the ions to the ionic liquid and the generation of secondary electrons from the ionic liquid by the ion irradiation. These effects are found to advance the discharge process and enhance the plasma production

Principle and applications of ionic thermometric detectors

International Nuclear Information System (INIS)

Rosenkranz, J.; Jakes, D.

1989-01-01

The basic principles of electric conductivity of ionic compounds as well as causes and the character of phase transformation in these systems are briefly explained. The design of ionic thermometric detectors, their function and some applications in thermometry are also described. (author). 3 figs., 1 tab., 7 refs

Thermodynamic estimation: Ionic materials

International Nuclear Information System (INIS)

Glasser, Leslie

2013-01-01

Thermodynamics establishes equilibrium relations among thermodynamic parameters (“properties”) and delineates the effects of variation of the thermodynamic functions (typically temperature and pressure) on those parameters. However, classical thermodynamics does not provide values for the necessary thermodynamic properties, which must be established by extra-thermodynamic means such as experiment, theoretical calculation, or empirical estimation. While many values may be found in the numerous collected tables in the literature, these are necessarily incomplete because either the experimental measurements have not been made or the materials may be hypothetical. The current paper presents a number of simple and relible estimation methods for thermodynamic properties, principally for ionic materials. The results may also be used as a check for obvious errors in published values. The estimation methods described are typically based on addition of properties of individual ions, or sums of properties of neutral ion groups (such as “double” salts, in the Simple Salt Approximation), or based upon correlations such as with formula unit volumes (Volume-Based Thermodynamics). - Graphical abstract: Thermodynamic properties of ionic materials may be readily estimated by summation of the properties of individual ions, by summation of the properties of ‘double salts’, and by correlation with formula volume. Such estimates may fill gaps in the literature, and may also be used as checks of published values. This simplicity arises from exploitation of the fact that repulsive energy terms are of short range and very similar across materials, while coulombic interactions provide a very large component of the attractive energy in ionic systems. Display Omitted - Highlights: • Estimation methods for thermodynamic properties of ionic materials are introduced. • Methods are based on summation of single ions, multiple salts, and correlations. • Heat capacity, entropy

Thermodynamics of interaction of ionic liquids with lipid monolayer.

Science.gov (United States)

Bhattacharya, G; Mitra, S; Mandal, P; Dutta, S; Giri, R P; Ghosh, S K

2018-06-01

Understanding the interaction of ionic liquids with cellular membrane becomes utterly important to comprehend the activities of these liquids in living organisms. Lipid monolayer formed at the air-water interface is employed as a model system to follow this interaction by investigating important thermodynamic parameters. The penetration kinetics of the imidazolium-based ionic liquid 1-decyl-3-methylimidazolium tetrafluoroborate ([DMIM][BF4]) into the zwitterionic 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid layer is found to follow the Boltzmann-like equation that reveals the characteristic time constant which is observed to be the function of initial surface pressure. The enthalpy and entropy calculated from temperature-dependent pressure-area isotherms of the monolayer show that the added ionic liquids bring about a disordering effect in the lipid film. The change in Gibbs free energy indicates that an ionic liquid with longer chain has a far greater disordering effect compared to an ionic liquid with shorter chain. The differential scanning calorimetric measurement on a multilamellar vesicle system shows the main phase transition temperature to shift to a lower value, which, again, indicates the disordering effect of the ionic liquid on lipid membrane. All these studies fundamentally point out that, when ionic liquids interact with lipid molecules, the self-assembled structure of a cellular membrane gets perturbed, which may be the mechanism of these molecules having adverse effects on living organisms.

Soft Ionization of Thermally Evaporated Hypergolic Ionic Liquid Aerosols

Energy Technology Data Exchange (ETDEWEB)

Koh, Christine J. [Univ. of California, Berkeley, CA (United States); Liu, Chen-Lin [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Harmon, Christopher W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Strasser, Daniel [Univ. of California, Berkeley, CA (United States); Golan, Amir [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kostko, Oleg [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chambreau, Steven D. [Edwards Air Force Base, ERC Inc., CA (United States); Vaghjiani, Ghanshyam L. [Air Force Research Laboratory, Edwards Air Force Base, CA (United States); Leone, Stephen R. [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2011-04-20

Isolated ion pairs of a conventional ionic liquid, 1-Ethyl-3-Methyl-Imidazolium Bis(trifluoromethylsulfonyl)imide ([Emim+][Tf₂N–]), and a reactive hypergolic ionic liquid, 1-Butyl-3-Methyl-Imidazolium Dicyanamide ([Bmim+][Dca–]), are generated by vaporizing ionic liquid submicrometer aerosol particles for the first time; the vaporized species are investigated by dissociative ionization with tunable vacuum ultraviolet (VUV) light, exhibiting clear intact cations, Emim⁺ and Bmim⁺, presumably originating from intact ion pairs. Mass spectra of ion pair vapor from an effusive source of the hypergolic ionic liquid show substantial reactive decomposition due to the internal energy of the molecules emanating from the source. Also, hotoionization efficiency curves in the near threshold ionization region of isolated ion pairs of [Emim⁺][Tf₂N^–] ionic liquid vapor are compared for an aerosol source and an effusive source, revealing changes in the appearance energy due to the amount of internal energy in the ion pairs. The aerosol source has a shift to higher threshold energy (~0.3 eV), attributed to reduced internal energy of the isolated ion pairs. Lastly, the method of ionic liquid submicrometer aerosol particle vaporization, for reactive ionic liquids such as hypergolic species, is a convenient, thermally “cooler” source of isolated intact ion pairs in the gas phase compared to effusive sources.

Static gas-liquid interfacial direct current discharge plasmas using ionic liquid cathode

International Nuclear Information System (INIS)

Kaneko, T.; Baba, K.; Hatakeyama, R.

2009-01-01

Due to the unique properties of ionic liquids such as their extremely low vapor pressure and high heat capacity, we have succeeded in creating the static and stable gas (plasmas)-liquid (ionic liquids) interfacial field using a direct current discharge under a low gas pressure condition. It is clarified that the ionic liquid works as a nonmetal liquid electrode, and furthermore, a secondary electron emission coefficient of the ionic liquid is larger than that of conventional metal electrodes. The plasma potential structure of the gas-liquid interfacial region, and resultant interactions between the plasma and the ionic liquid are revealed by changing a polarity of the electrode in the ionic liquid. By utilizing the ionic liquid as a cathode electrode, the positive ions in the plasma region are found to be irradiated to the ionic liquid. This ion irradiation causes physical and chemical reactions at the gas-liquid interfacial region without the vaporization of the ionic liquid.

Clinical experience with a non-ionic contrast medium (ultravist) in left ventriculography

International Nuclear Information System (INIS)

Lee, Ghi Jai; Park, Jae Hyung; Soe, Gwy Suk; Hong, Ju Hee; Han, Man Chung

1988-01-01

Non-ionic contrast medium, iopromide (Ultravist), was compared with ionic contrast medium, ioxitalamate (Telebrix), for efficacy and safety in 63 patients undergoing left ventriculography. In all patients, adverse symptoms and signs including pain, heat sense, nausea, vomiting, etc., were checked during and shortly after the injection. Blood pressure, heart rate, EKG and left ventricular pressure were also monitored during the study, and CBC, UA, BUN and creatinine were checked before and 24 hours after the study. The cineangiographic films were analysed and compared by 2 radiologists for the quality. Serious adverse effect did not occur in any case. Minor effects, especially nausea, were lee frequently caused by non-ionic contrast medium than by ionic contrast medium, and heat sense to non-ionic contrast medium was less severe than to ionic contrast medium. Except slightly elevated LVEDP at 1,5 minutes after the study in patients given ionic contrast medium, there was no significant change of electrophysiologic parameters and laboratory findings in both groups. In regard to image quality, there was no significant difference between ionic and non-ionic contrast medium. Thus non-ionic contrast medium, iopromide, appears to be safer for use in left ventriculography than the conventional ionic contrast medium, particularly in those patients at high risk of adverse effects.

Advanced Materials Development of Ionic Ceramics Using Ions Beam and its Suitable Applications as Stress Environment Sensor

International Nuclear Information System (INIS)

Lee, K. H.; Cho, D. H.; Won, J. O.; Cho, J. H.; Kim, J. Y.

2008-04-01

The perovskite oxides La 2 CuO 4 was prepared by auto-ignition method with citric acid as reductant and nitrate as oxidant at low temperatures. Single crystals of phase lanthanum copper oxide were implanted with 70-120 KeV argon and nitrogen ions at room temperature. The prepared materials have investigated the energy transition distribution and ion distribution for N 2 and Ar ion-implantation depth. Also, this ionic ceramic of ion implanted with N + and N 2 + energy 70 keV, dose 5 x 10 16 ions/cm 2 , and beam current density 8.91μm/cm 2 were studied on physio-chemical and characteristic. We have studied on the effect of ion implantation for ionic ceramics materials surface modification for the first year. The ion beam treated ionic ceramics were investigated into its chemical structure and its characteristics as observed by XRD, SEM-EDS, BET and DTA. The oxygen gas sensors based on lanthanum copper oxide were fabricated by screen-printing method an YSZ substrate using the powder prepared by the ion implanted ionic state ceramics. The sensor's response was evaluated by periodic variation of oxygen partial pressure. Recently, the oxygen gas sensors using concentration cells consisting of oxygen-ion-conductor have been currently used as the oxygen gas sensors to measure oxygen concentration of exhaust gas. And, Resistive response behavior with varying oxygen gas concentration on lanthanum copper oxide have been studied. Oxygen sensor was measured in the temperature range of 400 .deg. C ∼700 .deg. C and different concentrations of oxygen. The results show that the resistance of oxygen sensor using YSZ-La 2 CuO 4 decreases with an increase of temperature at given oxygen concentration, and it is good linearity. Also its sensor has faster response property at more than 500 .deg. C.

Influence of the ionic liquid 1-butyl-3-methylimidazolium bromide on amyloid fibrillogenesis in lysozyme: Evidence from photophysical and imaging studies.

Science.gov (United States)

Basu, Anirban; Bhattacharya, Subhash Chandra; Kumar, Gopinatha Suresh

2018-02-01

Many proteins can abnormally fold to form pathological amyloid deposits/aggregates that are responsible for various degenerative disorders called amyloidosis. Here we have examined the anti-amyloidogenic potency of an ionic liquid, 1-butyl-3-methylimidazolium bromide, using lysozyme as a model system. Thioflavin T fluorescence assay demonstrated that the ionic liquid suppressed the formation of lysozyme fibrils significantly. This observation was further confirmed by the Congo red assay. Fluorescence microscopy, intrinsic fluorescence studies, nile red fluorescence assay, ANS binding assay and circular dichroism studies also testified diminishing of the fibrillogenesis in the presence of ionic liquid. Formation of amyloid fibrils was also characterized by α to β conformational transition. From far-UV circular dichroism studies it was observed that the β-sheet content of the lysozyme samples decreased in the presence of the ionic liquid which in turn implied that fibrillogenesis was supressed by the ionic liquid. Atomic force microscopy imaging unequivocally established that the ionic liquid attenuated fibrillogenesis in lysozyme. These results may be useful for the development of more effective therapeutics for amyloidosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Dissolution of cellulose in ionic liquid: A review

Science.gov (United States)

Mohd, N.; Draman, S. F. S.; Salleh, M. S. N.; Yusof, N. B.

2017-02-01

Dissolution of cellulose with ionic liquids (IL) and deep eutectic solvent (DES) lets the comprehensive dissolution of cellulose. Basically, cellulose can be dissolved, in some hydrophilic ionic liquids, such as 1-butyl-3-methylimidazolium chloride (BMIMCl) and 1-allyl-3-methylimidazolium chloride (AMIMCl). Chloride based ionic liquids are suitable solvents for cellulose dissolution. Although the ILs is very useful in fine chemical industry, its application in the pharmaceutical and food industry have been very limited due to issues with toxicity, purity, and high cost. Seeing to these limitations, new green alternative solvent which is DES was used. This green solvents, may be definitely treated as the next-generation reagents for more sustainable industrial development. Thus, this review aims to discuss the dissolution of cellulose either with ionic liquids or DES and its application.

