Nowadays the knowledge of thermodynamic properties for amino acid ionic liquids (AAILs) has been paramount for the design of many chemical processes. In this present work, a series of cholinium-based AAILs ([Ch][AA]) were synthesized by neutralization of choline hydroxide solution with five amino acids and then were characterized by 1 H NMR, Fourier transform infrared (FT-IR), elemental analysis, thermogravimetry, and differential scanning calorimetry (DSC) analysis. Physico-chemical properties such as density, viscosity, refractive index, and conductivity were measured and correlated with the empirical equations in a wide temperature range. The thermal expansion coefficient values were also calculated from the acquired experimental density values. From the experimental data, it was found that the density, viscosity, and refractive index decreased while conductivity increased with the increase of temperature. The correlation results were proposed to be in good agreement with the experimental data, and optimal fitting parameters were presented. In addition, the coefficient of thermal expansion was considered to be independent of temperature in the range of (298.15 to 353.15) K.

A new strategy for multi-molar absorption of CO2 is reported based on activating a carboxylate group in amino acid ionic liquids. It was illustrated that introducing an electron-withdrawing site to amino acid anions could reduce the negative inductive effect of the amino group while simultaneously activating the carboxylate group to interact with CO2 very efficiently. An extremely high absorption capacity of CO2 (up to 1.69 mol mol(-1) ) in aminopolycarboxylate-based amino acid ionic liquids was thus achieved. The evidence of spectroscopic investigations and quantum-chemical calculations confirmed the interactions between two kinds of sites in the anion and CO2 that resulted in superior CO2 capacities.

in Wiley Online Library (wileyonlinelibrary.com)Amino acid ionic liquids (AAILs) are chemical solvents with high reactivity to CO 2 . However, they suffer from drastic increase in viscosity on the reaction with CO 2 , which significantly limits their application in the industrial capture of CO 2 . In this work, 1-ethyl-3-methylimidazolium acetate ([emim][Ac]) which also exhibits chemical affinity to CO 2 but low viscosity, and its viscosity does not increase drastically after CO 2 absorption, was proposed as the diluent for AAILs to fabricate hybrid materials. The AAIL1[emim][Ac] hybrids were found to display enhanced kinetics for CO 2 absorption, and their viscosity increase after CO 2 absorption are much less significant than pure AAILs. More importantly, owing to the fact that [emim][Ac] itself can absorb large amount of CO 2 , the AAIL1[emim][Ac] hybrids still have high absolute capacities of CO 2 . Such hybrid materials consisting of a chemical solvent plus another chemical solvent are believed to be a class of effective absorbents for CO 2 capture. a The mass fraction of [Ch][Pro] is 50%. b The mass fraction of [C 2 (N 114 ) 2 ][Gly] 2 is 40%. c The mass fraction of [N 1111 ][Gly] 2 is 40%. d The mass fraction of [C 2 OHmim][Gly] is 8%. e The mass fraction of [APmim][Gly] is 11%. f The mass fraction of DAIL is 50%. g The mass fraction of [DETA][Cl] is 36%. h The mass fraction of [P 4444 ][Gly] is 41%. i The mass fraction of [aP 4443 ][Gly] is 41%. j The mass fraction of [emim][Lys] is 49%. k The mass fraction of [emim][Gly] is 50%. l The mass fraction of MEA is 30%. m The mass fraction of MDEA is 50%. Figure 9. FTIR spectra of fresh and recycled [emim] [Gly]1[emim] [Ac].[Color figure can be viewed at wileyonlinelibrary.com]

In this work, a class of deep eutectic solvents (DESs) formulated by choline chloride (ChCl), phenol (PhOH), and ethylene glycol (EG) were designed and synthesized for NH 3 capture. The effects of temperature, pressure, and DES composition on NH 3 capacities were investigated systematically. By utilizing the weak acidity of PhOH, highly efficient and reversible absorption of NH 3 was realized in PhOH-based ternary DESs. The absorption capacities of NH 3 in prepared DESs can reach as high as 9.619 mol/kg (0.162 g/g) at 298.2 K and 101.3 kPa, ranking one of the best reported to date. The captured NH 3 could be easily stripped out at elevated temperature and reduced pressure, with negligible loss in NH 3 capacities after 10 adsorption−desorption cycles. The thermodynamic properties of the NH 3 absorption process, such as reaction equilibrium constants, Henry's constants, and absorption enthalpies, were also calculated with the assistance of thermodynamic modeling. It is found that the NH 3 absorption process exhibits a moderate enthalpy change of −36.91 kJ/mol, indicating the potentially energy-efficient feature of a subsequent desorption process. The results obtained herein suggest that PhOH-based ternary DESs are promising media for the capture of NH 3 from industrial gases.

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Electronic properties of boron nitride nanosheets were tamed by doping carbon atoms into the matrix for boosted aerobic catalytic performance.

Scheme 1. Chemical structures of the anion and the cation in aminopolycarboxylate-based ionic liquids.