Pub Date : 2025-12-01Epub Date: 2025-08-06DOI: 10.1016/j.jct.2025.107560
Evis Muzhaqi, Aycan Altun Kavaklı, Osman Nuri Şara, M. Ferdi Fellah
In this study, the density and viscosity of binary mixtures of triethanolamine (TEA) and ethanol were measured over the entire composition range at temperatures of 293.15 and 323.15 K under a pressure of 101.3 kPa. Correlations were obtained expressing density and viscosity values as a function of temperature. Excess molar volume (VE) and viscosity deviation (Δη) were calculated from the measured values. These properties were further fitted to the Redlich–Kister polynomial equation. Thermodynamic parameters such as partial molar volumes, apparent molar volumes, coefficients of thermal expansion, and excess Gibbs free energy of activation for viscous flow were also determined. Moreover, activation enthalpy and entropy values for viscous flow were evaluated. The experimental results and the Density Functional Theory (DFT) calculations were used to discuss the molecular interactions for binary mixtures of TEA and ethanol. Negative values of VE and Δη were observed across all studied temperatures and compositions, indicating strong specific interactions between TEA and ethanol molecules. There is a distinct difference in the temperature dependence of VE and Δη. As the temperature increases, the VE values become increasingly negative, while the Δη values decrease. Both experimental results and Density Functional Theory (DFT) calculations confirm the presence of intermolecular hydrogen bonding in the binary mixtures. Furthermore, FTIR spectroscopy suggests the possible presence of intermolecular interactions between the components.
{"title":"Experimental and computational (DFT) study of a binary system of triethanolamine and ethanol at temperatures from 293.15 to 323.15 K under 101.3 kPa","authors":"Evis Muzhaqi, Aycan Altun Kavaklı, Osman Nuri Şara, M. Ferdi Fellah","doi":"10.1016/j.jct.2025.107560","DOIUrl":"10.1016/j.jct.2025.107560","url":null,"abstract":"<div><div>In this study, the density and viscosity of binary mixtures of triethanolamine (TEA) and ethanol were measured over the entire composition range at temperatures of 293.15 and 323.15 K under a pressure of 101.3 kPa. Correlations were obtained expressing density and viscosity values as a function of temperature. Excess molar volume (V<sup>E</sup>) and viscosity deviation (Δη) were calculated from the measured values. These properties were further fitted to the Redlich–Kister polynomial equation. Thermodynamic parameters such as partial molar volumes, apparent molar volumes, coefficients of thermal expansion, and excess Gibbs free energy of activation for viscous flow were also determined. Moreover, activation enthalpy and entropy values for viscous flow were evaluated. The experimental results and the Density Functional Theory (DFT) calculations were used to discuss the molecular interactions for binary mixtures of TEA and ethanol. Negative values of V<sup>E</sup> and Δη were observed across all studied temperatures and compositions, indicating strong specific interactions between TEA and ethanol molecules. There is a distinct difference in the temperature dependence of V<sup>E</sup> and Δη. As the temperature increases, the V<sup>E</sup> values become increasingly negative, while the Δη values decrease. Both experimental results and Density Functional Theory (DFT) calculations confirm the presence of intermolecular hydrogen bonding in the binary mixtures. Furthermore, FTIR spectroscopy suggests the possible presence of intermolecular interactions between the components.</div></div>","PeriodicalId":54867,"journal":{"name":"Journal of Chemical Thermodynamics","volume":"211 ","pages":"Article 107560"},"PeriodicalIF":2.2,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144809684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-07-18DOI: 10.1016/j.jct.2025.107547
Na Di, Yu Liu, Chao Liu
Octamethyltrisiloxane (MDM)/Decamethyltetrasiloxane (MD2M) mixtures are considered one of the most suitable working fluids for high temperature Organic Rankine Cycle (ORC) systems and heat pump. As a critical thermophysical property, thermal conductivities of liquid siloxanes are important to understand heat transfer characteristics. In this study, thermal conductivities of MDM/MD2M mixtures (with MDM mass fraction wMDM = 0, 0.30, 0.50, 0.70, 1.00) were measured using a transient hot-wire method over a temperature range of 263.15–343.15 K and pressures up to 8 MPa. Then, an empirical model was proposed to reproduce the thermal conductivity regarding temperature and pressure, yielding an average absolute deviation of less than 1 %. In addition, the thermal conductivities of the MDM/MD2M systems were studied using the non-equilibrium molecular dynamics (NEMD) simulation. The predicted values show good consistency with the experimental results, confirming both the accuracy of the established model and the suitability of the selected force field, while offering a dependable computational method for predicting thermal conductivity. This work provides essential data and theoretical support for evaluating the heat transfer performance and selecting working fluids in MDM/MD2M-based ORC systems.