Rapid structural analysis of nanomaterials in aqueous solutions

Science.gov (United States)

Ryuzaki, Sou; Tsutsui, Makusu; He, Yuhui; Yokota, Kazumichi; Arima, Akihide; Morikawa, Takanori; Taniguchi, Masateru; Kawai, Tomoji

2017-04-01

Rapid structural analysis of nanoscale matter in a liquid environment represents innovative technologies that reveal the identities and functions of biologically important molecules. However, there is currently no method with high spatio-temporal resolution that can scan individual particles in solutions to gain structural information. Here we report the development of a nanopore platform realizing quantitative structural analysis for suspended nanomaterials in solutions with a high z-axis and xy-plane spatial resolution of 35.8 ± 1.1 and 12 nm, respectively. We used a low thickness-to-diameter aspect ratio pore architecture for achieving cross sectional areas of analyte (i.e. tomograms). Combining this with multiphysics simulation methods to translate ionic current data into tomograms, we demonstrated rapid structural analysis of single polystyrene (Pst) beads and single dumbbell-like Pst beads in aqueous solutions.

A group contribution method to estimate the densities of ionic liquids

International Nuclear Information System (INIS)

Qiao Yan; Ma Youguang; Huo Yan; Ma Peisheng; Xia Shuqian

2010-01-01

Densities of ionic liquids at different temperature and pressure were collected from 84 references. The collection contains 7381 data points derived from 123 pure ionic liquids and 13 kinds of binary ionic liquids mixtures. In terms of the collected database, a group contribution method based on 51 groups was used to predict the densities of ionic liquids. In group partition, the effect of interaction among several substitutes on the same center was considered. The same structure in different substitutes may have different group values. According to the estimation of pure ionic liquids' densities, the results show that the average relative error is 0.88% and the standard deviation (S) is 0.0181. Using the set of group values three pure ionic liquids densities were predicted, the average relative error is 0.27% and the S is 0.0048. For ionic liquid mixtures, they are thought considered as idea mixtures, so the group contribution method was used to estimate their densities and the average relative error is 1.22% with S is 0.0607. And the method can also be used to estimate the densities of MCl x type ionic liquids which are produced by mixing an ionic liquid with a Cl - anion and a kind of metal chloride.

Ionic Liquids: Radiation Chemistry, Solvation Dynamics and Reactivity Patterns

International Nuclear Information System (INIS)

Wishart, J.F.

2011-01-01

Ionic liquids (ILs) are a rapidly expanding family of condensed-phase media with important applications in energy production, nuclear fuel and waste processing, improving the efficiency and safety of industrial chemical processes, and pollution prevention. ILs generally have low volatilities and are combustion-resistant, highly conductive, recyclable and capable of dissolving a wide variety of materials. They are finding new uses in chemical synthesis, catalysis, separations chemistry, electrochemistry and other areas. Ionic liquids have dramatically different properties compared to conventional molecular solvents, and they provide a new and unusual environment to test our theoretical understanding of primary radiation chemistry, charge transfer and other reactions. We are interested in how IL properties influence physical and dynamical processes that determine the stability and lifetimes of reactive intermediates and thereby affect the courses of reactions and product distributions. We study these issues by characterization of primary radiolysis products and measurements of their yields and reactivity, quantification of electron solvation dynamics and scavenging of electrons in different states of solvation. From this knowledge we wish to learn how to predict radiolytic mechanisms and control them or mitigate their effects on the properties of materials used in nuclear fuel processing, for example, and to apply IL radiation chemistry to answer questions about general chemical reactivity in ionic liquids that will aid in the development of applications listed above. Very early in our radiolysis studies it became evident that the slow solvation dynamics of the excess electron in ILs (which vary over a wide viscosity range) increase the importance of pre-solvated electron reactivity and consequently alter product distributions and subsequent chemistry. This difference from conventional solvents has profound effects on predicting and controlling radiolytic yields

Evaluation of impedance spektra of ionic-transport materials by a random-walk approach considering electrode and bulk response

Czech Academy of Sciences Publication Activity Database

Patil, D. S.; Shimakawa, K.; Zima, Vítězslav; Macák, J.; Wágner, T.

2013-01-01

Roč. 113, č. 14 (2013), 143705_1-143705_4 ISSN 0021-8979 Institutional support: RVO:61389013 Keywords : impedance * ionic conductivity * chalcogenide glasses Subject RIV: CA - Inorganic Chemistry Impact factor: 2.185, year: 2013

Catalytic Ionic-Liquid Membranes: The Convergence of Ionic-Liquid Catalysis and Ionic-Liquid Membrane Separation Technologies.

Czech Academy of Sciences Publication Activity Database

Izák, Pavel; Bobbink, F.D.; Hulla, M.; Klepic, M.; Friess, K.; Hovorka, Š.; Dyson, P.J.

2018-01-01

Roč. 83, č. 1 (2018), s. 7-18 ISSN 2192-6506 R&D Projects: GA ČR(CZ) GA17-00089S; GA ČR GA17-05421S Institutional support: RVO:67985858 Keywords : heterogeneous catalysis * ionic liquids * membranes Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 2.797, year: 2016

Molecular simulation of ionic liquids: current status and future opportunities

International Nuclear Information System (INIS)

Maginn, E J

2009-01-01

Ionic liquids are salts that are liquid near ambient conditions. Interest in these unusual compounds has exploded in the last decade, both at the academic and commercial level. Molecular simulations based on classical potentials have played an important role in helping researchers understand how condensed phase properties of these materials are linked to chemical structure and composition. Simulations have also predicted many properties and unexpected phenomena that have subsequently been confirmed experimentally. The beneficial impact molecular simulations have had on this field is due in large part to excellent timing. Just when computing power and simulation methods matured to the point where complex fluids could be studied in great detail, a new class of materials virtually unknown to experimentalists came on the scene and demanded attention. This topical review explores some of the history of ionic liquid molecular simulations, and then gives examples of the recent use of molecular dynamics and Monte Carlo simulation in understanding the structure of ionic liquids, the sorption of small molecules in ionic liquids, the nature of ionic liquids in the vapor phase and the dynamics of ionic liquids. This review concludes with a discussion of some of the outstanding problems facing the ionic liquid modeling community and how condensed phase molecular simulation experts not presently working on ionic liquids might help advance the field. (topical review)

Ionic Liquid-Doped Gel Polymer Electrolyte for Flexible Lithium-Ion Polymer Batteries

Science.gov (United States)

Zhang, Ruisi; Chen, Yuanfen; Montazami, Reza

2015-01-01

Application of gel polymer electrolytes (GPE) in lithium-ion polymer batteries can address many shortcomings associated with liquid electrolyte lithium-ion batteries. Due to their physical structure, GPEs exhibit lower ion conductivity compared to their liquid counterparts. In this work, we have investigated and report improved ion conductivity in GPEs doped with ionic liquid. Samples containing ionic liquid at a variety of volume percentages (vol %) were characterized for their electrochemical and ionic properties. It is concluded that excess ionic liquid can damage internal structure of the batteries and result in unwanted electrochemical reactions; however, samples containing 40–50 vol % ionic liquid exhibit superior ionic properties and lower internal resistance compared to those containing less or more ionic liquids.

Predictions of Physicochemical Properties of Ionic Liquids with DFT

Directory of Open Access Journals (Sweden)

Karl Karu

2016-07-01

Full Text Available Nowadays, density functional theory (DFT-based high-throughput computational approach is becoming more efficient and, thus, attractive for finding advanced materials for electrochemical applications. In this work, we illustrate how theoretical models, computational methods, and informatics techniques can be put together to form a simple DFT-based throughput computational workflow for predicting physicochemical properties of room-temperature ionic liquids. The developed workflow has been used for screening a set of 48 ionic pairs and for analyzing the gathered data. The predicted relative electrochemical stabilities, ionic charges and dynamic properties of the investigated ionic liquids are discussed in the light of their potential practical applications.

Lipid extraction from microalgae using a single ionic liquid

Science.gov (United States)

Salvo, Roberto Di; Reich, Alton; Dykes, Jr., H. Waite H.; Teixeira, Rodrigo

2013-05-28

A one-step process for the lysis of microalgae cell walls and separation of the cellular lipids for use in biofuel production by utilizing a hydrophilic ionic liquid, 1-butyl-3-methylimidazolium. The hydrophilic ionic liquid both lyses the microalgae cell walls and forms two immiscible layers, one of which consists of the lipid contents of the lysed cells. After mixture of the hydrophilic ionic liquid with a suspension of microalgae cells, gravity causes a hydrophobic lipid phase to move to a top phase where it is removed from the mixture and purified. The hydrophilic ionic liquid is recycled to lyse new microalgae suspensions.

Are Ionic Liquids Good Boundary Lubricants? A Molecular Perspective

Directory of Open Access Journals (Sweden)

Romain Lhermerout

2018-01-01

Full Text Available The application of ionic liquids as lubricants has attracted substantial interest over the past decade and this has produced a rich literature. The aim of this review is to summarize the main findings about frictional behavior of ionic liquids in the boundary lubrication regime. We first recall why the unusual properties of ionic liquids make them very promising lubricants, and the molecular mechanisms at the origin of their lubricating behavior. We then point out the main challenges to be overcome in order to optimise ionic liquid lubricant performance for common applications. We finally discuss their use in the context of electroactive lubrication.

Rapid host immune response and viral dynamics in herpes simplex virus-2 infection

Science.gov (United States)

Schiffer, Joshua T; Corey, Lawrence

2014-01-01

Herpes Simplex Virus-2 (HSV-2) is episodically shed throughout the human genital tract. While high viral load correlates with development of genital ulcers, shedding also commonly occurs even when ulcers are not present, allowing for silent transmission during coitus and contributing to high seroprevalence of HSV-2 worldwide. Frequent viral reactivation occurs despite diverse and complementary host and viral mechanisms within ganglionic tissue that predispose towards latency, suggesting that viral replication may be constantly occurring in a small minority of neurons within the ganglia. Within genital mucosa, the in vivo expansion and clearance rates of HSV-2 are extremely rapid. Resident dendritic cells and memory HSV-specific T cells persist at prior sites of genital tract reactivation, and in conjunction with prompt innate recognition of infected cells, lead to rapid containment of infected cells. Shedding episodes vary greatly in duration and severity within a single person over time: this heterogeneity appears best explained by variation in the densities of host immunity across the genital tract. The fact that immune responses usually control viral replication in genital skin prior to development of lesions provides optimism that enhancing such responses could lead to effective vaccines and immunotherapies. PMID:23467247

Nanoscale Ionic Materials

KAUST Repository

Rodriguez, Robert; Herrera, Rafael; Archer, Lynden A.; Giannelis, Emmanuel P.

2008-01-01

Polymer nanocomposites (nanoparticles dispersed in a polymer matrix) have been the subject of intense research for almost two decades in both academic and industrial settings. This interest has been fueled by the ability of nanocomposites to not only improve the performance of polymers, but also by their ability to introduce new properties. Yet, there are still challenges that polymer nanocomposites must overcome to reach their full potential. In this Research News article we discuss a new class of hybrids termed nanoparticle ionic materials (NIMS). NIMS are organic-inorganic hybrid materials comprising a nanoparticle core functionalized with a covalently tethered ionic corona. They are facilely engineered to display flow properties that span the range from glassy solids to free flowing liquids. These new systems have unique properties that can overcome some of the challenges facing nanocomosite materials. © 2008 WILEY-VCH Verlag GmbH & Co. KGaA.

