Is seven the minimum number of water molecules per ion pair for assured biological activity in ionic liquid–water mixtures?

2015 ◽  
Vol 17 (22) ◽  
pp. 14454-14460 ◽  
Author(s):  
Hiroyuki Ohno ◽  
Kyoko Fujita ◽  
Yuki Kohno
Keyword(s):  
Phase Transition ◽  
Ionic Liquid ◽  
Biological Activity ◽  
Water Molecule ◽  
Liquid Water ◽  
Ion Pair ◽  
Water Molecules ◽  
Minimum Number ◽  
Transition Behaviour

The biological activity and phase transition behaviour of IL–water mixtures, called hydrated ILs, were found to change non-linearly at a water molecule to ion pair ratio of around 7 : 1.

Influence of water on phase transition and rheological behavior of cellulose/ionic liquid/water ternary systems

2016 ◽  
Vol 134 (22) ◽  
Author(s):  
Young Jae Lee ◽  
Mi Kyung Kwon ◽  
Sung Jun Lee ◽  
Sang Won Jeong ◽  
Hyun-Chul Kim ◽  
...  
Keyword(s):  
Phase Transition ◽  
Ionic Liquid ◽  
Liquid Water ◽  
Rheological Behavior ◽  
Ternary Systems ◽  
Influence Of Water

Dual stimuli-responsive phase transition of an ionic liquid/water mixture

2011 ◽  
Vol 47 (16) ◽  
pp. 4772 ◽  
Author(s):  
Yuki Kohno ◽  
Hiroki Arai ◽  
Hiroyuki Ohno
Keyword(s):  
Phase Transition ◽  
Ionic Liquid ◽  
Liquid Water ◽  
Water Mixture ◽  
Stimuli Responsive

A theoretical treatment of cation exchangers - III. The hydration of cations in polystyrene sulphonates

1955 ◽  
Vol 228 (1174) ◽  
pp. 322-341 ◽  
Keyword(s):  
Water Molecule ◽  
Water Activity ◽  
Adsorption Isotherms ◽  
Liquid Water ◽  
Adsorbed Water ◽  
Isopiestic Method ◽  
Water Molecules ◽  
Hydration Water ◽  
Monovalent Cations ◽  
Free Energies

The adsorption of water by the polystyrene sulphonates of cations has been investigated at 0 and 25° C, using an isopiestic method. The adsorption isotherm and the heats (enthalpies) and entropies of hydration have been obtained for the monovalent cations H, Li, Na, K, Cs, NH4, Ag and for the divalent cations Be, Mg, Ca, Sr, Ba, Hg. With the exception of H, which gives a smooth enthalpy-water-content curve, all monovalent cations show a more or less marked step in the differential enthalpy of adsorbed water between the first and second water molecule adsorbed per ion, thereafter the steps are less clearly defined. The differential entropies show similarities to those calculated for a B. E. T. isotherm, except that the curves show two minima which correspond to approximately 0.15 and 1.5 molecules of water/ion. The adsorption isotherms follow more or less the model of the B. E. T. isotherm, with several significant differences: ( a ) the volatility of the second and further water molecule/ion is not that of liquid water, but only tends to reach this value after several molecules/ion are adsorbed, and the energy levels of the first successive water molecules, though rising rapidly, differ substantially from that of liquid water; ( b ) the adsorption process of the first water molecule is significantly different from a Langmuir mechanism, and varies approximately as the one-half power of the water activity. The knowledge of the free energies, enthalpies and entropies permits a fair analysis of the hydration mechanism into its individual steps, which then permits a calculation of the standard state enthalpies and entropies of the first hydration steps. Both functions show a markedly linear relationship with the ionic radius of the unhydrated ion when summed up for the first two water molecules adsorbed. The knowledge of the adsorption isotherms permits one to differentiate between water adsorbed with zero free energy (swelling water) and the excess adsorbed water (cationic and anionic hydration water). The amount of hydration water associated with the cations has been obtained in this way both for mono- and divalent ions. The amount varies both with the water activity and with temperature. It is clear from the small free energies of hydration of all monovalent ions that the association of almost all water molecules is very loose, and is not related to the co-ordination number of the ions.

scholarly journals Role of Tf2N− anions in the ionic liquid–water distribution of europium(iii) chelates

RSC Advances ◽  
2017 ◽  
Vol 7 (13) ◽  
pp. 7610-7618 ◽  
Author(s):  
Hiroyuki Okamura ◽  
Noboru Aoyagi ◽  
Kojiro Shimojo ◽  
Hirochika Naganawa ◽  
Hisanori Imura
Keyword(s):  
Ionic Liquid ◽  
Fluorescence Spectroscopy ◽  
Liquid Water ◽  
Water Distribution ◽  
Laser Induced Fluorescence ◽  
Water Molecules ◽  
Time Resolved ◽  
Water Saturated

The replacement of water molecules of [Eu(tta)3(H2O)3] with Tf2N− was evidenced in water-saturated [Cnmim][Tf2N] by time-resolved laser-induced fluorescence spectroscopy.

Dynamic properties of water molecules in ionic liquid/water mixture with various alkyl chain length

2018 ◽  
Vol 264 ◽  
pp. 337-342 ◽  
Author(s):  
Kazuyoshi Kaneko ◽  
Koji Saihara ◽  
Yuichi Masuda ◽  
Yukihiro Yoshimura ◽  
Akio Shimizu
Keyword(s):  
Ionic Liquid ◽  
Chain Length ◽  
Liquid Water ◽  
Alkyl Chain ◽  
Dynamic Properties ◽  
Alkyl Chain Length ◽  
Water Molecules ◽  
Water Mixture

Theoretical studies of the 1-ethyl-3-methylimidazolium glycine, [EMIM][Gly], ionic liquid – water mixture — I. Prediction of the solvation and structural properties

2013 ◽  
Vol 91 (2) ◽  
pp. 143-154 ◽  
Author(s):  
Yang Wu ◽  
Li-Na Zhang ◽  
Jing-Rui Li ◽  
Xiao-Lin Zheng ◽  
Mei Hong
Keyword(s):  
Ionic Liquid ◽  
Liquid Water ◽  
Electronic Structures ◽  
Dipole Moments ◽  
Molecular State ◽  
Water Molecules ◽  
Theoretical Studies ◽  
Water Mixture ◽  
Interaction Energies ◽  
Water Effect

Gaussian-based HF/MP2 and DFT/B3LYP methods have been explored to study the microsolvation of glycine anion with water, [Gly]–(W)n, and 1-ethyl-3-methylimidazolium glycine ionic liquid (IL) with water, [EMIM][Gly](W)n, n = 1–6 and 12. The water molecules are either isolated or aggregated around [Gly]– and [EMIM][Gly]. Their electronic structures have been calculated clearly to verify the molecular state of H2O and the results were used to compare with experiments. The water effect on the interaction energies and local packing of [EMIM][Gly] is considered. We identified an important factor: the variation of [EMIM][Gly](W)n polarity with the different numbers of H2O. As the amount of H2O increases, the polar network is continuously broken up. The dipole moments are changed to be lowest when the H-bonding ability of [Gly]– is almost saturated. Meanwhile, the nonpolar groups of the cation form an enhanced aggregation. Such observation can provide initial insights for the experimental nanostructural evolution in the IL–water mixtures.

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