TY - JOUR
T1 - The role of water in cholinium carboxylate ionic liquid's aqueous solutions
AU - Patinha, David J S
AU - Tomé, Liliana C.
AU - Garcia, Helga
AU - Ferreira, Rui
AU - Pereira, Cristina Maria
AU - Rebelo, Luís Paulo N
AU - Marrucho Ferreira, Isabel Maria
PY - 2015
Y1 - 2015
N2 - Binary systems composed of water and cholinium carboxylate ionic liquids, namely cholinium lactate ([Ch][Lac]), cholinium propanoate ([Ch][Prop]) and cholinium malonate ([Ch][Mal]) were studied from the neat ionic liquid to very diluted aqueous solutions. Densities and viscosities were measured and atypical behaviors were observed, such as the increasing density of the binary [Ch][Prop] + H2O mixtures with increasing water content. In order to get molecular level insights on the IL + H2O solvation schemes, 1H NMR studies were performed. Large deviations were obtained in the anionÍs resonances when compared to those of the cation suggesting that water interacts preferentially with the anion counter-part of the ionic liquid. The increasing density of [Ch][Prop] + H2O system with increasing water content can be related to the orientation of the alkyl chains, as a result of their nanoscale organization. This behavior was confirmed through the study of the thermophysical properties of [Ch][Hex] + H2O mixtures, where this phenomenon is known to occur.
AB - Binary systems composed of water and cholinium carboxylate ionic liquids, namely cholinium lactate ([Ch][Lac]), cholinium propanoate ([Ch][Prop]) and cholinium malonate ([Ch][Mal]) were studied from the neat ionic liquid to very diluted aqueous solutions. Densities and viscosities were measured and atypical behaviors were observed, such as the increasing density of the binary [Ch][Prop] + H2O mixtures with increasing water content. In order to get molecular level insights on the IL + H2O solvation schemes, 1H NMR studies were performed. Large deviations were obtained in the anionÍs resonances when compared to those of the cation suggesting that water interacts preferentially with the anion counter-part of the ionic liquid. The increasing density of [Ch][Prop] + H2O system with increasing water content can be related to the orientation of the alkyl chains, as a result of their nanoscale organization. This behavior was confirmed through the study of the thermophysical properties of [Ch][Hex] + H2O mixtures, where this phenomenon is known to occur.
KW - (Water + IL) interactions
KW - Cholinium carboxylate
KW - Ionic liquids
KW - NMR
KW - Thermophysical properties
UR - http://www.scopus.com/inward/record.url?scp=84921464224&partnerID=8YFLogxK
U2 - 10.1016/j.jct.2014.12.020
DO - 10.1016/j.jct.2014.12.020
M3 - Article
AN - SCOPUS:84921464224
SN - 0021-9614
VL - 84
SP - 93
EP - 100
JO - Journal of Chemical Thermodynamics
JF - Journal of Chemical Thermodynamics
ER -