Pub Date : 2025-09-09DOI: 10.1016/j.ctta.2025.100220
R.D. Musa , B.D.V. Mathew , M. Salawu , E.S. Eyube
Accurate characterization of thermodynamic properties at high temperatures is essential for modeling chemical systems. However, widely used methods such as NASA polynomials, which are based on the rigid-rotor harmonic oscillator (RRHO) approximation, often fail to capture anharmonic vibrational effects. This study develops computational models using the simplified Pöschl-Teller (SPT) potential to describe the symmetric stretching mode in linear triatomic molecules, while harmonic oscillators are used for the remaining vibrational modes. Analytical expressions for entropy, enthalpy, Gibbs free energy, and heat capacity are derived from the partition function. The models, along with NASA polynomial fits, are applied to CO2, CS2, and N2O, using NIST-JANAF data for benchmarking. The SPT models yield mean percentage absolute errors (MPAE) below 2 % for enthalpy and heat capacity, and as low as 0.2 % for entropy and Gibbs free energy. While NASA polynomials perform well for CO2, they show significant deviations at elevated temperatures for CS2 and N2O. This study presents the first application of the SPT potential to linear triatomic molecules and demonstrates its effectiveness in improving thermodynamic characterization.
{"title":"Improved thermodynamic modeling of linear triatomic molecules using a hyperbolic Pöschl-Teller oscillator","authors":"R.D. Musa , B.D.V. Mathew , M. Salawu , E.S. Eyube","doi":"10.1016/j.ctta.2025.100220","DOIUrl":"10.1016/j.ctta.2025.100220","url":null,"abstract":"<div><div>Accurate characterization of thermodynamic properties at high temperatures is essential for modeling chemical systems. However, widely used methods such as NASA polynomials, which are based on the rigid-rotor harmonic oscillator (RRHO) approximation, often fail to capture anharmonic vibrational effects. This study develops computational models using the simplified Pöschl-Teller (SPT) potential to describe the symmetric stretching mode in linear triatomic molecules, while harmonic oscillators are used for the remaining vibrational modes. Analytical expressions for entropy, enthalpy, Gibbs free energy, and heat capacity are derived from the partition function. The models, along with NASA polynomial fits, are applied to CO<sub>2</sub>, CS<sub>2</sub>, and N<sub>2</sub>O, using NIST-JANAF data for benchmarking. The SPT models yield mean percentage absolute errors (MPAE) below 2 % for enthalpy and heat capacity, and as low as 0.2 % for entropy and Gibbs free energy. While NASA polynomials perform well for CO<sub>2</sub>, they show significant deviations at elevated temperatures for CS<sub>2</sub> and N<sub>2</sub>O. This study presents the first application of the SPT potential to linear triatomic molecules and demonstrates its effectiveness in improving thermodynamic characterization.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100220"},"PeriodicalIF":0.0,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-04DOI: 10.1016/j.ctta.2025.100219
Mathayo Gervas Mathias , Idzumi Okajima
Mathematical modeling for process control, simulation, optimization, and equipment design is necessary to gain technological insights. This study compares kinetic models and emphasizes thermodynamic aspects of rice bran oil extraction with CO2-expanded acetone. Analysis of extraction kinetic data shows that the modified Fick’s model is superior to Peleg’s model. A thermodynamic study demonstrates that adding CO2 to acetone lowers the activation energy by 68 %. Moreover, the enthalpy, entropy, and Gibbs free energy changes for CO2-expanded acetone extraction at 5.0 MPa, 25 °C, and a CO2 mole fraction of 0.76 are determined to be 141.10 KJ/mol, 9.80 J/mol, and –2.90 KJ/mol, respectively, indicating that the rice bran oil extraction process is endothermic, irreversible, and spontaneous. These findings enhance the design and scale-up of efficient bio-oil extraction processes using CO2-expanded acetone.
