Journal of Chemical Thermodynamics最新文献

{"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 ,&nbsp;Ilham Abala ,&nbsp;Mohamed Lifi ,&nbsp;Mohamed Dakkach ,&nbsp;Mohamed Allouch ,&nbsp;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":"2025-06-16","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}

{"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 &gt;2-butanol &gt;2-methyl-1-propanol &gt;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":"2025-06-12","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}

{"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 ,&nbsp;Ali Farajtabar ,&nbsp;Abolghasem Jouyban ,&nbsp;William E. Acree Jr ,&nbsp;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":"2025-06-06","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}

{"title":"Volumetric, transport and acoustic properties of [4-methyl-2-pentanol + 2-methoxyethanol, or 2-(2-methoxyethoxy)ethanol, or 2-{2-(2-methoxyethoxy)ethoxy}ethanol] at varying temperatures","authors":"Rachana Singh,&nbsp;Gyan Prakash Dubey","doi":"10.1016/j.jct.2025.107531","DOIUrl":"10.1016/j.jct.2025.107531","url":null,"abstract":"<div><div>Density (<span><math><mi>ρ</mi></math></span>), viscosity (<span><math><mi>η</mi></math></span>) and speed of sound (<em>u</em>) of pure components and binary mixtures of 4-methyl-2-pentanol with alkoxyethanols viz., 2-methoxyethanol, 2-(2-methoxyethoxy)ethanol and 2-{2-(2-methoxyethoxy)ethoxy}ethanol have been measured at T = (298.15, 303.15, 308.15) K over the entire range of composition at pressure p = 0.10 MPa. Thermodynamic properties such as excess molar volume (<span><math><msubsup><mi>V</mi><mi>m</mi><mi>E</mi></msubsup></math></span>), excess molar isentropic compressibility (<span><math><msubsup><mi>K</mi><mrow><mi>s</mi><mo>,</mo><mi>m</mi></mrow><mi>E</mi></msubsup></math></span>), deviation in speed of sound (<span><math><msup><mi>u</mi><mi>D</mi></msup></math></span>), deviation in viscosity (<em>Δη</em>) and excess Gibbs free energy of activation for viscous flow (<span><math><mi>Δ</mi><msup><mi>G</mi><mrow><mo>∗</mo><mi>E</mi></mrow></msup></math></span>) have been calculated using experimental data. The interaction between like and unlike molecules can be described using the excess or deviation properties. The Redlich-Kister polynomial equation has been used to correlate the values of the excess and deviation properties. Further, density values were used to calculate partial molar volumes (<span><math><msub><mover><mi>V</mi><mo>¯</mo></mover><mrow><mi>m</mi><mo>,</mo><mi>i</mi></mrow></msub></math></span>). Various semi-empirical relations have been considered to correlate the measured viscosities, including Grunberg-Nissan, Tamura-Kurata, Hind <em>et al</em>., Katti-Chaudhri, McAllister (three body interaction) model, Heric-Brewer and McAllister (four body interaction) model. In addition, Prigogine-Flory-Patterson (PFP) theory is used to obtain the <span><math><msubsup><mi>V</mi><mi>m</mi><mi>E</mi></msubsup></math></span> values. The results obtained are discussed in term of intermolecular interactions taking place between the molecules of liquid components under investigation.</div></div>","PeriodicalId":54867,"journal":{"name":"Journal of Chemical Thermodynamics","volume":"209 ","pages":"Article 107531"},"PeriodicalIF":2.2,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241787","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}

{"title":"Thermogravimetric kinetic study of catalytic and non-catalytic pyrolysis of PET bottles and micro carbon rod formation","authors":"Parul Dwivedi,&nbsp;Ashwani Kumar Rathore","doi":"10.1016/j.jct.2025.107530","DOIUrl":"10.1016/j.jct.2025.107530","url":null,"abstract":"<div><div>This study examined the thermogravimetric pyrolysis behaviour of Polyethylene Terephthalate (PET) bottles using catalysts like ferrocene (F), red mud (RM), a Ni/Cu/Mo multicomponent catalyst on kieselguhr, and ferrocene-red mud mixtures, with or without hydrogen peroxide. Heating rates of 10, 20, and 30 °C/min were used. The Kissinger–Akahira–Sunose (KAS) and Flynn–Wall–Ozawa (FWO) models determined activation energies (Ea), which were lower with catalysts compared to pure PET (189 kJ/mol). The lowest Ea (53 kJ/mol) was achieved with hydrogen peroxide, resulting in complete pyrolysis and no char. SEM analysis of the resulting char showed micro carbon rod (MCR) formations. The best catalyst can be chosen based on the needs of the final product. For example, if MCR creation is the goal, ferrocene and red mud may be the best choice; if full pyrolysis is the goal, H₂O₂ may provide the greatest result. The thermodynamic analysis, including ΔH, ΔG, and ΔS, indicated that the enthalpy values for catalyst-containing PETs are lower than those for pure PET. This suggests that the synergistic effect of catalytic pyrolysis likely reduces the energy required to form the activated complex during the thermal decomposition of PET.</div></div>","PeriodicalId":54867,"journal":{"name":"Journal of Chemical Thermodynamics","volume":"209 ","pages":"Article 107530"},"PeriodicalIF":2.2,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144212266","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}