{"title":"Experimental and molecular dynamics study on the thermal conductivity of Octamethyltrisiloxane (MDM)/Decamethyltetrasiloxane (MD2M) mixtures","authors":"Na Di, Yu Liu, Chao Liu","doi":"10.1016/j.jct.2025.107547","DOIUrl":"10.1016/j.jct.2025.107547","url":null,"abstract":"<div><div>Octamethyltrisiloxane (MDM)/Decamethyltetrasiloxane (MD<sub>2</sub>M) mixtures are considered one of the most suitable working fluids for high temperature Organic Rankine Cycle (ORC) systems and heat pump. As a critical thermophysical property, thermal conductivities of liquid siloxanes are important to understand heat transfer characteristics. In this study, thermal conductivities of MDM/MD<sub>2</sub>M mixtures (with MDM mass fraction <em>w</em><sub>MDM</sub> = 0, 0.30, 0.50, 0.70, 1.00) were measured using a transient hot-wire method over a temperature range of 263.15–343.15 K and pressures up to 8 MPa. Then, an empirical model was proposed to reproduce the thermal conductivity regarding temperature and pressure, yielding an average absolute deviation of less than 1 %. In addition, the thermal conductivities of the MDM/MD<sub>2</sub>M systems were studied using the non-equilibrium molecular dynamics (NEMD) simulation. The predicted values show good consistency with the experimental results, confirming both the accuracy of the established model and the suitability of the selected force field, while offering a dependable computational method for predicting thermal conductivity. This work provides essential data and theoretical support for evaluating the heat transfer performance and selecting working fluids in MDM/MD<sub>2</sub>M-based ORC systems.</div></div>","PeriodicalId":54867,"journal":{"name":"Journal of Chemical Thermodynamics","volume":"211 ","pages":"Article 107547"},"PeriodicalIF":2.2,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-06-16DOI: 10.1016/j.jct.2025.107535
Manale El Bachtioui , Ilham Abala , Mohamed Lifi , Mohamed Dakkach , Mohamed Allouch , Fernando Aguilar
New experimental data on density (), dynamic and kinematic viscosities, for the following ternary mixtures: 2-butanol (Belale and F.E. M'hamdi Alaoui, M. Lifi, Y.Chhiti, M. Elkhouakhi, L., 2020 (1)) + isopropyl ether (Alaoui et al., 2015 (2)) + 1-hexene (Abala and Lifi, 2021 (3)) and 2-propanol (Belale and F.E. M'hamdi Alaoui, M. Lifi, Y.Chhiti, M. Elkhouakhi, L., 2020 (1)) + isopropyl ether (Alaoui et al., 2015 (2)) + 1-hexene (Abala and Lifi, 2021 (3)) are presented in this work at four temperatures between 298.15 and 313.15 K and = 0.1 MPa. Additionally, the speed of sound () and refractive index () for the same ternary mixtures were measured at 298.15 K and 313.15 K. Various derived properties were calculated from the experimental results of these thermophysical properties, including excess volume, deviation in refractive index, , deviation in dynamic viscosity, deviations in speed of sound, isentropic compressibility, and deviation in isentropic compressibility, The Redlich-Kister equation and the typical semi-empirical Cibulka equations were used to correlate all of these derived properties. Moreover, the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) equation of state was employed to fit the experimental density data, and good agreement between the experimental and modeled density results for the binary mixtures studied.
