<div><div>Accurate prediction of brine viscosity is essential for the design and optimisation of desalination, hydrometallurgical, and energy-storage systems. In this work, machine-learning-based regression models were developed to predict the viscosity of binary brine systems containing KF, KCl, NaCl, <span><math><mrow><mi>M</mi><msub><mi>g</mi><mn>2</mn></msub><mi>S</mi><msub><mi>O</mi><mn>4</mn></msub></mrow></math></span>, Ca<span><math><mrow><mi>C</mi><msub><mi>l</mi><mn>2</mn></msub></mrow></math></span>, Mg<span><math><mrow><mi>C</mi><msub><mi>l</mi><mn>2</mn></msub></mrow></math></span>, and <span><math><mrow><mi>N</mi><msub><mi>a</mi><mn>2</mn></msub><mi>S</mi><msub><mi>O</mi><mn>4</mn></msub></mrow></math></span> over wide temperature and concentration ranges. Three boosting-based ensemble algorithms including AdaBoost, Gradient Boosting, and Extreme Gradient Boosting (XGBoost) were implemented within a unified pre-processing and hyperparameter-optimisation framework, with salt identity encoded using One-Hot Encoding and model parameters optimised via GridSearchCV with 5-fold cross-validation. Model performance was evaluated on an independent test set using MAE, MedAE, and <span><math><msup><mrow><mi>R</mi></mrow><mn>2</mn></msup></math></span>. Gradient Boosting achieved the highest accuracy (MAE = 1.13<span><math><mrow><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span> Pa·s, <span><math><msup><mrow><mi>R</mi></mrow><mn>2</mn></msup></math></span> = 97.20%), followed by XGBoost (MAE = 2.36 <span><math><mrow><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span> Pa·s, <span><math><mrow><msup><mrow><mi>R</mi></mrow><mn>2</mn></msup><mspace></mspace></mrow></math></span>= 91.81%) and AdaBoost (MAE = 2.10 <span><math><mrow><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span> Pa·s, <span><math><msup><mrow><mi>R</mi></mrow><mn>2</mn></msup></math></span> = 94.09%). Computational time analysis showed that Gradient Boosting offers a favourable balance between predictive accuracy and training efficiency, while XGBoost trains faster but exhibits reduced accuracy due to stronger regularization. Predictive uncertainty was quantified using a deep-ensemble-inspired approach, yielding mean uncertainty levels of 2.5 <span><math><mrow><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>5</mn></mrow></msup></mrow></math></span>, 5.6 <span><math><mrow><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>5</mn></mrow></msup></mrow></math></span>, and 9.3 <span><math><mrow><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>5</mn></mrow></msup></mrow></math></span> Pa·s for AdaBoost, Gradient Boosting, and XGBoost, respectively. Residual diagnostics confirmed symmetric error distributions and physically consistent trends, with viscosity increasing with concentration and decreasing with tem
{"title":"Boosting approach to brine viscosity estimation: Binary system development","authors":"Vinita Sangwan , Rashmi Bhardwaj , Andrés Soto-Bubert , Roberto Acevedo","doi":"10.1016/j.ctta.2026.100273","DOIUrl":"10.1016/j.ctta.2026.100273","url":null,"abstract":"<div><div>Accurate prediction of brine viscosity is essential for the design and optimisation of desalination, hydrometallurgical, and energy-storage systems. In this work, machine-learning-based regression models were developed to predict the viscosity of binary brine systems containing KF, KCl, NaCl, <span><math><mrow><mi>M</mi><msub><mi>g</mi><mn>2</mn></msub><mi>S</mi><msub><mi>O</mi><mn>4</mn></msub></mrow></math></span>, Ca<span><math><mrow><mi>C</mi><msub><mi>l</mi><mn>2</mn></msub></mrow></math></span>, Mg<span><math><mrow><mi>C</mi><msub><mi>l</mi><mn>2</mn></msub></mrow></math></span>, and <span><math><mrow><mi>N</mi><msub><mi>a</mi><mn>2</mn></msub><mi>S</mi><msub><mi>O</mi><mn>4</mn></msub></mrow></math></span> over wide temperature and concentration ranges. Three boosting-based ensemble algorithms including AdaBoost, Gradient Boosting, and Extreme Gradient Boosting (XGBoost) were implemented within a unified pre-processing and hyperparameter-optimisation framework, with salt identity encoded using One-Hot Encoding and model parameters optimised via GridSearchCV with 5-fold cross-validation. Model performance was evaluated on an independent test set using MAE, MedAE, and <span><math><msup><mrow><mi>R</mi></mrow><mn>2</mn></msup></math></span>. Gradient Boosting achieved the highest accuracy (MAE = 