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| Main Authors: | , , , , , |
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| Format: | Preprint |
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2024
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| Online Access: | https://arxiv.org/abs/2409.16912 |
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| _version_ | 1866929515121344512 |
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| author | González, Juan Antonio Martínez, Francisco Javier Sanz, Luis Felipe Hevia, Fernando de la Fuente, Isaías García Cobos, José Carlos |
| author_facet | González, Juan Antonio Martínez, Francisco Javier Sanz, Luis Felipe Hevia, Fernando de la Fuente, Isaías García Cobos, José Carlos |
| contents | Densities, $ρ$, and kinematic viscosities, $ν$, have been determined at atmospheric pressure and at (293.15-303.15) K for binary mixtures formed by methanol and one linear polyether of the type CH$_3$-O-(CH$_2$CH$_2$O)$_n$-CH$_3$ ($n$ = 2,3,4). The $ρ$ values are used to compute excess molar volumes, $V_{\text{m}}^{\text{E}}$, and, together with $ν$ results, dynamic viscosities ($η$). Deviations from linear dependence on mole fraction for viscosity, $Δη$, are also provided. Different semi-empirical equations have been employed to correlate viscosity data. Particularly, the equations used are: Grunberg-Nissan, Hind, Frenkel, Katti-Chaudhri, McAllister and Heric. Calculations show that better results are obtained from the Hind equation. The $V_{\text{m}}^{\text{E}}$ values are large and negative and contrast with the positive excess molar enthalpies, $H_{\text{m}}^{\text{E}}$, available in the literature, for these systems. This indicates that structural effects are dominant. The $Δη$ results are positive and correlate well with the difference in volume of the mixture compounds confirming the importance of structural effects. The temperature dependences of $η$ and of the molar volume have been used to calculate enthalpies, entropies and Gibbs energies, $ΔG^*$, of viscous flow. It is demonstrated that $ΔG^*$ is essentially determined by enthalpic effects. Methanol + CH$_3$-O-(CH$_2$CH$_2$O)$_n$-CH$_3$ mixtures have been treated in the framework of the ERAS model. Results on $H_{\text{m}}^{\text{E}}$ are acceptable, while the composition dependence of the $V_{\text{m}}^{\text{E}}$ curves is poorly represented. This has been ascribed to the existence of strong dipolar and structural effects in the present solutions. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2409_16912 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Volumetric and Viscosimetric Measurements for Methanol + CH$_3$-O-(CH$_2$CH$_2$O)$_n$-CH$_3$ ($n$ = 2, 3, 4) Mixtures at (293.15-303.15) K and Atmospheric Pressure: Application of the ERAS Model González, Juan Antonio Martínez, Francisco Javier Sanz, Luis Felipe Hevia, Fernando de la Fuente, Isaías García Cobos, José Carlos Chemical Physics Densities, $ρ$, and kinematic viscosities, $ν$, have been determined at atmospheric pressure and at (293.15-303.15) K for binary mixtures formed by methanol and one linear polyether of the type CH$_3$-O-(CH$_2$CH$_2$O)$_n$-CH$_3$ ($n$ = 2,3,4). The $ρ$ values are used to compute excess molar volumes, $V_{\text{m}}^{\text{E}}$, and, together with $ν$ results, dynamic viscosities ($η$). Deviations from linear dependence on mole fraction for viscosity, $Δη$, are also provided. Different semi-empirical equations have been employed to correlate viscosity data. Particularly, the equations used are: Grunberg-Nissan, Hind, Frenkel, Katti-Chaudhri, McAllister and Heric. Calculations show that better results are obtained from the Hind equation. The $V_{\text{m}}^{\text{E}}$ values are large and negative and contrast with the positive excess molar enthalpies, $H_{\text{m}}^{\text{E}}$, available in the literature, for these systems. This indicates that structural effects are dominant. The $Δη$ results are positive and correlate well with the difference in volume of the mixture compounds confirming the importance of structural effects. The temperature dependences of $η$ and of the molar volume have been used to calculate enthalpies, entropies and Gibbs energies, $ΔG^*$, of viscous flow. It is demonstrated that $ΔG^*$ is essentially determined by enthalpic effects. Methanol + CH$_3$-O-(CH$_2$CH$_2$O)$_n$-CH$_3$ mixtures have been treated in the framework of the ERAS model. Results on $H_{\text{m}}^{\text{E}}$ are acceptable, while the composition dependence of the $V_{\text{m}}^{\text{E}}$ curves is poorly represented. This has been ascribed to the existence of strong dipolar and structural effects in the present solutions. |
| title | Volumetric and Viscosimetric Measurements for Methanol + CH$_3$-O-(CH$_2$CH$_2$O)$_n$-CH$_3$ ($n$ = 2, 3, 4) Mixtures at (293.15-303.15) K and Atmospheric Pressure: Application of the ERAS Model |
| topic | Chemical Physics |
| url | https://arxiv.org/abs/2409.16912 |