Understanding solvation behavior of glucose in aqueous solutions of some deep eutectic solvents by thermodynamic approach

Journal of Molecular Liquids 289 (2019) 111000

Contents lists available at ScienceDirect

Journal of Molecular Liquids journal homepage: www.elsevier.com/locate/molliq

Understanding solvation behavior of glucose in aqueous solutions of some deep eutectic solvents by thermodynamic approach Hemayat Shekaari ⁎, Iraj Ahadzadeh, Sabah Karimi Department of Physical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran

a r t i c l e

i n f o

Article history: Received 18 March 2019 Received in revised form 16 May 2019 Accepted 18 May 2019 Available online 23 May 2019 Keywords: Deep eutectic solvent (DES) Glucose Viscosity Density Speed of sound

a b s t r a c t In this work, effect of different deep eutectic solvents (DES) based on choline chloride (ChCl) and dimethyl ammonium chloride (Dmac) as hydrogen bond acceptor and thiourea (Tio), glycerol (Gly), malonic acid (Mal) and urea as hydrogen bond donor on the thermodynamic and transport properties of glucose in aqueous solutions have been evaluated at T = 298.15 K. Viscosity, density and speed of sound data of the systems containing glucose in aqueous solutions of DES were measured in different mass percent of DES, wDES = (0.0010, 0.002, 0.0030, 0.0040). Apparent molar volume, apparent molar isentropic compressibility, transfer apparent molar volume and viscosity B-coefficient values of the systems studied were calculated using the experimental data. The results have been interpreted in terms of various solute–solvent interactions. The results indicate that the solute– solvent interactions in choline-based DESs should be stronger than that in the dimethyl ammonium-based DES and the most suitable DES to dehydrate of glucose is a choline chloride-glycerol eutectic mixture. © 2019 Elsevier B.V. All rights reserved.

1. Introduction Biomass is one of the major sources among the various types of new energy resources which is “the biodegradable components, wastes of agricultural products (including plant and animal material), forests and related industries, as well as industrial wastes and urban degradable components.” The downward trend of petrochemical sources to product of energy and chemicals components and raising concerns about greenhouse gases will shift the path for production of fuel towards renewable sources. Since biomass contains of valuable materials such as carbohydrate and other organic materials, they can create paths to make fuel vehicles. Two examples of biomasses are molasse and bagasse derived from cane processing, which contains various materials and cellulose. The hydrolysis of cellulose will break it and led to produce its monomers such as glucose. Glucose is the simplest and the most abundant monosaccharide in natural life. Since glucose is a hexose, it can be converted to hydroxymethylfurfural (HMF) in the presence of acidic catalytic via dehydration [1,2]. The selection of proper solvent to synthesis of HMF from glucose and other carbohydrates is vital which comes from dehydration of carbohydrates, including polymeric and monomeric carbohydrates such as cellulose, inulin, starch, sucrose, glucose and fructose. It acts as a bridge between the resources of biomass and the wide range of useful biochemical products, as illustrated in Fig. 1 [3].

⁎ Corresponding author at: Department of Physical Chemistry, University of Tabriz, Tabriz, Iran. E-mail address: [email protected] (H. Shekaari).

https://doi.org/10.1016/j.molliq.2019.111000 0167-7322/© 2019 Elsevier B.V. All rights reserved.

Green technology is seeking new and novel solvents to replace ordinary organic solvents presenting intrinsic toxicity and have high volatility, causing to evaporation of volatile organic compounds to the atmosphere. During decades ago, ionic liquids (ILs) have attracted much attention from the scientific community and industry processes, and the number of published papers in the literature has grown exponentially [4–6]. Major disadvantages of ILs are their toxicity, complicated synthesis method and purification. This makes them expensive and not preferable for the chemical industry, so there is need for other green and neoteric solvents. Preferably, such solvents should have similar physicochemical properties as ILs, and can be easily prepared from readily available compounds. This led to develop a new generation of green solvents as deep eutectic solvents (DESs). Nowadays they are used for many applications in research and many chemical processes in industry [7–9]. Recently, extraction of lignocellulose and its transformation into relevant carbohydrates such as glucose were performed in DES media [10–12]. On the other hand, in the past two decades a number of researchers have sought to determine a suitable solvent to dehydrate sugars and convert to other useful biochemical products. In order to development, design, and optimization of the mentioned processes, the knowledge of thermodynamic and transport properties such systems are needed. The knowledge of these properties can be used to interpret the present solute-solvent interaction in the systems studied. In spite of reports on the dehydration of sugars in the neoteric green solvents such as ionic liquids and deep eutectic solvents in recent years, there are limited studies on the thermodynamic properties of these types of processes.

2

H. Shekaari et al. / Journal of Molecular Liquids 289 (2019) 111000

Fig. 1. 5-HMF derivatives.

Some reports on the thermodynamic properties such as density, viscosity, solubility for sugar in aqueous solutions of DES have been given in the literature. Pandey and coworkers have measured density, viscosity of (choline chloride glycerol) deep eutectic solvent and its aqueous mixtures in the temperature range (283.15–363.15) K. The results highlight relatively stronger interactions, preferably H-bonding type, between water and glyceline (choline chloride-glycerol), as compared to those among water and among glyceline molecules, respectively [13]. Also, densities and the refractive indices of the deep eutectic solvents (ethaline: choline chloride-ethylene glycerol) and glyceline and their aqueous mixtures over the full compositions range were determined within the temperature range 293.15–323.15 K. They realized that the densities and refractive indices of the pure and aqueous mixtures

Table 2 Thermophysical properties of pure DESs. Pure DESs Chcl-Gly Chcl –Mala Chcl-Thiob Dmac-Gly Dmac –Mal Dmac – Urea a b

d∙10−3/kg∙m−3

u/m∙s−1

Molar mass/g mol−1

Ratio

1.183291 1.189952 1.361258 1.179194 1.183599 1.186139

1985.38 1798.54 1856.95 1892.29 1730.86 1875.69

323.82 347.74 291.86 265.72 289.66 201.66

1:2 1:2 1:2 1:2 1:2 1:2

303.15 K. 308.15 K.

Table 1 Table of the chemical used in this study. Chemical name

Source

Initial mole, fraction purity

Choline chloride

Sigma-Aldrich

0.996

GC a

Urea

Merck

0.98

GC

Glucose

Merck

0.98

GC

Thiourea (Thio)

Sigma-Aldrich

0.98

GC

Malonic acid (Mal)

Sigma-Aldrich

0.98

GC

Glycerol (Gly)

Sigma-Aldrich

0.99

GC

Dimethyl ammonium chloride

Sigma-Aldrich

0.99

GC

–

Structure

Analysis method

H. Shekaari et al. / Journal of Molecular Liquids 289 (2019) 111000

3

Table 3 Density (d) and speed of sound (u) data of D-glucose in the aqueous solutions of DES at T = 298.15 K and pressure p = 0.1 MPa.a,b wc 0.1 m1d/mol∙kg−1

0.2

d∙10−3/kg∙m−3

u/m∙s−1

m1/ mol∙kg−1

d∙10−3/kg∙m−3

0.0000 0.0250 0.0445 0.0645 0.0847 0.1004 0.1191 0.1390 0.1701 0.1968

1.015625 1.017138 1.018329 1.019551 1.020788 1.021745 1.022895 1.024123 1.026037 1.027687

1552.30 1553.40 1554.31 1555.34 1556.39 1557.21 1558.31 1559.48 1561.33 1563.01

0.0000 0.0249 0.0445 0.0652 0.0874 0.0997 0.1199 0.1403 0.1689 0.2003

1.034489 1.035923 1.037050 1.038256 1.039389 1.040264 1.041454 1.042647 1.044318 1.046161