1.13<span><math><mrow><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span> Pa·s, <span><math><msup><mrow><mi>R</mi></mrow><mn>2</mn></msup></math></span> = 97.20%), followed by XGBoost (MAE = 2.36 <span><math><mrow><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span> Pa·s, <span><math><mrow><msup><mrow><mi>R</mi></mrow><mn>2</mn></msup><mspace></mspace></mrow></math></span>= 91.81%) and AdaBoost (MAE = 2.10 <span><math><mrow><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span> Pa·s, <span><math><msup><mrow><mi>R</mi></mrow><mn>2</mn></msup></math></span> = 94.09%). Computational time analysis showed that Gradient Boosting offers a favourable balance between predictive accuracy and training efficiency, while XGBoost trains faster but exhibits reduced accuracy due to stronger regularization. Predictive uncertainty was quantified using a deep-ensemble-inspired approach, yielding mean uncertainty levels of 2.5 <span><math><mrow><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>5</mn></mrow></msup></mrow></math></span>, 5.6 <span><math><mrow><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>5</mn></mrow></msup></mrow></math></span>, and 9.3 <span><math><mrow><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>5</mn></mrow></msup></mrow></math></span> Pa·s for AdaBoost, Gradient Boosting, and XGBoost, respectively. Residual diagnostics confirmed symmetric error distributions and physically consistent trends, with viscosity increasing with concentration and decreasing with tem","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"21 ","pages":"Article 100273"},"PeriodicalIF":0.0,"publicationDate":"2026-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146073916","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}
Densities, viscosities and ultrasonic speeds of sodium gluconate in various aqueous molal solutions [m = (0.005–0.020) mol.kg-1] of β-cyclodextrin were measured at T = (298.15–318.15) K and ambient pressure P = 101 kPa. Several volumetric, viscometric, thermoacoustic and thermodynamic properties have been determined from the measured data like apparent molar volumes, standard partial molar volumes, apparent specific volumes, standard isobaric partial molar expansibilities and their temperature dependence, viscosity B-coefficients and solvation number, etc. Further, the standard volumes of transfer for sodium gluconate from water to aqueous β-cyclodextrin solutions were derived in order to have insights into the molecular interactions in the ternary solutions and the effects of molality, solute structure and temperature and taste behavior were examined. These findings showed that sodium gluconate acts as a structure maker and that the solute-solvent or ion-solvent interactions dominate in the ternary solutions. 1H NMR spectroscopic and computational studies were performed to substantiate these findings.
{"title":"Physico-chemical study on the solvation characteristics of sodium gluconate in aqueous β-cyclodextrin solutions at T= (298.15-318.15) K","authors":"Sachindra Kumar Singh , Dhurba Jyoti Roy , Pritika Gurung , Tanmoy Dutta , Biswajit Sinha","doi":"10.1016/j.ctta.2026.100270","DOIUrl":"10.1016/j.ctta.2026.100270","url":null,"abstract":"<div><div>Densities, viscosities and ultrasonic speeds of sodium gluconate in various aqueous molal solutions [<em>m</em> = (0.005–0.020) mol.kg<sup>-1</sup>] of β-cyclodextrin were measured at <em>T</em> = (298.15–318.15) K and ambient pressure <em>P</em> = 101 kPa. Several volumetric, viscometric, thermoacoustic and thermodynamic properties have been determined from the measured data like apparent molar volumes, standard partial molar volumes, apparent specific volumes, standard isobaric partial molar expansibilities and their temperature dependence, viscosity <em>B</em>-coefficients and solvation number, <em>etc</em>. Further, the standard volumes of transfer for sodium gluconate from water to aqueous β-cyclodextrin solutions were derived in order to have insights into the molecular interactions in the ternary solutions and the effects of molality, solute structure and temperature and taste behavior were examined. These findings showed that sodium gluconate acts as a structure maker and that the solute-solvent or ion-solvent interactions dominate in the ternary solutions. <sup>1</sup>H NMR spectroscopic and computational studies were performed to substantiate these findings.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"21 ","pages":"Article 100270"},"PeriodicalIF":0.0,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034599","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 : 2026-01-17DOI: 10.1016/j.ctta.2026.100268
