When the proper ingredients are added to an organic solvent, the repeating units form and assemble into nanojars, with the -2 charged anion bound tightly at the center. To remove anions from water, the researchers added the solvent containing the nanojar components, which formed an organic layer on top of the water.
Treating the organic layer with a weak acid causes the nanojars to fall apart, releasing the anions for disposal or recycling. The researchers have used nanojars to remove toxic anions from water. Environmental Protection Agency-permitted levels for drinking water -- really, really low levels," Mezei says. The nanojars have an even higher affinity for carbonate, and adding a molecule called 1,phenanthroline to the mixture produces nanojars that bind two carbonate ions each instead of one.
The team has also made nanojars that are selective for certain anions. By using two pyrazoles tethered by an ethylene linker as a building block, the researchers made nanojars that bind preferentially to carbonate.
More recently, they've shown that using two pyrazoles with a propylene linker produces sulfate-selective nanojars. These anion-selective nanojars will be important for applications in which only certain -2 charged ions should be removed.
The researchers have also been working on making the process more suitable for real-world applications. For example, they've swapped a weak base, trioctylamine, for the strong base, sodium hydroxide, originally used to make nanojars. Interestingly, trioctylamine causes nanojars to form with slightly different structures, which he refers to as "capped" nanojars, but they appear to bind carbonate just as tightly.
New research at Osaka City University has found that simply adding metal ions like aluminum and iron was enough to allow the production of malic acid, which contains 4 carbon atoms. We are Osaka City University - the oldest research university in Osaka.
With 9 undergraduate faculties and 11 graduate schools all dedicated to making urban life better, energy cleaner, and people healthier and happier, we have won numerous awards and have produced 2 Nobel laureates. Journal New Journal of Chemistry. Also the ion gel can absorb CO2 without solvent seeping at a high pressure of 3 MPa.
Improving CO 2 permeability in polymerized room-temperature ionic liquid gas separation membranes through the formation of a solid composite with a room-temperature ionic liquid. RTILs present a no. Perhaps most importantly, RTILs can be synthesized as monomers and polymd.
This new approach to polymer gas sepn. An aspartame-based, low mol. RTIL to sep. CO2 from N2. Gas permeability and burst pressure measurements of thick, melt-infused membranes revealed a trade-off between high CO2 permeability and good mech. Defect-free, composite membranes of gelled RTIL were successfully fabricated by choosing an appropriate porous membrane support hydrophobic polytetrafluoroethylene using a suitable coating technique roller coating. The thicknesses of the applied composite gel layers was We have demonstrated, for the first time, a polymer blend comprising poly vinylidene fluoride PVDF and a room-temp.
However, compared to miscible ionic liq. Most of these blend membranes outperform most reported materials and their gas transport and sepn. Therefore, they are potential materials for H2 purifn. High ionic liquid content polymeric gel membranes: Correlation of membrane structure with gas and vapour transport properties. In this paper the transport properties of ionic liq. This suggests a potential application in gas sepn. A correlation of the transport properties with Young's modulus is proposed for the first time.
It reveals a transition from diffusion-controlled transport to soly. Vapor permeation expts. Permeability, diffusion and soly. These correlations show clear and distinct trends for water, alcs. Polar compds.
The two classes show the opposite trends in permeability as a function of the crit. The same trends are obsd. On the other hand, diffusion is mainly correlated with the crit. Significant differences in the transport of toluene and cyclohexane suggest that these membranes are also suitable for the sepn.
The manuscript intends to give fundamental information on how the presence of IL influences the transport properties of polymeric membranes. We have demonstrated that a protic ionic liq. In this study, in order to fabricate a polymer electrolyte fuel cell, matrix polymers for [dema][TfO] are explored and sulfonated polyimides SPI , in which the sulfonic acid groups are in diethylmethylammonium form, are found to be highly compatible with [dema][TfO].
Polymer electrolyte membranes for non-humidified fuel cells are prepd. The SPI, with an ion exchange capacity of 2. ACS Appl. To investigate the effects of polymer structure on the properties of composite membranes including a protic ionic liq. Atomic force microscopy observation revealed that the multiblock copolymer SPI forms more developed phase sepn.
These results indicate that the flexibility of sulfonic acid groups and the connectivity of the ion conduction channel, which greatly depends on the sequence distribution, affect the ion conduction. Nonhumidified intermediate temperature fuel cells using protic ionic liquids.