{"title":"Thermodynamics of hydroxylbastnaesite","authors":"G.A. Agbanga ,&nbsp;M. Scharrer ,&nbsp;C.G. White ,&nbsp;B.F. Woodfield ,&nbsp;A. Navrotsky","doi":"10.1016/j.jct.2025.107529","DOIUrl":"10.1016/j.jct.2025.107529","url":null,"abstract":"<div><div>The mineral bastnaesite, REECO₃[F, OH] (REE = rare earth elements), is a major source of rare earth elements and can be found in commercial deposits such as Mountain Pass, California, and Bayan Obo, China. In addition, its natural and synthetic forms have been explored for applications in optical devices, phosphors, batteries, ceramics, and magnets, accounting for 41 % of the world's consumption of rare earth elements. Therefore, investigating and analyzing thermodynamic properties of REE minerals are crucial for understanding origin, improving extraction processes, and optimizing industrial applications. This study presents a detailed reevaluation of structural and thermodynamic properties of well-characterized synthetic hydroxyl bastnaesite compounds: LaCO₃OH, PrCO₃OH, NdCO₃OH, SmCO₃OH, and EuCO₃OH. Their standard enthalpies of formation (ΔH⁰_f) were determined by high temperature oxide melt solution calorimetry and standard entropy (S⁰) was obtained from low temperature heat capacity (c_p) measurement from 1.8 to 300 K, extrapolated to 600 K combined the Einstein and Debye models. These allowed calculation of the Gibbs energy of formation (ΔG⁰_f). Extrapolation of thermodynamic properties to the heavy REEs by relation to the ionic radius of the REE³⁺ cation and to higher temperatures using the experimental c_p fit provides stability constraints for hydroxylcarbonates allowing for modelling REE-H₂O-CO₂ systems.</div></div>","PeriodicalId":54867,"journal":{"name":"Journal of Chemical Thermodynamics","volume":"209 ","pages":"Article 107529"},"PeriodicalIF":2.2,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144231766","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}

{"title":"Determination and correlation of liquid-liquid equilibrium data for separation of cyclohexane + isopropyl alcohol systems with different extractants","authors":"Fangfang Dai,&nbsp;Meiyuan Peng,&nbsp;Chen Wang,&nbsp;Kang Zhang","doi":"10.1016/j.jct.2025.107525","DOIUrl":"10.1016/j.jct.2025.107525","url":null,"abstract":"<div><div>In this work, ethylene glycol (EG), formamide, and 1, 2-propanediol were identified as potential extractants for separating cyclohexane + isopropanol (IPA) azeotropic system. The σ-profile was analyzed using the Dmol³ module of Materials Studio, and the interaction energy between the components was calculated, indicating that EG is the most promising extractant. The liquid-liquid equilibrium (LLE) data for the cyclohexane + IPA + extractants system were measured at 303.15 K, 313.15 K and 323.15 K. When the temperature increases, the extraction capacities of EG and formamide decrease. Meanwhile, the temperature has less impact on the capacity of 1, 2-propanediol. EG has higher value of the distribution coefficient (D) and separation factor (S), indicating its superior effectiveness for separation. Othmer-Tobias and Hand equations were used to estimate the reliability and consistency of the LLE data. The nonrandom two-liquid (NRTL) and universal quasi-chemical (UNIQUAC) thermodynamic model in Aspen Plus 11 software were used to regress the LLE data, and the binary interaction parameters were calculated. The root mean square deviation (RMSD) values were all less than 0.02, indicating that the NRTL and UNIQUAC models can correlate experimental data well. Finally, the regressed binary interaction parameters were further validated using GUI-MATLAB software, confirming the reliability of the data regression.</div></div>","PeriodicalId":54867,"journal":{"name":"Journal of Chemical Thermodynamics","volume":"209 ","pages":"Article 107525"},"PeriodicalIF":2.2,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144271428","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}