Nanoscale Ionic Materials

KAUST Repository

Rodriguez, Robert

2008-11-18

Polymer nanocomposites (nanoparticles dispersed in a polymer matrix) have been the subject of intense research for almost two decades in both academic and industrial settings. This interest has been fueled by the ability of nanocomposites to not only improve the performance of polymers, but also by their ability to introduce new properties. Yet, there are still challenges that polymer nanocomposites must overcome to reach their full potential. In this Research News article we discuss a new class of hybrids termed nanoparticle ionic materials (NIMS). NIMS are organic-inorganic hybrid materials comprising a nanoparticle core functionalized with a covalently tethered ionic corona. They are facilely engineered to display flow properties that span the range from glassy solids to free flowing liquids. These new systems have unique properties that can overcome some of the challenges facing nanocomosite materials. © 2008 WILEY-VCH Verlag GmbH & Co. KGaA.

Avoiding math on a rapid timescale: Emotional responsivity and anxious attention in math anxiety.

Science.gov (United States)

Pizzie, Rachel G; Kraemer, David J M

2017-11-01

Math anxiety (MA) is characterized by negative feelings towards mathematics, resulting in avoidance of math classes and of careers that rely on mathematical skills. Focused on a long timescale, this research may miss important cognitive and affective processes that operate moment-to-moment, changing rapid reactions even when a student simply sees a math problem. Here, using fMRI with an attentional deployment paradigm, we show that MA influences rapid spontaneous emotional and attentional responses to mathematical stimuli upon brief presentation. Critically, participants viewed but did not attempt to solve the problems. Indicating increased threat reactivity to even brief presentations of math problems, increased MA was associated with increased amygdala response during math viewing trials. Functionally and anatomically defined amygdala ROIs yielded similar results, indicating robustness of the finding. Similar to the pattern of vigilance and avoidance observed in specific phobia, behavioral results of the attentional paradigm demonstrated that MA is associated with attentional disengagement for mathematical symbols. This attentional avoidance is specific to math stimuli; when viewing negatively-valenced images, MA is correlated with attentional engagement, similar to other forms of anxiety. These results indicate that even brief exposure to mathematics triggers a neural response related to threat avoidance in highly MA individuals. Copyright © 2017 Elsevier Inc. All rights reserved.

Ion Transport in Nanostructured Block Copolymer/Ionic Liquid Membranes

OpenAIRE

Hoarfrost, Megan Lane

2012-01-01

Incorporating an ionic liquid into one block copolymer microphase provides a platform for combining the outstanding electrochemical properties of ionic liquids with a number of favorable attributes provided by block copolymers. In particular, block copolymers thermodynamically self-assemble into well-ordered nanostructures, which can be engineered to provide a durable mechanical scaffold and template the ionic liquid into continuous ion-conducting nanochannels. Understanding how the additio...

Attenuating the alcohol allure: attentional broadening reduces rapid motivational response to alcohol pictures.

Science.gov (United States)

Ryerson, Nicole C; Neal, Lauren B; Gable, Philip A

2017-04-01

Past research has found that exposure to alcohol cues causes a narrowing of attentional scope and enhances the neural responses associated with approach motivation. The current research sought to determine if a manipulated broadened (global) attentional scope would reduce approach-motivated neural reactivity to alcohol pictures. In the current study, participants (n = 82) were exposed to alcohol and neutral pictures following either a global or local attentional scope manipulation. Early motivated attentional processing was assessed using the N1 event-related potential (ERP), a neurophysiological marker of rapid motivated attention. A global attentional scope reduced N1 amplitudes to alcohol pictures as compared to a local attentional scope. Self-reported binge drinking related to larger N1 amplitudes to alcohol pictures, but not to neutral pictures. Individuals with greater binge drinking experience demonstrated increased rapid motivated attentional processing to alcohol pictures. These results suggest that enhancing a global (vs. local) attentional scope attenuates rapid motivated attentional processing of alcohol pictures in comparison to neutral pictures. Graphical abstract ᅟ.

Hg⁰ removal from flue gas by ionic liquid/H₂O₂.

Science.gov (United States)

Cheng, Guangwen; Bai, Bofeng; Zhang, Qiang; Cai, Ming

2014-09-15

1-Alkyl-3-methylimidazolium chloride ionic liquids ([Cnmim] Cl, n=4, 6, 8) were prepared. The ionic liquid was then mixed with hydrogen peroxide (H2O2) to form an absorbent. The Hg(0) removal performance of the absorbent was investigated in a gas/liquid scrubber using simulated flue gas. It was found that the ionic liquid/H2O2 mixture was an excellent absorbent and could be used to remove Hg(0) from flue gas. When the mass ratio of H2O2 to ionic liquid was 0.5, the absorbent showed high Hg(0) removal efficiency (up to 98%). The Hg(0) removal efficiency usually increased with the absorption temperature, while decreased with the increase of alkyl chain length in ionic liquid molecule. The Hg(0) removal mechanism involved with Hg(0) oxidation by H2O2 and Hg(2+) transfer from aqueous phase to ionic liquid phase. Copyright © 2014 Elsevier B.V. All rights reserved.

Selective Ionic Transport Pathways in Phosphorene.

Science.gov (United States)

Nie, Anmin; Cheng, Yingchun; Ning, Shoucong; Foroozan, Tara; Yasaei, Poya; Li, Wen; Song, Boao; Yuan, Yifei; Chen, Lin; Salehi-Khojin, Amin; Mashayek, Farzad; Shahbazian-Yassar, Reza

2016-04-13

Despite many theoretical predictions indicating exceptionally low energy barriers of ionic transport in phosphorene, the ionic transport pathways in this two-dimensional (2D) material has not been experimentally demonstrated. Here, using in situ aberration-corrected transmission electron microscopy (TEM) and density functional theory, we studied sodium ion transport in phosphorene. Our high-resolution TEM imaging complemented by electron energy loss spectroscopy demonstrates a precise description of anisotropic sodium ions migration along the [100] direction in phosphorene. This work also provides new insight into the effect of surface and the edge sites on the transport properties of phosphorene. According to our observation, the sodium ion transport is preferred in zigzag edge rather than the armchair edge. The use of this highly selective ionic transport property may endow phosphorene with new functionalities for novel chemical device applications.

Mixed system of ionic liquid and non-ionic surfactants in aqueous media: Surface and thermodynamic properties

International Nuclear Information System (INIS)

Bhatt, Darshak; Maheria, Kalpana; Parikh, Jigisha

2014-01-01

Highlights: • Interaction of ionic liquid and ethylene oxide based non-ionic surfactants in aqueous media. • Evaluation of various surface properties and thermodynamic parameters. • Micellar growth ensues from exothermic to endothermic with increase in temperature. • Micelle formation is enthalpy driven at low temperature and entropy driven at higher temperature. • The micellization power and adsorption proficiency decreased at high IL concentrations. - Abstract: The mixed system of ionic liquid (IL) tetraethyl ammonium tetrafluoroborate [TEA(BF 4 )] and numerous ethylene oxide based non-ionic surfactants in aqueous media were studied using surface tension, viscosity and dynamic light scattering (DLS) measurements. Various surface properties like critical micelle concentration (cmc), maximum surface excess concentration (Γ max ), minimum surface area per surfactant molecule (A min ), surface tension at the cmc (γ cmc ), adsorption efficiency (pC 20 ), and effectiveness of surface tension reduction (π cmc ) as well as thermodynamic parameters of micellization have been determined. DLS and viscosity measurements revealed that the micellar growth was attributed to the bridged solvophilicity of the POE chain in surfactants at elevated temperatures. In most of the cases, the progression ensues from exothermic to endothermic with increase in temperature of the mixed system. Thermodynamic parameter indicates that the micelle formation process is enthalpy driven at low temperature and entropy driven at higher temperature

Competing covalent and ionic bonding in Ge-Sb-Te phase change materials.

Science.gov (United States)

Mukhopadhyay, Saikat; Sun, Jifeng; Subedi, Alaska; Siegrist, Theo; Singh, David J

2016-05-19

Ge2Sb2Te5 and related phase change materials are highly unusual in that they can be readily transformed between amorphous and crystalline states using very fast melt, quench, anneal cycles, although the resulting states are extremely long lived at ambient temperature. These states have remarkably different physical properties including very different optical constants in the visible in strong contrast to common glass formers such as silicates or phosphates. This behavior has been described in terms of resonant bonding, but puzzles remain, particularly regarding different physical properties of crystalline and amorphous phases. Here we show that there is a strong competition between ionic and covalent bonding in cubic phase providing a link between the chemical basis of phase change memory property and origins of giant responses of piezoelectric materials (PbTiO3, BiFeO3). This has important consequences for dynamical behavior in particular leading to a simultaneous hardening of acoustic modes and softening of high frequency optic modes in crystalline phase relative to amorphous. This different bonding in amorphous and crystalline phases provides a direct explanation for different physical properties and understanding of the combination of long time stability and rapid switching and may be useful in finding new phase change compositions with superior properties.

Particle self-assembly at ionic liquid-based interfaces.

Science.gov (United States)

Frost, Denzil S; Nofen, Elizabeth M; Dai, Lenore L

2014-04-01

This review presents an overview of the nature of ionic liquid (IL)-based interfaces and self-assembled particle morphologies of IL-in-water, oil- and water-in-IL, and novel IL-in-IL Pickering emulsions with emphasis on their unique phenomena, by means of experimental and computational studies. In IL-in-water Pickering emulsions, particles formed monolayers at ionic liquid-water interfaces and were close-packed on fully covered emulsion droplets or aggregated on partially covered droplets. Interestingly, other than equilibrating at the ionic liquid-water interfaces, microparticles with certain surface chemistries were extracted into the ionic liquid phase with a high efficiency. These experimental findings were supported by potential of mean force calculations, which showed large energy drops as hydrophobic particles crossed the interface into the IL phase. In the oil- and water-in-IL Pickering emulsions, microparticles with acidic surface chemistries formed monolayer bridges between the internal phase droplets rather than residing at the oil/water-ionic liquid interfaces, a significant deviation from traditional Pickering emulsion morphology. Molecular dynamics simulations revealed aspects of the mechanism behind this bridging phenomenon, including the role of the droplet phase, surface chemistry, and inter-particle film. Novel IL-in-IL Pickering emulsions exhibited an array of self-assembled morphologies including the previously observed particle absorption and bridging phenomena. The appearance of these morphologies depended on the particle surface chemistry as well as the ILs used. The incorporation of particle self-assembly with ionic liquid science allows for new applications at the intersection of these two fields, and have the potential to be numerous due to the tunability of the ionic liquids and particles incorporated, as well as the particle morphology by combining certain groups of particle surface chemistry, IL type (protic or aprotic), and whether oil

Direct synthesis of silver nanoparticles in ionic liquid

International Nuclear Information System (INIS)

Corrêa, Cíntia M.; Bizeto, Marcos A.; Camilo, Fernanda F.

