Electrical double layer capacitors (supercapacitors) can complement or replace batteries in electrical energy storage and harvesting applications, when high power delivery or uptake is needed. However, we need to substantially improve their performance to meet higher requirements of future systems, ranging from portable electronics to hybrid electric vehicles and large industrial equipment, by developing new materials and advancing our understanding of the electrochemical interfaces at the nanoscale. A limited energy density has been one of the main weaknesses of capacitive energy storage devices. The use of ionic liquids having the electrochemical stability window wider than the currently used organic electrolytes allow an increase in the energy density, which is proportional to voltage squared. A notable improvement in supercapacitor performance can be achieved due to the use of ionic liquid electrolytes with the voltage window >3 V. However, ionic conductivity of these IL at room temperature is just a few mS/cm. This explains why they are mainly used at elevated temperatures. Carbide-derived carbon (CDC) with an EMI/TFSI electrolyte has demonstrated capacitance of 160 F/g and ~90 F/cm3 at 60°C [1] and excellent performance of CDC electrodes at 100°C was recently shown [2]. However, microporous carbons may not be the best choice for low-temperature applications. A careful choice of both the anion and the cation allows the design of high-voltage supercapacitors capable of operating in an extended temperature range. For applications in the temperature range â?"50°C to +100°C, a mix of ionic liquids with slightly different cations, but the same ion has been successfully used in combination with nanotube and carbon onion electrodes [3]. A possibility of choosing from a huge variety of combinations of anions and cations offers the potential for designing an IL electrolyte with a high ionic conductivity and a voltage window of >3.5 V at room temperature. The research on ionic liquids for supercapacitors is expected to play an important role in the improvement of capacitor performance in the coming years. Understanding charge storage mechanisms at the interface between ionic liquid and a charged high-surface area carbon electrode is required for successful use of these electrolytes. This presentation will discuss the development of advanced nanostructured carbon materials that can work with materials.

Lithium-ion batteries have been widely used in portable electronic devices, and also been proposed as power sources for electric vehicles and large-scale energy storage. However, the performance of current lithium ion batteries can not meet the requirements in these areas, in terms of high power density, long cycle life, and high safety. Spinel Li4Ti5O12, as a zero-strain insertion material with a relatively high Li storage voltage of 1.54 V, has been considered as a promising anode material for long-life batteries. However, the low electric conductivity (~10-13 S/cm) of the pure Li4Ti5O12 hinders its application in these fields. The most effective way to improve the electric conductivity of Li4Ti5O12 is to coat high-conductive carbon or metal on their surface of nanoparticles or porous particles; however, the conventional carbon-coating processes are either complex or have to be performed at high temperature (> 600 oC). In addition, there are few reports on tuning the composition of the coating layer to obtain the best electrochemical performance. Here we propose a new approach to coat electrode materials by a thin uniform layer of nitrogen-doped (N-doped) carbon pyrolyzed from ionic liquids at rather low temperature. Both the rate performance and cycling performance have been significantly improved after N-doped carbon coating. The specific capacities of the coated Li4Ti5O12 with 7 wt.% N-doped carbon are 145 and 129 mAh/g at current rates of 5C and 10C, respectively, which are much higher than the pristine sample (60 and 15 mAh/g). At a current rate of 2C, the capacity retention of 83% can be achieved after 2200 cycles for the coated sample in a half cell, compared with the capacity retention of 73% after 100 cycles for the pristine sample. The excellent performance of the N-doped carbon-coated Li4Ti5O12 can be attributed to the surface modification by N-doped carbon which not only greatly enhances the electric conductivity but also remarkably increases the surface stability of Li4Ti5O12. Furthermore, the effects of carbon coating layer, with and without nitrogen-dopants, on the electrochemical performance of Li4Ti5O12 were investigated. The comparative experimental and DFT results show that the Li storage performance of Li4Ti5O12 samples coated by nitrogen-doped carbon is advantageous over the carbon coated sample. This proposed approach is relatively simple, yet very effective, and owing to its versatility can also be extended to modify other electrode materials for electrochemical devices. Acknowledgements The authors thank the invaluable discussion with Prof. Sheng Meng. This work was supported by funding from the 100 Talent Project of the Chinese Academy of Sciences, â?o863â? Project (2009AA033101) and NSFC (50972164). References [1] L. Zhao, Y. S. Hu, H. Li, Z. X. Wang, L. Q. Chen, Adv. Mater., 2011, 23, 1385. [2] Z. J. Ding, L. Zhao, L. M. Suo, Y. Jiao, S. Meng, Y. S. Hu, Z. X. Wang, L. Q. Chen, Phys. Chem. Chem. Phys. 2011, 13, 15127.

Room temperature ionic liquids (RTILs) have unique characteristics such as low volatility, non-flammability, high ionic conductivity, and high chemical stability. RTILs are now promising electrolytes for lithium secondary batteries, because the thermal stability of the batteries is strongly desired. We focus on lithium ionic liquids which can conduct Li+ cation. Clear liquids can be obtained by simple mixing of glyme (triglyme or tetraglyme) with lithium bis(trifluoromethylsulfonyl)amide (Li[TFSA]) in a molar ratio of 1:1. The equimolar complex [Li(triglyme or tetraglyme)1][TFSA] maintains a stable liquid state over a wide temperature range and can be regarded as a room-temperature ionic liquid consisting of a [Li(glyme)1]+ complex cation and a [TFSA]- anion, exhibiting high self-dissociativity (ionicity) at room temperature. The oxidative stability of the glyme molecules is enhanced by the complex formation with Li+ cations. The electrochemical oxidation of [Li(glyme)1][TFSA] takes place at the electrode potential of ~5 V vs. Li/Li+, while the oxidation of solutions containing excess glyme molecules ([Li(glyme)x][TFSA], x > 1) occurs at around 4 V. This enhancement of oxidative stability is due to the donation of lone pairs of ether oxygen atoms to the Li+ cation, resulting in lowering of the highest occupied molecular orbital (HOMO) energy level of a glyme molecule, which is confirmed by ab initio molecular orbital calculations. The solvation state of a Li+ cation and ion conduction mechanism in the [Li(glyme)x][TFSA] solutions is elucidated by means of nuclear magnetic resonance (NMR) and electrochemical methods. The experimental results strongly suggest that Li+ cation conduction in the equimolar complex takes place by the migration of [Li(glyme)1]+ cations and [TFSA]- anions, whereas the ligand exchange mechanism is overlapped when interfacial electrochemical reactions of [Li(glyme)1]+ cations occur. The ligand exchange conduction mode is typically seen in a lithium battery with a configuration of [Li anode | [Li(glyme)1][TFSA] | LiCoO2 cathode] when the discharge reaction of a LiCoO2 cathode, i.e., de-solvation of [Li(glyme)1]+ and insertion of the resultant Li+ into the cathode, occurs at the electrode-electrolyte interface. The battery can be operated for more than 200 charge-discharge cycles in the cell voltage range of 3.0â?"4.2 V, regardless of the use of ether-based electrolyte, because the ligand exchange rate is much faster than the electrode reaction rate.

Li-ion batteries (LIB) are dominant in portable electronic market as power sources owing to their advantages in voltage and energy densities as compared with other battery technologies [1]. The current state-of-art electrolytes for LIB are mixtures of ethylene carbonate (EC) with either dimethyl carbonate (DMC) or diethylene carbonate (DEC), which are highly flammable organic solvents and have safety concerns. As an alternative, ionic liquids (ILs) having negligible vapor pressure, low flammability, wide electrochemical window, high ionic conductivity and high thermal stability are idea candidate for safe electrolytes.[2] On the other hand, solid polymeric electrolytes (SPEs), which can be used as both an ion conducting media and separator in rechargeable lithium batteries, have many advantages over liquid electrolytes such as low cost design, flexibility in sizes and shapes, and also most importantly in safety, which make them ideal candidates for electric vehicle batteries. [3] The combination of ionic liquids and polymer electrolyte, i.e. ionic liquid based gel polymer electrolytes, possess the benefit of both systems, have higher ionic conductivity than that of dry polymer electrolytes, and thus provide high power capability. [4] In this talk I will cover our research in ionic liquid electrolytes and ionic liquid based gel polymer electrolytes. The physicochemical properties of these electrolytes such as thermal property, ionic conductivity, self-diffusion coefficients, and electrochemical stability, as well as performance in half cells of graphite||Li, Li4Ti5O12||Li, Li||LiFePO4 will be presented. Acknowledgements: This research was supported by the U.S. Department of Energyâ?Ts Office of Basic Energy Science, Division of Materials Sciences and Engineering, under contract with UT-Battelle, LLC. References: 1. K. Xu, Chem Rev, 2004, 104, 4303. 2. M. Armand, F. Endres, D. R. MacFarlane, H. Ohno, B. Scrosati, Nat. Mater., 2009, 8, 621. 3. X. G. Sun, C. L. Reeder, J. B. Kerr, Macromolecules, 2004, 37, 2219. 4. J. H. Shin, W. A. Henderson, S. Passerini, Electrochem. Commun., 2003, 5, 1016.

Efficient production of hydrogen from water is an important goal that would represent a significant step towards truly sustainable supplies of energy. Ultimately, solar-driven water electrolysis could supply most of the worldâ?Ts fuel needs, while on a more immediate timeframe there is growing interest in generating hydrogen from non-fossil energy sources (nuclear, wind and solar) as a fossil fuel replacement. However, water electrolysis is currently too low in efficiency to be practical, due mainly to energy losses at the water oxidation electrode. We describe here a novel catalyst material that has high efficiency in both electrically driven and solar driven modes. The oxygen generating catalyst is based on manganese oxide that is stabilized and sensitized by a surface phosphorylation reaction in an ionic liquid electrodeposition process. The catalyst supports high rates of water oxidation and exhibits a light stimulation effect such that water oxidation rates are even higher under illumination. More than 80 hours of continuous water oxidation have been demonstrated.

Classification of ionic liquids (ILs) into â?oPoorâ? (or sub-ionic), â?oGoodâ? and â?oSuperionicâ? ILs has become a familiar application of the Walden plot, which relates the ionic mobility (represented by the easily measured equivalent conductivity) to the easily measured fluidity of the system. Superprotonic ILs (SPILs) are protic ILs in which the equivalent conductivity is in excess of that predicted by the Walden rule, using aqueous KCl as the standard for viscosity control of ionic mobility. SPILs are of special interest in fuel cell technology where the ideal electrolyte would be one that conducts like an aqueous solution but is mechanically solid, i.e. where the mechanism of conductivity is completely decoupled from the mechanical flow process. Here we explore two alternative methods of achieving a significant decoupling of the conductivity from the viscous flow process while maintaining conductivity at the level of that of the commercially relevant electrolyte, hydrated phosphoric acid, while maintaining the system totally anhydrous. Data for a third system with much greater decoupling at the expense of some decrease in conductivity, will be included in the comparison, under the description â?osystem Xâ?. The first of the two high conductivity systems is based on a simple improvement on the phosphoric acid system, achieved by removing the water and increasing the viscosity to compensate the consequent small loss of conductivity. The latter can be recovered by raising the temperature, a possibility opened up by the lower vapor pressure of water over the system. High decoupling in this system is achieved by taking advantage of the short O-O distance between neighboring phosphate groups which is associated with a favorable hydrogen bonded network structure within which the Grotthus mechanism operates efficiently (as in supercooled dilute aqueous HCl). The second method is a more interesting one, the possibility of which was suggested by the proton energy level diagram recently introduced by this group - the subject of a separate presentation from this group. In this method the forces restraining the motion of the proton are reduced by moving the entire proton-donor acceptor system of protic ionic liquids into the superacidic domain. In this domain the forces restraining the motion of the proton are reduced to small values by providing an environment with just enough screening for the proton to avoid instability. Under these conditions the proton motion passes from Grotthus-like, requiring molecular group reorientations, towards a free proton hopping mechanism ( the ideal limit of which would merit the description of â?oproton plasmaâ?). This limit is intellectually intriguing but has the disadvantage that the system is difficult to control in consequence of its extreme proton (chemical) activity.