{"title":"Rice bran oil extraction with CO2-expanded acetone: kinetics modeling, and thermodynamics aspects","authors":"Mathayo Gervas Mathias , Idzumi Okajima","doi":"10.1016/j.ctta.2025.100219","DOIUrl":"10.1016/j.ctta.2025.100219","url":null,"abstract":"<div><div>Mathematical modeling for process control, simulation, optimization, and equipment design is necessary to gain technological insights. This study compares kinetic models and emphasizes thermodynamic aspects of rice bran oil extraction with CO<sub>2</sub>-expanded acetone. Analysis of extraction kinetic data shows that the modified Fick’s model is superior to Peleg’s model. A thermodynamic study demonstrates that adding CO<sub>2</sub> to acetone lowers the activation energy by 68 %. Moreover, the enthalpy, entropy, and Gibbs free energy changes for CO<sub>2</sub>-expanded acetone extraction at 5.0 MPa, 25 °C, and a CO<sub>2</sub> mole fraction of 0.76 are determined to be 141.10 KJ/mol, 9.80 J/mol, and –2.90 KJ/mol, respectively, indicating that the rice bran oil extraction process is endothermic, irreversible, and spontaneous. These findings enhance the design and scale-up of efficient bio-oil extraction processes using CO<sub>2</sub>-expanded acetone.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100219"},"PeriodicalIF":0.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145019613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-01DOI: 10.1016/j.ctta.2025.100218
Vignesh Elangovan , Ramanipriya Mahalingam , Mohammad Junaid , Goutam Saha
The inherently low thermal conductivity of phase change materials (PCMs) poses a significant limitation to the performance of latent heat thermal energy storage (LHTES) systems. This study presents a comprehensive numerical investigation into the melting behavior of RT-27 PCM within a two-dimensional chamfered dual-enclosure, equipped with internal and external aluminum fins of four distinct geometries: rectangular, triangular, U-shaped, and wavy. The system is subjected to constant heat fluxes of 500, 1000, 1500, and 2000 W/m². The enthalpy–porosity method is employed in ANSYS Fluent 2021 to solve the governing equations, and model validation is performed against experimental data to ensure reliability. Results demonstrate that fin geometry substantially influences melting rate, thermal uniformity, and energy storage efficiency. At a heat flux of 1000 W/m², the U-shaped fin achieved complete melting in 2000 s, with an average temperature of 365 K and stored energy of ∼160 kJ/kg. In contrast, the triangular fin exhibited the slowest response, completing melting in 2700 s with a lower average temperature of 315 K and energy storage of ∼75 kJ/kg. Increasing heat flux to 2000 W/m² reduced melting time to 1400 s in the U-shaped configuration, confirming its superior thermal performance. The wavy and rectangular fins also showed favorable results, balancing thermal response and uniformity. The findings confirm that the integration of U-shaped and rectangular fins enhances heat propagation, reduces phase-change duration, and improves energy storage capacity. These insights provide a strategic framework for designing compact, high-efficiency LHTES systems for applications in energy, electronics, and thermal management technologies.
{"title":"Enhanced thermal response of phase change materials using optimized fin geometries in a dual-enclosure heat storage unit","authors":"Vignesh Elangovan , Ramanipriya Mahalingam , Mohammad Junaid , Goutam Saha","doi":"10.1016/j.ctta.2025.100218","DOIUrl":"10.1016/j.ctta.2025.100218","url":null,"abstract":"<div><div>The inherently low thermal conductivity of phase change materials (PCMs) poses a significant limitation to the performance of latent heat thermal energy storage (LHTES) systems. This study presents a comprehensive numerical investigation into the melting behavior of RT-27 PCM within a two-dimensional chamfered dual-enclosure, equipped with internal and external aluminum fins of four distinct geometries: rectangular, triangular, U-shaped, and wavy. The system is subjected to constant heat fluxes of 500, 1000, 1500, and 2000 W/m². The enthalpy–porosity method is employed in ANSYS Fluent 2021 to solve the governing equations, and model validation is performed against experimental data to ensure reliability. Results demonstrate that fin geometry substantially influences melting rate, thermal uniformity, and energy storage efficiency. At a heat flux of 1000 W/m², the U-shaped fin achieved complete melting in 2000 s, with an average temperature of 365 K and stored energy of ∼160 kJ/kg. In contrast, the triangular fin exhibited the slowest response, completing melting in 2700 s with a lower average temperature of 315 K and energy storage of ∼75 kJ/kg. Increasing heat flux to 2000 W/m² reduced melting time to 1400 s in the U-shaped configuration, confirming its superior thermal performance. The wavy and rectangular fins also showed favorable results, balancing thermal response and uniformity. The findings confirm that the integration of U-shaped and rectangular fins enhances heat propagation, reduces phase-change duration, and improves energy storage capacity. These insights provide a strategic framework for designing compact, high-efficiency LHTES systems for applications in energy, electronics, and thermal management technologies.