下列三元混合物的密度（ρ），动态和运动粘度，ημ的新实验数据：2-丁醇（Belale和F.E. M'hamdi Alaoui， M. Lifi， Y.Chhiti， M. Elkhouakhi， L., 2020(1)） +异丙基醚（Alaoui等，2015(2)）+ 1-己烯（Abala和Lifi， 2021(3)）和2-丙醇（Belale和F.E. M'hamdi Alaoui， M. Lifi， Y.Chhiti， M. Elkhouakhi， L., 2020(1)） +异丙基醚（Alaoui等，2015(2)）+ 1-己烯（Abala和Lifi， 2021(3)）在298.15至313.15 K和p = 0.1 MPa之间的四种温度下进行了研究。此外，在298.15 K和313.15 K下测量了相同三元混合物的声速(u)和折射率（nD）。根据这些热物理性质的实验结果计算了各种衍生性质，包括多余体积，VE，折射率偏差，∆nD，动态粘度偏差，∆η，声速偏差，∆u，等熵可压缩性，ks和等熵可压缩性偏差，∆ks。Redlich-Kister方程和典型的半经验Cibulka方程被用来关联所有这些导出的性质。采用微扰链统计关联流体理论（PC-SAFT）状态方程对实验密度数据进行拟合，实验结果与模型结果吻合较好。
{"title":"Measurement, correlation, and modeling of volumetric, viscosimetric, acoustic, and optical properties in ternary mixtures of alcohols, ethers, and hydrocarbons between 298.15 and 313.15 K","authors":"Manale El Bachtioui , Ilham Abala , Mohamed Lifi , Mohamed Dakkach , Mohamed Allouch , Fernando Aguilar","doi":"10.1016/j.jct.2025.107535","DOIUrl":"10.1016/j.jct.2025.107535","url":null,"abstract":"<div><div>New experimental data on density (<span><math><mrow><mi>ρ</mi></mrow></math></span>), dynamic and kinematic viscosities, <span><math><mrow><mfenced><mi>η</mi><mi>μ</mi></mfenced></mrow></math></span> for the following ternary mixtures: 2-butanol (Belale and F.E. M'hamdi Alaoui, M. Lifi, Y.Chhiti, M. Elkhouakhi, L., 2020 (1)) + isopropyl ether (Alaoui et al., 2015 (2)) + 1-hexene (Abala and Lifi, 2021 (3)) and 2-propanol (Belale and F.E. M'hamdi Alaoui, M. Lifi, Y.Chhiti, M. Elkhouakhi, L., 2020 (1)) + isopropyl ether (Alaoui et al., 2015 (2)) + 1-hexene (Abala and Lifi, 2021 (3)) are presented in this work at four temperatures between 298.15 and 313.15 K and <span><math><mrow><mi>p</mi></mrow></math></span> = 0.1 MPa. Additionally, the speed of sound (<span><math><mrow><mi>u</mi></mrow></math></span>) and refractive index (<span><math><mrow><msub><mi>n</mi><mi>D</mi></msub></mrow></math></span>) for the same ternary mixtures were measured at 298.15 K and 313.15 K. Various derived properties were calculated from the experimental results of these thermophysical properties, including excess volume, <span><math><mrow><msup><mi>V</mi><mi>E</mi></msup><mo>,</mo></mrow></math></span> deviation in refractive index, <span><math><mrow><mo>∆</mo><msub><mi>n</mi><mi>D</mi></msub></mrow></math></span>, deviation in dynamic viscosity, <span><math><mrow><mo>∆</mo><mi>η</mi><mo>,</mo></mrow></math></span> deviations in speed of sound, <span><math><mrow><mo>∆</mo><mi>u</mi><mo>,</mo></mrow></math></span> isentropic compressibility, <span><math><mrow><msub><mi>k</mi><mi>s</mi></msub><mo>,</mo></mrow></math></span> and deviation in isentropic compressibility, <span><math><mrow><mo>∆</mo><msub><mi>k</mi><mi>s</mi></msub><mo>.</mo></mrow></math></span> The Redlich-Kister equation and the typical semi-empirical Cibulka equations were used to correlate all of these derived properties. Moreover, the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) equation of state was employed to fit the experimental density data, and good agreement between the experimental and modeled density results for the binary mixtures studied.</div></div>","PeriodicalId":54867,"journal":{"name":"Journal of Chemical Thermodynamics","volume":"210 ","pages":"Article 107535"},"PeriodicalIF":2.2,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144306992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, we explored the thermophysical properties of a mixture composed of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][NTf2]) ionic liquid (IL) and the organic solvent 2-ethoxyethanol (2-EE). We meticulously measured the density, speed of sound, and refractive index across the full range of mixture compositions at temperatures of 298.15, 303.15, 308.15, 313.15, and 318.15 K under atmospheric pressure. Additionally, we calculated various excess parameters, such as excess molar volume, excess isentropic compressibility, excess isobaric thermal expansion coefficient, deviation in refractive index, and partial molar quantities, based on our experimental data. These parameters were then analyzed using the Redlich-Kister polynomial equation to understand the mixture's behavior better. Our findings revealed strong attractive forces within the IL-rich areas of the [Emim][NTf2] and 2-EE binary mixture, indicating significant intermolecular interactions. The strength and nature of these interactions were further supported and illuminated through ATR-FTIR and Molecular Dynamics (MD) simulation studies, providing a comprehensive insight into the molecular dynamics within these mixtures.