2016-01-01

Ionic liquids have structural organization at nanoscale that can trigger the spontaneous ordering of structures in nanoscopic range. Due to this characteristic, several metal nanoparticles have been prepared in this media. In this paper, we describe the direct preparation of silver nanoparticles in the following imidazolium ionic liquids: 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1,2-dimethyl-3-butylimidazolium bis(trifluoromethanesulfonyl)imide, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-octyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, and in citrate tetrabutylammonium, that is an ionic liquid that acts as solvent and reducing agent at the same time. We also evaluated the morphology of the nanoparticles and the stability of the dispersions. Spherical silver nanoparticles with surface Plasmon bands in the range of 400–430 nm were produced in all the ionic liquids, with the only exception for the 1-octyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide that produced a black precipitate. The best results were obtained by using 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and citrate tetrabutylammonium ionic liquids. The former resulted in concentrated spherical silver nanoparticles dispersion (ca. 1.0 mM of Ag) with diameters ranging from 6 to 12 nm and by adding polyvinylpyrrolidone (PVP) to the dispersions they became stable for at least 1 month. The citrate tetrabutylammonium ionic liquid produced even more concentrated dispersion of spherical silver nanoparticles with diameters ranging from 2 to 6 nm. These dispersions were quite stable without the need of PVP, since the Plasmon band in the electronic absorption spectra remained unaltered for months after the preparation. The citrate tetrabutylammonium ionic liquid offers a slow kinetic for the silver nanoparticle formation as the citrate is a milder reducing agent than borohydride.Graphical Abstract

Direct synthesis of silver nanoparticles in ionic liquid

Energy Technology Data Exchange (ETDEWEB)

Corrêa, Cíntia M.; Bizeto, Marcos A.; Camilo, Fernanda F., E-mail: ffcamilo@unifesp.br [Universidade Federal de São Paulo, Laboratório de Materiais Híbridos, Departamento de Ciências Exatas e da Terra, Instituto de Ciências Ambientais, Químicas e Farmacêuticas (Brazil)

2016-05-15

Ionic liquids have structural organization at nanoscale that can trigger the spontaneous ordering of structures in nanoscopic range. Due to this characteristic, several metal nanoparticles have been prepared in this media. In this paper, we describe the direct preparation of silver nanoparticles in the following imidazolium ionic liquids: 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1,2-dimethyl-3-butylimidazolium bis(trifluoromethanesulfonyl)imide, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-octyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, and in citrate tetrabutylammonium, that is an ionic liquid that acts as solvent and reducing agent at the same time. We also evaluated the morphology of the nanoparticles and the stability of the dispersions. Spherical silver nanoparticles with surface Plasmon bands in the range of 400–430 nm were produced in all the ionic liquids, with the only exception for the 1-octyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide that produced a black precipitate. The best results were obtained by using 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and citrate tetrabutylammonium ionic liquids. The former resulted in concentrated spherical silver nanoparticles dispersion (ca. 1.0 mM of Ag) with diameters ranging from 6 to 12 nm and by adding polyvinylpyrrolidone (PVP) to the dispersions they became stable for at least 1 month. The citrate tetrabutylammonium ionic liquid produced even more concentrated dispersion of spherical silver nanoparticles with diameters ranging from 2 to 6 nm. These dispersions were quite stable without the need of PVP, since the Plasmon band in the electronic absorption spectra remained unaltered for months after the preparation. The citrate tetrabutylammonium ionic liquid offers a slow kinetic for the silver nanoparticle formation as the citrate is a milder reducing agent than borohydride.Graphical Abstract.

VOC and HAP recovery using ionic liquids

Energy Technology Data Exchange (ETDEWEB)

Michael R. Milota : Kaichang Li

2007-05-29

During the manufacture of wood composites, paper, and to a lesser extent, lumber, large amounts of volatile organic compounds (VOCs) such as terpenes, formaldehyde, and methanol are emitted to air. Some of these compounds are hazardous air pollutants (HAPs). The air pollutants produced in the forest products industry are difficult to manage because the concentrations are very low. Presently, regenerative thermal oxidizers (RTOs and RCOs) are commonly used for the destruction of VOCs and HAPs. RTOs consume large amounts of natural gas to heat air and moisture. The combustion of natural gas generates increased CO2 and NOx, which have negative implications for global warming and air quality. The aforementioned problems are addressed by an absorption system containing a room-temperature ionic liquid (RTIL) as an absorbent. RTILs are salts, but are in liquid states at room temperature. RTILs, an emerging technology, are receiving much attention as replacements for organic solvents in industrial processes with significant cost and environmental benefits. Some of these processes include organic synthesis, extraction, and metal deposition. RTILs would be excellent absorbents for exhausts from wood products facilities because of their unique properties: no measurable vapor pressure, high solubility of wide range of organic compounds, thermal stability to 200°C (almost 400°F), and immisciblity with water. Room temperature ionic liquids were tested as possible absorbents. Four were imidizolium-based and were eight phosphonium-based. The imidizolium-based ionic liquids proved to be unstable at the conditions tested and in the presence of water. The phosphonium-based ionic liquids were stable. Most were good absorbents; however, cleaning the contaminates from the ionic liquids was problematic. This was overcome with a higher temperature (120°C) than originally proposed and a very low pressure (1 kPa. Absorption trials were conducted with tetradecy

Physical Chemistry of Reaction Dynamics in Ionic Liquid

Energy Technology Data Exchange (ETDEWEB)

Maroncelli, Mark [Pennsylvania State Univ., University Park, PA (United States)

2016-10-02

Work completed over the past year mainly involves finishing studies related to solvation dynamics in ionic liquids, amplifying and extending our initial PFG-NMR work on solute diffusion, and learning how to probe rotational dynamics in ionic liquids.

Factors affecting the stability and performance of ionic liquid-based planar transient photodetectors.

Science.gov (United States)

Dalgleish, Simon; Reissig, Louisa; Hu, Laigui; Matsushita, Michio M; Sudo, Yuki; Awaga, Kunio

2015-05-12

A novel planar architecture has been developed for the study of photodetectors utilizing the transient photocurrent response induced by a metal/insulator/semiconductor/metal (MISM) structured device, where the insulator is an ionic liquid (IL-MISM). Using vanadyl 2,3-naphthalocyanine, which absorbs in the communications-relevant near-infrared wavelength region (λ(max,film) ≈ 850 nm), in conjunction with C60 as a bulk heterojunction, the high capacitance of the formed electric double layers at the ionic liquid interfaces yields high charge separation efficiency within the semiconductor layer, and the minimal potential drop in the bulk ionic liquid allows the electrodes to be offset by distances of over 7 mm. Furthermore, the decrease in operational speed with increased electrode separation is beneficial for a clear modeling of the waveform of the photocurrent signal, free from the influence of measurement circuitry. Despite the use of a molecular semiconductor as the active layer in conjunction with a liquid insulating layer, devices with a stability of several days could be achieved, and the operational stability of such devices was shown to be dependent solely on the solubility of the active layer in the ionic liquid, even under atmospheric conditions. Furthermore, the greatly simplified device construction process, which does not rely on transparent electrode materials or direct electrode deposition, provides a highly reproducible platform for the study of the electronic processes within IL-MISM detectors that is largely free from architectural constraints.

Novel applications of ionic liquids in materials processing

International Nuclear Information System (INIS)

Reddy, Ramana G

2009-01-01

Ionic liquids are mixtures of organic and inorganic salts which are liquids at room temperature. Several potential applications of ionic liquids in the field of materials processing are electrowinning and electrodeposition of metals and alloys, electrolysis of active metals at low temperature, liquid-liquid extraction of metals. Results using 1-butyl-3-methylimidazolium chloride with AlCl 3 at low temperatures yielded high purity aluminium deposits (>99.9% pure) and current efficiencies >98%. Titanium and aluminium were co-deposited with/without the addition of TiCl 4 with up to 27 wt% Ti in the deposit with current efficiencies in the range of 78-85 %. Certain ionic liquids are potential replacements for thermal oils and molten salts as heat transfer fluids in solar energy applications due to high thermal stability, very low corrosivity and substantial sensible heat retentivity. The calculated storage densities for several chloride and fluoride ionic liquids are in the range of 160-210 MJ/m 3 . A 3-D mathematical model was developed to simulate the large scale electrowinning of aluminium. Since ionic liquids processing results in their low energy consumption, low pollutant emissions many more materials processing applications are expected in future.

Biomass Conversion in Ionic Liquids - in-situ Investigations

DEFF Research Database (Denmark)

Kunov-Kruse, Andreas Jonas

Due to rising oil prices and global warming caused by CO2 emissions, there is an increased demand for new types of fuels and chemicals derived from biomass. This thesis investigates catalytic conversion of cellulose into sugars in ionic liquids and the important platform chemical 5-hydroxymethylf......Due to rising oil prices and global warming caused by CO2 emissions, there is an increased demand for new types of fuels and chemicals derived from biomass. This thesis investigates catalytic conversion of cellulose into sugars in ionic liquids and the important platform chemical 5......-hydroxymethylfurfural (HMF). The thesis focuses on kinetic and mechanistic investigations using new in-situ FTIR spectroscopic methods based on the ATR-principle. At first the kinetics of cellulose hydrolysis and the simultaneously HMF formation was investigated in the ionic liquid 1-butyl-2,3-dimethylimidazolium...... activation energies suggest that the ionic liquid acts co-catalytic by stabilizing the oxocarbenium transition state. The chromium catalyzed conversion of glucose to HMF in ionic liquid 1-butyl-3-methylimidazolium chloride with CrCl3⋅6H2O and CrCl2 as catalysts was investigated. The CrCl3⋅6H2O catalyst...

Synthetic generation of influenza vaccine viruses for rapid response to pandemics.

Science.gov (United States)

Dormitzer, Philip R; Suphaphiphat, Pirada; Gibson, Daniel G; Wentworth, David E; Stockwell, Timothy B; Algire, Mikkel A; Alperovich, Nina; Barro, Mario; Brown, David M; Craig, Stewart; Dattilo, Brian M; Denisova, Evgeniya A; De Souza, Ivna; Eickmann, Markus; Dugan, Vivien G; Ferrari, Annette; Gomila, Raul C; Han, Liqun; Judge, Casey; Mane, Sarthak; Matrosovich, Mikhail; Merryman, Chuck; Palladino, Giuseppe; Palmer, Gene A; Spencer, Terika; Strecker, Thomas; Trusheim, Heidi; Uhlendorff, Jennifer; Wen, Yingxia; Yee, Anthony C; Zaveri, Jayshree; Zhou, Bin; Becker, Stephan; Donabedian, Armen; Mason, Peter W; Glass, John I; Rappuoli, Rino; Venter, J Craig

2013-05-15

During the 2009 H1N1 influenza pandemic, vaccines for the virus became available in large quantities only after human infections peaked. To accelerate vaccine availability for future pandemics, we developed a synthetic approach that very rapidly generated vaccine viruses from sequence data. Beginning with hemagglutinin (HA) and neuraminidase (NA) gene sequences, we combined an enzymatic, cell-free gene assembly technique with enzymatic error correction to allow rapid, accurate gene synthesis. We then used these synthetic HA and NA genes to transfect Madin-Darby canine kidney (MDCK) cells that were qualified for vaccine manufacture with viral RNA expression constructs encoding HA and NA and plasmid DNAs encoding viral backbone genes. Viruses for use in vaccines were rescued from these MDCK cells. We performed this rescue with improved vaccine virus backbones, increasing the yield of the essential vaccine antigen, HA. Generation of synthetic vaccine seeds, together with more efficient vaccine release assays, would accelerate responses to influenza pandemics through a system of instantaneous electronic data exchange followed by real-time, geographically dispersed vaccine production.

Ionic conducting poly-benzimidazoles; Polybenzimidazoles conducteurs ioniques

Energy Technology Data Exchange (ETDEWEB)

Jouanneau, J

2006-11-15

Over the last years, many research works have been focused on new clean energy systems. Hydrogen fuel cell seems to be the most promising one. However, the large scale development of this technology is still limited by some key elements. One of them is the polymer electrolyte membrane 'Nafion' currently used, for which the ratio performance/cost is too low. The investigations we carried out during this thesis work are related to a new class of ionic conducting polymer, the sulfonated poly-benzimidazoles (sPBI). Poly-benzimidazoles (PBI) are aromatic heterocyclic polymers well-known for their excellent thermal and chemical stability. Ionic conduction properties are obtained by having strong acid groups (sulfonic acid SO{sub 3}H) on the macromolecular structure. For that purpose, we first synthesized sulfonated monomers. Their poly-condensation with an appropriate non-sulfonated co-monomer yields to sPBI with sulfonation range from 0 to 100 per cent. Three different sPBI structures were obtained, and verified by appropriate analytical techniques. We also showed that the protocol used for the synthesis resulted in high molecular weights polymers. We prepared ionic conducting membrane by casting sPBI solutions on glass plates. Their properties of stability, water swelling and ionic conductivity were investigated. Surprisingly, the behaviour of sPBI was quite different from the other sulfonated aromatic polymers with same amount of SO{sub 3}H, their stability was much higher, but their water swelling and ionic conductivity were quite low. We attributed these differences to strong ionic interactions between the sulfonic acid groups and the basic benzimidazole groups of our polymers. However, we managed to solve this problem synthesizing very highly sulfonated PBI, obtaining membranes with a good balance between all the properties necessary. (author)

Study of thioglycosylation in ionic liquids

Directory of Open Access Journals (Sweden)

Ragauskas Arthur

2006-06-01

Full Text Available Abstract A novel, green chemistry, glycosylation strategy was developed based upon the use of ionic liquids. Research studies demonstrated that thiomethyl glycosides could readily be activated with methyl trifluoromethane sulfonate, using 1-butyl-3-methylimidazolium tetrafluoroborate as a solvent. This green chemistry glycosylation strategy provided disaccharides with typical yields averaging 75%. The ionic liquid solvent could be readily reused for five sequential glycosylation reactions with no impact on product yield.