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100218"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145019611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gas hydrates present significant potential for gas storage applications, particularly when various additives are employed to enhance their efficacy. With carbon dioxide (CO2) gas hydrates the focus is on gas capture and storage in geological landforms while methane (CH4) gas hydrates have been eye-marked for energy storage. To effectively utilize gas hydrates across various sectors, it is essential to understand the phase equilibrium conditions for each system, including those involving CH4/CO2 and various additives. Nanoparticles enhance the formation rate of gas hydrates and show promising potential for gas storage applications. In this study, phase equilibrium conditions of CO2 and CH4 hydrates in the presence of CuO and Al2O3 nanoparticles, graphene nanoplatelets, graphite powder, magnesium nitrate hexahydrate MgN2O6·6H2O, ZnO microparticles, sodium dodecyl sulfate (SDS) and silica sand were measured, experimentally. The measured temperature and pressure conditions for CH4 hydrate systems were 277.72 to 283.03 K and 4.907 to 7.77 MPa respectively. While for CO2 hydrate systems, the measured temperature and pressure were 279.11 to 283.73 K and 3.395 to 5.52 MPa, respectively. Results showed that for both CH4 and CO2 hydrate systems, the nanoparticles and powders acted as the thermodynamic inhibitor by shifting the hydrate phase equilibrium to the higher pressure and lower temperature conditions, while they acted as the kinetic promotors by improving the rate of hydrate formation and decreasing the hydrate formation time. The silica sand acts as an inhibitor over a certain range as well as a promoter in the other end for the CO2 and CH4 systems.
{"title":"Effects of nanoparticle, microparticles and silica sand on CO2 and CH4 gas hydrates phase equilibria","authors":"Phakamile Ndlovu , Saeideh Babaee , Paramespri Naidoo","doi":"10.1016/j.ctta.2025.100217","DOIUrl":"10.1016/j.ctta.2025.100217","url":null,"abstract":"<div><div>Gas hydrates present significant potential for gas storage applications, particularly when various additives are employed to enhance their efficacy. With carbon dioxide (CO<sub>2</sub>) gas hydrates the focus is on gas capture and storage in geological landforms while methane (CH<sub>4</sub>) gas hydrates have been eye-marked for energy storage. To effectively utilize gas hydrates across various sectors, it is essential to understand the phase equilibrium conditions for each system, including those involving CH<sub>4</sub>/CO<sub>2</sub> and various additives. Nanoparticles enhance the formation rate of gas hydrates and show promising potential for gas storage applications. In this study, phase equilibrium conditions of CO<sub>2</sub> and CH<sub>4</sub> hydrates in the presence of CuO and Al<sub>2</sub>O<sub>3</sub> nanoparticles, graphene nanoplatelets, graphite powder, magnesium nitrate hexahydrate MgN<sub>2</sub>O<sub>6</sub>·6H<sub>2</sub>O, ZnO microparticles, sodium dodecyl sulfate (SDS) and silica sand were measured, experimentally. The measured temperature and pressure conditions for CH<sub>4</sub> hydrate systems were 277.72 to 283.03 K and 4.907 to 7.77 MPa respectively. While for CO<sub>2</sub> hydrate systems, the measured temperature and pressure were 279.11 to 283.73 K and 3.395 to 5.52 MPa, respectively. Results showed that for both CH<sub>4</sub> and CO<sub>2</sub> hydrate systems, the nanoparticles and powders acted as the thermodynamic inhibitor by shifting the hydrate phase equilibrium to the higher pressure and lower temperature conditions, while they acted as the kinetic promotors by improving the rate of hydrate formation and decreasing the hydrate formation time. The silica sand acts as an inhibitor over a certain range as well as a promoter in the other end for the CO<sub>2</sub> and CH<sub>4</sub> systems.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100217"},"PeriodicalIF":0.0,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The molecular behavior of ternary liquid systems containing potassium benzoate and water-soluble organic acids (tartaric and lactobionic acids) was studied through measurements of density and ultrasonic velocity at varying concentrations (0.000-0.035) mol‧kg−1 and temperature varying from (288.15-318.15) K. Derived thermodynamic parameters such as apparent and partial molar volumes, apparent and partial molar isentropic compressibilities, expansibilities, transfer characteristics, thermal expansion coefficients, interaction coefficients were analyzed through investigated data from DSA 5000 M to understand interactions. The structural influence of solutes in the solution, whether promoting or disrupting molecular order was interpreted using Hepler’s thermodynamic criterion and the co-sphere overlap hypothesis. Hydration numbers were estimated using Passynski’s relation based on compressibility data. These results contribute to the progress of stable and efficient formulations across various chemical, food, cosmetic, and pharmaceutical formulations.