ChCl + Mal 0.0000 0.0254 0.0448 0.0650 0.0849 0.0999 0.1201 0.1399 0.1696

1.024796 1.026340 1.027515 1.028759 1.029970 1.030918 1.032167 1.033359 1.035242

1532.23 1533.41 1534.34 1535.36 1536.45 1537.24 1538.42 1539.75 1541.62

0.0000 0.0249 0.0449 0.0646 0.0850 0.0999 0.1200 0.1397 0.1700

ChCl + Thio 0.0000 0.0253 0.0449 0.0649 0.0846 0.0998 0.1196 0.1398 0.1701

1.017382 1.018951 1.020167 1.021422 1.022659 1.023621 1.024926 1.026226 1.028135

1548.85 1550.25 1551.36 1552.47 1553.63 1554.51 1555.60 1556.76 1558.55

Dmac + Gly 0.0000 0.0254 0.0451 0.0641 0.0851 0.1003 0.1206 0.1392 0.1704 0.2000

1.016587 1.018136 1.019308 1.020406 1.021591 1.022413 1.023509 1.024481 1.026080 1.027523

Dmac + Mal 0.0000 0.0250 0.0451 0.0649 0.0851 0.1001 0.1202 0.1395 0.1704 0.2000 Dmac + Urea 0.0000 0.0249 0.0451 0.0650 0.0845 0.0999 0.1199 0.1383 0.1692 0.2000 a b c d

0.3 u/m∙s−1

m1/mol∙kg−1

0.4

d∙10−3/kg∙m−3

u/m∙s−1

m1/mol∙kg−1

d∙10−3/kg∙m−3

u/m∙s−1

ChCl + Gly 1610.68 0.0000 1611.68 0.0252 1612.54 0.0447 1613.46 0.0647 1614.46 0.0849 1615.21 0.0998 1616.32 0.1201 1617.50 0.1397 1619.24 0.1698 1621.16 0.2004

1.054077 1.055464 1.056563 1.057677 1.058815 1.059664 1.060808 1.061916 1.063634 1.065372

1672.78 1673.88 1674.74 1675.65 1676.57 1677.26 1678.29 1679.24 1680.70 1682.35

0.0000 0.0250 0.0450 0.0649 0.0851 0.1000 0.1200 0.1398 0.1701 0.2000

1.073822 1.075117 1.076179 1.077238 1.078317 1.079124 1.080211 1.081297 1.082935 1.084580

1736.38 1737.15 1737.85 1738.55 1739.39 1740.02 1740.93 1741.88 1743.34 1744.89

1.054595 1.055995 1.057142 1.058271 1.059440 1.060320 1.061475 1.062658 1.064392

1568.38 1569.50 1570.48 1571.48 1572.64 1573.47 1574.65 1575.87 1577.74

0.0000 0.0247 0.0447 0.0649 0.0852 0.1000 0.1191 0.1401 0.1701

1.082706 1.084021 1.085108 1.086205 1.087310 1.088126 1.089175 1.090307 1.091983

1601.74 1602.98 1604.00 1605.12 1606.27 1607.17 1608.30 1609.67 1611.56

0.0000 0.0249 0.0449 0.0648 0.0846 0.1001 0.1201 0.1399 0.1701

1.113055 1.114281 1.115271 1.116269 1.117270 1.118074 1.119119 1.120165 1.121709

1637.36 1638.34 1639.19 1640.10 1641.18 1641.96 1643.12 1644.26 1646.05

0.0000 0.0248 0.0451 0.0648 0.0847 0.0998 0.1200 0.1393 0.1697

1.038062 1.039514 1.040710 1.041870 1.043050 1.043955 1.045161 1.046337 1.048149

1600.72 1601.87 1602.88 1603.89 1604.92 1605.72 1606.85 1607.92 1609.70

0.0000 0.0251 0.0451 0.0649 0.0847 0.0995 0.1194 0.1393 0.1697

1.059112 1.060515 1.061640 1.062756 1.063915 1.064765 1.065915 1.067070 1.068832

1654.42 1655.64 1656.64 1657.65 1658.72 1659.50 1660.57 1661.68 1663.38

0.0000 0.0248 0.0451 0.0645 0.0844 0.0998 0.1199 0.1383 0.1703

1.080997 1.082308 1.083389 1.084435 1.085520 1.086370 1.087495 1.088514 1.090282

1709.27 1710.27 1711.15 1712.01 1712.88 1713.61 1714.52 1715.41 1716.94

1553.34 1554.77 1555.87 1556.95 1558.08 1558.83 1559.84 1560.61 1561.95 1562.94

0.0000 0.0251 0.0453 0.0642 0.0853 0.1002 0.1203 0.1393 0.1702 0.2001

1.036096 1.037600 1.038728 1.039792 1.040955 1.041764 1.042827 1.043761 1.045314 1.046688

1609.95 1611.50 1612.66 1613.73 1614.88 1615.70 1616.64 1617.53 1618.86 1619.84

0.0000 0.0249 0.0453 0.0640 0.0848 0.1000 0.1201 0.1394 0.1700 0.1999

1.055626 1.057069 1.058148 1.059178 1.060279 1.061035 1.062055 1.062962 1.064418 1.065756

1664.05 1665.62 1666.82 1667.90 1668.98 1669.78 1670.84 1671.71 1672.85 1673.94

0.0000 0.0252 0.0450 0.0642 0.0854 0.1001 0.1202 0.1394 0.1703 0.2001

1.075156 1.076538 1.077588 1.078574 1.079653 1.080406 1.081383 1.082243 1.083642 1.084924

1702.05 1703.62 1704.75 1705.85 1706.98 1707.78 1708.74 1709.71 1711.15 1712.35

1.014670 1.016221 1.017440 1.018609 1.019758 1.020597 1.021708 1.022733 1.024332 1.025813

1531.08 1532.53 1533.68 1534.75 1535.89 1536.67 1537.68 1538.58 1539.99 1541.26

0.0000 0.0251 0.0450 0.0647 0.0853 0.1003 0.1201 0.1398 0.1702 0.2001

1.048347 1.049828 1.050983 1.052082 1.053182 1.053972 1.055032 1.056012 1.057542 1.058947

1559.88 1561.49 1562.74 1563.90 1565.05 1565.87 1566.93 1567.92 1569.29 1570.36

0.0000 0.0248 0.0452 0.0648 0.0854 0.1002 0.1203 0.1397 0.1702 0.2000

1.082020 1.083418 1.084505 1.085541 1.086577 1.087323 1.088302 1.089212 1.090612 1.091931

1596.08 1597.85 1599.21 1600.49 1601.69 1602.62 1603.66 1604.68 1606.01 1607.10

0.0000 0.0252 0.0449 0.0646 0.0853 0.1003 0.1200 0.1397 0.1702 0.2001

1.115673 1.116975 1.117998 1.118974 1.119951 1.120644 1.121564 1.122414 1.123707 1.124873

1625.79 1627.77 1629.29 1630.69 1631.99 1632.92 1634.06 1635.09 1636.67 1638.24

1.017321 1.018898 1.020153 1.021381 1.022548 1.023442 1.024605 1.025655 1.027376 1.029017

1556.71 1558.17 1559.31 1560.39 1561.45 1562.29 1563.35 1564.29 1565.73 1567.05

0.0000 0.0249 0.0447 0.0652 0.0848 0.0978 0.1195 0.1380 0.1706 0.2000

1.036792 1.038298 1.039475 1.040669 1.041781 1.042495 1.043688 1.044682 1.046432 1.047916

1613.44 1615.04 1616.26 1617.48 1618.55 1619.25 1620.36 1621.33 1622.64 1623.92

0.0000 0.0249 0.0453 0.0647 0.0850 0.0985 0.1199 0.1379 0.1703 0.2000

1.056175 1.057628 1.058790 1.059884 1.061003 1.061718 1.062856 1.063784 1.065425 1.066856

1666.02 1667.82 1669.15 1670.37 1671.59 1672.39 1673.63 1674.57 1675.96 1677.22

0.0000 0.0248 0.0443 0.0648 0.0846 0.0998 0.1195 0.1399 0.1704 0.2001

1.066524 1.067933 1.069007 1.070129 1.071181 1.071982 1.073002 1.074008 1.075522 1.076884

1693.75 1695.56 1696.92 1698.25 1699.46 1700.31 1701.25 1702.327 1703.65 1704.76

Standard uncertainties (u) for each variable are u(d) = 0.15 kg m−3; u(u) = 0.5 m s−1; u(T) = 0.005 K; u(p) = 0.5 kPa; respectively. Relative standard uncertainties (u) for molality of D-glucose and mass fraction of DES are u(mglucose) = 0.01 and u(wDES) = 0.0001, respectively. w is the mass fraction of DES in water. m1 is the molal concentration of glucose in the binary solution of DES water.