Characterization and Functionality of Immidazolium Ionic Liquids Modified Magnetic Nanoparticles

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Ying Li

2013-01-01

Full Text Available 1,3-Dialkylimidazolium-based ionic liquids were chemically synthesized and bonded on the surface of magnetic nanoparticles (MNPs with easy one-step reaction. The obtained six kinds of ionic liquid modified MNPs were characterized with transmission electron microscopy, thermogravimetric analysis, magnetization, and FTIR, which owned the high adsorption capacity due to the nanometer size and high-density modification with ionic liquids. Functionality of MNPs with ionic liquids greatly influenced the solubility of the MNPs with organic solvents depending on the alkyl chain length and the anions of the ionic liquids. Moreover, the obtained MNPs showed the specific extraction efficiency to organic pollutant, polycyclic aromatic hydrocarbons, while superparamagnetic property of the MNPs facilitated the convenient separation of MNPs from the bulks water samples.

Ion transport properties of lithium ionic liquids and their ion gels

International Nuclear Information System (INIS)

Shobukawa, Hitoshi; Tokuda, Hiroyuki; Susan, Md. Abu Bin Hasan; Watanabe, Masayoshi

2005-01-01

A new series of lithium ionic liquids were prepared by introducing of two electron-withdrawing trifluoroacetyl groups in borate salts containing two methoxy-oligo(ethylene oxide) groups in the structures. Successive substitution reactions of oligo-ethylene glycol monomethyl ether and trifluroacetic acid from LiBH 4 yielded the lithium salts, which were clear and colorless liquids at room temperature. The fundamental physicochemical properties, such as density, thermal property, viscosity, ionic conductivity, self-diffusion coefficients, and electrochemical stability, were measured. The lithium ionic liquids had self-dissociation ability and conducted ions even in the absence of organic solvents. New polymer electrolytes, named 'ion gels', were prepared by radical cross-linking reactions of a poly(ethylene oxide-co-propylene oxide)tri-acrylate macromonomer in the presence the lithium ionic liquid. An increase in the glass transition temperatures (T g ) of the ion gels was very small even with increasing lithium ionic liquid concentration, and the T g 's were lower than that of the ionic liquid itself. The ionic conductivity of the ion gels surpassed that of the lithium ionic liquid in the bulk at certain compositions

Survey of the pharmacology of non-ionic X-ray contrast media

International Nuclear Information System (INIS)

Turnheim, K.

1986-01-01

The non-ionic X-ray contrast media metrizamide, iopamidol, iohexol, and iopromide do not bind calcium and are less hyperosmolar than the conventional ionic contrast media, for instance amidotrizoate (diatrizoate), iothalamte, or ioglicate. Hence the use of non-ionic contrast media is associated with less undesirable side-effects that are attributable to hypertonicity such as an increase in circulating plasma volume, decreased deformability of red blood cells, damage of vascular endothelium with consequent activation of blood coagulation, the complement system and fibrinolysis, increased release of bradykinin and histamine, cardiac arrhythimas, diuresis, vasodilation and decreased blood pressure, pain and heat sensation. Because of less dilution the quality of imaging is also better. According to the intravenous LD 50 in experimental animals the acute toxicity of non-ionic contrast media is lower than that of ionic media. With respect to contrast quality and the rate of side-effects tha various non-ionic contrast media appear to be equivalent. Despite their higher price and higher viscosity it is probable that the non-ionic contrast media will replace the classical ionic media, especially in angio- and myelography. (Author)

Ionic-Liquid Based Separation of Azeotropic Mixtures

DEFF Research Database (Denmark)

Kulajanpeng, Kusuma; Suriyapraphadilok, Uthaiporn; Gani, Rafiqul

2014-01-01

methodology for the screening of ionic liquids (ILs) as entrainers for ILs-based separation processes in binary aqueous azeotropic systems (e.g., water + ethanol and water + isopropanol) is presented. Ionic liquids as entrainers were first screened based on a combination of criteria such as stabi......methodology for the screening of ionic liquids (ILs) as entrainers for ILs-based separation processes in binary aqueous azeotropic systems (e.g., water + ethanol and water + isopropanol) is presented. Ionic liquids as entrainers were first screened based on a combination of criteria...... [C1MIM][DMP]. For the final evaluation, the best candidates for aqueous systems were used as entrainers, and then the vapor-liquid equilibrium (VLE) of the ternary systems containing ILs was predicted by the Non Random Two Liquids (NRTL) model to confirm the breaking of the azeotrope. Based...... on minimum concentration of the ILs required to break the given azeotrope, the best ILs as entrainers for water + ethanol and water + isopropanol azeotropic mixtures were [C1MIM][DMP] and [C2MIM][N(CN)2], respectively....

Dissolution of agro-waste in ionic liquids

International Nuclear Information System (INIS)

Lee, Kiat Moon; Ngoh, Gek Cheng; Chua, Adeline Seak May

2010-01-01

Full text: There are abundant of agro-wastes being produced in Malaysia. One of the largely produced agro wastes is the sago hampas. It is known as a strong environmental pollutant due to its cellulosic fibrous material. However, the presence of the starch, cellulose and hemicelluloses in the hampas can be converted into valuable products such as reducing sugars. Hence, this study was performed to investigate the ability of ionic liquids in hydrolysing the ligno celluloses biomass into reducing sugars. Three types of ionic liquids were used, 1-butyl-3-methylimidazolium chloride (BMIM Cl), 1-ethyl-3- methylimidazolium acetate (EMIM Ac) and 1-ethyl-3-methylimidazolium diethyl phosphate (EMIM DEP). The reaction was performed by heating the reaction mixture of sago hampas and ionic liquids at 100 degree Celsius. The concentrations of reducing sugars in the hydrolysates were determined by DNS method. Maximum concentration of reducing sugars were 0.424, 0.299, 0.260 mg/ml for BmimCl, EmimAc and EmimDEP respectively. These concluded that the selected ionic liquids were inefficient in hydrolysing the sago hampas to reducing sugars. (author)

Modelling and Control of Ionic Electroactive Polymer Actuators under Varying Humidity Conditions

Directory of Open Access Journals (Sweden)

S. Sunjai Nakshatharan

2018-02-01

Full Text Available In this work, we address the problem of position control of ionic electroactive polymer soft actuators under varying relative humidity conditions. The impact of humidity on the actuation performance of ionic actuators is studied through frequency response and impedance spectroscopy analysis. Considering the uncertain performance of the actuator under varying humidity conditions, an adaptable model using the neural network method is developed. The model uses relative humidity magnitude as one of the model parameters, making it robust to different environmental conditions. Utilizing the model, a closed-loop controller based on the model predictive controller is developed for position control of the actuator. The developed model and controller are experimentally verified and found to be capable of predicting and controlling the actuators with excellent tracking accuracy under relative humidity conditions varying in the range of 10–90%.

Ionic Liquid-Doped Gel Polymer Electrolyte for Flexible Lithium-Ion Polymer Batteries

Directory of Open Access Journals (Sweden)

Ruisi Zhang

2015-05-01

Full Text Available Application of gel polymer electrolytes (GPE in lithium-ion polymer batteries can address many shortcomings associated with liquid electrolyte lithium-ion batteries. Due to their physical structure, GPEs exhibit lower ion conductivity compared to their liquid counterparts. In this work, we have investigated and report improved ion conductivity in GPEs doped with ionic liquid. Samples containing ionic liquid at a variety of volume percentages (vol % were characterized for their electrochemical and ionic properties. It is concluded that excess ionic liquid can damage internal structure of the batteries and result in unwanted electrochemical reactions; however, samples containing 40–50 vol % ionic liquid exhibit superior ionic properties and lower internal resistance compared to those containing less or more ionic liquids.

Charge state distribution of ionic kryptons after photoionization

International Nuclear Information System (INIS)

Cai Xiaohong

1992-01-01

Monochromatic X-rays from the 2.3 GeV synchrotron at University Bonn (Germany) are employed for inner shell excitation of krypton. Various ionic kryptons and a number of electrons are produced due to photoionization. In order to study the equilibrium charge state distribution of ionic kryptons, a time of flight mass spectrometer is set up and used to measure the resulting ionic charge spectra with photo energies near the L 1 - , L 2 - and L 3 - absorption edges of krypton. The energy dependence of relative probabilities is presented

Lattice model of ionic liquid confined by metal electrodes

Science.gov (United States)

Girotto, Matheus; Malossi, Rodrigo M.; dos Santos, Alexandre P.; Levin, Yan

2018-05-01

We study, using Monte Carlo simulations, the density profiles and differential capacitance of ionic liquids confined by metal electrodes. To compute the electrostatic energy, we use the recently developed approach based on periodic Green's functions. The method also allows us to easily calculate the induced charge on the electrodes permitting an efficient implementation of simulations in a constant electrostatic potential ensemble. To speed up the simulations further, we model the ionic liquid as a lattice Coulomb gas and precalculate the interaction potential between the ions. We show that the lattice model captures the transition between camel-shaped and bell-shaped capacitance curves—the latter characteristic of ionic liquids (strong coupling limit) and the former of electrolytes (weak coupling). We observe the appearance of a second peak in the differential capacitance at ≈0.5 V for 2:1 ionic liquids, as the packing fraction is increased. Finally, we show that ionic size asymmetry decreases substantially the capacitance maximum, when all other parameters are kept fixed.

Thermophysical properties of hydroxyl ammonium ionic liquids

International Nuclear Information System (INIS)

Kurnia, K.A.; Wilfred, C.D.; Murugesan, T.

2009-01-01

The thermophysical properties of hydroxyl ammonium ionic liquids: density ρ, T = (293.15 to 363.15) K; dynamic viscosity η, T = (298.2 to 348.2) K; and refractive indices n D , T = (293.15 to 333.15) K have been measured. The coefficients of thermal expansion α, values were calculated from the experimental density results using an empirical correlation for T = (293.15 to 363.15) K. The variation of volume expansion of ionic liquids studied was found to be independent of temperature within the range covered in the present work. The thermal decomposition temperature 'T d ' for all the six hydroxyl ammonium ionic liquids is also investigated using thermogravimetric analyzer (TGA)

Natural terpene derivatives as new structural task-specific ionic liquids to enhance the enantiorecognition of acidic enantiomers on teicoplanin-based stationary phase by high-performance liquid chromatography.

Science.gov (United States)

Flieger, Jolanta; Feder-Kubis, Joanna; Tatarczak-Michalewska, Małgorzata; Płazińska, Anita; Madejska, Anna; Swatko-Ossor, Marta

2017-06-01

We present the specific cooperative effect of a semisynthetic glycopeptide antibiotic teicoplanin and chiral ionic liquids containing the (1R,2S,5R)-(-)-menthol moiety on the chiral recognition of enantiomers of mandelic acid, vanilmandelic acid, and phenyllactic acid. Experiments were performed chromatographically on an Astec Chirobiotic T chiral stationary phase applying the mobile phase with the addition of the chiral ionic liquids. The stereoselective binding of enantiomers to teicoplanin in presence of new chiral ionic liquids were evaluated applying thermodynamic measurements and the docking simulations. Both the experimental and theoretical methods revealed that the chiral recognition of enantiomers in the presence of new chiral ionic liquids was enthalpy driven. The changes of the teicoplanin conformation occurring upon binding of the chiral ionic liquids are responsible for the differences in the standard changes in Gibbs energy (ΔG 0 ) values obtained for complexes formed by the R and S enantiomers and teicoplanin. Docking simulations revealed the steric adjustment between the chiral ionic liquids cyclohexane ring (chair conformation) and the β-d-glucosamine ring of teicoplanin and additionally hydrophobic interactions between the decanoic aliphatic chain of teicoplanin and the alkyl group of the tested salts. The obtained terpene derivatives can be considered as "structural task-specific ionic liquids" responsible for enhancing the chiral resolution in synergistic systems with two chiral selectors. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Organosilica Membrane with Ionic Liquid Properties for Separation of Toluene/H₂ Mixture.