{"title":"Thermodynamic analysis of tartaric and lactobionic acids with aqueous potassium benzoate mixtures through volumetric and acoustic methods","authors":"Ashpinder Kaur Gill , Nabaparna Chakraborty , K.C. Juglan","doi":"10.1016/j.ctta.2025.100216","DOIUrl":"10.1016/j.ctta.2025.100216","url":null,"abstract":"<div><div>The molecular behavior of ternary liquid systems containing potassium benzoate and water-soluble organic acids (tartaric and lactobionic acids) was studied through measurements of density and ultrasonic velocity at varying concentrations (0.000-0.035) mol‧kg<sup>−1</sup> and temperature varying from (288.15-318.15) K. Derived thermodynamic parameters such as apparent and partial molar volumes, apparent and partial molar isentropic compressibilities, expansibilities, transfer characteristics, thermal expansion coefficients, interaction coefficients were analyzed through investigated data from DSA 5000 M to understand interactions. The structural influence of solutes in the solution, whether promoting or disrupting molecular order was interpreted using Hepler’s thermodynamic criterion and the co-sphere overlap hypothesis. Hydration numbers were estimated using Passynski’s relation based on compressibility data. These results contribute to the progress of stable and efficient formulations across various chemical, food, cosmetic, and pharmaceutical formulations.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100216"},"PeriodicalIF":0.0,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145019612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The persistent degradation of Pipeline steels in acidic environments demands effective, low-toxicity inhibitors that are deployable at industrial scale. Plant-based extracts have emerged as promising candidates, but their mechanistic understanding, especially when applied to high-grade pipeline steels under realistic service conditions, is limited. This study aims to evaluate the corrosion inhibition performance and adsorption mechanism of Sclerocarya birrea (marula) ethanolic leaf extract on API 5 L X42 pipeline steel in 1 M H2SO4. A combined experimental-computational approach was adopted, integrating gravimetric analysis, Open Circuit Potential, Electrochemical Impedance Spectroscopy, and Potentiodynamic Polarization at 303, 313, and 323 K with inhibitor concentrations of 0, 10, and 20 g·L-1, applying rigorous error analysis to ensure reproducibility. Spectroscopic and chromatographic analyses (FTIR, UV–Vis, GC–MS, XRD, Raman) revealed oxygen-bearing and π-rich phytoconstituents as active adsorption centers. Maximum inhibition efficiency of 93% (weight-loss) was achieved at 20 g·L⁻¹ and 303 K, with electrochemical data showing increased charge-transfer resistance (1489 → 6359 Ω·cm2) and decreased corrosion current density, consistent with mixed-type inhibition dominated by anodic suppression. Thermodynamic analysis revealed ΔG ads values of -9.2 to -10.2 kJ·mol⁻¹, indicating predominantly physisorption, and positive ΔH (up to +47.99 kJ·mol-1), suggesting endothermic adsorption. Adsorption followed the Temkin model (R² up to 0.985), implying lateral molecular interactions. Density Functional Theory and Monte Carlo simulations confirmed favorable adsorption geometries on Fe(110) surfaces and highlighted phytol derivatives as the strongest adsorbates. The study demonstrates that S. birrea extract forms a robust, eco-friendly protective layer capable of mitigating acid-induced corrosion of pipeline steel.