The growing markets of portable devices, hybrid electric vehicles and renewable energies demand for high-power energy sources.^[1] In this regard, supercapacitors have attracted much attention due to their high specific power, fast charge/discharge rates and long life cycle, bridging the gap between conventional capacitors and batteries.^[2] Concerning the charge-storage mechanism, supercapacitors are classified into electrical double layer capacitors (EDLC) and pseudocapacitors. The capacitance arises from a physical charge separation commonly known for carbon electrodes or Faradaic reactions at metal compounds or heteroatom dopants in carbons, respectively.^[3] Hybrid supercapacitors reveal a promising approach to overcome limitations of each system benefiting from the combination of an excellent reversibility of EDLCs and high power densities of pseudocapacitors.^[4] In this context, we recently described the synthesis of nitrogen-doped carbon using ionic liquids (IL) as precursors.^[5] Since IL are liquid solvents at ambient temperature with negligible vapor pressure, simple processing, mixing and dissolution of further precursors is possible. The facile one-pot synthesis of composites of metal nitride nanoparticles in a nitrogen-doped carbon matrix using IL as nitrogen/carbon source will be presented. Furthermore, the tunability of the surface area by an in situ activation approach as well as the superior performance of the composites as electrodes for supercapacitors will be shown. [1] Wang, G., L. Zhang, and J. Zhang, A review of electrode materials for electrochemical supercapacitors. Chemical Society Reviews, 2011. [2] Jayalakshmi, M. and K. Balasubramanian, Simple Capacitors to Supercapacitors - An Overview. International Journal of Electrochemical Science, 2008. 3(11): p. 1196-1217. [3] Zhai, Y., et al., Carbon Materials for Chemical Capacitive Energy Storage. Advanced Materials, 2011: p. n/a-n/a. [4] Perera, S.D., et al., Vanadium Oxide Nanowireâ?"Carbon Nanotube Binder-Free Flexible Electrodes for Supercapacitors. Advanced Energy Materials, 2011. 1(5): p. 936-945. [5] Paraknowitsch, J.P., A. Thomas, and M. Antonietti, A detailed view on the polycondensation of ionic liquid monomers towards nitrogen doped carbon materials. Journal of Materials Chemistry, 2010. 20(32): p. 6746-6758.

One of the most fascinating properties of ionic liquids in electrochemistry is that they have wide electrochemical windows that allow to deposit reactive elements like aluminium, silicon, tantalum and other ones. Furthermore conducting polymers can be made easily in ionic liquids. By a combination of template methods with electrodeposition 3D ordered macroporous (3DOM) materials and free standing nanowires are accessible. It will be shown that 3DOM structures of Ge, Si and Al can be made as well as 3DOM structures of conducting polymers. Such materials are not only interesting for photonic applications but also as materials in lithium(ion) secondary batteries. Furthermore free standing Al and Si nanowires can be made, and such materials are also interesting for future generation secondary batteries.

The superior chemical/physical properties of room temperature ionic liquids (RTILs), such as unlimited functional combinations through synthesis, wide electrochemical windows, high ion conductivities and low environmental impacts render them great promise in the development of advanced electrolytes for electrochemical energy storage systems, including batteries/fuel cells and supercapacitors. However, our knowledge of the atomic/nanoscale reactivity at interfaces of RTILs with electrodes, usually carbon-based materials, remain scares due to the incomplete understanding of interfacial structures and processes in-situ and real-time encountered in real operation conditions. In this talk, we will present our efforts to obtain a molecular-scale perspective of the interactions of RTIL electrolytes with carbon surfaces near â?oreal worldâ? conditions. Structures of imidazolium-based RTILs (like BMIM-Tf2N) on atomically flat graphene (epitaxially grown on a SiC substrate), an ideal model fluid-solid interface system, were investigated by coupling high-resolution interface X-ray scattering techniques with molecular modeling-simulation approaches. Two central findings can be concluded from our integrated modeling-simulation-experimental studies. On intrinsically uncharged graphene surface, the first well-defined liquid layer of BMIM-Tf2N appears to be a mixed layer of cations and anions species. Moreover, a significant densification for the first layer with respect to the bulk RTIL density, beyond what classical MD simulations predict by using simple graphene-RTIL cross-interaction parameters, was observed from the X-ray determined electron density profile. The anomalous density enhancement for the interfacial layer can be explained quantitatively by taking into accounts the contributions of image charge forces and polarizability of graphene sheet, extended Ï?-Ï? interactions between hexagon carbon rings and imidazolium groups, and nanoaggregations due to the long tail entanglements of BMIM cations. On electrified graphene surfaces, RTIL exhibits distinct molecule layering indicating the sensitivity of interfacial RTIL structures to electrostatic interactions. An alternative cation/anion layering as a function of surface potentials can be quantified by both the X-ray determined and MD generated electron density profiles. At a high voltage smaller than that for decomposition, the resulting interfacial charge density profile indicates a RTIL double layer structure with a charge overscreening, where the first liquid layer at graphene surface accumulates more countercharges than is on the surface. The overscreening observation is consistent with the prediction of a simple mean-field theory capturing short-range Coulomb correlations within the length of order the ion size.

The talk deals with the thermal polycondensation of ionic liquid monomers and polymers to N-doped carbons, which can be understood as resin-like organic metals. Conductivity results as well as first model reactions using the materials in catalytic active electrodes are presented. Structural variations and the use of catalytic transformation schemes also enable the generation of systems with controlled porosity and nanostructure.

Ionothermal synthesis is the use of ionic liquids as both solvent and structure directing agent in the formation of unusual materials with unique structure and function. Originally designed for the synthesis of porous solids, the technique has been extended to almost all types of inorganic, organic and hybrid materials, with Morris particularly concentrating on new zeolites, metal-organic frameworks and magnetic hybrids. The research has exploited the distinctive features of ionic liquids to develop a synthetic methodology that is now widely used. These features lead to the possibility of entirely new concepts that are unique to the ionothermal method, such as the use of ambient pressure solvothermal conditions, the controlled delivery of structure directing agents, anion control (and the exquisite control over water as a mineraliser it allows) and effective chiral induction etc, which have enabled the synthesis of many new materials that cannot be accessed using other routes. One particular feature of ionothermal chemistry â?" anion control â?" has particularly important consequences. Changing the anion of an ionic liquid has major effects on the properties of an ionothermal synthesis, leading to the preparation of solids such as a porous AlPO cloverite (a material that has eluded the community for almost 20 years) and the first example of a d1 kagome lattice recently published, and the first non-d9 candidate for a Quantum Spin Liquid Material. Changing the anion to one that is chiral can lead to the induction of a homochiral (i.e. the bulk sample is all of one hand) solid that is built only from achiral building units. In this presentation I will explore how we have used ionic liquids to design syntheses that lead to materials that are not accessible using other methods, paying particular attention to the properties of the ionic liquid that lead to novel outcomes.

There are certain properties of ionic liquids (ILs) such as the excellent solubility of number of substances, their good thermal stability or their intrinsic ionic character that make them especially suitable for use as media for the preparation of materials. In these cases, ILs can act as a regular solvent, as a solvent which shows a more or less controlled SDA effect or even as a molecular precursor with a well-defined composition, structure, and reactivity (the termed next generation â?oall-in-oneâ? solventâ?"templateâ?"reactant ILs). Within this context, ILs have also emerged as an interesting media to carry out different polymerizations. However, the replacement is yet difficult to justify in economical terms because of the cost of common ILs unless the resulting polymer offer certain specific properties attainable only because of their use. A related class of ILs named deep-eutectic solvents (DESs) may offer an interesting alternative. DESs are obtained by complexion of quaternary ammonium salts with hydrogen-bond donors. DESs share many characteristics of conventional ILs (e.g. nonreactive with water, nonvolatile and biodegradable) while offering certain advantages (e.g. high purity and low cost, among the most significant). Our work has been lately focussed on some particular polymerization processes that are carried out at relatively high temperatures and where DESs are not only simple substitutes to water or organic solvents in providing a reaction media of a certain viscosity and with negligible vapour pressure but also the molecular precursors and even the SDA for the preparation of polymers with both controlled morphology and chemical composition and hence, with interesting perspectives for their application in catalysis, energy or biomedicine. References: 1. Gutierrez, M. C.; Rubio, F.; del Monte, F. Chem. Mater. 2010, 22, 2711-2719. 2. Carriazo, D.; Gutierrez, M. C.; Ferrer, M. L.; del Monte, F. Chem. Mater. 2010, 22, 6146â?"6152. 3. Gutierrez, M. C.; Carriazo, D.; Ania, C.; Parra, J.; Ferrer, M. L.; del Monte, F. Energy Environ. Sci. 2011, DOI: 10.1039/C1EE01463C 4. Gutierrez, M. C.; Carriazo, D.; Tamayo, A.; Jiménez, R.; Picó, F.; Rojo, J. M.; Ferrer, M. L.; del Monte, F. Chem.-A Eur. J. 2011, DOI: 10.1002/chem.201101679 5. Serrano, M. C.; Gutierrez, M. C.; Jimenez, R.; Ferrer, M. L.; del Monte, F. Chem. Commun. 2011, Submitted 6. Mota-Morales, J. D.; Gutierrez, M. C.; Sanchez, I. C.; Luna-Bárcenas, G.; del Monte, F. Chem. Commun. 2011, 47, 5328-5330

In the context of reducing global emissions of CO2, believed to be partly responsible for global warming and climate change, the use of CO2 as industrially useful chemical feedstock is a major issue. Indeed, CO2 can be seen as a sustainable carbon source, in terms of renewability, abundance, and non-toxicity. Thus, the development of new efficient (heterogeneous) catalysts for CO2 conversion remains of major concern. Among others, ionic liquids showed promising results in the conversion of CO2 to organic carbonates, which, due to their high oxidation state, appear to be an interesting synthetic target. Recently ionic nanoparticle networks (INN) were reported in the frame of the remarkable development of new inorganic-organic hybrid materials based on nanoparticle assembly. The original method we developed to synthesize 3-D networks is based on the functionalization of metal oxide nanoparticles with ionic linkers, the bridging ligands containing imidazolium units. The combination of high imidazolium content with the presence of metal centers, also able to coordinate to CO2 molecules, makes the hybrid materials INN highly promising catalyst for CO2 activation reactions. Moreover, the INN materials are solid which allow an easy separation of the catalyst after reaction. Moreover, the imidazolium bridging units in the final hybrid material renders the INN tailorable. For example, anion metathesis allows tuning the hydrophilic character of the hybrid material; as a consequence hexafluorophosphate INN will be hydrophobic whereas chloride INN is hydrophilic. In this communication, we will report the efficient use of the chloride INNs as base catalysts for the cycloaddition of CO2 to different starting epoxides. The reactions were performed under relatively mild conditions (e.g. low CO2 pressure) in comparison with reported results. In this communication the catalytic performances of INN with mono- and di-imidazolium bridging units as well as with various counter anions will be presented.

Ionic liquids with nitrogen containing cations and cyano-functionalised anions have been shown to be suitable precursors for N-doped carbon materials. N-doped graphitic carbon materials with nitrogen atoms directly incorporated into the graphitic sheets can be synthesized by simply annealing the ionic liquid precursors in an inert gas atmosphere. The bulk materials exhibit high stability against oxidation and good electric conductivities. The material could further be improved by inducing different nanostructures exhibiting high active surface areas. Varying the inorganic templates the morphologies can be easily altered; e.g. hierarchically porous monoliths can be obtained and applied as electrodes.[1, 2] Of course this novel concept is not limited to the mere thermolysis of ionic liquid precursors. It is further possible to apply and extend the use of ionic liquids as carbon precursors. On the one hand carbon nanotubes can be coated with a layer of N-doped carbon using ionic liquid precursors. The N-doped carbon layer causes a remarkable increase of stability of Pt nanoparticles loaded on the composite material for electrocatalysis, which has been investigated by in-situ SAXS studies in fuel cells. The N-doped carbon layer significantly reduces the tendency of the nanoparticles to agglomerate and thus improves the efficiency of the entire fuel cell.[3] On the other hand the reactivity of the ionic liquids was transferred to other fields of materials chemistry. Most recently an ionic liquid surfactant that is combining the structure directing properties of an amphiphile with the reactivity of a precursor for N-doped carbon has been introduced. A composite of silica and N-doped carbon consisting of submicron sized mesoporous spheres could be prepared in a one pot synthesis.[4] Besides it is feasible to exploit the coordinating properties of the dicyanamide anion synthesizing tetradicyanamidocobaltates and the respective nickelates. Pyridinium- and imidazolium derivatives as countercations yield metal containing ionic liquids with manifold potential for materials synthesis. They can be applied for the in-situ synthesis of metal and metal oxide loaded mesoporous silicas and carbon/silica-composites without the necessity of any additional wet impregnation steps. Rod-like or discotic nanoparticles on mesoporous carbon/silica composite supports could thus be successfully synthesised in one step.[5] The chemistry of ionic liquids for their use as carbon precursors was elucidated and applied. It was thus possible to contribute to establishing a novel type of precursor system that represents a highly promising candidate for numerous applications in carbon chemistry and materials synthesis in general. /// References: [1] J. Mater. Chem. 2010, 20, 6746. [2]Adv. Mater. 2010, 22, 87. [3]X. Tuaev, J.P. Paraknowitsch, R. Illgen, A. Thomas, Strasser, submitted. [4]J. Mater. Chem. 2011, 21, 15537. [5]J.P. Paraknowitsch, O. Sukhbat, A. Thomas, submitted.