Science.gov (United States)

Hirota, Yuichiro; Maeda, Yohei; Yamamoto, Yusuke; Miyamoto, Manabu; Nishiyama, Norikazu

2017-08-03

In this study, we present a new concept in chemically stabilized ionic liquid membranes: an ionic liquid organosilica (ILOS) membrane, which is an organosilica membrane with ionic liquid-like properties. A silylated ionic liquid was used as a precursor for synthesis. The permselectivity, permeation mechanism, and stability of the membrane in the H₂/toluene binary system were then compared with a supported ionic liquid membrane. The membrane showed a superior separation factor of toluene/H₂ (>17,000) in a binary mixture system based on a solution-diffusion mechanism with improved durability over the supported ionic liquid membrane.

Potentiostat for Characterizing Microstructures at Ionic Liquid/Electrode Interfaces

Science.gov (United States)

2015-10-10

reviewed journals (N/A for none) C. Zibart, D. Parr, B. Egan, H. Morris, A. Tivanski, L. M. Haverhals, “Investigation of Structure at Gold- Ionic Liquid ...into our electrochemistry program. In short, the instrument has been of great service to characterize ionic liquid -based (IL-based) electrolyte...Aug-2014 14-Nov-2014 Approved for Public Release; Distribution Unlimited Final Report: Potentiostat for Characterizing Microstructures at Ionic Liquid

Ionic Liquids in Polymer Design: From Energy to Health

Science.gov (United States)

2016-10-19

of Papers published in non peer- reviewed journals: Final Report: Ionic Liquids in Polymer Design: From Energy to Health Report Title ACS Symposium...SECURITY CLASSIFICATION OF: ACS Symposium: Ionic Liquids in Polymer Design: From Energy to Health at Fall 2015 ACS Meeting in Boston, MA The...combination of ionic liquids and polymers has emerged as an active field of exploration in polymer science, where new materials have be realized for

Crosslinked Polymer Ionic Liquid/Ionic Liquid Blends Prepared by Photopolymerization as Solid-State Electrolytes in Supercapacitors.

Science.gov (United States)

Wang, Po-Hsin; Wang, Tzong-Liu; Lin, Wen-Churng; Lin, Hung-Yin; Lee, Mei-Hwa; Yang, Chien-Hsin

2018-04-07

A photopolymerization method is used to prepare a mixture of polymer ionic liquid (PIL) and ionic liquid (IL). This mixture is used as a solid-state electrolyte in carbon nanoparticle (CNP)-based symmetric supercapacitors. The solid electrolyte is a binary mixture of a PIL and its corresponding IL. The PIL matrix is a cross-linked polyelectrolyte with an imidazole salt cation coupled with two anions of Br - in PIL-M-(Br) and TFSI - in PIL-M-(TFSI), respectively. The corresponding ionic liquids have imidazolium salt cation coupled with two anions of Br - and TFSI - , respectively. This study investigates the electrochemical characteristics of PILs and their corresponding IL mixtures used as a solid electrolyte in supercapacitors. Results show that a specific capacitance, maximum power density and energy density of 87 and 58 F·g - ¹, 40 and 48 kW·kg - ¹, and 107 and 59.9 Wh·kg - ¹ were achieved in supercapacitors based on (PIL-M-(Br)) and (PIL-M-(TFSI)) solid electrolytes, respectively.

Use of ionic liquids as coordination ligands for organometallic catalysts

Science.gov (United States)

Li, Zaiwei [Moreno Valley, CA; Tang, Yongchun [Walnut, CA; Cheng,; Jihong, [Arcadia, CA

2009-11-10

Aspects of the present invention relate to compositions and methods for the use of ionic liquids with dissolved metal compounds as catalysts for a variety of chemical reactions. Ionic liquids are salts that generally are liquids at room temperature, and are capable of dissolving a many types of compounds that are relatively insoluble in aqueous or organic solvent systems. Specifically, ionic liquids may dissolve metal compounds to produce homogeneous and heterogeneous organometallic catalysts. One industrially-important chemical reaction that may be catalyzed by metal-containing ionic liquid catalysts is the conversion of methane to methanol.

Recent developments in biocatalysis in multiphasic ionic liquid reaction systems.

Science.gov (United States)

Meyer, Lars-Erik; von Langermann, Jan; Kragl, Udo

2018-06-01

Ionic liquids are well known and frequently used 'designer solvents' for biocatalytic reactions. This review highlights recent achievements in the field of multiphasic ionic liquid-based reaction concepts. It covers classical biphasic systems including supported ionic liquid phases, thermo-regulated multi-component solvent systems (TMS) and polymerized ionic liquids. These powerful concepts combine unique reaction conditions with a high potential for future applications on a laboratory and industrial scale. The presence of a multiphasic system simplifies downstream processing due to the distribution of the catalyst and reactants in different phases.

Application of Ionic Liquids in High Performance Reversed-Phase Chromatography

Directory of Open Access Journals (Sweden)

Wentao Bi

2009-06-01

Full Text Available Ionic liquids, considered “green” chemicals, are widely used in many areas of analytical chemistry due to their unique properties. Recently, ionic liquids have been used as a kind of novel additive in separation and combined with silica to synthesize new stationary phase as separation media. This review will focus on the properties and mechanisms of ionic liquids and their potential applications as mobile phase modifier and surface-bonded stationary phase in reversed-phase high performance liquid chromatography (RP-HPLC. Ionic liquids demonstrate advantages and potential in chromatographic field.

Torsten Almén (1931-2016): the father of non-ionic iodine contrast media.

Science.gov (United States)

Nyman, Ulf; Ekberg, Olle; Aspelin, Peter

2016-09-01

The Swedish radiologist Torsten Almén is the first clinical radiologist ever to have made a fundamental contribution to intravascular contrast medium design, the development of non-ionic contrast media. He became emotionally triggered by the patients' severe pain each time he injected the ionic "high-osmolar" contrast media when performing peripheral arteriographies in the early 1960s. One day he got a flash of genius that combined the observation of pain, a pathophysiological theory and how to eliminate it with suitable contrast media chemistry. After self-studies in chemistry he developed the concept of iodine contrast media not dissociating into ions in solution to reduce their osmolality and even reach plasma isotonicity. He offered several pharmaceutical companies his concept of mono- and polymeric non-ionic agents but without response, since it was considered against the chemical laws of that time. Contrast media constructed as salts and dissociating into ions in solution was regarded an absolute necessity to achieve high enough water solubility and concentration for diagnostic purposes. Finally a small Norwegian company, Nyegaard & Co., took up his idea 1968 and together they developed the essentially painless "low-osmolar" monomeric non-ionic metrizamide (Amipaque) released in 1974 and iohexol (Omipaque) in 1982 followed by the "iso-osmolar" dimeric non-ionic iodixanol (Visipaque) released in 1993. This has implied a profound paradigm shift with regard to reduction of both hypertonic and chemotoxic side effects, which have been a prerequisite for the today's widespread use of contrast medium-enhanced CT and advanced endovascular interventional techniques even in fragile patients. © The Foundation Acta Radiologica 2016.

Interagency partnering for weed prevention--progress on development of a National Early Detection and Rapid Response System for Invasive Plants in the United States

Science.gov (United States)

Westbrooks, R.; Westbrooks, R.

2011-01-01

Over the past 50 years, experience has shown that interagency groups provide an effective forum for addressing various invasive species issues and challenges on multiple land units. However, more importantly, they can also provide a coordinated framework for early detection, reporting, identification and vouchering, rapid assessment, and rapid response to new and emerging invasive plants in the United States. Interagency collaboration maximizes the use of available expertise, resources, and authority for promoting early detection and rapid response (EDRR) as the preferred management option for addressing new and emerging invasive plants. Currently, an interagency effort is underway to develop a National EDRR System for Invasive Plants in the United States. The proposed system will include structural and informational elements. Structural elements of the system include a network of interagency partner groups to facilitate early detection and rapid response to new invasive plants, including the Federal Interagency Committee for the Management of Noxious and Exotic Weeds (FICMNEW), State Invasive Species Councils, State Early Detection and Rapid Response Coordinating Committees, State Volunteer Detection and Reporting Networks, Invasive Plant Task Forces, and Cooperative Weed Management Areas. Informational elements and products being developed include Regional Invasive Plant Atlases, and EDRR Guidelines for EDRR Volunteer Network Training, Rapid Assessment and Rapid Response, and Criteria for Selection of EDRR Species. System science and technical support elements which are provided by cooperating state and federal scientists, include EDRR guidelines, training curriculum for EDRR volunteers and agency field personnel, plant identification and vouchering, rapid assessments, as well as predictive modeling and ecological range studies for invasive plant species.

Thermal annealing and ionic abrasion in ZnTe

International Nuclear Information System (INIS)

Bensahel, D.

1975-01-01

Thermal annealing of the ZnTe crystal is studied first in order to obtain information on the aspect of the penetration profile. Ionic abrasion is then investigated to find out whether it produces the same effects as ionic implantation, especially for luminescence [fr

Ionic Liquid-Based Ultrasonic/Microwave-Assisted Extraction of ...

African Journals Online (AJOL)

Conclusion: Compared with traditional methods, IL-UMAE method uses Ionic liquid-solvent which greatly shortens the extraction time. IL-UMAE as a simple, effective and environmentally friendly approach shows a broad prospect for active ingredient extraction. Keywords: Dioscorea zingiberensis Steroidal saponins, Ionic ...

Natural gas purification using supported ionic liquid membrane

NARCIS (Netherlands)

Althuluth, M.A.M.; Overbeek, J.P.; Wees, H.J.; Zubeir, L.F.; Haije, W.G.; Berrouk, A.S.; Peters, C.J.; Kroon, M.C.

2015-01-01

This paper examines the possibility of the application of a supported ionic liquid membrane (SILM) for natural gas purification. The ionic liquid (IL) 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ([emim][FAP]) was impregnated successfully in the ¿-alumina layer of a tubular

Rapid and Sensitive Detection of Bacteria Response to Antibiotics Using Nanoporous Membrane and Graphene Quantum Dot (GQDs-Based Electrochemical Biosensors

Directory of Open Access Journals (Sweden)

Weiwei Ye

2017-05-01

Full Text Available The wide abuse of antibiotics has accelerated bacterial multiresistance, which means there is a need to develop tools for rapid detection and characterization of bacterial response to antibiotics in the management of infections. In the study, an electrochemical biosensor based on nanoporous alumina membrane and graphene quantum dots (GQDs was developed for bacterial response to antibiotics detection. Anti-Salmonella antibody was conjugated with amino-modified GQDs by glutaraldehyde and immobilized on silanized nanoporous alumina membranes for Salmonella bacteria capture. The impedance signals across nanoporous membranes could monitor the capture of bacteria on nanoporous membranes as well as bacterial response to antibiotics. This nanoporous membrane and GQD-based electrochemical biosensor achieved rapid detection of bacterial response to antibiotics within 30 min, and the detection limit could reach the pM level. It was capable of investigating the response of bacteria exposed to antibiotics much more rapidly and conveniently than traditional tools. The capability of studying the dynamic effects of antibiotics on bacteria has potential applications in the field of monitoring disease therapy, detecting comprehensive food safety hazards and even life in hostile environment.

Recent development of ionic liquid stationary phases for liquid chromatography.