{"title":"Eco-friendly corrosion inhibition of API 5L X42 steel in acidic media using Sclerocarya birrea leaf extract: Experimental, thermodynamic and computational insights","authors":"Phenyo Shathani, Enoch Nifise Ogunmuyiwa, Babatunde Abiodun Obadele, Oluseyi Philip Oladijo","doi":"10.1016/j.ctta.2025.100215","DOIUrl":"10.1016/j.ctta.2025.100215","url":null,"abstract":"<div><div>The persistent degradation of Pipeline steels in acidic environments demands effective, low-toxicity inhibitors that are deployable at industrial scale. Plant-based extracts have emerged as promising candidates, but their mechanistic understanding, especially when applied to high-grade pipeline steels under realistic service conditions, is limited. This study aims to evaluate the corrosion inhibition performance and adsorption mechanism of <em>Sclerocarya birrea</em> (marula) ethanolic leaf extract on API 5 L X42 pipeline steel in 1 M H<sub>2</sub>SO<sub>4</sub>. A combined experimental-computational approach was adopted, integrating gravimetric analysis, Open Circuit Potential, Electrochemical Impedance Spectroscopy, and Potentiodynamic Polarization at 303, 313, and 323 K with inhibitor concentrations of 0, 10, and 20 <em>g</em>·L<sup>-1</sup>, applying rigorous error analysis to ensure reproducibility. Spectroscopic and chromatographic analyses (FTIR, UV–Vis, GC–MS, XRD, Raman) revealed oxygen-bearing and π-rich phytoconstituents as active adsorption centers. Maximum inhibition efficiency of 93% (weight-loss) was achieved at 20 <em>g</em>·L⁻¹ and 303 K, with electrochemical data showing increased charge-transfer resistance (1489 → 6359 Ω·cm<sup>2</sup>) and decreased corrosion current density, consistent with mixed-type inhibition dominated by anodic suppression. Thermodynamic analysis revealed ΔG ads values of -9.2 to -10.2 kJ·mol⁻¹, indicating predominantly physisorption, and positive ΔH (up to +47.99 kJ·mol<sup>-1</sup>), suggesting endothermic adsorption. Adsorption followed the Temkin model (R² up to 0.985), implying lateral molecular interactions. Density Functional Theory and Monte Carlo simulations confirmed favorable adsorption geometries on Fe(110) surfaces and highlighted phytol derivatives as the strongest adsorbates. The study demonstrates that <em>S. birrea</em> extract forms a robust, eco-friendly protective layer capable of mitigating acid-induced corrosion of pipeline steel.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100215"},"PeriodicalIF":0.0,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144920009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-27DOI: 10.1016/j.ctta.2025.100214
M. Durga Bhavani , T.S. Krishna , A. Hernandez , A.K. Nain
The study presents the investigation of molecular interactions in blended mixtures of 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4] + propyl acetate from the measurements of density, ρ and speed of sound, u of pure 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4], propyl acetate and their mixtures across entire mole fraction range at temperature from 298.15 – 323.15 K with an interval of 5 K and at pressure, p = 100 kPa. The excess properties for the mixtures, partial molar properties (volume/compressibility), excess partial molar properties (volume/compressibility) of the components across entire mole fraction range; and at infinite dilution were been calculated. The excess molar volumes of these mixtures were predicted theoretically using PFP theory and the results were compared with experimental values. The density data of these mixtures was modelled using PC-SAFT model, whereas a number of models were applied to predict the speed of sound theoretically. Additionally, the FT-IR spectra of pure [BMIM][BF4], propyl acetate and their near equimolar mixture were recorded and examined to validate the nature and extent of dominant intermolecular interactions.