Although many efforts have been devoted into the preparation of nanoporous aluminophosphates and aluminosilicates, the range of materials that can be synthesized is still limited. Recently, ionothermal synthesis was introduced to the preparation of zeolite and metal-organic frameworks by Morris and his co-workers. The utilization of ILs and DES as solvents to replace traditional aqueous solutions in material synthesis offers new opportunities in synthesis of inorganic solids with unique frameworks, which cannot be obtained through other methods due to highly ionic environment under synthetic conditions. In this presentation, we will demonstrate the feasibility to fabricate nanoporous first row transition metal phosphates as potential materials for energy applications through ionothermal approach. Beginning with a cobalt precursor, we have successfully synthesized blue crystals with a very high yield (>95%). Single crystal XRD analysis revealed the structure of this crystal is layered with cobalt phosphate seating in one layer and various cations forming the other layer. The distance between two layers is ~12 Ã., which is capable to host guest ions, e.g. Li+ and H+, through ion exchange. Such a capability is extremely important for this material to be act as intercalation cathode material for lithium-ion battery or as oxygen evolution catalyst for solar fuel production. A composition of (CH3NH3)[CoPO4]4(H2PO4) was obtained from the refinement of single crystal XRD results. By increasing the reaction time, the layered crystals underwent a phase transition to a three-dimensional structure with a composition of (NH4)2(NH3CH3)3[CoPO4]5. The cobalt phosphate clusters are linked by bridge oxygen atoms to form a 3D nanoporous network with an average pore size of ~6 Ã.. These materials represent the first examples of cobalt phosphate frameworks obtained from ionothermal synthesis. We also investigated the template effect in this method by replacing N,Nâ?T-dimethylurea with N,Nâ?T-trimethyleneurea in the initial mixture. This combination results in a new compound, which has NH3(CH2)3NH32+ filled in the pores with a pore size about 7 Ã.. It clearly demonstrated the feasibility to tune the pore structure and size through choosing different cations. In addition, water effects in the ionothermal synthesis of cobalt phosphates have been investigated. With a small amount of water, the methyl ammonium decomposition is somehow accelerated and forms ammonium ions, resulting in a new crystal, NH4CoPO4 hexagonal phase. Further increase of water content will lead to a pink precipitate, NH4CoPO4 hydrate, which has been synthesized through a hydrothermal approach. This observation clearly demonstrates that water plays a critical role in the ionothermal synthesis and the crystal structures could be tuned by adjusting the water concentration in the ILs.

Doubtless, ILs provide a flexible liquid platform for catalysis by transition metal nanoparticles. Indeed, ILs can act as the â?osolventâ?, stabilizer, ligand and support for MNPs. It is now possible to design metal nanoparticle catalysts for specific applications, in particular for the selective hydrogenation of arenes under very mild reaction conditions. Indeed, it appears that soluble MNPs in ILs behave as â?osingle-site metal catalystsâ? for the hydrogenation of alkenes, but as â?osoluble-likeâ? heterogeneous catalysts for the reduction of arenes or in Fischer-Tropsh synthesis. These MNPs may serve as simple reservoirs of soluble monometallic catalysts for C-C coupling reactions, such as the Heck reactions. The catalytic activity, selectivity and the stability of MNPs in non-functionalized ILs is related mainly to the surface electronic stabilization provided by protective layers of discrete supramolecular imidazolium aggregates, non-polar imidazolium alkyl side chains and/or NHC species as well as surface hydrogen species, together with an oxide layer when present on the metal surface. The introduction of moieties on the imidazolium side chain, such as N-, O- and S-containing groups, or ligands (mainly P- and N-containing ligands) provide extra stabilization of MNPs through coordination to the metal surface which allows for modulating the selectivity of the catalyst, akin to classical organometallic/coordination catalysis. ILs are therefore among the premiere â?osolutionsâ? for the generation of tailor-made soluble nanomaterials for catalysis. In particular, the use of functionalized ILs and ionophilic ligands open a new window of opportunity for these soluble metal nanoparticles in catalysis, both in terms of selectivity and activity. Most important, ILs can be used as immobilizing agents, and a simple thin film of the ionic liquid is necessary to give the desired properties for the catalytic device (stability, selectivity, etc.), thus significantly reducing the mass-transfer problems usually associated with reactions performed when ILs are used as solvents.

The ultimate - and so far largely unmet - goal in developing more efficient catalytic materials is to combine the selectivity, specificity and synthetic availability offered by homogeneous catalysis with the ease of processing and the robustness that can be realized with heterogeneous catalysis. It is exactly this challenge that has, to a great extent, stimulated our research over the past ten years. Based on our sound expertise in ionic liquids and molten salts, two different concepts aiming for introducing more uniformity and molecular control into catalysis with macroscopically solid contacts have been investigated in our group. The so-called â?oSupported Ionic Liquid Phase (SILP)â? catalysis concept is based on a classical homogeneous catalyst that is dissolved in a thin film of ionic liquid with the latter being dispersed over the high internal surface area of a porous support. In SILP materials the dissolved catalyst still acts microscopically as a homogeneously dissolved metal complex in its uniform ionic liquid environment, while â?" macroscopically - a dry solid forms that can be processed in reactor concepts traditionally applied in heterogeneous catalysis, e.g. fixed-bed reactors. The Solid Catalyst with Ionic Liquid Layer (SCILL) concept, in contrast, is based on a traditional heterogeneous catalyst material. The latter is coated with a thin film of ionic liquid or molten salt to induce specific modifications of the catalytic performance. These modifications origin from either a modified reactant concentration at the active site (owing to the ionic liquidâ?Ts differential solubility) and/or from a chemical modification of the catalytic sites (owing to the ionic liquidâ?Ts reactivity with the active surface site) in a ligand-like fashion. Due to their extremely low vapor pressure, the IL film resides on the catalyst surface under the reaction conditions of continuous gas-phase experiments. Our contribution will present first the preparation and characterization of SILP and SCILL materials. Applications in hydroformylation and water-gas-shift (WGS) catalysis (SILP catalysis) as well as in methanol steam reforming (SCILL catalysis) will be discussed in more detail. As a particular highlight, the first attempt to combine the SILP and the SCILL approach in a bifunctional catalyst material will be presented for the hydroisomerization of octane.

Emission of acidic gases such as NOx and SOx and COx from e.g. energy production by fossil fuels in power plants, is a major concern in relation to atmospheric pollution and climate changes. Therefore, these gases have to be effectively removed from flue gases. Presently this is mainly achieved by relatively energy intensive and resource demanding technologies via selective catalytic reduction (SCR) of NOX with ammonia, by gypsum formation after SO2 wet-scrubbing while organic amines are being used as absorbents in CO2 scrubbers. This leads to concern about, e.g. intensive energy requirements for desorption, corrosion of steel pipes and pumps, CO2 absorption capacity and thermal decomposition of the amine. In this work, we demonstrate how ionic liquids (IL) can be tuned by design to perform as selective, high-capacity absorbents of environmentally problematic flue gases like, e.g. SO2 , NO ,NO2 and CO2 . Reversible absorption has been obtained for several different 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 results show that CO2 , NO, NO2 and SO2 can be reversible and selective absorbed using different ILs and that SILP absorbers are promising materials for industrial flue gas cleaning. Absorption / desorption dynamics can be tuned by temperature, pressure ,gas concentrations and the properties of the porous carrier.

Porous carbon materials are known for their applicability in gas separation, water purification and catalyst supports as well as important new areas in electrochemistry (e.g. electrodes for supercapacitors and fuel cell catalysts). Especially in these new topical application areas a lot of interest aroused lately due to possible coupling of advantageous structural properties and unique chemistry. The preparation of high content nitrogen doped and conductive graphitic carbons (g-carbons) can be achieved by employing ionic liquids (ILs) as precursors. ILs can easily infiltrate template structures, whilst from a process standpoint they possess no vapor pressure meaning carbonization can be conducted without high-pressure or special safety concerns. The liquid precursor state, high ionic interactions and the negligible vapor pressure allow facile shaping of the final product and introduction of high surface areas via templating strategies.[1-3] We and others have recently shown that mesoporous carbon with structurally integrated nitrogen acts as an inexpensive and highly active metal-free catalyst in the oxygen reduction reaction (ORR) important in polymer electrolyte membrane fuel cells (PEMFCs).[4, 5] Herein oxygen is directly reduced to water usually in a four electron mechanism. In a two electron mechanism oxygen is first reduced to intermediate hydrogen peroxide (H2O2) and due to the high reactivity of H2O2 a fast second two electron reduction step produces water. As continuation of the achieved results, which often showed electron transfer numbers4 we could recently produce a highly selective nitrogen doped carbon catalyst for the selective electrocatalytic reduction of oxygen to hydrogen peroxide in a pure two electron mechanism being promising for a cheap, green and safe production of the important industrial chemical.[6] An introduction to the precursor system as well as the synthesis and properties of highly active catalysts for the two and four electron mechanism will be presented. [1] J. P. Paraknowitsch, A. Thomas, M. Antonietti, Journal of Materials Chemistry 2010, 20, 6746. [2] J. P. Paraknowitsch, J. Zhang, D. Su, A. Thomas, M. Antonietti, Advanced Materials 2010, 22, 87. [3] X. Wang, S. Dai, Angewandte Chemie International Edition 2010, 49, 6664. [4] W. Yang, T.-P. Fellinger, M. Antonietti, Journal of the American Chemical Society 2011, 133, 206. [5] R. Liu, D. Wu, X. Feng, K. Müllen, Angewandte Chemie International Edition 2010, 49, 2565. [6] T. P. Fellinger, F. Hasché, P. Strasser, M. Antonietti, 2011-submitted.

The interface between low temperature plasmas (or gas discharges) and ionic liquids is interesting for two reasons: (a) Their low vapor pressure allows to use ionic liquids as fluid â?oelectrodesâ? for plasmas. (b) The plasma can be used to polarize the surface of the IL electrically without mechanical contact. Thus, electrochemical processes can be initiated at the surface of an IL with free electrons (plasma-reduction) or free gaseous ions (plasma-oxidation) from the plasma. This new type of interface has only recently been investigated, but attracts growing interest due to a number of potential applications. In this contribution, we analyze the possible electro¬chemical experiments with ILs in reactive and inert plasmas and present experimental examples for the de-position of metal nanoparticles (Cu, Ag, Au, Pd) at the surface of different ILs by plasma-reduction. Metal deposition at free IL surfaces by plasma reduction is a new type of process, and the possible mechanism of this process is discussed. The influence of IL properties is tested by the systematic variation of the IL cation, and the correlation between IL density, surface tension and viscosity on the deposition process will be discussed.

Atomic force microscope force measurements have been used to investigate the nanostructure of ionic liquids near solid surfaces. The force profiles reveal how the structure of the ions varies with distance from the surface. Close to the substrate the ions are arranged into relatively well ordered layers, which decay to the bulk liquid morphology over several nanometers. The level of liquid nanostructure increases when a potential is applied to a conducting gold surface, as does the strength of the attraction of counterions to the substrate. These results have implications for electrochemical processes in ionic liquids. Lateral force measurements reveal that the frictional response is dependent on the number of ion pair layers between the surfaces in addition to the sliding speed. At high shear rates surface induced shear thinning is detected.

Ionic Liquids (ILs) are a novel class of materials with interesting physico-chemical properties and promising application potential. During the last years a variety of interesting IL-based concepts have been proposed, thereby increasing the demand for a thorough understanding of fundamental IL properties. With respect to new catalytic materials two innovative concepts were developed, namely â?oSupported Ionic Liquid Phaseâ? (SILP) catalysis [1] and the â?oSolid Catalyst with Ionic Liquid Layerâ? (SCILL) system [2]. For these concepts the interface of the IL with the gas phase (or vacuum) or with the supporting solid play a crucial role. Due to their negligible vapour pressure, ILs and in particular their surfaces and interfaces can, in contrast to normal liquids, be investigated by all ultrahigh vacuum-based methods of surface science [3], in particular by using angle resolved X-ray photoelectron spectroscopy [4-6]. This allows determining their properties with the same atomic level accuracy that is presently common for solid surfaces and conventional adsorbate systems. Apart from the investigation of the specific properties of ionic liquids, which are relevant for many applications, this also opens the possibility to obtain more detailed insight in the general physical and chemical properties of liquids. In this presentation the surface and interface properties of several imidazolium-based ionic liquids will be presented [3-6], including the surface composition of non-functionalized hydrophobic ILs and PEG-functionalized hydrophilic ILs, the growth behaviour and the properties of ultrathin IL layers on various substrates, the properties of dissolved catalyst complexes and the in-situ monitoring of organic liquid phase reactions. [1] A. Riisager, P. Wasserscheid, R. van Hal, R. Fehrmann, J. Catal. 219 (2003)452. [2] U. Kernchen, B. Etzold, W. Korth, A. Jess, Chem. Eng. Technol. 8 (2007) 985. [3] H.-P. Steinrück, Surf. Sci. 604 (2010) 481. [4] K. R. J. Lovelock, I. J. Villar-Garcia, F. Maier, H.-P. Steinrück, P. Licence, Chem. Rev. 110 (2010) 5158. [5] H.-P. Steinrück, J. Libuda, P. Wasserscheid, T. Cremer, C. Kolbeck, M. Laurin, F. Maier, M. Sobota, P. S. Schulz, M. Stark, Adv. Mater. 23 (2011) 2571. [6] F. Maier, J. M. Gottfried, J. Rossa, D. Gerhard, P. S. Schulz, W. Schwieger, P. Wasserscheid, H.-P. Steinrück, Angew. Chem. Int. Ed. 45 (2006) 7778.