{"title":"Exploring molecular interactions through thermophysical properties and molecular dynamics simulations in [Emim][NTf2] and 2-EE mixtures","authors":"Nagarjuna Babu Etukuri , Sreenivasa Rao Aangothu , Sowjanya Prathipati , Srinivasa Reddy Munnangi , Bala Murali Krishna Khandapu , J.N. Pavan Kumar Chintala , Hari Babu Bollikolla","doi":"10.1016/j.jct.2025.107536","DOIUrl":"10.1016/j.jct.2025.107536","url":null,"abstract":"<div><div>In this study, we explored the thermophysical properties of a mixture composed of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][NTf<sub>2</sub>]) ionic liquid (IL) and the organic solvent 2-ethoxyethanol (2-EE). We meticulously measured the density, speed of sound, and refractive index across the full range of mixture compositions at temperatures of 298.15, 303.15, 308.15, 313.15, and 318.15 K under atmospheric pressure. Additionally, we calculated various excess parameters, such as excess molar volume, excess isentropic compressibility, excess isobaric thermal expansion coefficient, deviation in refractive index, and partial molar quantities, based on our experimental data. These parameters were then analyzed using the Redlich-Kister polynomial equation to understand the mixture's behavior better. Our findings revealed strong attractive forces within the IL-rich areas of the [Emim][NTf<sub>2</sub>] and 2-EE binary mixture, indicating significant intermolecular interactions. The strength and nature of these interactions were further supported and illuminated through ATR-FTIR and Molecular Dynamics (MD) simulation studies, providing a comprehensive insight into the molecular dynamics within these mixtures.</div></div>","PeriodicalId":54867,"journal":{"name":"Journal of Chemical Thermodynamics","volume":"210 ","pages":"Article 107536"},"PeriodicalIF":2.2,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144596390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-07-10DOI: 10.1016/j.jct.2025.107545
Aarthi Sai Meghana Munnangi , Hara Krishna Reddy Koppolu , Sk Md Nayeem , Prathap Koppolu , Srinivasa Reddy Munnangi
Binary solvent mixtures are increasingly significant due to their ability to enhance reaction rates, modify solubility, and optimize technological separation processes. Among such mixtures, γ-butyrolactone (GBL) and dimethylformamide (DMF) are noteworthy for their versatility in various applicative fields, including pharmaceuticals, coatings, and adhesives. This study integrates experimental methods with molecular dynamics simulations and machine learning techniques to investigate the physicochemical properties and intermolecular interactions of the GBL-DMF binary system across different temperatures and compositions. The measured densities (ρ), speeds of sound (u), and refractive indices (nD) of the binary mixtures were used to calculate excess molar volume (), excess isentropic compressibility (), and refractive index deviations (), which together give an overview of how the molecules interact with each other, suggesting the presence of strong molecular interactions such as hydrogen bonding and dipole-dipole forces. These observations are further corroborated by molecular dynamics simulations, which align well with the experimental data. Additionally, machine learning algorithms, including Random Forest, Gradient Boosting, XGBoost, and H2O AutoML, were employed to predict density. Among these, H2O AutoML demonstrated superior precision with an R2 value of 0.984. This multifaceted approach, combining experimental, computational, and predictive methodologies, offers valuable insights into the design of solvent systems for industrial applications and supports sustainable development efforts.
{"title":"Experimental and molecular dynamics study of molecular interactions in γ-butyrolactone – dimethyl formamide systems with machine learning based density predictions","authors":"Aarthi Sai Meghana Munnangi , Hara Krishna Reddy Koppolu , Sk Md Nayeem , Prathap Koppolu , Srinivasa Reddy Munnangi","doi":"10.1016/j.jct.2025.107545","DOIUrl":"10.1016/j.jct.2025.107545","url":null,"abstract":"<div><div>Binary solvent mixtures are increasingly significant due to their ability to enhance reaction rates, modify solubility, and optimize technological separation processes. Among such mixtures, γ-butyrolactone (GBL) and dimethylformamide (DMF) are noteworthy for their versatility in various applicative fields, including pharmaceuticals, coatings, and adhesives. This study integrates experimental methods with molecular dynamics simulations and machine learning techniques to investigate the physicochemical properties and intermolecular interactions of the GBL-DMF binary system across different temperatures and compositions. The measured densities (<em>ρ</em>), speeds of sound (<em>u</em>), and refractive indices (<em>n</em><sub>D</sub>) of the binary mixtures were used to calculate excess molar volume (<span><math><msubsup><mi>V</mi><mi>m</mi><mi>E</mi></msubsup></math></span>), excess isentropic compressibility (<span><math><msubsup><mi>κ</mi><mi>s</mi><mi>E</mi></msubsup></math></span>), and refractive index deviations (<span><math><msub><mo>∆</mo><mo>∅</mo></msub><msub><mi>n</mi><mi>D</mi></msub></math></span>), which