10.1021/acs.iecr.8b01249.s001
Emanuel A. Crespo
Emanuel A.
Crespo
Liliana P. Silva
Liliana P.
Silva
Mónia A.
R. Martins
Mónia A.
R.
Martins
Mark Bülow
Mark
Bülow
Olga Ferreira
Olga
Ferreira
Gabriele Sadowski
Gabriele
Sadowski
Christoph Held
Christoph
Held
Simão P. Pinho
Simão P.
Pinho
João A. P. Coutinho
João
A. P. Coutinho
The Role of Polyfunctionality in the Formation of
[Ch]Cl-Carboxylic Acid-Based Deep Eutectic Solvents
American Chemical Society
2018
HBD
HBA
eutectic points coordinates
eutectic mixtures
DES
acid
modeling
interaction
nonideality
Ch
PC-SAFT
phase diagrams
monofunctional hydrogen-bond donors
SLE
2018-07-19 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/The_Role_of_Polyfunctionality_in_the_Formation_of_Ch_Cl-Carboxylic_Acid-Based_Deep_Eutectic_Solvents/6900968
Aiming at providing
an extensive characterization of the solid–liquid equilibria
(SLE) of deep eutectic solvents (DESs), the phase diagrams of nine
eutectic mixtures composed of choline chloride ([Ch]Cl) and (poly)carboxylic
acids, commonly reported in the literature as DESs, were measured
experimentally. Contrarily to the behavior reported for eutectic mixtures
composed of [Ch]Cl (hydrogen-bond acceptor, HBA) and monofunctional
hydrogen-bond donors (HBD) such as fatty acids and fatty alcohols,
which have recently been shown to be almost ideal mixtures, a significant
decrease of the melting temperature, at the eutectic point, was observed
for most of the systems studied. This melting temperature depression
was attributed to a pronounced nonideality of the liquid phase induced
by the strong hydrogen-bond interactions between the two mixture components.
Perturbed-chain statistical associating fluid theory (PC-SAFT) was
used to describe these interactions physically. PC-SAFT allowed accurately
modeling the experimental phase diagrams over the entire concentration
and temperature ranges. Depending on the kind of mixture, up to two
temperature-independent binary interaction parameters between HBA
and HBD were applied. The PC-SAFT approach was used to provide trustworthy
information on the nonideality of the liquid phase (expressed as the
activity coefficients of HBA and HBD) as well as to estimate the eutectic
points coordinates. The experimental data along with the modeling
results allowed us to infer about the importance of the HBD’s
chemical structure on the formation of [Ch]Cl-based DESs.