Ionic liquids have found widespread use in a number of applications, especially as electrolytes in electrochemical capacitors and PEM fuel cells. Protic ionic liquids (PILs), formed by mixing Bronsted acids and bases, are particularly interesting given their high ionic conductivities, wide temperature range of operation, and intrinsically anhydrous conduction. In order to improve their performance, a detailed understanding of the proton dynamics are required, both on a macroscopic and microscopic level. Though a number of techniques are able to address the macroscopic properties of these materials, neutron scattering provides a unique window into the microscopic motions of the conducting protons. Here we discuss the proton dynamics in a class of PILs using quasielastic neutron scattering (QENS), a technique that is able to probe the dynamics on picosecond to nanosecond time scales. At these time scales, in addition to diffusive motions, there are indications of transient molecular species that could play a significant role in the macroscopic conductivity. The interplay of these different motions will be critically important for the understanding of the detailed mechanisms of protonic conductivity in these systems.

Room-temperature ionic liquids (ILs) exhibit a unique set of properties, leading to opportunities for numerous applications. We set out to obtain a better understanding of both interfacial and aggregation behavior of charged surfactants within ILs. Because of their extremely low vapor pressure, ILs lend themselves to ultra-high vacuum techniques such as X-ray photoelectron spectroscopy (XPS) that complement traditional tensiometry. XPS confirms the surface acitivity of charged surfactants at IL interfaces, and reveals further unique information. For example, surfactant counterions are completely dissociated from the interface, leading to ion exchange between the surfactant and IL. In particular at short chain lengths, the large extent of ion exchange can begin to influence the overall surface charge of the system. Solubility phase diagrams and isotherms were then constructed, revealing the critical role of temperature. From the aggregation behavior, a connection between solubility of the surfactant and the physical properties of the underlying ionic liquid was established. By using a mean-field approach, we conclude that the interfacial energy is crucial in both solubility and aggregation behavior. The role of IL chemistry is important, and is reflected in the net attractive interactions across the interface. The results here give insight into explaining the nature of self-assembly of surfactants at IL interfaces and the interaction between solutes and IL solvents.

The Fluid Interface Reactions, Structures and Transport (FIRST) Energy Frontier Research Center, funded by DOEâ?Ts Office of Basic Energy Sciences, is primarily located at Oak Ridge National Laboratory, with participating partners at Argonne National Laboratory and six universities. Room Temperature Ion Liquid (RTIL) research in the Center is primarily focused on understanding the structural, dynamic and transport properties of these unique electrolytes for electrical energy storage applications (e.g. batteries, supercapacitors), where their low vapor pressures and high electrochemical stabilities can result in enhanced energy and power densities. In particular, we are interested in determining ionic transport and desolvation processes at carbon electrode and other charged surfaces as a function of temperature, surface potential and degree of nanoconfinement. I will review our integrated molecular modeling, electrochemical, X-ray and neutron scattering, NMR, and fluorescence correlation spectroscopic studies of these unique electrolytes at flat and nanotextured surfaces and within nanopores. Examples of new results of our research include detection of faster-than bulk fluid diffusional dynamics and oscillatory capacitance for RTILs in carbon nanopores, dual diffusion properties of dye molecules in bulk RTILS related to local structuring of RTIL cations, and suppression of crystallization at low temperature under nanoconfinement.

The tuneable properties of RT-ILs allow for a vast range of applications and are achieved by careful selection of their cation and anion (1 - 3). Combination of RT-ILs and silica mesoporous supports might create unique materials with the advantageous properties of both components. Such systems can serve model materials for studies of solid-liquid interfaces in confined media providing an important scientific challenge of understanding structure and dynamics on different time and length scales and requiring application of advanced NMR, XRD, thermal methods as well as computer modelling. Two classes of supported ionic liquid phases (SILP) have been prepared in which [bmim]OTf and [bmim]CH₃SO ₃ were confined within the mesoporous silicas at varying loadings. Advanced NMR experiments have provided an important insight into the structure and orientation of both confined RTILs. For both classes of SILP studied, ¹H linewidths, T₁ relaxation times and ¹H-¹³C CP dynamics identified the presence of a less mobile surface confined layer at both high and low loadings with a more mobile bulk material emerging in the centre of the mesopores as loading increased. The orientation of the RTILs with respect to the pore surface was probed by ¹H-²⁹Si HETCOR experiments and in both cases showed the butyl chains and N-methyls to interact more closely with the pore surface. Computer modelling of the [bmim]OTf intercalates confirmed the orientation of the cation and predicted that the anion would sit in closest proximity to the pore surface in the cavity created by surface hydroxyls interacting with the terminal methyl groups of the cation. The encapsulation of [bmim]CH₃SO₃ leads to formation of new support specific phases with properties very different from the original IL. These transformations are discussed in terms of long-range ordering and local structure and dynamics. References: 1. P. Wasserscheid and T. Welton, Ionic Liquids in Synthesis, 2007. 2. L. Li et al J. Mol. Cat. A 2004, 209, 227. 3. N. Winterton, Clean Technologies and Environmental Policy, 2010, 12, 325.

The viscoelastic properties and ionic conductivity of ion gels based on the self-assembly of a poly(styrene-b-ethylene oxide-b-styrene) (SOS) triblock copolymer in the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([EMI][TFSA]) were investigated over the composition range of 10 â?" 50 wt% SOS and the temperature range of 25 â?" 160 °C. The S end-blocks associate into micelles, whereas the O mid-blocks are well-solvated by this ionic liquid. The ion gel with 10 wt% SOS melts at 54 °C, suggesting chain pull-out of the S end-blocks. Ion gels with 20 â?" 50 wt% SOS do not melt and show two plateaus in the storage modulus over the temperature and frequency ranges measured. The one at lower temperatures is that of an entangled network of O strands with S cross-links. The other plateau at higher temperatures is that of a congested micelle solution with S cores and O coronas, which has a power law dependence on domain spacing similar to diblock melts. The ionic conductivity of the ion gels is compared to O homopolymer solutions at similar polymer concentrations. The conductivity is reduced by a factor of 2 or less, decreases with increasing S volume fraction, and follows predictions based on a simple obstruction model.

Sandalwood oil is best known as a sweet, warm, and woody essential oil used as a body fragrance and as an ingredient in fragrant products such as incense, perfumes, aftershaves, aromatherapy oil and other cosmetics. Currently, sandalwood oil is obtained from sandalwood by steam distillation, supercritical fluid extraction (e.g. supercritical CO₂), or by solvent extraction. The successful application of ionic liquids (ILs, salts with melting points below 100 °C) in the biomass area indicates that ILs might be a promising solvent to extract sandalwood oil. This presentation will discuss our results on extraction of sandalwood oil from sandalwood root using ILs. It was found that sandalwood could be dissolved in both 1-ethyl-3-methylimidazolium acetate ([C₂mim]OAc) and 1,3-diethylimidazolium acetate ([C₂C₂im]OAc). Sandalwood oil was extracted from the sandalwood/IL solutions using diethyl ether, which forms a biphasic system with the ILs. The main components of the obtained sandalwood oil (i.e. α-santalol and β-santalol) were confirmed by GC-MS, FT-IR and NMR. After the extraction of sandalwood oil, cellulose-rich material and free lignin were regenerated from the wood/IL solutions, thus allowing an integrated process of separating all the major components of sandalwood, the biopolymers and oil.

The ion-specific rotational dynamics of cations and anions in the room temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [C₄mim]PF₆ have been investigated in the supercooled liquid and glassy states using ¹³C, ³¹P and ¹⁹F NMR spectroscopy. The α relaxation process of the supercooled liquid corresponds well with that of the isotropic rotational reorientation of the [C₄mim]⁺ cations. The timescale of the reorientational motion of the butyl chains in the cations is found to be slower than that of the rotational isomerization of the imidazolium ring. This unintuitive result can be attributed to the presence of local structures in the form of polar and nonpolar nanodomains in the liquid and strong and different steric and coulombic interactions between the rings or chains in the cations and such domains. On the other hand, the constituent PF₆^{â^'} anions show a dynamical transition near ~ 230 K from a high temperature regime dominated by free rotational diffusion to restricted rotation or librational motion dominating at lower temperatures. This transition temperature can be identified with the mode coupling critical temperature T_c. The librational motion has a characteristic timescale on the order of 10^-10 s with an activation energy of ~ 0.15 eV typical of a β relaxation process. This dynamical process continues below T_g, well into the glassy state of this ionic liquid.

ILs often get associated with green chemistry as they get promoted as alternative synthesis media. However, more and more criticism appeared questioning this. And indeed, not all IL chemistry is environmentally friendly. But ionic liquids, if carefully and sensibly chosen, offer due to their modular character and connected unique set of chemical and physical properties a tremendous potential for nanomaterials synthesis. Indeed, the application of ionic liquids in the synthesis of metal, oxide and fluoride nano-materials is highly beneficial. Nanoparticle size and morphology can be easily controlled by the ionic liquid. It is even possible to control the crystal phase in case of oxide and fluoride particles. This is extremely important as these parameters influence the properties of the obtained material. By carefully selecting the ionic liquid and the reaction conditions it is possible to synthesise high-performance nanomaterials for energy related applications.

Ultracapacitors, one class of the electrochemical energy storage device, possess two porous electrodes and an electrolyte. Due to the limitations of commonly used activated charcoals and other carbons as electrodes, new nanoporous materials need to be explored. Both the ion size of the electrolyte and the pore size of the carbon electrode require optimization to improve the charge transfer and energy storage. Therefore, nanomaterials with high surface area such as reduced graphite oxide (rGO) are preferable. Beyond optimizing the electrode material, considerable effort has been invested in optimizing the electrolyte. Circumventing the limitations of water-based electrolytes, ionic liquidsâ?T(ILs) low volatility, non-flammability, thermal stability and good solvating ability are promising. This study focuses on the interactions between ILs (N-methyl-N,N,N-tris(2-hydroxy-ethyl)ammonium iodide, N-methyl-N,N,N-tris(2-hydroxyethyl)ammonium methylsulfate, 1-butyl-3-methylimidazolium methylsulfate, and N-octyl-N-methylpiperidinium methylsulfate) and rGO. ILs are found to intercalate into the graphitic structure, and exfoliation is then performed via thermal reduction of GO. We perform powder x-ray diffraction analysis to characterize the interlayer distance of rGO intercalated with ILs. For instance, its d-spacing increases by about 4-12 Ã. after intercalating as-synthesized GO (d-spacing approximately 9 Ã.) with N-methyl-N,N,N-tris(2-hydroxyethyl) ammonium methylsulfate at room temperature. Further annealing at high temperatures such as 300-500°C led to the disappearance of the reflection associated with the (002) orientation of GO as a result of thermal exfoliation. To explore the functionalization (covalent versus non-covalent), we use in-situ infrared absorption spectroscopy measurements to investigate the reduction mechanism of the GO/IL composites. After annealing the composites, the loss of C-N and C-O species is identified by the disappearance of peaks at ~1000-1500 cm^-1 and 800-1200 cm^-1, respectively. The degree of expansion and exfoliation varies after annealing at ~500°C, depending on the type of IL used. The individual effects of the ILsâ?T cations and anions, as well as the solvent (deionized water versus propylene carbonate, PC), on the expansion of graphene is also examined. Based on our experimental findings, we find that long tail ammonium chains with methylsulfate anions increases the efficiency of the thermal reduction of GO. Moreover, the use of PC as an intercalation solvent promoted thermal reduction of the GO/IL composites. The formation of sheet-to-sheet bonding was also studied with x-ray photoelectron spectroscopy. In conclusion, this work impacts the design of ILs and rGO in an effort to optimize the compositesâ?T properties for their implementation in ultracapacitors. *Research supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award DE-SC001951.