together give an overview of how the molecules interact with each other, suggesting the presence of strong molecular interactions such as hydrogen bonding and dipole-dipole forces. These observations are further corroborated by molecular dynamics simulations, which align well with the experimental data. Additionally, machine learning algorithms, including Random Forest, Gradient Boosting, XGBoost, and H2O AutoML, were employed to predict density. Among these, H2O AutoML demonstrated superior precision with an R<sup>2</sup> value of 0.984. This multifaceted approach, combining experimental, computational, and predictive methodologies, offers valuable insights into the design of solvent systems for industrial applications and supports sustainable development efforts.</div></div>","PeriodicalId":54867,"journal":{"name":"Journal of Chemical Thermodynamics","volume":"210 ","pages":"Article 107545"},"PeriodicalIF":2.2,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-06-10DOI: 10.1016/j.jct.2025.107534
Xiaoyu Yao , Bo Tang , Jinxing Wu , Xueqiang Dong , Qingqing Yang , Huifang Kang , Jun Shen
Due to excellent environmental and thermophysical properties, CO2 has been used in many areas, such as commercial refrigeration, car air-conditioning, and heat pump drying systems in the past years. However, the low critical temperature and high critical pressure of carbon dioxide limit these applications. A potential approach to address these limitations is to create a mixture of carbon dioxide with other working fluids, such as hydrofluoroolefins or hydrochlorofluoroolefins, which exhibit lower critical temperatures and higher critical pressures. The R744 + R1233zd(E) mixture is a potential alternative working fluid. In this work, the critical properties of R744 + R1233zd(E) binary mixtures including molar composition, critical density, critical temperature, and critical pressure were experimentally measured by a variable volume system with metal bellows. The critical point is determined by judging the intensity of the critical opalescence and the reappearance of the gas-liquid phase interface. Without accounting for the fact that the purity of pure components falls short of 100 %, the combined expanded uncertainty of molar composition, critical temperature, critical density, and critical pressure is (with confidence of 0.95, k value of 2) 0.012, 50 mK, 0.6 %, and 21 kPa. The critical data obtained from the experiment are correlated with the simplified Tang et al.'s model by the Redlich-Kister approach. Both of the two fitting methods can reproduce the critical locus of the R744 + R1233zd(E) binary mixture with high precision. According to the classification of Schneider and van Konynenburg and Scott, the R744 + R1233zd(E) mixture belongs to the first class of type I mixtures, which means the critical locus is a continuous curve, and the critical pressure has a maximum value
{"title":"Measurement of critical properties for the binary mixture of R744 (carbon dioxide) + R1233zd(E) (trans-1-chloro-3,3,3-trifluoro-1-propene)","authors":"Xiaoyu Yao , Bo Tang , Jinxing Wu , Xueqiang Dong , Qingqing Yang , Huifang Kang , Jun Shen","doi":"10.1016/j.jct.2025.107534","DOIUrl":"10.1016/j.jct.2025.107534","url":null,"abstract":"<div><div>Due to excellent environmental and thermophysical properties, CO<sub>2</sub> has been used in many areas, such as commercial refrigeration, car air-conditioning, and heat pump drying systems in the past years. However, the low critical temperature and high critical pressure of carbon dioxide limit these applications. A potential approach to address these limitations is to create a mixture of carbon dioxide with other working fluids, such as hydrofluoroolefins or hydrochlorofluoroolefins, which exhibit lower critical temperatures and higher critical pressures. The R744 + R1233zd(E) mixture is a potential alternative working fluid. In this work, the critical properties of R744 + R1233zd(E) binary mixtures including molar composition, critical density, critical temperature, and critical pressure were experimentally measured by a variable volume system with metal bellows. The critical point is determined by judging the intensity of the critical opalescence and the reappearance of the gas-liquid phase interface. Without accounting for the fact that the purity of pure components falls short of 100 %, the combined expanded uncertainty of molar composition, critical temperature, critical density, and critical pressure is (with confidence of 0.95, <em>k</em> value of 2) 0.012, 50 mK, 0.6 %, and 21 kPa. The critical data obtained from the experiment are correlated with the simplified Tang et al.'s model by the Redlich-Kister approach. Both of the two fitting methods can reproduce the critical locus of the R744 + R1233zd(E) binary mixture with high precision. According to the classification of Schneider and van Konynenburg and Scott, the R744 + R1233zd(E) mixture belongs to the first class of type I mixtures, which means the critical locus is a continuous curve, and the critical pressure has a maximum value</div></div>","PeriodicalId":54867,"journal":{"name":"Journal of Chemical Thermodynamics","volume":"210 ","pages":"Article 107534"},"PeriodicalIF":2.2,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144366498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-06-12DOI: 10.1016/j.jct.2025.107528