The characterization of a protic ionic liq. In terms of physicochem. Proton conduction occurs mainly via the vehicle mechanism in [dema][TfO] and the p transference no. The p-exchange mechanism contributes to the fuel cell system in operation, where deprotonated amines are continuously generated by the cathodic reaction, and polarization of the cell is avoided.
Six-membered sulfonated polyimides in the diethylmethylammonium form exhibit excellent compatibility with [dema][TfO]. The protic ionic liq. Protic ionic liquids: Fuel cell applications. MRS Bull. Cambridge University Press. We have investigated protic ionic liqs. PILs as proton conductors for non-humidified intermediate-temp. PILs exhibit proton cond. The wide mol. Solid thin films contg. The fuel cell performance can be further improved by the optimization of the catalyst layer and with further research on PILs.
Printable polymer actuators from ionic liquid, soluble polyimide, and ubiquitous carbon materials. We present here printable high-performance polymer actuators comprising ionic liq.
IL , sol. Polymer electrolytes with high ionic cond. The developed polymer electrolytes comprised a sol. The resulting polymer actuators have a trilaminar elec. Displacement, response speed, and durability of the actuators depended on the combination of carbons. The displacement of the actuators was proportional to the accumulated elec.
The ILs functioned as plasticizers of the SPI, making the composite membranes softer lower Young's modulus and larger elongation at break. The SPI membrane behaved as a gas barrier membrane; however, the addn. The transport properties of ionic liq. These composite membranes enable favorable CO2 sepn.
The diffusion coeffs. On the other hand, the selective soly. Consequently, the permeation coeff. PCO2 of the membranes increases with increasing IL content without decreasing the sepn. Green Chem. Amino acid ionic liqs. PILs , which are supposed to be acidic ionic liqs. Acid dissocn. The first acid dissocn.
The actual pH values of [AA]X 0. Their H0 values 0. Various frameworks of amino acid cations and five anions including nitrate NO3- , chloride Cl- , perchlorate ClO4- , trifluoromethanesulfonate OTf- and trifluoroacetate TfA- anions were used to investigate the cationic and anionic effect on the acidity of AAILs. The exptl. Fundamental properties and practical applications of ionic liquids: concluding remarks.
The Faraday Discussion on Ionic Liqs. Fundamental understanding of behavior of liqs. However, the conference almost entirely omitted discussion of the potential role of ionic liqs. Although initial claims of ionic liqs. ILs being green were overstated, the search for green ionic liqs.
Some confusion in the field has been caused by an overemphasis on the environmental impacts of ILs themselves, despite the fact that the manuf.
Because some ILs contain cores that are highly resistant to degrdn. The author offers suggestions as to how to tackle the problem of searching for greener ILs, including a greater focus on the impacts of the synthetic pathways of relevant ions.
Development of cost-effective biodiesel from microalgae using protic ionic liquids. There are still constraints to algae-sourced biodiesel commercialization owing to the high cost and energy consumption of biomass cultivation and lipid extn.
The use of "low-cost" protic ILs based on tetramethylguanidinium and 1,8-diazabicyclo[5. High extn. Wang, Jiayi; Greaves, Tamar L. The thermal phase transitions and physicochem. Structure-property comparisons for this series were investigated for alkyl- and cyclic amino acid cations, and ethoxy and methoxy groups on the cation, combined with nitrate or various carboxylate-contg.
All the protic fused salts were found to be 'fragile'. Most of the protic fused salts exhibited a glass transition, with the transition temps. Viscosities and conductivities ranged from 0. The protic ionic liqs. Lamellar or hexagonal liq. Protic ionic liquids: preparation, characterization, and proton free energy level representation. The authors give a perspective on the relations between inorg. ILs , including members with m. The paper presents the synthesis and properties melting, boiling, glass temps.
These proton-transfer ILs have interesting properties, including the ability to serve as electrolytes in solvent-free fuel cell systems. This work provides a basis for assessing their relation to aprotic ILs by means of a Gurney-type proton-transfer free energy level diagram, with approx. The energy level scheme allows verifying the relation between solvent-free acidic and basic electrolytes, and the familiar aq.
Physicochemical properties determined by DeltapKa for protic ionic liquids based on an organic super-strong base with various Bronsted acids. Abu Bin Hasan; Watanabe, Masayoshi. Neutralization of an org.
The physicochem. The generated PILs have melting temps. The viscosity, ionic cond. The relative cationic and anionic self-diffusion coeffs. Key factor governing the physicochemical properties and extent of proton transfer in protic ionic liquids: DeltapKa or chemical structure? In order to identify the key factor governing the transport properties and extent of proton transfer in protic ionic liqs. The bulk physicochem. The thermal stability of all PILs, as analyzed by thermogravimetric anal.