{"title":"Thermophysical and spectroscopic study of molecular interactions in 1-butyl-3-methylimidazolium tetrafluoroborate + propyl acetate system at ambient temperatures: Experimental and theoretical approach","authors":"M. Durga Bhavani , T.S. Krishna , A. Hernandez , A.K. Nain","doi":"10.1016/j.ctta.2025.100214","DOIUrl":"10.1016/j.ctta.2025.100214","url":null,"abstract":"<div><div>The study presents the investigation of molecular interactions in blended mixtures of 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF<sub>4</sub>] + propyl acetate from the measurements of density, <em>ρ</em> and speed of sound, <em>u</em> of pure 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF<sub>4</sub>], propyl acetate and their mixtures across entire mole fraction range at temperature from 298.15 – 323.15 K with an interval of 5 K and at pressure, <em>p</em> = 100 kPa. The excess properties for the mixtures, partial molar properties (volume/compressibility), excess partial molar properties (volume/compressibility) of the components across entire mole fraction range; and at infinite dilution were been calculated. The excess molar volumes of these mixtures were predicted theoretically using PFP theory and the results were compared with experimental values. The density data of these mixtures was modelled using PC-SAFT model, whereas a number of models were applied to predict the speed of sound theoretically. Additionally, the FT-IR spectra of pure [BMIM][BF<sub>4</sub>], propyl acetate and their near equimolar mixture were recorded and examined to validate the nature and extent of dominant intermolecular interactions.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100214"},"PeriodicalIF":0.0,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145019676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-21DOI: 10.1016/j.ctta.2025.100213
Subhasri Ganji , Ariel Hernández , T.S. Krishna , Ranjan Dey , D. Ramachandran
This study investigates the thermophysical properties of binary liquid mixtures of propylene glycol (PG) with ether alcohols-propylene glycol monopropyl ether (2-PE) and ethylene glycol monobutyl ether (2-BE)-across the entire composition range at temperatures T= (298.15 - 323.15) K. Viscosity measurements were performed at T= (298.15 - 308.15) K. From the experimental data, excess properties such as molar volume, isentropic compressibility, speed of sound, isobaric thermal expansion coefficient, and deviation in viscosity were calculated. Partial molar properties and their excess values, including those at infinite dilution, were also derived. The excess properties were correlated using the Redlich-Kister polynomial, and the results were analysed using the Prigogine-Flory-Patterson theory to explore intermolecular interactions. Viscosity correlations were carried out using empirical and semi-empirical models, while density was modelled using the perturbed chain statistical associating fluid theory (PC-SAFT), accounting for hydrogen bonding effects. The speed of sound was predicted using Schaaff’s collision factor theory (SCFT) and Nomoto’s relation (NR), with density data from PC-SAFT as input. Viscosity modelling employed free volume theory (FVT) as a fitted approach. The findings provide insights into the thermophysical behaviour of these mixtures and the role of intermolecular interactions.
{"title":"Theoretical and experimental study of molecular interaction between Propylene glycol and Ether alcohols","authors":"Subhasri Ganji , Ariel Hernández , T.S. Krishna , Ranjan Dey , D. Ramachandran","doi":"10.1016/j.ctta.2025.100213","DOIUrl":"10.1016/j.ctta.2025.100213","url":null,"abstract":"<div><div>This study investigates the thermophysical properties of binary liquid mixtures of propylene glycol (PG) with ether alcohols-propylene glycol monopropyl ether (2-PE) and ethylene glycol monobutyl ether (2-BE)-across the entire composition range at temperatures T= (298.15 - 323.15) K. Viscosity measurements were performed at T= (298.15 - 308.15) K. From the experimental data, excess properties such as molar volume, isentropic compressibility, speed of sound, isobaric thermal expansion coefficient, and deviation in viscosity were calculated. Partial molar properties and their excess values, including those at infinite dilution, were also derived. The excess properties were correlated using the Redlich-Kister polynomial, and the results were analysed using the Prigogine-Flory-Patterson theory to explore intermolecular interactions. Viscosity correlations were carried out using empirical and semi-empirical models, while density was modelled using the perturbed chain statistical associating fluid theory (PC-SAFT), accounting for hydrogen bonding effects. The speed of sound was predicted using Schaaff’s collision factor theory (SCFT) and Nomoto’s relation (NR), with density data from PC-SAFT as input. Viscosity modelling employed free volume theory (FVT) as a fitted approach. The findings provide insights into the thermophysical behaviour of these mixtures and the role of intermolecular interactions.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100213"},"PeriodicalIF":0.0,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144922534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-19DOI: 10.1016/j.ctta.2025.100212