Ionic liquids are often considered as promising solvents for battery electrolytes, in particular in the case of lithium electrolytes. In this paper we report on systematic studies of the properties (e. g. electrical conductivity) of dispersions of nano-scaled and mesoporous silica and other filler materials with different ionic liquids (plus lithium conducting salt). In most cases, a conductivity depression is observed upon adding the nano-scaled fillers materials. However, in exceptional cases of mesoporous filler materials with well defined pore diamter, we observed an increase in the electrical conductivity. The electrical properties of these IL dispersions (or IL/inorganic filler composites) are discussed in the context of the "soggy sand" model and in the light of recent results on the structure of near-surface films of ILs. The results on ILs are compared with systematic studies on conventional organic electrolytes.

Ionic liquids (ILs) exhibit unique properties and consequently have been an area of intense focus. We have investigated properties of binary systems consisting of a polymer and an IL. Certain polymers in ILs undergo phase separation with a variation in temperature. Unlike polymers in typical molecular solvents, the phase separation of polymers in non-volatile ILs may afford novel thermoresponsive materials and material systems that can be used over a wide range of temperature and pressure condition, thereby attracting considerable interest in these polymer/ IL combinations. From the standpoint of fundamental science, it is exceptionally important to understand how the solubility of polymers in ILs is determined. Investigation of the phase behavior of polymers over a wide range of temperature and concentration, using thermally stable ILs as solvents, is also important from the practical perspective. In previous research, we reported the lower critical solution temperature (LCST) phase separation behavior of polyethers in water. We found the polarity which depends on the structure of the side chain determined LCST behavior of the polyether in water. Recently, we found that poly(ethyl glycidyl ether) (PEGE) exhibits LCST phase behavior not only in water but also in certain ILs. PEGE, which was synthesized by ring-opening anionic polymerization of the corresponding epoxide monomer in the presence of an appropriate base, exhibits LCST in 1-alkyl-3-methylimidazolium bis(trifluoromethane sulfonyl)amide ([Cnmim][NTf2]), but was immiscible in [Cnmim]-based ILs with different anions. We tried to understand the miscibility of PEGE in different ILs in terms of Lewis acidity and basicity of the ILs. PEGE was more miscible with increasing the alkyl chain length. On the other hand, in ILs with highly basic anion, imidazolium cations preferentially interact with strongly basic anions rather than oxygen atom of the polyether, particulary with the C2 proton of imidazolium cation, leading to lower miscibility. Competition between anion-cation and polyether-cation interaction appear to be correlated with the miscibility of PEGE in the ILs. In addition, we found that the hydrogen bonds between the ether oxygen atoms of PEGE and the aromatic hydrogen atoms of imidazolium cations play an important role in the miscibility of PEGE. Other polyether derivatives having different hydrophobic side chain were also examined to study the effect of hydrophobicity of polyether on the miscibility in ILs. Furthermore, we will discuss thermodynamic aspects of PEGE/[Cnmim][NTf2] binary systems. From full phase diagrams of PEGE/IL binary mixtures and the DSC analysis, thermodynamic aspects of the dissolution of PEGE into the ILs are analyzed by mean of vanâ?Tt Hoff plots of the partition coefficients. The thermodynamic parameters (Î"H and Î"S values for dissolution of a polyether into an IL) may allow more-detailed discussion about the LCST phase behavior.

The object of the this work is the theoretical study by molecular modeling and simulation of the system consisting of a geminal zwitterionic liquid composition dissolved in water with high content of divalent ions, such as sea water or water from the oil well (water congenital) or aromatic hydrocarbon solvents, with application as wettability modifiers for rocks such as limestone, in the presence of brines with high content of divalent ions such as calcium, magnesium, barium and strontium, high temperature and high pressure, in order to enhanced oil recovery processes oil to increase oil production.

Recently, Ionic Nanoparticle Networks (INN) were reported, based on imidazolium bridged nanoparticles. These new hybrid materials revealed original features, such as luminescent properties or porosity, depending strongly on the nanoparticles grafting density. For gas sequestration or gas separation applications, but even more for photoluminescence applications, the structure of the hybrid material has to be investigated. The position of the chlorine anions, compensating the imidazolium bridging units is a very promising information to investigate the accessibility of the imidazolium functionalities. We report in this work the structural characterization of silica INN focusing on the chlorine atoms. Experimental solid state NMR results were combined with periodic DFT structural models and the corresponding calculated NMR parameters. An â?oexoticâ? nucleus like 35Cl (which suffers from a rather low sensitivity) is very interesting in such systems and requires the use of very high field NMR spectrometers. Moreover, 1H/X/Y correlations experiments can be quite informative for such hybrid materials, in particular when 1H spectra are well resolved thanks to the use of an ultra fast MAS probe (70 kHz.

Practical electrolyte applications require the optimization of a wide range of properties. Unfortunately, for ionic liquid (IL)-based electrolytes, the link between cation structure, transport properties (conductivity, viscosity), and thermophysical properties (phase transitions) has not been widely studied. ILs composed of the bis(trifluoromethansulfonyl)imide anion (TFSI-) and various cations were therefore prepared and characterized. Salts with cations containing heteroatoms (e.g., N-alkyl-N-methypyrrolidinium, N-alkyl-N-methylmorpholinium, etc.), and their mixtures with LiTFSI, have been compared with analogous salts without the heteroatoms in which the cation ring size and alkyl chain length (propyl to pentyl) have been varied. The substitution of an ether group into the N-alkyl-N-methylpyrrolidinium cation increases the salt's liquidus range, but has little effect on the transport properties relative to the ILs without heteroatoms, in sharp contrast to the N-alkyl-N-methylpyrrolidinium salts.

Ionic liquids (ILs) are room temperature molten salts and have attracted much attention because of their unique properties. The characteristics of ILs are (electro) chemical stability, thermal stability, high ionic conductivity, nonvolatility, and nonflamability. Many studies concerning ILs have been devoted to developing next-generation materials, such as those used in electrochemical devices, separation and catalytic processes. We have investigated compatible binary systems consisting of synthetic polymers and ILs, aiming at utilizing them as solid electrolyte of energy conversion and storage devices. In addition, we have recently focused on unique phase transition of polymers (polymers gels) in ILs in response to external stimuli such as temperature. It was found for the first time that poly(N-isopropylacrylamide) (PNIPAm)â?"the most well-known and widely studied synthetic polymer that shows a lower critical solution temperature (LCST) behaviour in an aqueous solutionâ?"exhibited upper critical solution temperature (UCST) behaviour in an IL. Furthermore, Lodge and co-workers reported interesting property of block copolymer self-assembly in an IL. In particular, diblock copolymer consisting of polybutadiene (PB) and poly(ethylene oxide) (PEO) can form micelle having PB-core and PEO-shell both in water and in a hydrophobic IL. They have demonstrated the micelle reversibly shuttles between water and the water-immiscible IL phases by changing temperature. Here, we show preparation and characterization of a novel nano-gel which can transfer between water and hydrophobic IL phases by changes in temperature. Thermo-sensitive diblock copolymers (a precursor of the nano-gel), consisting of PEO as the first segment and random copolymer of NIPAm and N-acryloyloxysuccinimide (NAS) as the second one, could be successfully prepared by a combined use of anionic-ring-opening polymerization of EO from phenothiazine as a starting material and reversible addition-fragmentation chain transfer polymerization. A coupling reaction of P(NIPAm-r-NAS) with ethylene diamine gave a cross-linked PNIPAm network surrounded by well-solvated PEO coronas. Swelling ratio both in water and IL phases of the nano-gel was monitored by using dynamic light scattering (DLS) technique. A round trip nano-gel process could be directly detected by Tyndall effect without introducing additional labeling. The nano-gel was swollen in water phase at low temperature but shrunken with an increase in temperature due to the LCST nature of PNIPAm-core network. In contrast, the nano-gel exhibited opposite phase behavior in an IL, i.e., low-temperature shrunken and high-temperature swollen states. The nano-gel can be potentially utilized for a load-transfer-release micro-reactor system in hydrophobic IL and water biphasic conditions.

Ionic liquids are famous for their role as a green solvent for chemical reactions. Aside from well-known physical properties such as high viscosity and negligible vapour pressure, some ionic liquids are also intrinsically acidic, allowing them to catalyse acid-base reactions. In this work, the acidity of ionic liquids was investigated, using two methods. The first one is the conventional Hammett measurement using basic dyes. 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([C4C1im][NTf2]) was used as a non-acidic reference ionic liquid. Comparison of the absorbance coefficient of the dyes in a particular ionic liquid with that in [C4C1im][NTf2] resulted in the acidity value of that ionic liquid. The second method used the more recently developed acid probe mesityl oxide. The difference in chemical shift between signals at ca 124 ppm and 155 ppm was recorded as Î"δ. Plotting of Î"δ against concentration of the ionic liquids in acetonitrile produced their acidity values.

One of the problem of Barium strontium titanate(BST) for application in tunable microwave devices is hard to achieve a low dielectric loss with a high tunability and good temperature stability. In order to improve the dielectric temperature stability of BST materials, BaTiO₃ and SrTiO₃ powders were mixed by stoichiometric proportion of Ba_0.75Sr_0.25TiO₃, and then ball milled for 24h. Undoped and doped TiO₂(1.5mol.%)ceramic samples with intra-grain compositional gradients were fabricated, respectively, with the help of Ba_0.75Sr_0.25TiO₃ sol-aided sintering. The densification, microstructure and dielectric properties of the sintered ceramics have been investigated. XRD results reveal that all of the sintered samples exhibit a perovskite structure with absence of second phases. Compared with the pure Ba_0.75Sr_0.25TiO₃, the curie temperatures of TiO₂-doped Ba_0.75Sr_0.25TiO₃ appears a slight migration towards higher temperatures. The dielectric temperature stability of the TiO₂-doped Ba_0.75Sr_0.25TiO₃ is better than the pure sample at temperature range from 80^oC to 230^oC and at our test frequency from 10KHZ to 100KHZ. Moreover, at frequency of 100 KHz and temperature range from 80^oC to 230^oC, the dielectric loss of the TiO₂-- doped BST is about 0.005, that is much less than the dielectric loss of the undoped BST. The low dielectric of the TiO₂- doped BST is useful for tunable microwave applications.

There is growing shift from conventional liquid electrolytes towards solid polymer electrolytes in lithium ion batteries due to the many advantages of the latter including safety, mechanical stability and thin film manufacturability. One of the main issues in semi-crystalline solid polymer electrolytes is their lower ion conductivity compared to liquid electrolytes. Nanoscale fillers are known to enhance ion conductivity (1 to 3 orders of magnitude) without compromising the mechanical properties of the polymer electrolyte. In this study, we have identified more than 20 factors that can affect lithium ion conductivity in polymer nanocomposite electrolytes (PNEs) classified into six major categories including the polymer host, lithium salt, filler, plasticizer, fabrication process, and testing conditions. We have developed a semi-empirical free-volume based model for ion conductivity enhancement in PNEs and verified good fitting with experimental results. We propose two dominant mechanisms involved in ion conductivity enhancement in PNEs including polymer free-volume expansion and Li salt dissociation enhancement.

The design and manipulation of efficient and rapid transport pathways for ion and electron are key issues in the development of power and energy density of energy storage devices. Here, we demonstrate that the nanohybridization of ionic liquid (IL) and cobalt hydroxide nanofiber via ionothermal synthesis leads to a promotion of simultaneous ion and electron transfer by a tailored favorable morphology and surface chemistry, resulting in a high rate capability and long term stability of pseudocapacitor. The construction of the porous network structure of IL-Co(OH2) nanofibers achieved excellent textile properties with 4.8 nm of mesopore size and 400.4 m2 gâ?"1 of large surface area, thus the inner electrochemical active sites can be fully accessed with electrolyte ions, making ion diffusion length shorter. More importantly,the electron transfer was triggered by means of the facilitated intercalation/de-intercalation process of protons as a consequence of strong interactions with ILs and Co(OH)2. This enhancement of ion and electron transfer of hybrid enabled to more improve electrochemical characteristics, compared to the bare Co(OH)2, showing a high specific capacitance of 859 F gâ?"1 at 1 A gâ?"1, high rate capability (~95% retention at 30 A gâ?"1), and excellent cycling performance (~96% retention over 1000 cycles). The hybridization strategy described in this work can be expected to extend the applicability into other electrochemical devices, making it possible to create diverse functionalities of nanohybrids with varying constitutive components.