PILs with secondary amines showed higher viscosity and lower ionic cond. Protic ionic liqs. PILs were prepd. The m. The origin of the difference in the properties of these two series of PILs was investigated based on the evaluation of the molar concn. The molar concn. Ab initio geometrical optimization and calcn. Further comparison with the ion pairs of tetra-alkylammonium-based aprotic ILs AILs having cations with the same no. However, the magnitude of the attraction and the directionality of the interactions in the ion pairs of the allylammonium-based PILs did not differ appreciably from those of the propylammonium-based counterparts.
It is concluded that the allyl group facilitates the formation of more compact structures of the PILs without enhancing the interionic interactions with consequently higher molar concn.
The viscosity increased and the ionicity decreased with increasing nos. Thus, among the PILs explored in this study, allyldimethylammonium trifluoromethanesulfonate [N11a][TfO] exhibited the highest ionic cond. Size matters! On the way to ionic liquid systems without ion pairing.
Several, partly new, ionic liqs. ILs contg. Their temp. Ion-specific self-diffusion consts. In general, self-diffusion consts. Ionicities were calcd.
From these observations it was concluded that [Al hfip 4]--based ILs come close to systems without any interactions, and this hypothesis is underlined with a Hirshfeld anal.
Shallow Coulomb potential wells are responsible for the high mobility of ILs with such anions. CO 2 solubility and physical properties of N - 2-hydroxyethyl pyridinium bis trifluoromethanesulfonyl amide. Fluid Phase Equilib. The densities, viscosities, and elec. The pressure-vol. The densities and transport properties were well reproduced with a second order polynomial and Vogel-Fulcher-Tamman equations, resp. The Walden plot double logarithm graph of molar cond.
The molar volume in the liq. The vol. As a result, the satd. Gaussian 09 , Revision A. Google Scholar There is no corresponding record for this reference. MP2 energy evaluation by direct methods. An efficient algorithm is presented for evaluating the second order Moeller-Plesset MP2 energy directly from two-electron integrals in the AO basis, i.
The floating point operation count and memory requirements are analyzed, and illustrative calcns. This direct MP2 method should be useful for large mol. Studies in Molecular Structure. Potential curve for the interaction of two helium atoms in single-configuration L. Single-configuration L. Comparison with available exptl. An a priori account is given of both the van der Waals min. The details of repulsion and of bonding in the van der Waals region are analyzed in terms of at. The calculation of small molecular interactions by the differences of separate total energies.
Some procedures with reduced errors. A new direct difference method for the computation of mol. It appears that these new features can give a strong redn. It has been generally accepted that this problem is dominated by unresolved difficulties and the relation of the new methods of these apparent difficulties is analyzed here. Bronsted acid-base ionic liquids for fuel cell electrolytes. A simple protic ionic liq.
RSC Adv. High conductivity molten salts based on the imide ion. The bis trifluoromethanesulfonyl imide ion has recently been used in its lithium salt as a useful ion in solid polymer electrolytes because of the reduced degree of ion interaction its diffuse charge generates.
In this work we have synthesized a no. The salts all show reduced m. In some cases they are molten at room temp. This latter group of salts have been characterized with respect to their properties as ionic liqs. Many of the salts are glass forming, exhibiting glass transition temps. Aki, Sudhir N. Previously we have shown that supercrit. Subsequently, ionic liqs. Therefore, an understanding of the phase behavior of carbon dioxide with ionic liqs.
We present measurements of the soly. As expected, the soly. To investigate the influence of the anion, seven of the ILs studied have 1-butylmethylimidazolium [bmim] as the cation. The other ILs considered in the study, chosen to investigate the influence of varying no.
Results show that the soly. In particular, CO2 soly. Also, we observe that an increase in the alkyl chain length on the cation increases the CO2 soly. Interactions in ion pairs of protic ionic liquids: comparison with aprotic ionic liquids.
American Institute of Physics. The stabilization energies for the formation Eform of 11 ion pairs of protic and aprotic ionic liqs.
The interactions in the ion pairs of protic ionic liqs. The same trend was obsd. The optimized geometries, in which the anions locate on the counter side of the cations, are The electrostatic interaction, which is the major source of the attraction in the ion pairs, is responsible for the directionality of the interactions and detg.
Magnitude and directionality of interaction in ion pairs of ionic liquids: relationship with ionic conductivity. The intermol.
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