Cho Louis Akenji , Olivier Holtomo , Tabod Charles Tabod
The Montreal protocol aimed at phasing out refrigerants with high global warming potentials (GWPs), high ozone depletion potential, and then expanding research in developing refrigerants that are more environmentally friendly. Therefore, the investigation of the atmospheric implications on the hydrofluoroolefins 2-methylpropene (MP) and 2-trifluoromethylpropene (tFMP) were done using computational means. These compounds have major applications as refrigerant. The thermochemistry of the process of removal was studied using the PW6B95/Def2-TZVP. This has resulted in the exothermic and spontaneous reactions of MP, tFMP with ●OH radicals. The enthalpy and free energy of reactions as well as the bond dissociations show that the methyl group, -CH3, easily releases the H-atom than the other sites of hydrogen abstraction. The kinetics of the said reactions were performed through the MPWB1K/Def2-QZVPP//Def2-TZVP method. The branching ratios of the reaction channels were studied and show that the H-abstraction from the =CH2 contributes more to rate constant than the other sites containing H-atom. The latter was calculated over a temperature range of 200 – 400 K and was accurately fitted. The rate coefficient at 298 K and 1 atm yielded 9.28 × 10-14 and 2.16 × 10-13 cm3molecule-1s-1. These allowed to assess the atmospheric lifetimes of MP and tFMP, which gave 124.7 days and 53.6 days, respectively. Using the B3LYP/6-31 G (3df,p) level of theory, the radiative forcing efficiencies (REs) were estimated through the IR absorption cross section. The potential energy distribution (PED) of vibrational modes shows that RE is mainly obtained by the torsional vibration H-C-C-C for MP and the stretching of C-F bonds for tFMP. The global warming potentials (GWPs) of MP and tFMP, obtained using their atmospheric lifetimes and REs, yielded low values over the time horizon times 20, 100, and 500 years. The functional group -CF3 showed lowering effect of GWP. The estimated photochemical ozone creation potential (POCP) are also low for both compounds indicating their very low contribution to ozone production in the troposphere. Therefore, MP and tFMP are both environmentally friendly compounds.
{"title":"Investigating atmospheric implications for the reaction of ●OH with CH2=C(CH3)-CX3, X=(H,F): Perspective on future refrigerant","authors":"Cho Louis Akenji , Olivier Holtomo , Tabod Charles Tabod","doi":"10.1016/j.ctta.2025.100212","DOIUrl":"10.1016/j.ctta.2025.100212","url":null,"abstract":"<div><div>The Montreal protocol aimed at phasing out refrigerants with high global warming potentials (GWPs), high ozone depletion potential, and then expanding research in developing refrigerants that are more environmentally friendly. Therefore, the investigation of the atmospheric implications on the hydrofluoroolefins 2-methylpropene (MP) and 2-trifluoromethylpropene (tFMP) were done using computational means. These compounds have major applications as refrigerant. The thermochemistry of the process of removal was studied using the PW6B95/Def2-TZVP. This has resulted in the exothermic and spontaneous reactions of MP, tFMP with <sup>●</sup>OH radicals. The enthalpy and free energy of reactions as well as the bond dissociations show that the methyl group, -CH<sub>3</sub>, easily releases the H-atom than the other sites of hydrogen abstraction. The kinetics of the said reactions were performed through the MPWB1K/Def2-QZVPP//Def2-TZVP method. The branching ratios of the reaction channels were studied and show that the H-abstraction from the =CH<sub>2</sub> contributes more to rate constant than the other sites containing H-atom. The latter was calculated over a temperature range of 200 – 400 K and was accurately fitted. The rate coefficient at 298 K and 1 atm yielded 9.28 × 10<sup>-14</sup> and 2.16 × 10<sup>-13</sup> cm<sup>3</sup>molecule<sup>-1</sup>s<sup>-1</sup>. These allowed to assess the atmospheric lifetimes of MP and tFMP, which gave 124.7 days and 53.6 days, respectively. Using the B3LYP/6-31 G (3df,p) level of theory, the radiative forcing efficiencies (REs) were estimated through the IR absorption cross section. The potential energy distribution (PED) of vibrational modes shows that RE is mainly obtained by the torsional vibration H-C-C-C for MP and the stretching of C-F bonds for tFMP. The global warming potentials (GWPs) of MP and tFMP, obtained using their atmospheric lifetimes and REs, yielded low values over the time horizon times 20, 100, and 500 years. The functional group -CF<sub>3</sub> showed lowering effect of GWP. The estimated photochemical ozone creation potential (POCP) are also low for both compounds indicating their very low contribution to ozone production in the troposphere. Therefore, MP and tFMP are both environmentally friendly compounds.