Anil Kumar Nain
The speeds of sound, u and viscosities, η of butyl acrylate +1-butanol/2-butanol/2-methyl-1-propanol/2-methyl-2-propanol binary mixtures across the entire composition range were measured at ambient temperatures and pressure, p = 100 kPa. Using the measured data, viz., excess isentropic compressibilities, excess intermolecular free lengths, excess speeds of sound, excess molar isentropic compressibilities, excess specific acoustic impedances and deviations in viscosity were evaluated. The partial molar isentropic compressibilities and excess partial molar isentropic compressibilities of the components over whole composition range; and at infinite dilution are calculated. The variation of these parameters has been interpreted in relations to intermolecular interactions in these mixtures. The results indicate that the extent of butyl acrylate-alkanol interactions follow the order: 1-butanol >2-butanol >2-methyl-1-propanol >2-methyl-2-propanol. The speeds of sound were theoretically calculated by means of various theories/relations and the viscosities of these mixtures were correlated by means of several empirical and semi-empirical equations and the outcomes are compared with experimental data. The relative applicability of these theories/relations has been discussed. Further to confirm the nature and extent of prevailing intermolecular interactions, the FT-IR spectra of pure butyl acrylate, isomeric butanols and their near equimolar mixtures were recorded and analyzed to validate the prevailing interactions.
{"title":"Acoustic, viscometric and spectroscopic study of molecular interactions in butyl acrylate + 1-butanol, + 2-butanol, + 2-methyl-1-propanol, + 2-methyl-2-propanol systems at different temperatures: Experimental and theoretical approach","authors":"Anil Kumar Nain","doi":"10.1016/j.jct.2025.107528","DOIUrl":"10.1016/j.jct.2025.107528","url":null,"abstract":"<div><div>The speeds of sound, <em>u</em> and viscosities, <em>η</em> of butyl acrylate +1-butanol/2-butanol/2-methyl-1-propanol/2-methyl-2-propanol binary mixtures across the entire composition range were measured at ambient temperatures and pressure, <em>p</em> = 100 kPa. Using the measured data, <em>viz.</em>, excess isentropic compressibilities, excess intermolecular free lengths, excess speeds of sound, excess molar isentropic compressibilities, excess specific acoustic impedances and deviations in viscosity were evaluated. The partial molar isentropic compressibilities and excess partial molar isentropic compressibilities of the components over whole composition range; and at infinite dilution are calculated. The variation of these parameters has been interpreted in relations to intermolecular interactions in these mixtures. The results indicate that the extent of butyl acrylate-alkanol interactions follow the order: 1-butanol >2-butanol >2-methyl-1-propanol >2-methyl-2-propanol. The speeds of sound were theoretically calculated by means of various theories/relations and the viscosities of these mixtures were correlated by means of several empirical and semi-empirical equations and the outcomes are compared with experimental data. The relative applicability of these theories/relations has been discussed. Further to confirm the nature and extent of prevailing intermolecular interactions, the FT-IR spectra of pure butyl acrylate, isomeric butanols and their near equimolar mixtures were recorded and analyzed to validate the prevailing interactions.</div></div>","PeriodicalId":54867,"journal":{"name":"Journal of Chemical Thermodynamics","volume":"210 ","pages":"Article 107528"},"PeriodicalIF":2.2,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144298209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-05-22DOI: 10.1016/j.jct.2025.107516
Katrina Avery , Melanie Lindblom , Liza Peoples , Erdogan Kiran , Mark T. Devlin
This study examines the influence of viscosity index modifiers on the high-pressure and temperature thermophysical and rheological properties of a mineral base oil, Ultra S4. The viscosity index modifiers tested included polymethacrylates, ethylene-propylene block copolymers and star-styrene butadiene copolymers. Densities were determined at pressures in the range of 10–35 MPa and at 298, 323, 348, 373, and 398 K using a high-pressure variable-volume view-cell. The density data were then correlated with the Sanchez-Lacombe Equation of State from which the thermodynamic properties of isothermal compressibility, isobaric expansivity and internal pressure were derived. Viscosities were determined at pressures in the range of 10–45 MPa and at 298, 323, 348 and 373 K using a uniquely designed high-pressure rotational viscometer. High pressure density and viscosity results were correlated with free volume and density-scaling equations to provide further insight into molecular packing and interactions. Additionally, intrinsic viscosity measurements were performed to evaluate the semi-dilute regime and the radius of gyration at 30 °C and 50 °C.