Peter J. Skrdla , Peter Šimon
Differential scanning calorimetry (DSC) is a useful tool for studying the nucleation rate-limited kinetics of crystallization from the melt. However, applying popular isoconversional methods of thermal analysis to such calorimetric data often yields incorrect values of the activation energy, . Against this backdrop, we investigate the classical dataset for the temperature-dependent rate of crystallization of piperine from the melt [Tammann G. Ueber die Abhängigkeit der Zahl der Kerne, welche sich in verschiedenen unterkühlten Flüssigkeiten bilden, von der Temperatur. Z. Phys. Chem. 1898;25: 441–479] to demonstrate that the Turnbull-Fisher (T-F) equation describing nucleation kinetics generates meaningful values, across the entire temperature range, only when it is decoupled from isoconversional or Arrhenius analysis. This is accomplished by digitizing, replotting, and subsequently analyzing the Tammann dataset through application of the T-F equation, alone, the T-F equation used in conjunction with isoconversional analysis, and, lastly, the T-F equation combined with the Arrhenius equation. While the latter two methodologies are discussed thoroughly in a recent work [Vyazovkin S, Sbirrazzuoli N. Non-isothermal crystallization kinetics by DSC: Practical overview. Processes. 2023;11:1438], our goal is to reveal that the fundamental problem with those approaches that results in reporting of negative activation energies is that they are reliant on the assumption of Arrhenius kinetics. That is because T-F kinetics can exhibit both Arrhenius (at large supercooling from the melt) and non-Arrhenius (at moderate supercooling) behavior, depending on the temperature. Consistent with the predictions of classical nucleation theory (CNT), values for nucleation rate-limited conversions are generally positive even though the specific rate often increases at higher degrees of cooling. Reports of negative activation energies are simply a mathematical artifact caused by ignoring the mismatch between Arrhenius and T-F kinetics.
差示扫描量热法（DSC）是研究熔体结晶成核速率限制动力学的有效工具。然而，将流行的等转换热分析方法应用于此类量热数据通常会产生不正确的活化能值。在此背景下，我们研究了熔体中胡椒碱结晶速率的经典数据集[Tammann G. Ueber die Abhängigkeit der Zahl der Kerne, welche sich in verschiedenen unterkhlten flsigkeiten bilden, von der temperature]。z。化学1898;[25] 441-479]证明了描述成核动力学的特恩布尔-费舍尔（T-F）方程在整个温度范围内产生有意义的Ea值，只有当它与等转换或阿伦尼乌斯分析解耦时。这是通过单独应用T-F方程、T-F方程与等转换分析结合使用，以及最后将T-F方程与Arrhenius方程结合使用，对Tammann数据集进行数字化、重新绘制和随后的分析来实现的。而后两种方法在最近的工作中进行了深入的讨论[Vyazovkin S， Sbirrazzuoli N.]。流程。2023;[11:14 . 38]，我们的目标是揭示那些导致报告负活化能的方法的根本问题在于它们依赖于阿伦尼乌斯动力学的假设。这是因为T-F动力学可以根据温度表现出阿伦尼乌斯（熔体的大过冷）和非阿伦尼乌斯（中等过冷）行为。与经典成核理论（CNT）的预测一致，成核速率有限的转化的Ea值通常是正的，即使在较高的冷却度下比速率通常会增加。负活化能的报告仅仅是由于忽略了阿累尼乌斯和T-F动力学之间的不匹配而引起的数学假象。
{"title":"Isoconversional methods of thermal analysis yield activation energies that lack physical meaning for Turnbull-Fisher kinetics: Case study of crystallization of piperine from the melt","authors":"Peter J. Skrdla , Peter Šimon","doi":"10.1016/j.ctta.2026.100268","DOIUrl":"10.1016/j.ctta.2026.100268","url":null,"abstract":"<div><div>Differential scanning calorimetry (DSC) is a useful tool for studying the nucleation rate-limited kinetics of crystallization from the melt. However, applying popular isoconversional methods of thermal analysis to such calorimetric data often yields incorrect values of the activation energy, <span><math><msub><mi>E</mi><mi>a</mi></msub></math></span>. Against this backdrop, we investigate the classical dataset for the temperature-dependent rate of crystallization of piperine from the melt [Tammann G. Ueber die Abhängigkeit der Zahl der Kerne, welche sich in verschiedenen unterkühlten Flüssigkeiten bilden, von der Temperatur. Z. Phys. Chem. 1898;25: 441–479] to demonstrate that the Turnbull-Fisher (T-F) equation describing nucleation kinetics generates meaningful <span><math><msub><mi>E</mi><mi>a</mi></msub></math></span> values, across the entire temperature range, only when it is decoupled from isoconversional or Arrhenius analysis. This is accomplished by digitizing, replotting, and subsequently analyzing the Tammann dataset through application of the T-F equation, alone, the T-F equation used in conjunction with isoconversional analysis, and, lastly, the T-F equation combined with the Arrhenius equation. While the latter two methodologies are discussed thoroughly in a recent work [Vyazovkin S, Sbirrazzuoli N. Non-isothermal crystallization kinetics by DSC: Practical overview. Processes. 