{"title":"Volumetric, FT-IR, and optical properties of 2–amino-1-butanol with isomeric butanol at 298.15 K–318.15 K using PFP theory and graph theoretical approach","authors":"Sweety Verma ,&nbsp;Kavitha Kumari ,&nbsp;Suman Gahlyan ,&nbsp;Ji Hoon Kim ,&nbsp;Juwon Min ,&nbsp;Sanjeev Maken","doi":"10.1016/j.jct.2025.107524","DOIUrl":"10.1016/j.jct.2025.107524","url":null,"abstract":"<div><div>The density and optical properties of binary mixtures containing 2–amino 1–butanol (2AB) and isomeric butanol were measured over a temperature range (298.15–318.15) K and 0.1 MPa pressure. Using these measurements, excess molar volume (<span><math><msup><msub><mi>V</mi><mi>m</mi></msub><mi>E</mi></msup></math></span>) and deviation in refractive index (<span><math><mi>Δ</mi><msub><mi>n</mi><mi>D</mi></msub></math></span>) were computed. The negative <span><math><msup><msub><mi>V</mi><mi>m</mi></msub><mi>E</mi></msup></math></span>values, at equimolar composition, follow the order: tert-butanol &gt; sec-butanol &gt; isobutanol &gt; n-butanol, while the <span><math><mi>Δ</mi><msub><mi>n</mi><mi>D</mi></msub></math></span> exhibit the opposite trend. The Prigogine–Flory–Patterson theory and the Graph theoretical approach were applied to interpret the <span><math><msup><msub><mi>V</mi><mi>m</mi></msub><mi>E</mi></msup></math></span> data at 298.15 K, respectively. Moreover, the molecular species of various components are predicted to exist in both pure and mixed states by the GTA. Furthermore, FT–IR spectroscopy confirmed the formation of hydrogen bonding between the molecules of the components. The <span><math><msup><msub><mi>V</mi><mi>m</mi></msub><mi>E</mi></msup></math></span> values decrease with increasing temperature, while the <span><math><mi>Δ</mi><msub><mi>n</mi><mi>D</mi></msub></math></span> values increase with increasing temperature. Various mixing rules were applied to calculate <span><math><msub><mi>n</mi><mi>D</mi></msub></math></span> theoretically. This study aims to expand the database of thermophysical properties for amine-alcohol mixtures, providing a reference for engineers and scientists developing advanced CO₂ capture technologies.</div></div>","PeriodicalId":54867,"journal":{"name":"Journal of Chemical Thermodynamics","volume":"209 ","pages":"Article 107524"},"PeriodicalIF":2.2,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144212267","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}

{"title":"A simplified method for enhanced accuracy in calculating adsorption thermodynamic parameters","authors":"Tijana Ivanović ,&nbsp;Tijana Tomović ,&nbsp;Daniela Popović ,&nbsp;Jelena Miladinović ,&nbsp;Mouad Arrad ,&nbsp;Zoran Miladinović","doi":"10.1016/j.jct.2025.107517","DOIUrl":"10.1016/j.jct.2025.107517","url":null,"abstract":"<div><div>This study investigates the thermodynamic parameters of phosphate adsorption on activated carbon using the Pitzer ion-interaction model. The adsorption data were analyzed using the Langmuir and Sips models, both providing satisfactory fits. Maximum adsorption (plateau) occurred at an equilibrium phosphate concentration of 60.8 mmol⋅ dm⁻³ (pH = 5.1), with an adsorption capacity of 7.03 mmol⋅g⁻¹. The Pitzer model was used to calculate the activity coefficient of phosphates, considering the influence of all ions in the solution on the adsorption plateau. The maximum degree of dissociation of H₂PO₄^-(aq) ions was determined to be <em>x</em>_d(2) = 0.0026, taking hydrolysis into account. The activity coefficient of KH₂PO₄ in the mixed solution {K₂HPO₄ + KH₂PO₄ + H₃PO₄}(aq) was found to be <em>γ</em>_± = 0.7788, while in a pure KH₂PO₄ solution at the same ionic strength corresponding to the plateau, it is <em>γ</em>_± = 0.7790. Given the minor difference in activity coefficient, the mixed solution could be approximated as a pure KH₂PO₄(aq) for thermodynamic analysis, which greatly simplified the calculations. The Gibbs free energy was Δ<em>G</em>_L <!--> = − 8.6200 ± 0.0004 (kJ⋅mol⁻¹) using the Langmuir equilibrium constant shifting to Δ<em>G</em>_a = − 9.240 ± 0.006 (kJ⋅mol⁻¹) when accounting for activity coefficient and the thermodynamic equilibrium constant. With the Sips model, the Gibbs free energy was Δ<em>G</em>_<em>S</em> <!--> = − 9.620 ± 0.004 (kJ⋅mol⁻¹) and further refinement using phosphate activity coefficient gave Δ<em>G</em>_a <!--> = −10.235 ± 0.007 (kJ⋅mol⁻¹). The absolute differences in adsorption energy were approximately 7 % (Langmuir) and 6 % (Sips), highlighting the importance of considering ionic activities.</div></div>","PeriodicalId":54867,"journal":{"name":"Journal of Chemical Thermodynamics","volume":"208 ","pages":"Article 107517"},"PeriodicalIF":2.2,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144138152","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}

{"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 ,&nbsp;Melanie Lindblom ,&nbsp;Liza Peoples ,&nbsp;Erdogan Kiran ,&nbsp;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":"2025-05-22","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}