4

wc 0.1 m1d/mol∙kg−1

0.2

0.3

0.4

106 Vφ/m3·mol−1

1014 κφ/m3·mol−1·Pa−1

m1/mol∙kg−1

106 Vφ/m3·mol−1

1014 κφ/m3·mol−1·Pa−1

m1/mol∙kg−1

106 Vϕ/m3·mol−1

1014 κϕ/m3·mol−1·Pa−1

m1/mol∙kg−1

106 Vϕ/m3·mol−1

1014 κϕ/m3·mol−1·Pa−1

ChCl + Gly 0.0250 0.0445 0.0645 0.0847 0.1004 0.1191 0.1390 0.1701 0.1968

118.434 118.134 117.931 117.686 117.554 117.352 117.136 116.832 116.566

0.149 0.069 −0.046 −0.124 −0.165 −0.259 −0.335 −0.430 −0.517

0.0249 0.0445 0.0652 0.0847 0.0997 0.1199 0.1403 0.1689 0.2003

120.231 120.013 119.709 119.521 119.329 119.077 118.885 118.628 118.365

0.679 0.586 0.529 0.427 0.377 0.290 0.207 0.097 0.008

0.0252 0.0447 0.0647 0.0849 0.0998 0.1201 0.1397 0.1698 0.2004

121.125 120.590 120.445 120.164 119.890 119.710 119.520 119.175 118.910

0.738 0.698 0.670 0.641 0.612 0.563 0.537 0.500 0.441

0.0250 0.0450 0.0649 0.0851 0.1000 0.1200 0.1397 0.1700 0.2000

122.646 122.088 121.752 121.426 121.197 120.867 120.543 120.246 119.910

1.373 1.279 1.233 1.148 1.101 1.030 0.963 0.892 0.819

ChCl + Mal 0.0254 0.0448 0.0650 0.0849 0.0999 0.1201 0.1399 0.1696

117.735 117.681 117.242 117.178 116.730 116.513 116.523 115.956

0.024 −0.013 −0.104 −0.187 −0.247 −0.335 −0.449 −0.576

0.0249 0.0449 0.0646 0.0850 0.1000 0.1200 0.1397 0.1700

120.093 119.544 119.232 119.005 118.721 118.486 118.043 117.899

0.577 0.454 0.352 0.257 0.202 0.121 0.027 −0.051

0.0247 0.0447 0.0649 0.0852 0.1000 0.1191 0.1401 0.1701

120.833 120.311 120.013 119.767 119.537 119.350 119.285 118.852

0.626 0.575 0.490 0.427 0.364 0.320 0.253 0.176

0.0249 0.0449 0.0648 0.0846 0.1000 0.1201 0.1399 0.1700

122.043 121.787 121.471 121.173 120.806 120.443 120.067 119.830

1.310 1.239 1.161 1.035 0.980 0.883 0.808 0.726

ChCl + Thio 0.0253 0.0449 0.0649 0.0846 0.0998 0.1196 0.1398

117.057 116.835 116.427 116.234 115.989 115.286 114.970

−0.533 −0.581 −0.608 −0.655 −0.684 −0.724 −0.753

0.0248 0.0451 0.0648 0.0847 0.0998 0.1200 0.1393

119.027 118.746 118.557 118.355 118.097 117.856 117.497

0.328 0.240 0.180 0.138 0.097 −0.036 −0.016

0.0251 0.0451 0.0646 0.0847 0.0995 0.1194 0.1393

120.058 119.785 119.378 119.009 118.815 118.558 118.274

0.516 0.458 0.402 0.348 0.304 0.257 0.219

0.0248 0.0451 0.0645 0.0844 0.0998 0.1199 0.1383

121.272 120.989 120.657 120.282 119.974 119.549 119.293

1.021 0.956 0.909 0.859 0.814 0.755 0.716

H. Shekaari et al. / Journal of Molecular Liquids 289 (2019) 111000

Table 4 The apparent molar volume (Vφ) and apparent molar isentropic compressibility (κφ) of D-glucose in aqueous solutions of DES at T = 298.15 K and at pressure p = 0.1 MPa.a,b