2023;11:1438], our goal is to reveal that the fundamental problem with those approaches that results in reporting of negative activation energies is that they are reliant on the assumption of Arrhenius kinetics. That is because T-F kinetics can exhibit both Arrhenius (at large supercooling from the melt) and non-Arrhenius (at moderate supercooling) behavior, depending on the temperature. Consistent with the predictions of classical nucleation theory (CNT), <span><math><msub><mi>E</mi><mi>a</mi></msub></math></span> values for nucleation rate-limited conversions are generally positive even though the specific rate often increases at higher degrees of cooling. Reports of negative activation energies are simply a mathematical artifact caused by ignoring the mismatch between Arrhenius and T-F kinetics.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"21 ","pages":"Article 100268"},"PeriodicalIF":0.0,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034693","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}
Arisaema propinquum, a medicinal plant that has unexplored properties, is found in the Himalayas. It was studied regarding its effects on the thermodynamic characteristics and micellization of sodium dodecyl sulphate (SDS) in mixtures of hydroethanol solvents. This study conducted a thorough analysis of the effects of temperature, solvents, and extracts from both leaves and rhizomes on SDS micellization, thereby highlighting the possibility of developing eco-friendly surfactant formulations. Conductivity measurements were performed up to the critical micelle concentration in different ethanol concentrations (0%, 10%, 30%, and 70% v/v) at the specified temperature range (293.15 K - 308.15 K) as part of the experimental evaluation. Thermodynamic parameters such as standard Gibbs free energy (), enthalpy (), and entropy (), were determined, indicating that micellization occurs spontaneously, is mainly influenced by entropy, and is significantly influenced by temperature-solvent composition. Density functional theory (DFT)-based computational investigations have demonstrated that the addition of SDS not only enhances its reactivity but also its stability when mixed with ethanol. This is evident in the reduction of the HOMO-LUMO energy gap and changes in the electron distribution, allowing for detectable alterations in the species. Notably, the process of micellization was gradually shifted from endothermic to exothermic as the concentration of ethanol increased, with 70% v/v ethanol being the most favourable for both enthalpy and entropy. The results not only provide a better understanding of the molecular level of hydrophobic interactions in mixed solvent systems but also highlight the usefulness of plant-derived modifiers in pharmaceutical applications, such as antimicrobial and anticancer studies, among others.
在喜马拉雅山脉发现了一种药用植物，具有未开发的特性。研究了其对十二烷基硫酸钠（SDS）在混合氢乙醇溶剂中的热力学特性和胶束化的影响。本研究深入分析了温度、溶剂、叶和根茎提取物对SDS胶束的影响，从而强调了开发环保型表面活性剂配方的可能性。在规定的温度范围（293.15 K - 308.15 K）下，在不同乙醇浓度（0%、10%、30%和70% v/v）下进行电导率测量，直至临界胶束浓度，作为实验评估的一部分。测定了标准吉布斯自由能（ΔGm0）、焓（ΔHm0）和熵（ΔSm0）等热力学参数，表明胶束反应是自发发生的，主要受熵的影响，温度-溶剂组成对胶束反应的影响较大。基于密度泛函理论（DFT）的计算研究表明，SDS的加入不仅提高了其反应活性，而且在与乙醇混合时提高了其稳定性。这在HOMO-LUMO能隙的减小和电子分布的变化中是明显的，允许在物种中检测到变化。值得注意的是，随着乙醇浓度的增加，胶束化过程逐渐由吸热向放热转变，其中70% v/v乙醇对焓和熵都最有利。该结果不仅提供了对混合溶剂体系中疏水相互作用的分子水平的更好理解，而且还强调了植物源改性剂在药物应用中的有用性，例如抗菌和抗癌研究等。
{"title":"Exploring the physicochemical and computational insights of Arisaema propinquum Schott with sodium dodecyl sulfate in hydroethanolic system","authors":"Deepika B. Prashar , Parveen Kumar , Sunil Kumar , Hemant Sood , Munish Sharma","doi":"10.1016/j.ctta.2026.100269","DOIUrl":"10.1016/j.ctta.2026.100269","url":null,"abstract":"<div><div><em>Arisaema propinquum,</em> a medicinal plant that has unexplored properties, is found in the Himalayas. It was studied regarding its effects on the thermodynamic characteristics and micellization of sodium dodecyl sulphate (SDS) in mixtures of hydroethanol solvents. This study conducted a thorough analysis of the effects of temperature, solvents, and extracts from both leaves and rhizomes on SDS micellization, thereby highlighting the possibility of developing eco-friendly surfactant formulations. Conductivity measurements were performed up to the critical micelle concentration in different ethanol concentrations (0%, 10%, 30%, and 70% v/v) at the specified temperature range (293.15 K - 308.15 K) as part of the experimental evaluation<em>.