Science.gov (United States)

Shi, Xianzhe; Qiao, Lizhen; Xu, Guowang

2015-11-13

Based on their particular physicochemical characteristics, ionic liquids have been widely applied in many fields of analytical chemistry. Many types of ionic liquids were immobilized on a support like silica or monolith as stationary phases for liquid chromatography. Moreover, different approaches were developed to bond covalently ionic liquids onto the supporting materials. The obtained ionic liquid stationary phases show multi-mode mechanism including hydrophobic, hydrophilic, hydrogen bond, anion exchange, π-π, and dipole-dipole interactions. Therefore, they could be used in different chromatographic modes including ion-exchange, RPLC, NPLC and HILIC to separate various classes of compounds. This review mainly summarizes the immobilized patterns and types of ionic liquid stationary phases, their retention mechanisms and applications in the recent five years. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterization of the rapid transcriptional response to long-term sensitization training in Aplysia californica.

Science.gov (United States)

Herdegen, Samantha; Holmes, Geraldine; Cyriac, Ashly; Calin-Jageman, Irina E; Calin-Jageman, Robert J

2014-12-01

We used a custom-designed microarray and quantitative PCR to characterize the rapid transcriptional response to long-term sensitization training in the marine mollusk Aplysia californica. Aplysia were exposed to repeated noxious shocks to one side of the body, a procedure known to induce a long-lasting, transcription-dependent increase in reflex responsiveness that is restricted to the side of training. One hour after training, pleural ganglia from the trained and untrained sides of the body were harvested; these ganglia contain the sensory nociceptors which help mediate the expression of long-term sensitization memory. Microarray analysis from 8 biological replicates suggests that long-term sensitization training rapidly regulates at least 81 transcripts. We used qPCR to test a subset of these transcripts and found that 83% were confirmed in the same samples, and 86% of these were again confirmed in an independent sample. Thus, our new microarray design shows strong convergent and predictive validity for analyzing the transcriptional correlates of memory in Aplysia. Fully validated transcripts include some previously identified as regulated in this paradigm (ApC/EBP and ApEgr) but also include novel findings. Specifically, we show that long-term sensitization training rapidly up-regulates the expression of transcripts which may encode Aplysia homologs of a C/EBPγ transcription factor, a glycine transporter (GlyT2), and a vacuolar-protein-sorting-associated protein (VPS36). Copyright © 2014 Elsevier Inc. All rights reserved.

Integration of palliative care in the context of rapid response: a report from the Improving Palliative Care in the ICU advisory board.

Science.gov (United States)

Nelson, Judith E; Mathews, Kusum S; Weissman, David E; Brasel, Karen J; Campbell, Margaret; Curtis, J Randall; Frontera, Jennifer A; Gabriel, Michelle; Hays, Ross M; Mosenthal, Anne C; Mulkerin, Colleen; Puntillo, Kathleen A; Ray, Daniel E; Weiss, Stefanie P; Bassett, Rick; Boss, Renee D; Lustbader, Dana R

2015-02-01

Rapid response teams (RRTs) can effectively foster discussions about appropriate goals of care and address other emergent palliative care needs of patients and families facing life-threatening illness on hospital wards. In this article, The Improving Palliative Care in the ICU (IPAL-ICU) Project brings together interdisciplinary expertise and existing data to address the following: special challenges for providing palliative care in the rapid response setting, knowledge and skills needed by RRTs for delivery of high-quality palliative care, and strategies for improving the integration of palliative care with rapid response critical care. We discuss key components of communication with patients, families, and primary clinicians to develop a goal-directed treatment approach during a rapid response event. We also highlight the need for RRT expertise to initiate symptom relief. Strategies including specific clinician training and system initiatives are then recommended for RRT care improvement. We conclude by suggesting that as evaluation of their impact on other outcomes continues, performance by RRTs in meeting palliative care needs of patients and families should also be measured and improved.

Direct Capture of Organic Acids From Fermentation Media Using Ionic Liquids

Energy Technology Data Exchange (ETDEWEB)

Klasson, K.T.

2004-11-03

Several ionic liquids have been investigated for the extraction of organic acids from fermentation broth. Partitioning of representative organic acids (lactic, acetic, and succinic) between aqueous solution and nine hydrophobic ionic liquids was measured. The extraction efficiencies were strongly dependent on pH of the aqueous phase. Distribution coefficient was very good (approximately 60) at low succinic acid concentrations for one of the ionic liquids (trihexyltetradecylphosphonium methanesulfonate) at neutral pH. However, this ionic liquid had to be diluted with nonanol due to its high viscosity in order to be useful. A diluent (trioctylamine) was also added to this mixture. The results suggest that an extraction system based on ionic liquids may be feasible for succinic acid recovery from fermentation broth and that two ideal extraction stages are needed to reduce the concentration from 33 g/L to 1 g/L of succinic acid. Further studies are needed to evaluate other issues related to practical applications, including ionic liquid loss in the process, toxicity effects of ionic liquids during simultaneous fermentation and extractions.

Effects of ionic and nonionic contrast media on cardiohemodynamics and quality of radiographic image during canine angiography

International Nuclear Information System (INIS)

Nakamura, H.; Kurata, M.; Haruta, K.; Takeda, K.

1994-01-01

Cardiovascular responses and radiographic image quality during cerebral angiography, aortofemoral angiography and left ventriculography with nonionic ioxilan, iohexol or iopamidol were compared with those of ionic sodium meglumine diatrizoate in pentobarbital anesthetized dogs. Injection of all contrast media caused cardiovascular changes to a greater or lesser degree, e.g., hypotension, bradycardia, tachycardia, a decrease in left ventricular pressure (LVP) and its first derivative (dP/dt), and prolongation of the P-Q and Q-T intervals. Ionic diatrizoate had a greater effect on cardiovascular parameters than nonionic contrast media during angiography in all areas. Moreover, diatrizoate produced cardiac arrhythmias and prominent changes in blood rheology concerned with blood viscosity and deformability of the erythrocyte. The cause of various effects of contrast media seemed to lie mainly in osmolality, viscosity and partially ionic additives. The radiographic image quality of all of the contrast media used was similar, but nonionic ioxilan and iohexol with lower iodine content and low osmolality gave better radio opacity than ionic diatrizoate in cerebral angiography. These results suggested that nonionic contrast media should be recommended as a diagnostic tool for both animals and human patients in poor health

Ionic secondary emission SIMS principles and instrumentation

International Nuclear Information System (INIS)

Darque-Ceretti, E.; Migeon, H.N.; Aucouturier, M.

1998-01-01

The ionic analysis by secondary emission (SIMS) is one of material analysis based on the ions bombardment. That is micro-analysis method in taking into account that the dimensions of the analysed volume are under the micrometer. This paper details in a first part some ionic secondary emission principle to introduce a description of the instrumentation: microprobe, ions production, spectrometers. (A.L.B.)

Absorption of Flue-Gas Components by Ionic Liquids

DEFF Research Database (Denmark)

Kolding, Helene; Thomassen, Peter Langelund; Mossin, Susanne

2014-01-01

Gas separation by ionic liquids (ILs) is a promising new research field with several potential applications of industrial interest. Thus cleaning of industrial off gases seems to be attractive by use of ILs and Supported Ionic Liquid Phase (SILP) materials. The potential of selected ILs...

Near-wall molecular ordering of dilute ionic liquids

NARCIS (Netherlands)

Jitvisate, Monchai; Seddon, James Richard Thorley

2017-01-01

The interfacial behavior of ionic liquids promises tunable lubrication as well as playing an integral role in ion diffusion for electron transfer. Diluting the ionic liquids optimizes bulk parameters, such as electric conductivity, and one would expect dilution to disrupt the near-wall molecular

Thermophysical properties of phosphonium-based ionic liquids

Science.gov (United States)

Bhattacharjee, Arijit; Lopes-da-Silva, José A.; Freire, Mara G.; Coutinho, João A. P.; Carvalho, Pedro J.

2015-01-01

Experimental data for density, viscosity, refractive index and surface tension of four phosphonium-based ionic liquids were measured in the temperature range between (288.15 and 353.15) K and at atmospheric pressure. The ionic liquids considered include tri(isobutyl) methylphosphonium tosylate, [Pi(444)1][Tos], tri(butyl)methylphosphonium methylsulfate, [P4441][CH3SO4], tri(butyl)ethylphosphonium diethylphosphate, [P4442][(C2H5O)2PO2], and tetraoctylphosphonium bromide, [P8888][Br]. Additionally, derivative properties, such as the isobaric thermal expansion coefficient, the surface thermodynamic properties and the critical temperatures for the investigated ionic liquids were also estimated and are presented and discussed. Group contribution methods were evaluated and fitted to the density, viscosity and refractive index experimental data. PMID:26435574

Thermophysical properties of phosphonium-based ionic liquids.

Science.gov (United States)

Bhattacharjee, Arijit; Lopes-da-Silva, José A; Freire, Mara G; Coutinho, João A P; Carvalho, Pedro J

2015-08-25

Experimental data for density, viscosity, refractive index and surface tension of four phosphonium-based ionic liquids were measured in the temperature range between (288.15 and 353.15) K and at atmospheric pressure. The ionic liquids considered include tri(isobutyl) methylphosphonium tosylate, [P i (444)1 ][Tos], tri(butyl)methylphosphonium methylsulfate, [P 4441 ][CH 3 SO 4 ], tri(butyl)ethylphosphonium diethylphosphate, [P 4442 ][(C 2 H 5 O) 2 PO 2 ], and tetraoctylphosphonium bromide, [P 8888 ][Br]. Additionally, derivative properties, such as the isobaric thermal expansion coefficient, the surface thermodynamic properties and the critical temperatures for the investigated ionic liquids were also estimated and are presented and discussed. Group contribution methods were evaluated and fitted to the density, viscosity and refractive index experimental data.

Induction of Ca2+-dependent cyclosporin A-insensitive nonspecific permeability of the inner membrane of liver mitochondria and cytochrome c release by α,ω-hexadecanedioic acid in media of varying ionic strength.

Science.gov (United States)

Dubinin, M V; Vedernikov, A A; Khoroshavina, E I; Samartsev, V N

2014-06-01

In liver mitochondria loaded with Ca2+ or Sr(2+), α,ω-hexadecanedioic acid (HDA) can induce nonspecific permeability of the inner membrane (mitochondrial pore) by the mechanism insensitive to cyclosporin A (CsA). In this work we studied the effect of ionic strength of the incubation medium on the kinetics of the processes that accompany Ca2+-dependent induction of the mitochondrial pore by fatty acid: organelle swelling, Ca2+ release from the matrix, changes in transmembrane potential (Δψ) and rate of oxygen consumption, and the release of cytochrome c from the intermembrane space. Two basic incubation media were used: sucrose medium and isotonic ionic medium containing KCl without sucrose. We found that 200 μM Ca2+ and 20 μM HDA in the presence of CsA effectively induce high-amplitude swelling of mitochondria both in the case of sucrose and in the ionic incubation medium. In the presence of CsA, mitochondria can rapidly absorb Ca2+ and retain it in the matrix for a while without reducing Δψ. Upon incubation in the ionic medium, mitochondria retain most of the added Ca2+ in the matrix for a short time without reducing the Δψ. In both cases the addition of HDA to the mitochondria 2 min after the introduction of Ca2+ leads to the rapid release of these ions from the matrix and total drop in Δψ. The mitochondrial swelling induced by Ca2+ and HDA in non-ionic medium is accompanied by almost maximal stimulation of respiration. Under the same conditions, but during incubation of mitochondria in the ionic medium, it is necessary to add cytochrome c for significant stimulation of respiration. The mitochondrial swelling induced by Ca2+ and HDA leads to the release of cytochrome c in a larger amount in the case of ionic medium than for the sucrose medium. We conclude that high ionic strength of the incubation medium determines the massive release of cytochrome c from mitochondria and liberates it from the respiratory chain, which leads to blockade of electron

Fluorination effects on the thermodynamic, thermophysical and surface properties of ionic liquids

International Nuclear Information System (INIS)

Vieira, N.S.M.; Luís, A.; Reis, P.M.; Carvalho, P.J.; Lopes-da-Silva, J.A.; Esperança, J.M.S.S.; Araújo, J.M.M.; Rebelo, L.P.N.; Freire, M.G.; Pereiro, A.B.