114.798

−0.786

0.1697

117.250

−0.088

0.1697

117.956

0.154

0.1703

118.966

0.650

Dmac + Gly 0.0254 0.0451 0.0641 0.0851 0.1003 0.1206 0.1392 0.1704 0.2000

118.066 118.493 119.089 119.702 120.336 120.859 121.391 122.167 122.970

−0.499 −0.455 −0.416 −0.332 −0.228 −0.142 −0.012 0.140 0.335

0.0251 0.0453 0.0642 0.0853 0.1002 0.1203 0.1393 0.1702 0.2001

118.586 119.189 119.712 120.102 120.592 121.105 121.676 122.396 123.273

−0.363 −0.278 −0.188 −0.111 −0.046 0.075 0.163 0.313 0.504

0.0249 0.0453 0.0640 0.0848 0.1000 0.1201 0.1394 0.1700 0.1999

119.552 120.171 120.504 121.039 121.657 122.084 122.510 123.332 124.008

−0.063 −0.007 0.069 0.189 0.264 0.325 0.403 0.591 0.721

0.0252 0.0450 0.0642 0.0854 0.1001 0.1202 0.1394 0.1703 0.2001

120.370 120.619 121.025 121.318 121.698 122.190 122.703 123.504 124.173

0.183 0.265 0.312 0.378 0.432 0.521 0.568 0.676 0.784

Dmac + Mal 0.0250 0.0451 0.0649 0.0851 0.1001 0.1202 0.1395 0.1704 0.2000

117.057 117.578 118.149 118.855 119.355 119.858 120.460 121.320 122.082

−0.760 −0.691 −0.581 −0.520 −0.438 −0.344 −0.231 −0.078 0.061

0.0251 0.0450 0.0647 0.0853 0.1003 0.1201 0.1398 0.1702 0.2001

117.729 118.371 119.065 119.575 120.083 120.483 120.973 121.680 122.374

−0.594 −0.491 −0.365 −0.269 −0.183 −0.094 −0.007 0.163 0.357

0.0248 0.0452 0.0648 0.0854 0.1002 0.1203 0.1397 0.1702 0.2000

118.538 119.165 119.775 120.232 120.667 121.163 121.659 122.457 123.034

−0.415 −0.307 0.201 −0.084 −0.026 0.105 0.199 0.397 0.570

0.0252 0.0449 0.0646 0.0853 0.1003 0.1200 0.1397 0.1702 0.2001

119.457 119.812 120.262 120.608 121.048 121.467 121.922 122.713 123.493

−0.337 −0.250 −0.141 −0.021 0.071 0.189 0.299 0.455 0.565

Dmac + Urea 0.0249 0.0451 0.0650 0.0845 0.0999 0.1199 0.1383 0.1692 0.2000

115.637 116.054 116.306 116.705 117.191 117.552 117.883 118.505 119.199

−0.805 −0.716 −0.636 −0.577 −0.523 −0.468 −0.411 −0.281 −0.142

0.0249 0.0447 0.0652 0.0848 0.0978 0.1195 0.1380 0.1706 0.2000

117.362 117.655 117.967 118.429 118.879 119.294 119.666 120.063 120.710

−0.583 −0.507 −0.436 −0.325 −0.251 −0.153 −0.093 0.080 0.218

0.0249 0.0453 0.0647 0.0850 0.0985 0.1199 0.1379 0.1703 0.2000

118.133 118.508 118.797 119.127 119.506 119.879 120.232 120.815 121.458

−0.558 −0.410 −0.314 −0.226 −0.166 −0.094 −0.014 0.167 0.302

0.0248 0.0443 0.0648 0.0846 0.0998 0.1195 0.1399 0.1704 0.2000

118.856 119.334 119.566 119.991 120.204 120.537 121.028 121.478 122.181

−0.388 −0.308 −0.216 −0.116 −0.039 0.092 0.190 0.321 0.476

a b c d

Standard uncertainties (u) for each variable are u(d) = 0.15 kg m−3; u(u) = 0.5 m s−1; u(T) = 0.005 K; u(p) = 0.5 kPa; respectively. Relative standard uncertainties (u) for molality of D-glucose and mass fraction of DES are u(mglucose) = 0.01 and u(wDES) = 0.0001, respectively. w is the mass fraction of DES in water. m1 is the molal concentration of glucose in the binary solution of DES water.

H. Shekaari et al. / Journal of Molecular Liquids 289 (2019) 111000

0.1701

5

6

H. Shekaari et al. / Journal of Molecular Liquids 289 (2019) 111000

decreased linearly with increasing temperature and increased with increasing DES mole fraction [14]. In recent years, there has been an increasing interest in understanding of behavior of carbohydrates in novel and green solvents such as ionic liquid and DES and their effect on the interactions between carbohydrates and aqueous solutions of DES or ionic liquid. Several studies have presented estimates of interactions between the constituent components of solution in ternary systems such as (carbohydrates DES water), but there is still insufficient data for clarify of nature of interactions. Knuz and et al investigated the physicochemical properties of ternary system containing DES ( choline chloride urea) and glucose or sorbitol. The refractive index, density, viscosity, decomposition temperatures, and glass transition temperatures were measured for these systems [15]. It is determined the solubility of the sugar derived molecules such as furfural (FF), hydroxymethylfurfural (HMF), dimethyladipate, glucose, fructose, cyclopentanediol, cyclopentanone, and tetrahydrofurfurylalcohol. In this study the Kamlet-Taft parameters of the DESs, and correlations with the solubility data were determined and , it is also measured the thermophysical properties (viscosity, decomposition temperature) of the six DESs (five hydrophilic and one hydrophobic). The hydrophobic DES showed the most interesting solubility properties (highest solubility for FF and HMF, and lowest solubility for the monosaccharides glucose and fructose) [16]. In spite of fantastic applications of DES [17–20], the thermodynamic and transport properties such as the acoustic, volumetric and viscometric properties of the systems containing glucose in the presence of deep eutectic solvents have not been reported yet. Therefore, to develope, optimise and production processes using deep eutectic solvents, it is important to obtain information about the thermodynamic and transport properties of these systems. Determination of such therphysical properties also provides useful and important information on the interactions between solvent and solute. The stronger interaction of glucose as solute with the aqueous solutions of DESs as solvent supplies, the greater probability of chemical reaction, such as dehydration. In this study, effect of some choline chloride and dimethyl ammonium chloride based DES on the volumetric, acoustic and viscometric properties of glucose in aqueous solutions of (ChCl Thio), (ChCl Mal), (ChCl Gly), (Dmac Urea), (Dmac Gly), (Dmac Mal) as deep eutectic solvents (DES) were investigated at 298.15 K. Some of the thermodynamic and transport quantities such as apparent molar volume (Vφ), the standard partial molar volume (V0φ ), transfer volume (ΔtrV0φ ), the apparent molar isentropic compressibility (Kφ) and the viscosity B–coefficient values were obtained using the density, speed of sound and viscosity data. The results have been interpreted in terms of the present solute–solute and solute–solvent interactions in the systems studied. 2. Experimental 2.1. Materials The names, CAS numbers, abbreviations, purity in mass fraction of the used chemicals used in this work are listed in the Table 1. The duble distilled and deionized water used to prepare of the solutions. 2.2. Preparation of DESs In this study, The DESs were prepared by mixing the hydrogen bond acceptor (HBA) (choline chloride and dimethyl ammonium chloride) and hydrogen bond donor (HBD) (thiourea, urea, glycerol and malonic acid). The six systems consist of (HBA and HBD) were synthesized by mixing HBA and HBD at a 1:2 molar ratio, heating at 80 °C until colourless and clear liquid eutectic mixtures were produced. The trace water content was removed a vacuum oven at 90 °C.

Water content was measured in the choline based DES and dimethyl ammonium based DES by Karl Fischer method using a Karl Fischer titrator (751 GPD Titrino-Metrohm, Herisau, Switzerland) and was less than 0.07% and 0.1%, respectively. The thermophysical properties of pure DESs are listed in Table 2. 2.3. Apparatus and procedure The experimental densities were measured by a vibrating tube densimeter (DSA5000 densimeter and speed of sound analyzer, Anton Paar). The apparatus was calibrated with doubly distilled, deionized, degassed water and dry air at atmospheric pressure. Temperature was kept constant within ±1.0 × 10−3 K using the Peltier device built in densimeter. The uncertainty of density and speed of sound were 5.0 × 10−2 kg·m−3 and 0.5 m·s−1, respectively. Viscosity of the solutions by a digital viscometer (Lovis 2000M, Anton Paar) was measured. This viscometer is based on the concept of a falling sphere inside a capillary of known diameter. Two laser sensors at the two ends of the capillary detect the small metal sphere and allow the determination of the time elapsed during its fall between the two positions. Average time is automatically recorded for the desired number of successive runs. The temperature of the capillary is controlled by a Peltier device within a precision of ±0.01 K. In each measurement, uncertainty of the viscosity measurements was 0.001 mPa s. To weigh glucose and prepare solutions used from an analytical balance (CP224 S Sartorius Co.) with precision of 1 × 10−4 g. All solutions were prepared by using deionized, distilled, and degassed water. 3. Results and discussion 3.1. Volumetric results The experimental density (d) data for binary solutions of (glucose water) and ternary solutions of (glucose DES water) at different mass fractions of DES (w), wDES = (0. 0010, 0.0020, 0.0030 and 0.0040) at T = 298.15 K are reported in Table 3. The experimental density data of binary system is in agreement with those reported in literature [21]. The apparent molar volumes of glucose were calculated using the following equation [22].

Vφ ¼

M ðd−d0 Þ  d mdd0

ð1Þ

where M and m are the molar mass of glucose, molality of the solution, d0 and d, are the densities of the solvent (DES water) and the solution, respectively. The values of apparent molar volumes of glucose in the studied solutions are listed in Table 4 and its varations is shown in Figs. 2 and 3. As it can be seen from these figures, the Vφ values were increased by increasing the concentration of DESs. The standard partial molar volumes V0φ were calculated using the following equation [23]; V φ ¼ V 0φ þ Sv m

ð2Þ

where Sv is the experimental slope and V0φ is the standard partial molar volume which provide useful information about solute-solute and solute-solvent interactions, respectively. The calculated values of V0φ and Sv for the investigated systems are given in Table 5. The values of Sv are negative in choline-based DESs and are positive in dimethyl ammonium-based DESs which indicate weaker solute-solute interactions in choline-based DESs rather than dimethyl ammonium-based DESs. The values of V0φ also increase with increasing functional groups in HBAs with fixed HBD. These quantity is for glucose in the aqueous

H. Shekaari et al. / Journal of Molecular Liquids 289 (2019) 111000

106 VФ/m 3 ·mol -1

121 120 119 118 117 116 0.00

0.05

0.10

0.15

0.20

0.25

m/mol·kg -1 Fig. 2. The apparent molar volumes of D-glucose vs. its molality m in aqueous solutions of different DES wDES = 0.2 at T = 298.15 K: (▲), ChCl:Thio;(■), ChCl:Mal; (●), ChCl:Gly.

