US EPA

1791443 

Journal Article 

Formation of Deep Eutectic Solvents by Phenols and Choline Chloride and Their Physical Properties 

Guo, W; Hou, Y; Ren, S; Tian, S; Wu, W 

2013 

Yes 

Journal of Chemical and Engineering Data
ISSN: 0021-9568
EISSN: 1520-5134 

58 

4 

866-872 

10.1021/je300997v 

WOS:000317553600005 

Novel deep eutectic solvents (DES) based on three different
hydrogen-bond donors (HBD), namely phenol, o-cresol, and 2,3-xylenol, and choline chloride (ChCl)
were successfully synthesized with different mole ratios of HBD to ChCl. Melting temperature of
these DES were measured. Compared with an ideal mixture of the two components, the freezing
temperature of the DES depresses greatly from (120 to 127) K. The physical properties, such as
density, viscosity, and conductivity of phenol-based and o-cresol-based DES were determined at
atmospheric pressure and temperatures from (293.2 to 318.2) K at an interval of 5 K. The results
show that the type of HBD, the mole ratio of HBD to ChCl, and temperature have great influences
on the physical properties of DES. Densities and viscosities of DES formed by phenol and ChCl
decrease with increases of temperature and phenol content. The conductivities of the DES are from
(1.40 to 7.06) mS.cm(-1), similar to that of room temperature ionic liquids. The conductivities
of the DES increase with an increase of temperature, and reach the highest values at phenol to
ChCl mole ratios of 4.00 to 5.00. The temperature dependence of densities and conductivities for
these DES were correlated by an empirical second-order polynomial with relative deviations less
than 0.91 %, and the viscosities were fitted to the VTF equation with relative deviations less
than 0.52 %.