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100212"},"PeriodicalIF":0.0,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144892977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-16DOI: 10.1016/j.ctta.2025.100211
Javier Temoltzi-Avila , Vicente Rico-Ramírez, Gustavo A. Iglesias-Silva
We present a correlation that accurately captures both solute–solvent and solute–solute interactions. This model is particularly effective in representing concentrated electrolytes, such as those encountered in batteries and industrial brines, thereby offering significant utility for advanced industrial applications. In this work, we have used two models based upon an extended solvation theory to correlate the temperature dependence of activity coefficients, osmotic coefficients, and dilution enthalpies for binary aqueous electrolyte systems. In the first model, the Debye Hückel equation is used with the solvation model (DH-MS model); in the second, the Pitzer-Debye-Hückel equation is used with the same solvation model (PDH-MS model). We have compared the correlating performance of these two models with the Archer extended Pitzer model. Forty-seven aqueous solutions with electrolytes 1:1, 1:2, 2:1 and 2:2 have been used to test these models. When correlating the activity and osmotic coefficients, the average percentage deviation from the Archer model is slightly higher than from the solvation models. In the case of dilution enthalpies, the DH-MS model is better in 63.64 % of the systems, followed by the PDH-MS model with 36.36%. In the case of dilution enthalpies, the Archer model does not outperform the solvation models in any of the systems studied.
我们提出了一种准确捕获溶质-溶剂和溶质-溶质相互作用的相关性。该模型在表示浓缩电解质方面特别有效，例如在电池和工业盐水中遇到的电解质，从而为先进的工业应用提供了重要的实用性。在这项工作中，我们使用了两个基于扩展溶剂化理论的模型来关联二元水电解质系统的活度系数，渗透系数和稀释焓的温度依赖性。在第一个模型中，将Debye h ckel方程与溶剂化模型（DH-MS模型）结合使用；在第二种情况下，pitzer - debye - h ckel方程与相同的溶剂化模型（PDH-MS模型）一起使用。我们将这两种模型的相关性能与Archer扩展的Pitzer模型进行了比较。47水溶液电解质1:1,1:2,2:1和2:2已被用来测试这些模型。当将活度和渗透系数相关联时，Archer模型的平均百分比偏差略高于溶剂化模型。在稀释焓情况下，DH-MS模型在63.64%的体系中较好，其次是PDH-MS模型，占36.36%。在稀释焓的情况下，Archer模型在所研究的任何系统中都不优于溶剂化模型。
{"title":"Dilution enthalpies, osmotic and activity coefficients of aqueous electrolyte binary systems at different temperatures using an extended solvation theory","authors":"Javier Temoltzi-Avila , Vicente Rico-Ramírez, Gustavo A. Iglesias-Silva","doi":"10.1016/j.ctta.2025.100211","DOIUrl":"10.1016/j.ctta.2025.100211","url":null,"abstract":"<div><div>We present a correlation that accurately captures both solute–solvent and solute–solute interactions. This model is particularly effective in representing concentrated electrolytes, such as those encountered in batteries and industrial brines, thereby offering significant utility for advanced industrial applications. In this work, we have used two models based upon an extended solvation theory to correlate the temperature dependence of activity coefficients, osmotic coefficients, and dilution enthalpies for binary aqueous electrolyte systems. In the first model, the Debye Hückel equation is used with the solvation model (DH-MS model); in the second, the Pitzer-Debye-Hückel equation is used with the same solvation model (PDH-MS model). We have compared the correlating performance of these two models with the Archer extended Pitzer model. Forty-seven aqueous solutions with electrolytes 1:1, 1:2, 2:1 and 2:2 have been used to test these models. When correlating the activity and osmotic coefficients, the average percentage deviation from the Archer model is slightly higher than from the solvation models. In the case of dilution enthalpies, the DH-MS model is better in 63.64 % of the systems, followed by the PDH-MS model with 36.36%. In the case of dilution enthalpies, the Archer model does not outperform the solvation models in any of the systems studied.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100211"},"PeriodicalIF":0.0,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144890497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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