DES solutions are as the following trends: ðChCl þ GlyÞN ðChCl þ MalÞN ðChCl þ ThioÞ ðDmac þ GlyÞN ðDmac þ MalÞN ðDmac þ ureaÞ: The values of V0φ in ahe molecular dynamic simulationqueous solution of choline-based DESs are more than dimethyl ammonium-based DESs as the following order: ðChCl þ GlyÞ N ðDmac þ GlyÞ; ðChCl þ MalÞN ðDmac þ MalÞ

which weakened by addition of choline chloride based DESs and dimethyl ammonium chloride. At infinite dilution the solute–solute interactions are negligible; hence, each solute is surrounded only by the solvent molecules and being infinitely distant with other, therefore, the values of V0φ as well as their temperature-dependence provide valuable information of the solute–solvent interactions [26]. The molecular dynamic simulations on DESs based on choline chloride demonstrated that anion−HBD interactions play an important role and dominant interactions are depending on anion type [27]. Infrared spectra of pure malonic acid and ChCl-Mal DES showed changes in the OH stretch region. However, results from the simulations suggest multiple types of hydrogen bonds occurring in this region of the spectra, inOH(choline)⋯Cl−, and malonic cluding OH(malonic)⋯Cl−, acid⋯malonic acid interactions. In the carbonyl stretching region, the two main bands observed for malonic acid either disappear or shift frequency values [27]. Therefore, malonic acid not only has strong hydrogen bond intermolecular interactions but also, interacts with chloride anion, consequently, it led to higher values of V0φ . On the other hand, glycerol is a polyol and having the variety in orientation of hydroxyl groups which cause strong intermolecular interactions, anion-HBD and cation-HBD. Intermolecular interaction between glycerol and choline chloride has been studied Toner and Weng in 2018. They indicated that water molecules intensify the interaction between choline chloride and glycerol molecules which this behaviour is observed in about 35.8 wt% water [28]. The values of ΔtrV0φ (in m3·mol−1) for transfer of glucose from water to aqueous solutions of DES based on choline chloride and dimethyl ammonium chloride (Eq. 3) are reported in Table 5. Δtr V 0φ ¼ V 0φ ðaqueous solution of DESÞ‐V 0φ ðwaterÞ

It was found that the alkyl chain length of DES plays a vital role in controlling the density and thus, an increase or decrease in alkyl chain length can change the density of a DES. In this case, it was observed that an increase in the alkyl chain length decreased the DES density. The main difference between choline chloride and dimethyl ammonium chloride is due to the presence of a hydroxyl group in choline cation, somehow that the hydroxyl group interacts with the hydrogens of the HBD groups [24,25]. Another possible reason for the interaction is the presence of methyl groups in choline chloride can led to steric hindrance and interactions. Also, the values of Sv may be attributed the existence of hydroxyl group in choline cation and the corresponding hydrogen-bonding with hydroxyl groups of glucose. In all of the systems Sv values decrease with increasing the weight fraction of DES. This behaviour is due to glucose–glucose interactions

124 106 VФ/m 3 ·mol -1

123 122 121 120

7

ð3Þ

The analysis of these results can be used as according to the cosphere overlap model [29,30]: This model expresses the types of present interactions between the components of the ternary studied systems can be summarized as follows: (1) the polar−ionic group interactions between chloride anion-polar groups of HBD (2) polar−polar group interactions between hydroxyl group of choline cation and polar groups of HBD via the hydrogen bonding (3) polar−nonpolar group interactions between polar groups of HBA and HBD and alkyl groups (4) nonpolar−nonpolar group interactions between nonpolar groups of choline chloride and alkyl groups of HBD. The positive ΔtrV0φ values show that the dominance types 1,2 interactions and negative values also, indicate that the types 3 and 4 are dominant. According to Table 5, the values of ΔtrV0φ at all concentrations of DES are positive and increase at higher concentration of DESs. Therefore, it seems polar–polar interactions are dominant and chloride ion of choline chloride and polar groups of HBD led to increase ΔtrV0φ values. By transferring glucose from water to solutions (DES water) some of hydrogen bonds between glucose and water molecules were replaced with hydrogen bond between glucose and DES, therefore, ΔtrV0φ become positive which strengthened at higher concentration of DES. 3.2. Acoustical properties

119

The speed of sound data (u), for the systems investigated are listed in Table 3. The apparent molar isentropic compressibility Kφ is calculated as fallow [31]:

118 117 116 0

0.05

0.1

0.15

m/mol·kg

0.2

0.25

-1

Fig. 3. The apparent molar volumes of D-glucose vs. its molality m in aqueous solutions of different DES for wDES = 0.2 at T = 298.15 K: (▲), Dmac:Urea; (■), Dmac:Mal; (●), Dmac: Gly.

Kφ ¼

K s d0 −K 0s d K s M þ mdd0 d

ð4Þ

1 is the isentropic compressibility. The values of Kφ for du2 glucose in the aqueous solutions of DESs at T = 298 K are reported in where K s ¼

8

H. Shekaari et al. / Journal of Molecular Liquids 289 (2019) 111000

Table 5 Standard partial molar volume (V0ϕ), experimental slope (Sv), transfer volume (ΔtrV0ϕ), partial molar isentropic compressibility (κ0ϕ) and experimental slope (SK) values for D-glucose in aqueous solutions of different DES at T = 298.15 K. 106V0ϕ /m3·mol−1