{"title":"Impact of viscosity index modifiers with different architectures and functionalities on the thermophysical properties and viscosity of a mineral base oil","authors":"Katrina Avery , Melanie Lindblom , Liza Peoples , Erdogan Kiran , Mark T. Devlin","doi":"10.1016/j.jct.2025.107516","DOIUrl":"10.1016/j.jct.2025.107516","url":null,"abstract":"<div><div>This study examines the influence of viscosity index modifiers on the high-pressure and temperature thermophysical and rheological properties of a mineral base oil, Ultra S4. The viscosity index modifiers tested included polymethacrylates, ethylene-propylene block copolymers and star-styrene butadiene copolymers. Densities were determined at pressures in the range of 10–35 MPa and at 298, 323, 348, 373, and 398 K using a high-pressure variable-volume view-cell. The density data were then correlated with the Sanchez-Lacombe Equation of State from which the thermodynamic properties of isothermal compressibility, isobaric expansivity and internal pressure were derived. Viscosities were determined at pressures in the range of 10–45 MPa and at 298, 323, 348 and 373 K using a uniquely designed high-pressure rotational viscometer. High pressure density and viscosity results were correlated with free volume and density-scaling equations to provide further insight into molecular packing and interactions. Additionally, intrinsic viscosity measurements were performed to evaluate the semi-dilute regime and the radius of gyration at 30 °C and 50 °C.</div></div>","PeriodicalId":54867,"journal":{"name":"Journal of Chemical Thermodynamics","volume":"210 ","pages":"Article 107516"},"PeriodicalIF":2.2,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144298567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Densities, speeds of sound and viscosities for the binary liquid mixtures containing Triethylamine with 1-propanol, 1-butanol and 1-pentanol are reported in this article. Densities and speeds of sound were measured at (293.15, 298.15, 303.15 and 308.15) K and 0.1 MPa over the entire range of compositions. Viscosities were measured at (298.15, 303.15 and 308.15) K and 0.1 MPa over whole composition range. The measured data were processed to obtain a number of thermodynamic parameters viz. excess molar volume (), excess isentropic compressibility (), deviation in speed of sound (uD), deviation in viscosity (Δη), excess Gibb’s free energy of activation for viscous flow (). The parameters were analyzed in the light of intermolecular interactions and various effects on these. Spectroscopic investigations (FTIR) were performed to get more information about happenings at molecular level and to find more support for the results. The computed data along with experimental data were also correlated to compositions using Redlich-Kister type polynomial and Jouyben-Acree model respectively. Some existing models of viscosity (Gurunberg-Nissan model, Tamura-Kurata model, Hind-McLaughlin et al. model, Katti-Chaudhri model, McAllister’s three-body interaction model, Heric-Brewer three-parameters model, McAllister’s four-body interaction model) were tested for their application to studied mixtures.
{"title":"Volumetric, acoustic, viscometric and spectroscopic studies of binary liquid mixtures containing triethylamine with 1-propanol, 1-butanol and 1-pentanol","authors":"Seema Rani , Gyan Prakash Dubey , Suvercha Chauhan , Prabjot Kaur","doi":"10.1016/j.jct.2025.107532","DOIUrl":"10.1016/j.jct.2025.107532","url":null,"abstract":"<div><div>Densities, speeds of sound and viscosities for the binary liquid mixtures containing Triethylamine with 1-propanol, 1-butanol and 1-pentanol are reported in this article. Densities and speeds of sound were measured at (293.15, 298.15, 303.15 and 308.15) K and 0.1 MPa over the entire range of compositions. Viscosities were measured at (298.15, 303.15 and 308.15) K and 0.1 MPa over whole composition range. The measured data were processed to obtain a number of thermodynamic parameters viz. excess molar volume (<span><math><msubsup><mi>V</mi><mi>m</mi><mi>E</mi></msubsup></math></span>), excess isentropic compressibility (<span><math><msubsup><mi>κ</mi><mi>S</mi><mi>E</mi></msubsup></math></span>), deviation in speed of sound (<em>u</em><sup><em>D</em></sup>), deviation in viscosity (<em>Δη</em>), excess Gibb’s free energy of activation for viscous flow (<span><math><mo>∆</mo><msup><mi>G</mi><mrow><mo>∗</mo><mi>E</mi></mrow></msup></math></span>). The parameters were analyzed in the light of intermolecular interactions and various effects on these. Spectroscopic investigations (FTIR) were performed to get more information about happenings at molecular level and to find more support for the results. The computed data along with experimental data were also correlated to compositions using Redlich-Kister type polynomial and Jouyben-Acree model respectively. Some existing models of viscosity (Gurunberg-Nissan model, Tamura-Kurata model, Hind-McLaughlin et al. model, Katti-Chaudhri model, McAllister’s three-body interaction model, Heric-Brewer three-parameters model, McAllister’s four-body interaction model) were tested for their application to studied mixtures.</div></div>","PeriodicalId":54867,"journal":{"name":"Journal of Chemical Thermodynamics","volume":"210 ","pages":"Article 107532"},"PeriodicalIF":2.2,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144366497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-06-06DOI: 10.1016/j.jct.2025.107533