2016-01-01

Highlights: • Surface tension of fluorinated ionic liquids. • Thermophysical properties of fluorinated ionic liquids. • Thermal properties and thermodynamic functions. - Abstract: This paper reports the thermal, thermodynamic, thermophysical and surface properties of eight ionic liquids with fluorinated alkyl side chain lengths equal or greater than four carbon atoms. Melting and decomposition temperatures were determined together with experimental densities, surface tensions, refractive indices, dynamic viscosities and ionic conductivities in a temperature interval ranging from (293.15 to 353.15) K. The surface properties of these fluorinated ionic liquids were discussed and several thermodynamic functions, as well as critical temperatures, were estimated. Coefficients of isobaric thermal expansion, molecular volumes and free volume effects were calculated from experimental values of density and refractive index and compared with previous data. Finally, Walden plots were used to evaluate the ionicity of the investigated ionic liquids.

Ionic Liquids: The Synergistic Catalytic Effect in the Synthesis of Cyclic Carbonates

Directory of Open Access Journals (Sweden)

Flora T.T. Ng

2013-10-01

Full Text Available This review presents the synergistic effect in the catalytic system of ionic liquids (ILs for the synthesis of cyclic carbonate from carbon dioxide and epoxide. The emphasis of this review is on three aspects: the catalytic system of metal-based ionic liquids, the catalytic system of hydrogen bond-promoted ionic liquids and supported ionic liquids. Metal and ionic liquids show a synergistic effect on the cycloaddition reactions of epoxides. The cations and anions of ionic liquids show a synergistic effect on the cycloaddition reactions. The functional groups in cations or supports combined with the anions have a synergistic effect on the cycloaddition reactions. Synergistic catalytic effects of ILs play an important role of promoting the cycloaddition reactions of epoxides. The design of catalytic system of ionic liquids will be possible if the synergistic effect on a molecular level is understood.

Ionic liquid-doped polyaniline and its redox activities in the zwitterionic biological buffer MOPS

International Nuclear Information System (INIS)

Qu, Ke; Zeng, Xiangqun

2016-01-01

The electropolymerization of aniline in several common imidazolium-based ionic liquids has been accomplished successfully with the potentiodynamic method. Considering the fact that imidazolium-based ionic liquids are acidic, they have been selected as the electrolyte for the electropolymerization of aniline, eliminating the usage of extra inorganic or organic acids. The ionic liquids not only serve as the reaction media, exerting the unique favorable π-π interactions between the imidazolium rings and benzene rings of aniline monomer or the growing polymer, but also act as the dopants to render different properties to the resulting polyaniline. Among the tested imidazolium-based ionic liquids, [BMIM][BF_4], [BMIM][PF_6], [BMIM][NTf_2], [EMIM][ES] and [HMIM][FAP], polyaniline doped by the hydrophilic ionic liquid [BMIM][BF_4] displays the good electrochemical responses in the biologically important MOPS (3-(N-Morpholino)-propanesulfonic acid) solution with 2.34 × 10"−"3 M of sulfuric acid additive. NMR, UV–vis and electrochemical impedance experiments were performed to further characterize the polyaniline/[BMIM][BF_4] composite. In contrast, polyaniline that is doped by the hydrophobic ionic liquid [BMIM][PF_6] is electroactive in the MOPS solution in the absence of the acid additive, with a pH of 5, extending the working pH range of polyaniline, which is typically electroactive in the solutions with the pH values less than 3. It is suggested that the effective hydrogen bonding interactions between BF_4 anion and water facilitate its hydrolysis in the microenvironment of the polymer backbone to provide the acidic protons, which are beneficial to the adjustment of the microenvironments of the polyaniline system and thus renders its observed well-resolved reversible pair of redox peaks in the MOPS solution. PF_6 anion, on the other hand, with its larger size and less basicity, has the weaker interaction with water, thus releasing the protons in a relatively slow

Controlling adsorption and passivation properties of bovine serum albumin on silica surfaces by ionic strength modulation and cross-linking.

Science.gov (United States)

Park, Jae Hyeon; Sut, Tun Naw; Jackman, Joshua A; Ferhan, Abdul Rahim; Yoon, Bo Kyeong; Cho, Nam-Joon

2017-03-29

Understanding the physicochemical factors that influence protein adsorption onto solid supports holds wide relevance for fundamental insights into protein structure and function as well as for applications such as surface passivation. Ionic strength is a key parameter that influences protein adsorption, although how its modulation might be utilized to prepare well-coated protein adlayers remains to be explored. Herein, we investigated how ionic strength can be utilized to control the adsorption and passivation properties of bovine serum albumin (BSA) on silica surfaces. As protein stability in solution can influence adsorption kinetics, the size distribution and secondary structure of proteins in solution were first characterized by dynamic light scattering (DLS), nanoparticle tracking analysis (NTA), and circular dichroism (CD) spectroscopy. A non-monotonic correlation between ionic strength and protein aggregation was observed and attributed to colloidal agglomeration, while the primarily α-helical character of the protein in solution was maintained in all cases. Quartz crystal microbalance-dissipation (QCM-D) experiments were then conducted in order to track protein adsorption onto silica surfaces as a function of ionic strength, and the measurement responses indicated that total protein uptake at saturation coverage is lower with increasing ionic strength. In turn, the QCM-D data and the corresponding Voigt-Voinova model analysis support that the surface area per bound protein molecule is greater with increasing ionic strength. While higher protein uptake under lower ionic strengths by itself did not result in greater surface passivation under subsequent physiologically relevant conditions, the treatment of adsorbed protein layers with a gluteraldehyde cross-linking agent stabilized the bound protein in this case and significantly improved surface passivation. Collectively, our findings demonstrate that ionic strength modulation influences BSA adsorption

Ionic Liquids in HPLC and CE: A Hope for Future.

Science.gov (United States)

Ali, Imran; Suhail, Mohd; Sanagi, Mohd Marsin; Aboul-Enein, Hassan Y

2017-07-04

The ionic liquids (ILs) are salts with melting points below 100°C. These are called as ionic fluids, ionic melts, liquid electrolytes, fused salts, liquid salts, ionic glasses, designer solvents, green solvents and solvents of the future. These have a wide range of applications, including medical, pharmaceutical and chemical sciences. Nowadays, their use is increasing greatly in separation science, especially in chromatography and capillary electrophoresis due to their remarkable properties. The present article describes the importance of ILs in high-performance liquid chromatography and capillary electrophoresis. Efforts were also made to highlight the future expectations of ILs.

Ionic Size Effects: Generalized Boltzmann Distributions, Counterion Stratification, and Modified Debye Length.

Science.gov (United States)

Liu, Bo; Liu, Pei; Xu, Zhenli; Zhou, Shenggao

2013-10-01

Near a charged surface, counterions of different valences and sizes cluster; and their concentration profiles stratify. At a distance from such a surface larger than the Debye length, the electric field is screened by counterions. Recent studies by a variational mean-field approach that includes ionic size effects and by Monte Carlo simulations both suggest that the counterion stratification is determined by the ionic valence-to-volume ratios. Central in the mean-field approach is a free-energy functional of ionic concentrations in which the ionic size effects are included through the entropic effect of solvent molecules. The corresponding equilibrium conditions define the generalized Boltzmann distributions relating the ionic concentrations to the electrostatic potential. This paper presents a detailed analysis and numerical calculations of such a free-energy functional to understand the dependence of the ionic charge density on the electrostatic potential through the generalized Boltzmann distributions, the role of ionic valence-to-volume ratios in the counterion stratification, and the modification of Debye length due to the effect of ionic sizes.

Corrosion behavior of construction materials for ionic liquid hydrogen compressor

DEFF Research Database (Denmark)

Arjomand Kermani, Nasrin; Petrushina, Irina; Nikiforov, Aleksey Valerievich

2016-01-01

The corrosion behavior of various commercially available stainless steels and nickel-based alloys as possible construction materials for components which are in direct contact with one of five different ionic liquids was evaluated. The ionic liquids, namely: 1-ethyl-3-methylimidazolium triflate, 1...... liquid hydrogen compressor. An electrochemical cell was specially designed, and steady-state cyclic voltammetry was used to measure the corrosion resistance of the alloys in the ionic liquids at 23 °C, under atmospheric pressure. The results showed a very high corrosion resistance and high stability...... for all the alloys tested. The two stainless steels, AISI 316L and AISI 347 showed higher corrosion resistance compared to AISI 321 in all the ionic liquids tested. It was observed that small addition of molybdenum, tantalum, and niobium to the alloys increased the corrosion stability in the ionic liquids...

Oxidative desulfurization of fuel oil by pyridinium-based ionic liquids.

Science.gov (United States)

Zhao, Dishun; Wang, Yanan; Duan, Erhong

2009-10-28

In this work, an N-butyl-pyridinium-based ionic liquid [BPy]BF(4) was prepared. The effect of extraction desulfurization on model oil with thiophene and dibenzothiophene (DBT) was investigated. Ionic liquids and hydrogen peroxide (30%) were tested in extraction-oxidation desulfurization of model oil. The results show that the ionic liquid [BPy]BF(4) has a better desulfurization effect. The best technological conditions are: V(IL)/V(Oil) /V(H(2)O(2)) = 1:1:0.4, temperature 55 degrees C, the time 30 min. The ratio of desulfurization to thiophene and DBT reached 78.5% and 84.3% respectively, which is much higher than extraction desulfurization with simple ionic liquids. Under these conditions, the effect of desulfurization on gasoline was also investigated. The used ionic liquids can be recycled up to four times after regeneration.

Oxidative Desulfurization of Fuel Oil by Pyridinium-Based Ionic Liquids

Directory of Open Access Journals (Sweden)

Erhong Duan

2009-10-01

Full Text Available In this work, an N-butyl-pyridinium-based ionic liquid [BPy]BF4 was prepared. The effect of extraction desulfurization on model oil with thiophene and dibenzothiophene (DBT was investigated. Ionic liquids and hydrogen peroxide (30% were tested in extraction-oxidation desulfurization of model oil. The results show that the ionic liquid [BPy]BF4 has a better desulfurization effect. The best technological conditions are: V(IL/V(Oil /V(H2O2 = 1:1:0.4, temperature 55 °C, the time 30 min. The ratio of desulfurization to thiophene and DBT reached 78.5% and 84.3% respectively, which is much higher than extraction desulfurization with simple ionic liquids. Under these conditions, the effect of desulfurization on gasoline was also investigated. The used ionic liquids can be recycled up to four times after regeneration.

Quantitative Determination on Ionic-Liquid-Gating Control of Interfacial Magnetism.

Science.gov (United States)

Zhao, Shishun; Zhou, Ziyao; Peng, Bin; Zhu, Mingmin; Feng, Mengmeng; Yang, Qu; Yan, Yuan; Ren, Wei; Ye, Zuo-Guang; Liu, Yaohua; Liu, Ming

2017-05-01

Ionic-liquid gating on a functional thin film with a low voltage has drawn a lot of attention due to rich chemical, electronic, and magnetic phenomena at the interface. Here, a key challenge in quantitative determination of voltage-controlled magnetic anisotropy (VCMA) in Au/[DEME] + [TFSI] - /Co field-effect transistor heterostructures is addressed. The magnetic anisotropy change as response to the gating voltage is precisely detected by in situ electron spin resonance measurements. A reversible change of magnetic anisotropy up to 219 Oe is achieved with a low gating voltage of 1.5 V at room temperature, corresponding to a record high VCMA coefficient of ≈146 Oe V -1 . Two gating effects, the electrostatic doping and electrochemical reaction, are distinguished at various gating voltage regions, as confirmed by X-ray photoelectron spectroscopy and atomic force microscopy experiments. This work shows a unique ionic-liquid-gating system for strong interfacial magnetoelectric coupling with many practical advantages, paving the way toward ion-liquid-gating spintronic/electronic devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.