106Sv/m3·mol−2·kg

106ΔtrV0ϕ /m3·mol−1

1014κ0ϕ /m3·mol−1·Pa−1

1014SK/kg m3·mol−2·Pa−1

ChCl + Gly 0.1 0.2 0.3 0.4

118.63 ± 0.05 120.44 ± 0.01 121.23 ± 0.02 122.79 ± 0.02

−10.64 ± 0.04 −10.79 ± 0.09 −12.11 ± 0.20 −15.27 ± 0.16

6.96 8.77 9.56 11.12

0.223 ± 0.01 0.766 ± 0.01 0.777 ± 0.02 1.427 ± 0.02

−3.885 ± 0.01 −3.896 ± 0.01 −1.682 ± 0.02 −3.178 ± 0.02

ChCl + Mal 0.1 0.2 0.3 0.4

118.12 ± 0.03 120.29 ± 0.03 120.927 ± 0.02 122.49 ± 0.03

−12.53 ± 0.25 −15.08 ± 0.31 −15.53 ± 0.18 −16.37 ± 0.24

6.45 8.62 9.42 10.82

0.166 ± 0.01 0.655 ± 0.01 0.703 ± 0.01 1.416 ± 0.01

−4.289 ± 0.06 −4.373 ± 0.08 −3.180 ± 0.08 −4.247 ± 0.11

ChCl + Thio 0.1 0.2 0.3 0.4

117.55 ± 0.05 119.35 ± 0.05 120.37 ± 0.03 121.69 ± 0.07

−17.14 ± 0.42 −12.59 ± 0.41 −14.91 ± 0.31 −16.84 ± 0.67

5.53 7.68 8.70 10.02

−0.498 ± 0.01 0.375 ± 0.01 0.542 ± 0.01 1.053 ± 0.01

−1.788 ± 0.09 −2.795 ± 0.10 −2.106 ± 0.07 −2.093 ± 0.09

Dmac + Gly 0.1 0.2 0.3 0.4

117.30 ± 0.04 117.95 ± 0.04 118.95 ± 0.08 119.59 ± 0.06

28.77 ± 0.32 26.43 ± 0.39 25.63 ± 0.76 22.42 ± 0.53

5.63 6.28 7.28 7.92

−0.695 ± 0.01 −0.508 ± 0.05 −0.204 ± 0.01 0.001 ± 0.01

4.901 ± 0.11 4.892 ± 0.04 4.570 ± 0.11 3.409 ± 0.07

Dmac + Mal 0.1 0.2 0.3 0.4

116.33 ± 0.04 117.27 ± 0.04 118.03 ± 0.08 118.76 ± 0.06

29.24 ± 0.32 26.22 ± 0.39 25.74 ± 0.76 23.13 ± 0.53

4.66 5.60 6.36 7.09

−0.903 ± 0.01 −0.724 ± 0.05 −0.567 ± 0.01 −0.477 ± 0.01

4.772 ± 0.11 5.278 ± 0.04 5.606 ± 0.11 5.538 ± 0.07

Dmac + Urea 0.1 0.2 0.3 0.4

115.08 ± 0.04 116.83 ± 0.04 117.61 ± 0.08 118.41 ± 0.06

20.40 ± 0.32 19.63 ± 0.39 18.99 ± 0.76 18.40 ± 0.53

3.41 5.16 5.94 6.74

−0.887 ± 0.01 −0.714 ± 0.05 −0.6398 ± 0.01 −0.530 ± 0.01

3.622 ± 0.11 4.64 ± 0.04 4.705 ± 0.11 5.028 ± 0.07

wa

a

w is the mass fraction of DES in water.

Table 4. The apparent molar isentropic compressibility Kφ has linear relation with molality of solute as [32]: K φ ¼ K 0φ þ Sk m

ð5Þ

where K0φ is the partial molar isentropic compressibility and Sk is the experimental slope. The K φ 0 values of the systems containing glucose in the aqueous solutions of DES are plotted in Figs. 4,5. K φ 0 is an important property and provides important information about compressibility of solvated solute and solute–solvent interactions at infinite dilution which each solute is surrounded only by the solvent molecules. The

partial molar isentropic compressibility can be obtained from the extrapolation of the apparent molar isentropic compressibility at infinite dilution. The calculated values of K0φ and Sk for all the studied systems are given in Table 5. The results of this table show that the values of K0φ increase with increasing the concentration of DES. It can be interpreted that solutesolvent interactions were increased with increasing the concentration of DES .

0.6 1014 KФ/m 3·mol -1·Pa-1

1014 KФ/m 3·mol -1·Pa-1

0.85 0.65 0.45 0.25 0.05 -0.15

0.4 0.2 0 -0.2 -0.4 -0.6 -0.8

0

0.05

0.1

0.15

m/mol·kg

0.2

0.25

-1

Fig. 4. The apparent molar isentropic compressibility of D-glucose vs. its molality m in aqueous solutions of different DES for wDES = 0.2 at T = 298.15 K: (▲), ChCl:Thio; (■), ChCl:Mal; (●), ChCl:Gly.

0

0.05

0.1

0.15

m/mol·kg

0.2

0.25

-1

Fig. 5. The apparent molar isentropic compressibility (Kφ) of D-glucose vs. its molality m in aqueous solutions of different DES for wDES = 0.2 at T = 298.15 K: (▲), Dmac:Urea; (■), Dmac:Mal; (●), Dmac:Gly.

H. Shekaari et al. / Journal of Molecular Liquids 289 (2019) 111000

9

Table 6 Viscosities of D-glucose (η) in aqueous different DES solutions at T = 298.15 K and P = 101.33 kPaa,b. wc 0.1