Min Zheng , Ali Farajtabar , Abolghasem Jouyban , William E. Acree Jr , Hongkun Zhao
At 298.15 Kelvin, the method of isothermal dissolution was utilized in this current work at 101.0 kPa to obtain the experimental solubility data for the quaternary terephthalic acid (TA), p-toluic acid (p-TLA) + 4-carboxybenzaldehyde (4-CBA) + N-methylpyrrolidone (NMP) system. Generation of the quaternary phase diagram was made through the Jãneck approach, which was based on the mutual solubility that was determined. Three zones of neat solid crystallization, one invariant point, along with three co-saturated curves, were included in the quaternary phase diagram. The three solids that were validated by Schreinemaker approach of wet residue were pure p-TLA, pure 4-CBA, and pure TAˑ2NMP, an adduct of TA with NMP with a mole ratio of 1:2. The area where TAˑ2NMP crystallizes is larger compared to that for p-TLA and 4-CBA. In addition, the model of NRTL was used to mathematically correlate and calculate the quaternary solid-liquid phase diagram. The experimental quaternary phase diagram was found to be in good agreement with the computed one obtained from the NRTL model as evidenced by a root-mean-square deviation of 0.14632 and a relative average deviation of 5.01 %. Separating TA from its mixtures by solvent adduct crystallization might be fundamentally supported by the quaternary phase diagram and thermodynamic models. Considering the investigation on the independent gradient model based on Hirshfeld partitions, as well as the 2D fingerprint plot and difference map of electron density, density difference and difference map of ELF analysis, the van der Waals forces are viewed as favorable weak interactions during the process of forming the adduct of TAˑ2NMP.
{"title":"Quaternary system of terephthalic acid +4-carboxybenzaldehyde + p-toluic acid + N-methylpyrrolidone: Mutual solubility determination and correlation together with quantum chemistry research","authors":"Min Zheng , Ali Farajtabar , Abolghasem Jouyban , William E. Acree Jr , Hongkun Zhao","doi":"10.1016/j.jct.2025.107533","DOIUrl":"10.1016/j.jct.2025.107533","url":null,"abstract":"<div><div>At 298.15 Kelvin, the method of isothermal dissolution was utilized in this current work at 101.0 kPa to obtain the experimental solubility data for the quaternary terephthalic acid (TA), <em>p</em>-toluic acid (<em>p</em>-TLA) + 4-carboxybenzaldehyde (4-CBA) + <em>N</em>-methylpyrrolidone (NMP) system. Generation of the quaternary phase diagram was made through the Jãneck approach, which was based on the mutual solubility that was determined. Three zones of neat solid crystallization, one invariant point, along with three co-saturated curves, were included in the quaternary phase diagram. The three solids that were validated by Schreinemaker approach of wet residue were pure <em>p</em>-TLA, pure 4-CBA, and pure TAˑ2NMP, an adduct of TA with NMP with a mole ratio of 1:2. The area where TAˑ2NMP crystallizes is larger compared to that for <em>p</em>-TLA and 4-CBA. In addition, the model of NRTL was used to mathematically correlate and calculate the quaternary solid-liquid phase diagram. The experimental quaternary phase diagram was found to be in good agreement with the computed one obtained from the NRTL model as evidenced by a root-mean-square deviation of 0.14632 and a relative average deviation of 5.01 %. Separating TA from its mixtures by solvent adduct crystallization might be fundamentally supported by the quaternary phase diagram and thermodynamic models. Considering the investigation on the independent gradient model based on Hirshfeld partitions, as well as the 2D fingerprint plot and difference map of electron density, density difference and difference map of ELF analysis, the van der Waals forces are viewed as favorable weak interactions during the process of forming the adduct of TAˑ2NMP.</div></div>","PeriodicalId":54867,"journal":{"name":"Journal of Chemical Thermodynamics","volume":"209 ","pages":"Article 107533"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144255220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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