Ionic liquids are more and more suggested as ideal substitutes for traditional solvents in catalysis, due to their ability in immobilizing transition-metal catalysts [1-2]. Besides the tunable chemical properties suitable for a modern synthetic approach, these alternative solvents provide a special stabilization towards the nanosized catalysts, by surrounding the metal nanoparticles with a protecting shell that impedes them to aggregate. Gold nanoparticles (Au-NPs) have attracted interest in catalysis since from the pioneering works by Haruta [3-4], who reported their use in the CO oxidation at low temperature. During the last decade, that interest has grown exponentially with main applications in the redox-type reactions [5]. Most of the efforts with gold nanoparticles in C-C bond forming reactions have been made by Cormaâ?Ts group [6]. In this context, during the last decade we reported a number of highly sustainable Pd-nanoparticles catalysed cross-coupling reactions carried out in ionic liquids (ILs) [7-8]. As a result of our success with Pd colloids, we have been interested in exploiting our protocols in gold nanoparticles catalysis. In this communication we present the first example of gold-catalysed Ullmann-type reductive homo-coupling of haloarenes corroborated by detailed studies (based on Transmission Electron Microscopy and X-ray Photoelectron Spectroscopy -XPS- analyses) on the dependence of the nanocatalyst size and morphology from the reaction conditions. In particular, XPS has been used to systematically asses the surface chemical composition of the nanocatalysts, providing pieces of information on the metal surface oxidation states. References 1 Pârvulescu, V. I.; Hardacre, C. Chem. Rev. 2007, 107, 2615-2665 2 Zhang, C.Z. Advances in Catalysis, 2006, 49, 153-237 3 M. Haruta, N. Yamada, T. Kobayashi, S. Iijima,J. Catat. 1989, 115, 301 4 M. Haruta, T. Kobayashi, H. Sano, N. Yamada, Chem. Lett. 1987, 405 5 D. Astruc in Nanoparticles and Catalysis, Wiley-VCH, Weinheim 2008 6 See for example González-Arellano, C.; Abad, A.; Corma, A.; Hermenegildo, G.; Iglesias, M.; Sà nchez, F. Angew. Chem. Int. Ed. 2007, 46, 1536 7 Calò, V.; Nacci, A.; Monopoli, A.; Cotugno, P. Chem. Eur. J.2009, 15, 1272; 8 Calò, V.; Nacci, A.; Monopoli, A.;Cotugno, P.; Angew. Chem. Int. Ed.2009, 48, 6101

We sought to develop a quantitative demonstration of the diamagnetic property of H2O that could be easily conducted in a high school classroom with a minimum of available materials and mathematical knowledge. Additionally, we investigated the effects of a magnetic field on H2O solutions containing NaCl and CuSO4. By mapping the deflection of an incident laser, we were able to determine both the size and shape of the deformation on the surface of the solution. Our findings strongly suggest that the change in gravitational energy density for each solution is due entirely to the effect of the magnetic field and surface tension forces.

Composites of ionic liquids (ILs) with inorganic nanoparticles and/or polymeric materials have attracted much interest as new materials, since they may be able to be used as solid electrolytes and other functional soft materials. In such systems, properties of the composite materials, such as transport, mechanical and optical properties, are mainly dominated by how the second component exists in ILs (i.e., dispersibility for colloidal systems and solubility for polymeric systems, respectively). With regard to the colloidal systems, dispersion of colloidal particles in aqueous and polar organic media has been generally attributed to the electrostatic repulsion between the particles because of the electric double layer formed on surface of colloidal particles. In ILs, however, high ionic strength of the ILs makes the electric double layer thinner and attenuates the electrostatic repulsion between the colloidal particles because of charge-screening effect. Thus, charged colloidal particles normally aggregate in ILs. In order to improve colloidal stability through steric repulsion and excluded volume effect, polymer chains were grafted onto the surface of silica nanoparticles. Poly(methyl methacrylate) were grafted on monodisperse silica nanoparticles (PMMA-g-NPs) by surface-initiated atom transfer radical polymerization, and we found that PMMA-g-NPs were well-suspended in 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([C2mim][NTf2]) which is good solvent for the grafted PMMA. In this study, we focus on the effect of ionic structure on the properties of dilute suspension and concentrated gel systems. First, the hydrodynamic radius (Rh) of PMMA-g-NPs in 1-alkyl-3-methylimidazolium ([Cnmim])-based ILs with different anionic structures was measured by dynamic right scattering to study the affinity of the ions to the grafted PMMA, which dictates the colloidal stability of PMMA-g-NPs. In a dilution system, PMMA-g-NPs were stably dispersed in [Cnmim][NTf2] (n=2, 4, 6, 8) and Rh was nearly independent of the alkyl chain length. On the other hand, Rh in [C4mim]-based ILs with different anion structures ([NTf2], [(C2F5SO2)2N], [PF6], [CF3SO3]) were drastically changed though the suspension still remained stable without any aggregation. Furthermore, PMMA-g-NPs were aggregated in certain [C4mim]-based ILs including [C4mim][BF4], [C4mim][CF3CO2] and so on. According to these results, the compatibility between PMMA and ILs especially depends on the anionic structure. In a concentrated system, the colloidal dispersion systems changed from liquid-like to solid-like with increasing particle concentration and exhibited angle independent structural color when [Cnmim][NTf2] was selected as dispersion media. It was revealed that the appearance of structural color in this system requires strong repulsive force between colloidal particles. Furthermore, the effect of suspended nanoparticles on the properties of composites will be also examined.

Carbon nanosheets are of large interest for electrodes in energy storage and conversion devices, as catalyst supports, and as membranes for gas separations. These carbons, also exhibiting slit-like mesopores, have been prepared from furfuryl alcohol and layered silicate templates. Recently, ionic liquids (ILs) with a cross-linkable ion have been demonstrated to form carbons with slit-like mesopores by thermal polymerization and carbonization without a hard-template. In the absence of a cross-linkable ion, hard-templates are required to induce a carbon yield from an IL precursor. The latter type of ILs, however, is inexpensive and largely available. Also, ILs offer several advantages over most organic carbon precursors for being non-volatile and environmentally friendly. Another advantage of using ILs is in the possibility to prepare low viscosity metal-based IL, with cations known to catalyze the graphitization of carbonaceous materials during low temperature treatments. Hence, in this work, a layered silicate, namely Magadiite [NaSi₇O₁₃(OH)₃.4(H₂O)], was used as template for high surface area carbon sheets from metal chloride modified ILs, such as nickel, iron, and cobalt. Magadiite was first intercalated with either, NiCl₂, FeCl₃, or CoCl₂ containing 1-butyl-3-methylimidazolium bromide, [Bmim][Br], in ultrasonic conditions, then composites were carbonized at 900°C, and the silicates etched with ammonium bifluoride (NH₄F.HF). Samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM)energy dispersive X-ray spectroscopy (EDS), Raman spectroscopy, powder X-ray diffraction (XRD), thermogravimetry (TG), and nitrogen adsorption at -196°C. Carbon nanosheets with graphitic domains, slit-like mesopores, large surface areas, and containing up to 35%wt. metal nanoparticles were obtained in large yields. This facile method may further allow for the large scale synthesis of these materials for the aforementioned applications. Acknowledgements: Work supported as part of Fluid Interface Reactions, Structures and Transport (FIRST) Center, Energy Frontier Research Center, U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.

We report a novel polymeric ionic liquid with a PEO backbone, poly(1-glycidyl-3-butyl imidazolium bis(trifluoromethanesulfonyl)imide) (polyGBIM-TFSI) with a Tg of â?"25 °C. PolyGBIM-TFSI has a high ionic conductivity (1.8 Ã- 10-5 S/cm at 30 °C, 1.4 x 10-3 S/cm at 90 °C), and is stable to >200 °C. To obtain higher conductivities, we synthesized a series of copolymers with 1-glycidyltriethylene glycol monomethyl ether. A copolymer with 1:1 molar ratio had the lowest Tg ( â?"41 °C) and highest conductivity (1.2 Ã- 10-4 S/cm at 30 °C, 5.0 Ã- 10-3 S/cm at 90 °C). These polymers are promising electrolytes for energy devices such as dye sensitized solar cells and lithium batteries.

The focus of this study is the relationship between phase behavior and anion conductivity of ion-containing block copolymers as a function of molecular weight, composition and cationic groups. Well-defined polystyrene-b-polychloromethylstyrene block copolymers were synthesized via nitroxide-mediated polymerization method with molecular weights between 2 to 20 kg/mol and mol fractions of chloromethylstyrene in the range of 15-40%. The chlorine group of the polychloromethylstyrene block was modified by reacting with either trimethylamine or n-butylimidazole. The results obtained from small-angle X-ray scattering showed lamellar morphologies for most systems. The temperature-dependence of the conductivity was assessed by performing measurements on membranes that were either immersed in water or in a controlled atmosphere at 98% of relative humidity.

Structure control of metal and semiconductor nanoparticles in nanometer scale has attracted much attention because the physicochemical properties can be varied depending on the size and shape of nanoparticles. Recently we have developed an extremely clean method to prepare metal nanoparticles, in which the sputter deposition of metal, such as Au and Ag, in ionic liquids (ILs) resulted in the formation of highly dispersed metal NPs having a size of 2~5 nm without additional stabilizing agents.(1,2) In this study, we prepared core/shell-structured indium metal nanoparticles and hollow indium oxide nanoparticles by the sputter deposition of indium (In) metal in ILs.(3) An IL of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI-BF4) was used and dried for 3 h at 393 K under vacuum. Sputter deposition of In in the IL was performed using a sputter coater with a discharge current of 10 mA under argon pressure of 2.0 Pa at room temperature. The sputter deposition of In in EMI-BF4 produced spherical nanoparticles without the formation of aggregated secondary particles. TEM observation revealed that individual particles had a core/shell structure with the average core size of 4.6 nm. The core was located almost at the center of the particle and then the shell having a uniform thickness (ca. 1.7 nm) covered the core surface. From XRD and TEM measurements, it was found that the core was a single crystal made of In metal, which was covered with an amorphous shell layer of In2O3. The core of In metal can be easily oxidized to indium oxide with a heat treatment. The In core/In2O3 shell particles were heat treated at 523 K in air. The TEM observation revealed that hollow particles were formed with the size of void space of ca. 4.1 nm, being comparable to that of In core in the original particles. Hollow particles had a polycrystalline shell wall composed of In2O3 nanoparticles with the shell thickness of about 2.0 nm. These facts indicated that the heat treatment of In-core/In2O3-shell particles in air removed the In metal core, resulting in the formation of hollow particles made of crystalline In2O3. Furthermore, the size of In metal nanoparticles varied by changing the kind of ionic liquids used, and then the void space of the resulting hollow In2O3 particles could be controlled from 4 to 10 nm by increasing the size of core/shell particles used as the starting materials. References (1) T. Torimoto, et al., App. Phys. Lett., 2006, 89, 243117. (2) K. Okazaki, et al., Chem. Commun., 2008, 691-693, (3)T. Suzuki, et al., Chem. Mater.,2010, 22, 5209.

Owing to their fascinating properties, ionic liquids (ILs) are now receiving a great deal of attention as alternatives to organic solvents and electrolyte solutions and as synthetic and dispersion media for colloidal systems. Colloidal stability is an essential factor for determining the properties and performance of colloidal systems combined with ILs. The remarkable properties of ILs primarily originate from their highly ionic nature. While such high ionic strength often causes colloidal aggregation in aqueous and organic suspensions, some colloidal particles can be well suspended in ILs without any stabilizers. First, we focus on recent experiments conducted to investigate the colloidal stability of bare and polymer-grafted silica nanoparticles and on the surface force between silica substrates and ILs. Three different repulsions between colloidal particles, i.e., electrostatic, steric, and solvation forces, are also highlighted, after which a possible interpretation of the results in terms of the stabilization mechanism in ILs, both in the presence and in the absence of stabilizers is proposed. The latter part provides an overview of our recent studies on colloidal soft materials with ILs. On the basis of dispersed states of the silica colloids in ILs, two different soft materials, colloidal gel and colloidal glass in ILs, were fabricated. The relationship between their functional properties, such as ionic transport, rheological properties, and optical properties, and the microstructure of the colloidal materials are also presented.