0.3

0.4

c/mol·dm−3

η/mPa·s

c/mol·dm−3

η/mPa·s

c/mol·dm−3

η/mPa·s

ChCl + Gly 0.0000 0.0280 0.0496 0.0721 0.0944 0.1118 0.1314 0.1527 0.1874 0.2131

1.093 1.128 1.140 1.156 1.166 1.177 1.190 1.205 1.216 1.236

0.0000 0.0285 0.0506 0.0742 0.0959 0.1126 0.1351 0.1584 0.1885 0.2244

1.406 1.450 1.470 1.485 1.502 1.519 1.535 1.553 1.574 1.600

0.0000 0.0293 0.0519 0.0750 0.0984 0.1144 0.1385 0.1602 0.1941 0.2285

1.888 2.002 2.006 2.024 2.044 2.069 2.094 2.105 2.121 2.147

0.0000 0.0297 0.0534 0.0767 0.1003 0.1177 0.1408 0.1634 0.1981 0.2319

2.654 2.785 2.820 2.844 2.877 2.902 2.941 3.008 3.038 3.063

ChCl + Mal 0.0000 0.0360 0.0633 0.0917 0.1195 0.1403 0.1683 0.1950 0.2362

1.091 1.105 1.119 1.133 1.148 1.157 1.164 1.178 1.196

0.0000 0.0362 0.0653 0.0934 0.1231 0.1444 0.1727 0.2008 0.2437

1.375 1.408 1.415 1.437 1.456 1.462 1.474 1.498 1.507

0.0000 0.0368 0.0665 0.0966 0.1265 0.1481 0.1747 0.2068 0.2499

1.755 1.826 1.845 1.868 1.884 1.898 1.914 1.929 1.946

0.0000 0.0383 0.0689 0.0992 0.1289 0.1524 0.1825 0.2118 0.2567

2.373 2.515 2.530 2.548 2.566 2.583 2.606 2.619 2.638

ChCl + Thio 0.0000 0.0356 0.0630 0.0907 0.1181 0.1392 0.1663 0.1940 0.2355

0.991 1.005 1.018 1.027 1.038 1.048 1.061 1.068 1.084

0.0000 0.0353 0.0646 0.0925 0.1208 0.1420 0.1700 0.1966 0.2395

1.149 1.162 1.177 1.192 1.207 1.221 1.231 1.244 1.259

0.0000 0.0365 0.0658 0.0940 0.1229 0.1438 0.1725 0.2008 0.2443

1.377 1.398 1.411 1.427 1.446 1.463 1.483 1.504 1.519

0.0000 0.0368 0.0672 0.0957 0.1244 0.1472 0.1769 0.2020 0.2499

1.730 1.778 1.798 1.813 1.834 1.848 1.871 1.893 1.911

Dmac + Gly 0.0000 0.0358 0.0632 0.0892 0.1188 0.1396 0.1675 0.1929 0.2354 0.2752

1.125 1.137 1.152 1.164 1.177 1.186 1.206 1.220 1.233 1.247

0.0000 0.0365 0.0644 0.0909 0.1210 0.1423 0.1707 0.1965 0.2398 0.2803

1.131 1.162 1.175 1.186 1.200 1.214 1.224 1.235 1.259 1.271

0.0000 0.0372 0.0656 0.0926 0.1233 0.1449 0.1738 0.2001 0.2442 0.2855

1.324 1.372 1.396 1.408 1.421 1.441 1.457 1.469 1.484 1.500

0.0000 0.0378 0.0668 0.0943 0.1255 0.1476 0.1770 0.2037 0.2486 0.2906

1.463 1.539 1.553 1.576 1.590 1.604 1.617 1.628 1.641 1.650

Dmac Mal 0.0000 0.0351 0.0632 0.0905 0.1186 0.1394 0.1665 0.1925 0.2350 0.2750

1.111 1.115 1.130 1.141 1.155 1.164 1.184 1.198 1.210 1.224

0.0000 0.0360 0.0650 0.0930 0.1220 0.1440 0.1720 0.1990 0.2430 0.2840

1.126 1.150 1.164 1.173 1.187 1.197 1.212 1.222 1.241 1.264

0.0000 0.0374 0.0673 0.0964 0.1263 0.1485 0.1774 0.2050 0.2502 0.2925

1.229 1.273 1.288 1.307 1.325 1.335 1.347 1.359 1.371 1.385

0.0000 0.0385 0.0694 0.0994 0.1302 0.1531 0.1828 0.2112 0.2578 0.3013

1.385 1.452 1.477 1.491 1.508 1.518 1.531 1.543 1.558 1.564

Dmac Urea 0.0000 0.0349 0.0633 0.0913 0.1177 0.1394 0.1667 0.1894 0.2331 0.2756

1.001 1.017 1.031 1.039 1.044 1.057 1.062 1.076 1.086 1.091

0.0000 0.0357 0.0637 0.0931 0.1206 0.1364 0.1693 0.1924 0.2407 0.2807

1.120 1.133 1.145 1.156 1.168 1.178 1.195 1.205 1.228 1.244

0.0000 0.0363 0.0657 0.0942 0.1233 0.1399 0.1730 0.1958 0.2447 0.2858

1.230 1.262 1.279 1.297 1.313 1.322 1.334 1.346 1.359 1.373

0.0000 0.0366 0.0646 0.0950 0.1236 0.1456 0.1741 0.2029 0.2469 0.2884

1.218 1.307 1.323 1.342 1.358 1.367 1.379 1.391 1.404 1.418

a b c d

cs/mol·dm−3

0.2 η/mPa·s

d

Standard uncertainties (u) for each variable are u(d) = 0.15 kg m−3; u(u) = 0.5 m s−1; u(T) = 0.005 K; u(p) = 5 kPa; respectively. Relative standard uncertainties (u) for molality of D-glucose and mass fraction of DES are u(mglucose) = 0.01 and u(wDES) = 0.0001, respectively. w is the mass fraction of DES in water. cs is the molar concentration of glucose in binary solution of (water DES).

10

H. Shekaari et al. / Journal of Molecular Liquids 289 (2019) 111000

1.70

Table 7 Viscosity B-coefficients (B) and standard deviations for D-glucose in aqueous DES solutions at T = 298.15 K.

1.60

w

1.50 η/mPa.s

1.40

0.1 0.2 0.3 0.4

1.30 1.20

0.1 0.2 0.3 0.4

1.10 1.00 0

0.05

0.1

0.15

0.2

0.25

0.3

c/mol·dm−3 Fig. 6. The viscosity of the solutions vs. glucose molarity c in aqueous solutions of DES for wDES = 0.2 at T = 298.15 K: (▲), ChCl:Thio; (■), ChCl:Mal;(●), ChCl:Gly.

3.3. Viscosity B–coefficient Viscometric properties as a transport property can also, provide helpful information on solute-solvent interactions and confirm the volumetric results. The experimental viscosity, η, data for the solutions containing of glucose in the aqueous solutions of DES were measured at T = 298.15 K given in Table 6. These result show an increase in the viscosity of the solutions with increasing of DES. The more functional groups and longer alkyl groups in the DES components lead to the stronger interaction between the compoundsand increasing the viscosity. The concentration dependency of viscosity was presented by Jones– Dole equation [33]: 0

1 þ BCÞ η ¼ η0 @1 þ AC 2

ð6Þ

η/mPa.s

where η is the viscosity of the solution and η0 is the viscosity of the solvent, C is molarity of the solution. The A-coefficient indicates the solutesolute interactions (called the Falkenhagen coefficient) which can be computed theoretically. Since it has small value compared to B value hence, it is neglected in the equation while the viscosity B-coefficient value is a measure of solute-solvent interactions in the solutions and also, depends on shape and size of solute molecules [34,35]. The plot of η values versus C is illustrated in Figs. 6 and 7 for choline-based DES

0.1 0.2 0.3 0.4 0.1 0.2 0.3 0.4 0.1 0.2 0.3 0.4 0.1 0.2 0.3 0.4

B/(dm3·mol−1) ChCl + Gly 0.630 ± 0.018 0.764 ± 0.011 0.856 ± 0.033 0.958 ± 0.041 ChCl + Mal 0.565 ± 0.017 0.665 ± 0.026 0.812 ± 0.017 0.909 ± 0.011 ChCl + Thio 0.517 ± 0.012 0.663 ± 0.019 0.770 ± 0.023 0.869 ± 0.018 Dmac + Gly 0.510 ± 0.020 0.635 ± 0.011 0.800 ± 0.025 1.204 ± 0.035 Dmac + Mal 0.507 ± 0.023 0.625 ± 0.009 0.807 ± 0.031 1.075 ± 0.033 Dmac + Urea 0.462 ± 0.020 0.419 ± 0.011 0.657 ± 0.030 0.821 ± 0.027

σ(B)/(dm3·mol−1) 0.009 0.023 0.064 0.082 0.013 0.032 0.068 0.127 0.009 0.020 0.033 0.065 0.007 0.023 0.034 0.113 0.009 0.022 0.053 0.097 0.011 0.009 0.034 0.054

and dimethyl ammonium-based DES, respectively. The viscosity Bcoefficients are calculated using least-square method given as Table 7. As can be seen from this table, the viscosity B-coefficient values increase at higher concentration of DES which can be interpreted in terms of hydrogen bonding between glucose and DESs. Troter indicated that alkyl chain lengthening, or fluorination of organic components causes an increase in van der Waals interactions and hydrogen bonds, which makes DESs more viscous [36]. The results indicate that the DES (ChCl-Gly) has the highest viscosity among other studied DESs and the following order are observed for viscosity B-coefficients. ðChCl þ GlyÞN ðChCl þ MalÞN ðChCl þ ThioÞ ðDmac þ GlyÞN ðDmac þ MalÞN ðDmac þ ureaÞ

1.30

4. Conclusion

1.25

The selection of proper neoteric green solvent (deep eutectic solvent) are so vital to dehydration of sugars. In this study, volumetric, acoustic and viscometric properties of glucose in the aqueous solutions of DES based on choline chloride and dimethyl ammonium were studied and several HBDs. The calculated standard partial molar volume V0φ , transfer volumes ΔtrV0φ , the values of partial molar isentropic compressibility K0φ, viscosity B-coefficient reveal that solute–solvent interaction were increased with increasing concentration of DES. It seems the suitable solvent system to dehydrate sugars is ChCl-Gly and glucose has stronger interactions with this solvent based on these thermophysical parameters.. Also, it is concluded that the solute– solvent interactions in choline-based DESs are stronger than that in the dimethyl ammonium-based DES.l.

1.20 1.15 1.10 0.00

0.05

0.10

0.15

0.20

0.25

0.30

c/mol·dm−3 Fig. 7. The viscosity of the solutions vs. glucose molarity c in aqueous solutions of DES for wDES = 0.2 at T = 298.15 K: (▲), Dmac:Urea; (■), Dmac:Mal; (●), Dmac:Gly.

