Deep eutectic solvents (DESs) have been the subject of interest in literature with a focus on replacing traditional solvents due to their green solvent’s characteristics. This study presents the experimental data on preparation and physicochemical properties of choline chloride and propionic acid deep eutectic solvent (CC:PA DES) and their aqueous binary mixtures in (298.15 to 353.15) K temperature range. The experimental density (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">$\rho$</EquationSource> <EquationSource Format="MATHML"><math> <mi>ρ</mi> </math></EquationSource> </InlineEquation>) data are fitted well by second degree polynomial equation in T. Molar entropy (<InlineEquation ID="IEq2"> <EquationSource Format="TEX">${S}^{0}$</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mrow> <mi>S</mi> </mrow> <mn>0</mn> </msup> </math></EquationSource> </InlineEquation>) and Lattice energy (<InlineEquation ID="IEq3"> <EquationSource Format="TEX">${U}_{pot}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>U</mi> <mrow> <mi mathvariant="italic">pot</mi> </mrow> </msub> </math></EquationSource> </InlineEquation>) are also calculated to explain the behavior of thermodynamic properties. Excess molar volume (<InlineEquation ID="IEq4"> <EquationSource Format="TEX">${V}^{E}$</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mrow> <mi>V</mi> </mrow> <mi>E</mi> </msup> </math></EquationSource> </InlineEquation>) is showing positive deviation from ideal behavior and the minimum of <InlineEquation ID="IEq5"> <EquationSource Format="TEX">${V}^{E}$</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mrow> <mi>V</mi> </mrow> <mi>E</mi> </msup> </math></EquationSource> </InlineEquation> vs. <InlineEquation ID="IEq6"> <EquationSource Format="TEX">${x}_{1}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>x</mi> <mn>1</mn> </msub> </math></EquationSource> </InlineEquation> lies at <InlineEquation ID="IEq7"> <EquationSource Format="TEX">${x}_{1}=0.5$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>=</mo> <mn>0.5</mn> </mrow> </math></EquationSource> </InlineEquation> (<InlineEquation ID="IEq8"> <EquationSource Format="TEX">${x}_{1}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>x</mi> <mn>1</mn> </msub> </math></EquationSource> </InlineEquation> = mole fraction of CC:PA DES in binary mixture). Plot of <InlineEquation ID="IEq9"> <EquationSource Format="TEX">${\overline{V} }_{i}^{E}$</EquationSource> <EquationSource Format="MATHML"><math> <msubsup> <mover> <mi>V</mi> <mo>¯</mo> </mover> <mrow> <mi>i</mi> </mrow> <mi>E</mi> </msubsup> </math></EquationSource> </InlineEquation> vs. <InlineEquation ID="IEq10"> <EquationSource Format="TEX">${x}_{1}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>x</mi> <mn>1</mn> </msub> </math></EquationSource> </InlineEquation> also cross each other at <InlineEquation ID="IEq11"> <EquationSource Format="TEX">${x}_{1}=0.5$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>=</mo> <mn>0.5</mn> </mrow> </math></EquationSource> </InlineEquation>. which supports the dominance of specific interactions. Viscosity deviation (<InlineEquation ID="IEq12"> <EquationSource Format="TEX">$\Delta \eta$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi mathvariant="normal">Δ</mi> <mi>η</mi> </mrow> </math></EquationSource> </InlineEquation>) is observed at <InlineEquation ID="IEq13"> <EquationSource Format="TEX">${x}_{1}=0.8$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>=</mo> <mn>0.8</mn> </mrow> </math></EquationSource> </InlineEquation>, supporting the interstitial accommodation of components molecules into each other. Comparison of Vogel–Fulcher–Tammann (VFT) equation and Arrhenius equation to investigate the temperature dependence of viscosity (<InlineEquation ID="IEq14"> <EquationSource Format="TEX">$\eta$</EquationSource> <EquationSource Format="MATHML"><math> <mi>η</mi> </math></EquationSource> </InlineEquation>) for <InlineEquation ID="IEq15"> <EquationSource Format="TEX">${x}_{1}=0-1.0$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>=</mo> <mn>0</mn> <mo>-</mo> <mn>1.0</mn> </mrow> </math></EquationSource> </InlineEquation> shows that VFT is better fitted model in studied temperature range T = (298.15 to 353.15) K. We demonstrated that the PC-SAFT equation of state can reliably predict the density of the pseudobinary CC:PA DES + water system. In addition, PC-SAFT was capable of correctly capture the qualitative behavior of the excess molar volume.

Experimental Measurements and Modeling of Different Physical Properties of CC:PA DES and Water in Range of (298.15 to 353.15) K and Atmospheric Pressure

期刊论文
发表日期：

2025年11月25日

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Aafia Sheikh,
Ariel Hernández

摘要

Deep eutectic solvents (DESs) have been the subject of interest in literature with a focus on replacing traditional solvents due to their green solvent’s characteristics. This study presents the experimental data on preparation and physicochemical properties of choline chloride and propionic acid deep eutectic solvent (CC:PA DES) and their aqueous binary mixtures in (298.15 to 353.15) K temperature range. The experimental density ( $\rho$ $ρ$ ) data are fitted well by second degree polynomial equation in T. Molar entropy ( ${S}^{0}$ $S^{0}$ ) and Lattice energy ( ${U}_{pot}$ $U_{pot}$ ) are also calculated to explain the behavior of thermodynamic properties. Excess molar volume ( ${V}^{E}$ $V^{E}$ ) is showing positive deviation from ideal behavior and the minimum of ${V}^{E}$ $V^{E}$ vs. ${x}_{1}$ $x_{1}$ lies at ${x}_{1}=0.5$ $x_{1} = 0.5$ ( ${x}_{1}$ $x_{1}$ = mole fraction of CC:PA DES in binary mixture). Plot of ${\overline{V} }_{i}^{E}$ ${\bar{V}}_{i}^{E}$ vs. ${x}_{1}$ $x_{1}$ also cross each other at ${x}_{1}=0.5$ $x_{1} = 0.5$ . which supports the dominance of specific interactions. Viscosity deviation ( $\Delta \eta$ $Δ η$ ) is observed at ${x}_{1}=0.8$ $x_{1} = 0.8$ , supporting the interstitial accommodation of components molecules into each other. Comparison of Vogel–Fulcher–Tammann (VFT) equation and Arrhenius equation to investigate the temperature dependence of viscosity ( $\eta$ $η$ ) for ${x}_{1}=0-1.0$ $x_{1} = 0 - 1.0$ shows that VFT is better fitted model in studied temperature range T = (298.15 to 353.15) K. We demonstrated that the PC-SAFT equation of state can reliably predict the density of the pseudobinary CC:PA DES + water system. In addition, PC-SAFT was capable of correctly capture the qualitative behavior of the excess molar volume.