Carbon nanotubes (CNTs) have received considerable attentions in the last two decades due to their very unusual electric, mechanical, optical, thermal and chemical properties. Processing of carbon nanomaterials in aqueous solution is of special interest, as their aqueous dispersions constitute products of a wide range of technologically important applications, including nanoelectronics, drug delivery, composite devices, optical sensors, etc. However, CNTs agglomerate easily when produced because of van der Waals and hydrophobic interactions. A solution to this problem is to disperse CNTs homogeneously using a stabilizer and deagglomeration agent. Generally, two stabilization techniques can be distinguished, namely, the covalent and the physical approaches. The former is based on surface modifications that attach molecules covalently to the carbon surface. Physical methods are dealing with blending or mixing of the CNTs with another phase or stabilizer. The latter is advantageous over the former, as it affects less the original unique properties of CNTs. This presentation introduces a novel type of temperature and ionic strength responsive carbon nanotube dispersions in aqueous media. As stabilizer a unique copolymer prepared via free radical polymerization of N-isopropylacrylamide (NIPAM) and an ionic liquid monomer 1-ethyl-3-vinylimidazolium bromide (EVImBr) is employed. These two monomers were selected as PNIPAM is a well-known thermosensitive polymer with a low critical solution temperature (LCST) of 32°C, close to human body temperature, whilst PEVImBr is a poly(ionic liquid) that can disperse CNTs by strong polarization interactions and responds to ionic strength in solution.[1] As discussed, these factors can be synergistically combined in the copolymer poly(NIPAM-co-EVImBr), generating an efficient and smart stabilizing system for CNTs, producing double stimuli-responsive dispersions.[2] Our experiments clearly illustrate the benefit of using such a copolymer as a multifunctional stabilizer - one can tune the stability of CNT aqueous dispersions over a wide temperature range and control the destabilization of CNTs precisely at a desired temperature, including the human body temperature, which could be a useful tool for potential biomedical applications. Equally significant, this approach can be expanded to other aromatic carbon nanostructures, like fullerenes and graphenes, as the intrinsic polarizable cation-Ï? interaction holds true for all carbon nanostructures. Reference 1. Antonietti, M.; Shen, Y.; Nakanishi, T.; Manuelian, M.; Campbell, R.; Gwee, L.; Elabd, Y. A.; Tambe, N.; Crombez, R.; Texter, J. ACS Appl. Mater. Inter. 2010, 2, 649-653. 2. Soll, S., Antonietti, M., Yuan, J. ACS Macro Lett. 2011, accepted

Metallic nanoparticles (NPs) under 10 nm present unique properties between the bulk and the molecular species. These objects are of crucial importance for the development of various applications. In particular, they are relevant to face the challenges raised by the miniaturization in the microelectronics industry. For such applications, the precise synthesis of nanomaterials with tailored properties (size and structure) is a pre-requisite. However, there is a lack of convenient synthetic routes to control these properties. Unlike traditional solvents, ionic liquids (ILs) can be used to generate metallic NPs by several physical and chemical routes and stabilize them in the absence of further additives.[1] Using these specific solvation properties of ILs, we have demonstrated a general route for the synthesis of mono- and bimetallic NPs by the decomposition of organometallic precursors.[2] In the case of bimetallic compounds, a difference in decomposition kinetics of the two OMs is added to the templating effect of ILs to further control the size and structure of resulting NPs.[3] Here, we report the synthesis under mild conditions of size-controlled mono- Ta(0) and bimetallic Ru-TaNPs. These materials could be interesting candidates for the elaboration of diffusion barriers in advanced interconnects. Controlled size monometallic Ta(0) NPs were formed at 25°C under 0.3 MPa H₂ during 3 days by the decomposition of tris(neopentyl)neopentylidenetantalum(V), in 1-butyl-3-methylimidazolium bistrifluoromethylsulphonylimide, C₁C ₄ImNTf₂. In order to increase solubility of this OM precursor, 2% wtn-pentane was added in the medium. NPs of 5±1 nm were obtained as observed by TEM. Their crystalline structure was resolved by HRTEM, and corresponds to fcc metallic Ta(0). In a second series of experiments, (η⁴-1,5-cyclooctadiene)(η⁶-1,3,5-cyclo-octatriene)ruthenium(0) was mixed with the Ta precursor (1:1 ratio). The 4h decomposition under 0.9 MPa H₂ at 100°C yielded homogeneously distributed NPs of 2.5±0.8 nm. This size is significantly smaller than for the pure metals under the same conditions (Ru forms partially agglomerated NPs of 6±4 nm, whereas Ta precipitates as bulk). The crystalline structure of these NPs resolved by HRTEM is compatible either with (i) pure Ru or (ii) Ru₄Ta. Therefore, two NPs structures are possible: (i) a Ru-core, Ta-shell or (ii) a Ru-Ta nanoalloy. Further investigations are under progress to assess the actual structure of these bimetallic NPs. [1] Dupont, J. et al., Chem. Soc. Rev.39, 1780 (2010). [2] Gutel, T. et al., J. Mater. Chem.17, 3290 (2007), ibid.19, 3624 (2009). Campbell, P.S. et al., Phys. Chem. Chem. Phys.12, 4217 (2010). Salas, G. et al., ibid.13, 13527 (2011). [3] Arquillière, P. et al., French Patent CEA/CNRS n°11 53743

Chitin, the second most plentiful biopolymer on earth after cellulose, is the most abundant polymer in the marine environment. It is the main component of the exoskeletons of arthropods, such as crustaceans and in the cell walls of fungi. Crustacean shells are currently the major source of chitin available for industrial processing. Annual synthesis of chitin in freshwater and marine ecosystems is about 600 and 1,600 million tons, respectively. The bioactivity, biocompatibility, and low toxicity of chitin make it suitable for commercial use, and contribute to the diversity of over 300 end-use applications, including water treatment, cosmetics and toiletries, food and beverages, agrochemicals, medical/healthcare, and cell culture. Traditionally chitin is produced from the exoskeletons of marine crustacean shell waste by a chemical- and waste-intensive method that involves acid demineralization, alkali deproteinization, and bleaching. The chitin produced still contains trace amount of mineral and protein and quality assurance for final product formulation is of concern. Taking advantage of the ability of Ionic Liquids (ILs, salts with melting points below 100 °C) to dissolve almost any type of biomass, we have developed an IL manufacturing process which allows for the extraction of chitin under relatively mild conditions, This revolutionary manufacturing process allows for the production of high quality chitin derivatives using new environmentally responsible techniques that are both cost efficient and that produce higher yields than traditional chitin extracting processes. In addition, the process will enable mass manufacturing of chitin based materials for emerging applications in the advanced wound care market and production of nano-composites for implant therapies that are currently not feasible.

A few ionic liquids (ILs) were found to exhibit temperature-sensitive lower critical solution temperature (LCST)-type phase transition after mixing with water. Change between homogneous mixture and phase separated liquid/liquid biphase was performed by small temperature change. LCST-type phase change was characterized by the unique temperature dependence that the solubility of water into IL phase increased by lowering temperature. The IL phase contains certain amount of water, and small amount of IL was dissolved in the water phase. Required factors for the ILs to show this LCST-type phase change was found to be the adequate hydrophobicity of the component ions. Neither hydrophobic nor hydrophilic ILs show such LCST-type phase change, but ILs having moderate hydrophobicity did. This reversible phase change has been applied to separate water soluble proteins. Solubility of proteins in the hydrated ILs deeply depended on the protein species. Some proteins completely dissolved in the IL phase and others did in the aqueous phase. Details of the affinity of these proteins and hydrated ILs will be proposed.

Imidazolium-salt-based ionic liquids display good ionic conductivity. This presentation will discuss the design and synthesis of imidazolium-salt-based monomers (mono-/di-ols, acrylates, methacrylates) and their conversion to polyelectrolytes (with imidazolium cations in the backbone and in pendant groups) for use in electromechanical actuators. The monomers are generally room temperature ionic liquids (RTILs) and the polyelectrolytes are viscous liquids at room temperature with glass transition temperatures (Tg) in the range of -40 oC to -70 oC. Monomer and polymer synthesis (with varied counter ions) and characterization using thermal analysis, NMR, SEC, conductivity measurements and X-ray scattering will be discussed.

Since the pioneering work of Sheng Dai et al.,[1] numerous articles reported sol-gel processes in ionic liquids (IL) involving the use of either formic acid solvolysis or hydrolysis, even though, to the best of our knowledge, a systematic comparison between the two sol-gel methods is still lacking to guide experimenters. However, the nature of both the anion and the substituent groups on the cation was shown to play a great role in the ability of imidazolium ILs to act as structure directing agents and catalysts for the sol-gel reaction.[2] Nowadays, a growing number of researches are devoted to ionogels (or ion gels), in which the ionic liquid is kept confined in the oxide network. Ionogels open considerable fields of applications, by combining the versatility of sol-gel process, which gives access to a wide range of supports, from pure metal oxides to organic-inorganic hybrids, and the unique advantage of ILs whose properties can be adjusted to specific tasks.[3] Here, the objective was to optimize the encapsulation of the IL (i.e. to minimize the expulsion of the IL), which implies to get highly mesoporous silica-based networks. Several sets of ionogels were prepared from imidazolium (or pyridinium) ILs by using either neutral water or formic acid (FA) as a reactant on various silica or organosilica sources as tetramethoxysilane (TMOS), a mixture of TMOS and methyltrimethoxysilane (MTMS) or a mixture of TMOS and an organically bridged precursor as 1,2-bis(triethoxysilyl)ethane (BTESE). The IL anion appeared to be the key criterion that determines the choice of the suitable method. Typically, FA solvolysis was confirmed to be a robust way to get non-exuding crack-free monoliths from TMOS and imidazolium (or pyridinium) ILs containing [NTf2] anion, whereas neutral hydrolysis was found to be the proper way with ILs containing [BF4] and [PF6] anions. The two methods could be used in the case of acetate anion. Other results were that: (i) with TMOS, the use of HCl aqueous solutions as catalysts brought no decisive advantage over neutral hydrolysis, which highlights the general catalytic activity of ILs themselves (ii) tetrafluoroborate anion (and to a lesser extent acetate anion) showed an outstanding catalytic activity in hydrolysis way; (iii) adding some little amounts (0.06 molar %) of an organically bridged precursor (e.g. BTESE) was shown to significantly enhance the porosity in FA solvolysis way. Various applications to the synthesis of task-specific ionogels will be given, from electrolyte membranes to luminescent devices and from catalyst to drug release systems. [1] Dai, S.; Ju, Y. H.; Gao, H. J.; Lin, J. S.; Pennycook, S. J.; Barnes, C. E. Chem. Commun. 2000, 3, 243-244. [2] Vioux, A.; Viau, L.; Volland, S.; Le Bideau, J. C. R. Chim. 2010, 13, 242-255. [3] Le Bideau, J.; Viau, L.; Vioux, A. Chem. Soc. Rev. 2011, 40, 907-925.

Ionic Liquids (ILs) have attracted considerable attention as alternative solvents for polymers and polymerization reactions, and consequently their phase behavior, at least for the case of IL-rich mixtures in which the polymer is the solute, has been well studied. Until now, there has been relatively little attention given to the cases where ILs are poor solvents for polymers, or indeed how this can be exploited to control surface properties of polymer blends. We have used neutron reflectometry to quantify the changes in polymer surfaces when in contact with ILs and the extent of swelling that occurs as a result of annealing. From these data we can measure the miscibility of ILs with incompatible polymer and estimate the interfacial tension of the polymer IL interface. Finally we demonstrate that the IL can be used as an alternative to solvent vapour annealing as an entirely new way of inducing polymer self-assembly within thin film blends containing functional polymers. This technique can be used to manipulate polymer self-organisation using extremely small quantities of ILs. Results for this study,[1] along with new data obtained by SANS suggesting micellisation of ILs in polymers will be presented. [1] Hutchings, L. R.; Douglas, C. J. R.; Rhodes, C. L.; Carswell, W. D.; Skoda, M. W. A.; Webster, J. R. P.; Thompson, R. L. Langmuir 2010, 26, 15486.

Ionic liquids have attracted great attention as dielectrics in electrolyte-gating experiments due to their exceptionally large specific capacitance and wide electrochemical windows. From a practical standpoint, it is desirable to minimize leakage and to control the fluidity of ionic liquids by adding structuring polymers. The resulting solid polymer electrolyte is referred to as an ion gel. In this work, we demonstrate a solvent-free, self-standing ion gel based on poly(vinylidene fluoride-co-hexafluoropropylene), P(VDF-HFP), and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, [EMI][TFSA], as a gate dielectric for thin-film transistors. Due to its high tensile strength the self-standing P(VDF-HFP) ion gel can be simply laminated on a layer of semiconductor using tweezers. Even with such a simple process, the adhesion between the self-standing ion gel and a semiconductor is strong enough to perform electrolyte-gating experiments. Due to the remarkably high capacitance of the ion gel, low-voltage operation (~1â^'2 V) and high on/off current ratios (> 10⁴) can be realized. We also observed that the ion gel can induce both holes and electrons in organic and inorganic semiconductors, respectively. These results demonstrate that the self-standing ion gel provides a convenient route to an electrolyte dielectric on a transistor.