H. Shekaari et al. / Journal of Molecular Liquids 289 (2019) 111000

Acknowledgements We are grateful to University of Tabriz research council for the financial support of this research. References [1] F. Menegazzo, E. Ghedini, Michela Signoretto, 5-hydroxymethylfurfural (hmf) production from real biomasses, Molecules 23 (9) (2018) 2201. [2] Y.B. Huang, Y. Fu, Hydrolysis of cellulose to glucose by solid acid catalysts, Green Chem. 15 (2013) 1095–1111. [3] M. Zuo Tang, Z. Li, H. Liu, C. Xiong, X. Zeng, Y. Sun, L. Hu, Sh. Liu, T. Lei, L. Lin, Green processing of lignocellulosic biomass and its derivatives in deep eutectic solvents, ChemSusChem 10 (13) (2017) 2696–2706 (X). [4] A. Paiva, R. Craveiro, I. Aroso, M. Martins, R.L. Reis, A. Rita C. Duarte, Natural deep eutectic solvents–solvents for the 21st century, ACS Sustainable Chem 2 (5) (2014) 1063–1071. [5] M. folic, R. gani, C. Jiménez-González, D.J.C. constable, Systematic selection of green solvents for organic reacting systems, Chin. J. Chem. Eng. 16 (3) (2008) 376–383. [6] H. Shekaari, M.T. Zafarani-Moattar, F. Ghaffari, Effect of some imidazolium-based ionic liquids with different anions on the thermodynamic properties of acetaminophen in aqueous media at T = 293.15 to 308.15 K, J. Chem. Eng. Data 62 (12) (2017) 4093–4107. [7] E.L. Smith, A.P. Abbott, K.S. Ryder, Deep eutectic solvents (DESs) and their applications, Chem. Rev. 114 (21) (2014) 11060–11082. [8] V. Fischer, Properties and Applications of Deep Eutectic Solvents and Low-melting Mixtures, 2015 (Thesis of the University of Regensburg (PhD). [9] Vânia I.B. Castro, F. Mano, R.L. Reis, A. Paiva, A.R.C. Duarte, Synthesis and physical and thermodynamic properties of lactic acid and malic acid-based natural deep eutectic solvents, J. Chem. Eng. Data 63 (7) (2018) 2548–2556. [10] B. Saha, M.M. Abu-Omar, Advances in 5-hydroxymethylfurfural production from biomass in biphasic solvents, Green Chem. 16 (2014) 24–38. [11] M. Zuo, K. Le, Z. Li, Y. Jiang, X. Zeng, X. Tang, ... L. Lin, Green process for production of 5-hydroxymethylfurfural from carbohydrates with high purity in deep eutectic solvents, Ind. Crop. Prod. 99 (2017) 1–6. [12] K.D.O. Vigier, G. Chatel, F. Jerome, Contribution of deep eutectic solvents for biomass processing: opportunities, challenges, and limitations, ChemCatChem 7 (8) (2015) 1250–1260. [13] A. Yadav, Sh. Trivedi, R. Rai, S. Pandey, Densities and dynamic viscosities of (choline chloride glycerol) deep eutectic solvent and its aqueous mixtures in the temperature range (283.15–363.15) K, Fluid Phase Equilib. 367 (2014) 135–142. [14] R.B. Leron, A.N. Soriano, M.H. Li, Densities and refractive indices of the deep eutectic solvents (choline chloride ethylene glycol or glycerol) and their aqueous mixtures at the temperature ranging from 298.15 to 333.15 K, Journal of the Taiwan Institute of Chemical Engineers 43 (2012) 551–557. [15] V. Fischer, W. Kunz, Properties of sugar-based low-melting mixtures, Journal Molecular Physics 112 (2014) 9–10. [16] Carin H.J.T. Dietz, Maaike C. Kroon, Martin van Sint Annaland, Fausto Gallucci, Thermophysical properties and solubility of different sugar-derived molecules in deep eutectic solvents, J. Chem. Eng. Data 62 (11) (2017) 3633–3641. [17] Q. Zhang, K.D.O. Vigier, S. Royer, F. Jerome, Deep eutectic solvents: syntheses, properties and applications, Chem. Soc. Rev. 41 (21) (2012) 7108–7146.

11

[18] X. Tang, M. Zuo, Z. Li, H. Liu, C. Xiong, X. Zeng, L. Lin, Green processing of lignocellulosic biomass and its derivatives in deep eutectic solvents, ChemSusChem 10 (13) (2017) 2696–2706. [19] P. Liu, J.W. Hao, L.P. Mo, Z.H. Zhang, Recent advances in the application of deep eutectic solvents as sustainable media as well as catalysts in organic reactions, RSC Adv. 5 (60) (2015) 48675–48704. [20] W. Guo, Y. Hou, W. Wu, S. Ren, S. Tian, K.N. Marsh, Separation of phenol from model oils with quaternary ammonium salts via forming deep eutectic solvents, Green Chem. 15 (2013) 226–229. [21] H. Shekaari, A. Kazempour, Thermodynamic properties of d-glucose in aqueous 1hexyl-3-methylimidazolium bromide solutions at 298.15 K, Fluid Phase Equilib. 336 (2012) 122–127. [22] M.T. Zafarani-Moattar, H. Shekaari, Volumetric and compressibility behaviour of ionic liquid, 1-n-butyl-3-methylimidazolium hexafluorophosphate and tetrabutylammonium hexafluorophosphate in organic solvents at T = 298.15 K, J. Chem. Eng 38 (2006) 624. [23] T.S. Banipal, P. Kapoor, Partial molal volumes and expansibilities of some amino acids in aqueous solutions, J. Indian Chem. Soc. 76 (9) (1999) 431–437. [24] Frederick G. Bordwell, Guo Zhen Ji, Effects of structural changes on acidities and homolytic bond dissociation energies of the hydrogen-nitrogen bonds in amidines, carboxamides, and thiocarboxamides, J. Am. Chem. Soc. 113 (22) (1991) 8398–8401. [25] Gergely Jakab, Carlo Tancon, Zhiguo Zhang, Katharina M. Lippert, Peter R. Schreiner, (Thio) urea organocatalyst equilibrium acidities in DMSO, Org. Lett. 14 (7) (2012) 1724–1727. [26] R. Sadeghi, A. Gholamireza, Thermodynamics of the ternary systems: (water glyycine, L-alanine and L-serine di-ammonium hydrogen citrate) from volumetric, compressibility, and (vapour liquid) equilibria measurements, J. Chem. Thermodynamics 43 (2011) 200–215. [27] Sasha L. Perkins, P. Paul, Coray M. Colina, Experimental and computational studies of choline chloride-based deep eutectic solvents, J. Chem. Eng. Data 59 (11) (2014) 3652–3662. [28] W. Lindong, Mehmet Toner, Janus-faced role of water in defining nanostructure of choline chloride/glycerol deep eutectic solvent, Phys. Chem. Chem. Phys. 20 (2018), 22455. [29] H. Shekaari, A. Kazempour, Ghasedi, Structure-making tendency of ionic liquids in the aqueous d-glucose solutions, Fluid Phase Equilib. 316 (2012) 102–108. [30] C.M. Romero, Negrete, effect of temperature on partial molar volumes and viscosities of aqueous solutions of α-DL-aminobutyric acid, DL-Norvaline and DL-Norleucine, Phys. Chem. Liq. 42 (3) (2004) 261–267. [31] Jacques E. Desnoyers, Marcel Arel, G. Perron, C. Jolicoeur, Apparent molal volumes of alkali halides in water at 25. deg. Influence of structural hydration interactions on the concentration dependence, J. Phys. Chem. 73 (1969) 3346–3351. [32] H. Shekaari, E. Armanfar, Apparent molar volumes and expansivities of aqueous solutions of ionic liquids, l-alkyl-3-methylimidazolium alkyl sulfate at T = (298.15–328.15) K, Fluid Phase Equilib. 303 (2011) 120–125. [33] G. Jones, M. Dole, J. Am, The viscosity of aqueous solutions of strong electrolytes with special reference to barium chloride, Chem. Soc. 51 (1929) 2950–2964. [34] C.M. Romero, F. Negrete, Effect of temperature on partial molar volumes and viscosities of aqueous solutions of α-DL-aminobutyric acid, DL-Norvaline and DLNorleucine, Phys. Chem. Liq. 42 (3) (2004) 261–267. [35] M.J. Iqbal, M.A. Chaudhry, Volumetric and viscometric studies of antidepressant drugs in aqueous medium at different temperatures, J. Chem. Eng. Data 54 (2009) 2772–2776.