With the depletion of fossil fuels, a renewable source of hydrocarbon-based feedstock chemicals needs to be found. A currently untapped source for these chemicals is biomass. Chitin, the second most abundant form of biomass, could be an excellent source of new feedstock chemicals. To date, the limiting factor in the use of chitin has been the difficultly to dissolve the biopolymer in traditional solvents. Ionic liquids have opened the door to new technologies involving chitin and other biopolymers. Some ionic liquids have the unique ability to disrupt the hydrogen bonding network that holds the polymer chains together without degrading the chemical structure of the polymer. Dissolution of chitin in ionic liquids opens up the chemical structure allowing reactions that were restricted in the past. This research investigates the use of Brønsted acid ionic liquids as catalysts for the hydrolysis of chitin in an ionic liquid solution. The catalyst initiate a hydrolysis reaction cleaving the β-1,4 linkages present in the biopolymer. The reaction will result in the production of N-acetylglucosamine and other degradation products. This presentation will discuss the conversion of chitin to N-acetylglucosamine and other dehydration products and the effects of structural changes on the production of the degradation products, temperature, and catalyst loading on the reaction products.

Throughout history mankind has exploited the remarkable properties of natural polymers such as silk and cellulose. In modern times, these natural materials still possess properties that rival the most advanced synthetic polymers. Recent work has shown ionic liquids to be effective solvents for the dissolution of a wide variety of natural polymers, and new materials can be created from these natural feedstocks by processes that involve their full dissolution and subsequent reconstitution. However, many reports show that the dissolution and reconstitution processes eliminate the native polymer structure, often with deleterious consequences to the physical properties of the resulting materials. Recently we have demonstrated a methodology we call â?onatural fiber weldingâ? which allows complex composite materials to be created while simultaneously retaining selected amounts of biopolymer in the native state. The key feature of natural fiber welding is its ability to open up and mobilize biopolymer structures to enable chemistry; this allows the manipulation and modification of natural materials and makes possible the imparting of new functionalities. Furthermore, dramatic enhancement and modification of physical and chemical properties can be realized without disruption to many of the desirable properties intrinsic to natural materials. By precisely regulating process variables such as the purity, type, amount, and placement of ionic liquid solvent as well as the time and temperature of treatment, we have demonstrated controlled reorganization of natural material hydrogen bonding networks. We are currently carrying out fundamental studies that are directed towards the characterization and development of the fiber welding process. These systematic studies are forming the foundation from which we will be developing advanced methods for processing and modification of materials using natural fiber welding.

The need for more selective and economical metal extractants is constantly growing. For an extractant to be efficient, one must design the extractant for the specific system from which the metal is being extracted. There is a current need for the extraction of uranium from various media. The extraction of uranium from seawater would provide a lack of dependence of foreign mining and a steady supply of uranium. The extraction of uranium from spent nuclear fuel would provide a higher potential for recycling within the system. These two environments are extremely different, one being a highly dilute system (3 ppb UO₂²⁺) and the other being a concentrated and highly acidic environment (7 M HNO₃). Both are extremely complicated. The amidoxime functional group has proved to be highly selective for extracting uranium from seawater. Attaching this selective ligand to a strong support could make this a viable process. Chitin is one of the most abundant biopolymers, second only to cellulose. Its biocompatibility, durability, and antimicrobial properties make it an excellent framework to build upon for an extractant. Chitin is present in the exoskeletons of crustaceans such as shrimp shells which are readily available as a waste product from the seafood industry. Recently our group was able to spin fibers of high purity, high molecular weight chitin directly from shrimp shells using ionic liquids. Ionic liquids (ILs) are being studied for their excellent solvent properties as well as their metal extraction properties. It has been shown that each characteristic can be tuned for a specific system. We have derivatized a hydrophobic IL with the amidoxime functionality, as well as added this extractant to chitin fibers via an IL solution process. This presentation will compare and contrast the synthesis, characterization, and extraction properties of these new liquid and solid materials.

Goal of the present work is to manufacture multifunctional cellulose textile fibres using ionic liquids as processing medium. Multiwall carbon nanotube (MWCNT)/cellulose composite fibers were processed from solutions in ethyl methylimidazolium acetate (EMIAc). Rheological percolation in MWCNT/Cellulose/EMIAc solution was observed above 1wt% MWCNT, while electrical percolation in oriented fibers was observed above 5wt% of MWCNTs with respect to the weight of the cellulose. Cellulose orientation and crystal size were significantly higher in the composite than in the control cellulose fiber. The axial electrical conductivity at 10wt% MWCNTs in these oriented fibers was more than 2000 S/m. Our study shows that ionic liquids can be used as a common solvent to disperse carbon nanotubes as well as to dissolve cellulose to manufacture multifuctional textiles with superior mechanical and electrical properties.

Heightened interest in energy independence and environmental awareness has accelerated the search for combustible fuel sources which are both renewable and have a low environmental impact. One promising route is the conversion of waste biomass into tailor-made fuels. An important aspect of this process is the low-energy separation of cellulose from the biomass. Ionic liquids (ILs) have been demonstrated capable of dissolving cellulose while being essentially non-volatile, making them strong candidates for "green" processing. However, full exploitation of ILs as a commercially viable processing medium requires better understanding of the dissolution mechanism. However, in spite of extensive research, many parts of this process remain uncertain. Using molecular dynamics simulations, we examine the behavior of cellulose in the ionic liquids [BMIM]Cl, [EMIM][Ac] and [DMIM][DMP] as well as water. All three of these ionic liquids have been observed to dissolve cellulose quite well yet have differently sized anions. We explore these differences and the impacts they have on their interactions with cellulose. First, we examine the dynamics of a single cellulose strand in these ionic liquids, and study the structural and dynamic properties, such as the radius of gyration and the number and lifetime of hydrogen bonds that are formed between the anions and cellulose. Next, we probe the dissolution mechanism of multiple, bound cellulose oligomers of varying lengths, examining interactions at the IL/cellulose interface and the breakup of inter-cellulose hydrogen bonds. We also study the relationship between the anion strength and the hydrogens in hydroxyl groups in determining the relative aggregation of cellulose chains in these different solvent media.

Functionalized ionic liquids have been prepared for a variety of applications, including energy storage, carbon capture and chemical synthesis. The incorporation of functional ions (either as the anion or as part of the cation) can often lead to unexpected solvent behaviour. I will discuss the interactions present in functionalized ionic liquids (hydrogen bonding, ion association, ion transport) and how these interactions can differ from systems containing unfunctionalized ions. Specific attention will be paid to molecular probes used to examine solvent-solvent and solvent-solute interactions, and how the electronic and solvation behaviours of these solvents can sometimes be in conflict. Applications will be discussed in solvation of organometallic species (with implications in homogeneous catalysis), interactions with biomass components (cellulose conversions for bioenergy) and ionic diffusion in mixtures of ionic liquids (links between transport and electrochemical properties).

The transfer of electrons in ionic liquids, between cations in different oxidation states, has been studied since the early days of ambient temperature molten salt systems1. It has been known for a comparable length of time that when the electron transfer occurs, some sort of compensation for the electron transfer is accomplished by the accompanying motion of another species or its equivalent2. In the case of aqueous systems like Cr3+ = Cr6+ + 3e- this is commonly represented as the coupled relocation of both oxides and electrons to yield the Cr2O72- species, and protons to maintain the charge balance. In ionic liquid systems with less drastic changes of oxidation numbers the mechanism is more appropriately thought of as a transfer of electron density from the anions that are near neighbor to the redox species, as the electron transfer occurs2. The compensating transfer of charge density is influenced by the nature of the anion environment of the species to/from which the electron transfer is occurring. Previously we have considered this phenomenon for the case in which the anions are â?ooxidicâ? in character2-4. Here we turn attention to ILs in which the relevant anions are halogens of very different polarizabilities, viz., bromide, chloride and fluoride. We will first review the essentials aspects of electron and proton transfers from external sources into the ionic liquid state, and will then compare the findings for the different cases of (1) aprotic4 and (2) protic IL media5. In the latter, the electron transfer can be assisted by, or compensated by, a proton transfer. References (1) Hussey, C. L.; King, L. A.; Wilkes, J. S. J. Electroanal. Chem. 1979, 102, 321. (2) Angell, C. A. Spectroscopic and electrochemical characterization of solute species in non-aqueous solvents. Plenum, New York, p 273 1977. (3) Angell, C. A. J. Solid State Electrochemistry (Bockris Fest) 2009, 13, 981. (4) Ueno, K.; Angell, C. A. J. Chem. Phys. (submitted) 2011. (5) Belieres, J.-P.; Angell, C. A. J. Phys. Chem.B 2007, 111, 4926.

The conformational freedom of the facile ring flip of N,N,-dialkylpyrrolidinium based ILs has been suggested as one of the reasons that these salts form ionic liquids. We have been using variable temperature NMR spectroscopy to investigate this phenomenon. When the ring flip is occurring at slower than the NMR timescale axial and equatorial signals are seen, which coalesce to a single average signal when the temperature is increased and the ring flip is faster. By measuring the temperatures at which coalescence occurs it is possible to calculate the activation energies of the ring flip. We have found that for N,N,-dialkylpyrrolidinium salts the ring flip is facile, with coalescence temperatures below 223K, while for N-methylpyrrolidinium hydrogensulphate it was considerably higher than room temperature. A range of anions were studied, which had a profound impact on the coalescence temperature. These results cast some doubt on the significance of the freedom of the ring flip in determining whether a salt is solid or liquid.

Immense interest in the recent days has been focused on the preparation and characterization of novel series of protic ionic liquids (PILs) with tunable physicochemical properties for their use in fuel cells due to unique physicochemical properties, such as, high ionic conductivity, good thermal stability, high electrochemical stability, negligible vapor pressure, and non-flammability along with proton conduction under anhydrous conditions. However, the correlation between the physicochemical properties and suitable parameters of PILs, still remains a challenge. In this study, we prepared a novel series of PILs and aim at correlating physicochemical properties with certain suitable parameters. We prepared a novel series of PILs by neutralization of a super-strong base, 1,8-diazabicyclo[5,4,0]undec-7-ene ([DBU]) with different Brønsted acids with wide variation in the Î"pKa of the constituent amine and the acids. Physicochemical properties of the PILs such as thermal behaviors, density, conductivities, viscosities, self-diffusion coefficients, vibrational stretching frequency, 1H-chemical shifts of N-H bond and open circuit potential (OCP) during oxygen reduction reaction (ORR) were studied. Thermogravimetric analyses (TGA), under isothermal and linear-temperature-increasing conditions, revealed that PILs with Î"pKa â?¥ 15 exhibit good thermal stability similar to typical aprotic ionic liquids (AILs). Most of the DBU-based PILs were liquid at ambient temperature. FT-IR spectra and the temperature dependence of NMR chemical shift for N-H proton indicated the presence of a hydrogen bond in the PILs between the protonated cation and the anion through N-H bond, strength and the extent of which are dependent on the Î"pKa. The hydrogen bond plays vital role in determining the physicochemical properties of the PILs. The ionicity evaluated by both PGSE-NMR method and Walden plot has been found to be low for the PILs with Î"pKa15, which might be due to incomplete proton transfer and ion-aggregation in-between back-proton-transferred neutral components and proton-transferred ions. The ionicity decreases with increasing temperature, with influence being more prominent for PILs with low Î"pKa and strong hydrogen bonds compared to those with high Î"pKa and weak hydrogen bonds. We assume that it is due to back proton transfer through shifting of equilibrium and imbalance between directional hydrogen bond and non-directional Coulombic interactions. Analyses of cyclic voltammetric results show that the OCP during ORR increases with increasing Î"pKa up to a value of 18. However, with further increase in the Î"pKa, the OCP gradually decreases. Physicochemical properties may be controlled by varying the structure of the constituent amine and the acid, in other words, the Î"pKa to tune protic ionic liquids for task-specific applications such as anhydrous proton conductors in mesothermal fuel cells.

N-alkyl-N-methylpyrrolidnium bis(trifluoromethanesulfonyl)imide (PY_1RTFSI) ionic liquids (ILs) have been thoroughly studied for use as electrolyte materials. While these ILs are highly conductive, they generally crystallize at temperatures above 0°C, which limits their usefulness in practical applications. Tailored mixtures consisting of two ILs may be able to both improve the conductivity of an IL-based electrolyte and extend the temperature range over which such an electrolyte remains liquid. A number of binary systems composed of two PY_1RTFSI ILs have been prepared and characterized. Physicochemical properties (density, viscosity, and ionic conductivity) and the phase behavior of these systems are reported. The lengths of the alkyl chains on the different cations play a significant role in determining both the phase behavior and the physicochemical properties of a given mixture. The presence of cations with shorter alkyl chains improves the conductivity of a mixture, but also constrains the liquidus range. Mixtures containing cations with substantially different alkyl chain lengths are also seen to readily phase separate at lower temperatures.