</em> Thermodynamic parameters such as standard Gibbs free energy (<span><math><mrow><mstyle><mi>Δ</mi></mstyle><msubsup><mi>G</mi><mi>m</mi><mn>0</mn></msubsup></mrow></math></span>), enthalpy (<span><math><mrow><mstyle><mi>Δ</mi></mstyle><msubsup><mi>H</mi><mi>m</mi><mn>0</mn></msubsup></mrow></math></span>), and entropy (<span><math><mrow><mstyle><mi>Δ</mi></mstyle><msubsup><mi>S</mi><mi>m</mi><mn>0</mn></msubsup></mrow></math></span>), were determined, indicating that micellization occurs spontaneously, is mainly influenced by entropy, and is significantly influenced by temperature-solvent composition. Density functional theory (DFT)-based computational investigations have demonstrated that the addition of SDS not only enhances its reactivity but also its stability when mixed with ethanol. This is evident in the reduction of the HOMO-LUMO energy gap and changes in the electron distribution, allowing for detectable alterations in the species. Notably, the process of micellization was gradually shifted from endothermic to exothermic as the concentration of ethanol increased, with 70% v/v ethanol being the most favourable for both enthalpy and entropy. The results not only provide a better understanding of the molecular level of hydrophobic interactions in mixed solvent systems but also highlight the usefulness of plant-derived modifiers in pharmaceutical applications, such as antimicrobial and anticancer studies, among others.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"21 ","pages":"Article 100269"},"PeriodicalIF":0.0,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034691","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 : 2026-01-14DOI: 10.1016/j.ctta.2026.100267
L. Cruz-Castro, A. Albiter
The replacement of CH4 hydrates with CO2 is a promising strategy for synergistic energy recovery and carbon sequestration; however, the influence of the physical state of injected CO2 within high-permeability sediments remains poorly understood. This study comparatively investigates gaseous and liquid CO2 injection into a coarse quartz sand matrix (711 µm). The results reveal an unexpected kinetic bottleneck for the liquid phase: despite the wide-pore structure that minimizes hydrodynamic resistance, CO2 liquid achieved a replacement efficiency of only 8.47%, compared to a maximum of 63.65% for CO2 gas. We identify that the low efficiency of CO2 liquid is not due to macroscopic flow limitations, but rather an "interfacial armoring" effect. In this mechanism, a dense CO2 hydrate film forms rapidly at the interface, blocking molecular diffusion a process exacerbated by the specific thermal energy demands and higher specific heat of the liquid phase. These findings demonstrate that high sediment permeability does not compensate for the thermodynamic constraints of liquid CO2, redefining site selection and phase criteria for large-scale carbon sequestration in continental margins.
{"title":"Investigation of CH4 hydrate formation and subsequent phase-dependent CO2 replacement kinetics in coarse porous media","authors":"L. Cruz-Castro, A. Albiter","doi":"10.1016/j.ctta.2026.100267","DOIUrl":"10.1016/j.ctta.2026.100267","url":null,"abstract":"<div><div>The replacement of CH<sub>4</sub> hydrates with CO<sub>2</sub> is a promising strategy for synergistic energy recovery and carbon sequestration; however, the influence of the physical state of injected CO<sub>2</sub> within high-permeability sediments remains poorly understood. This study comparatively investigates gaseous and liquid CO<sub>2</sub> injection into a coarse quartz sand matrix (711 µm). The results reveal an unexpected kinetic bottleneck for the liquid phase: despite the wide-pore structure that minimizes hydrodynamic resistance, CO<sub>2</sub> liquid achieved a replacement efficiency of only 8.47%, compared to a maximum of 63.65% for CO<sub>2</sub> gas. We identify that the low efficiency of CO<sub>2</sub> liquid is not due to macroscopic flow limitations, but rather an \"interfacial armoring\" effect. In this mechanism, a dense CO<sub>2</sub> hydrate film forms rapidly at the interface, blocking molecular diffusion a process exacerbated by the specific thermal energy demands and higher specific heat of the liquid phase. These findings demonstrate that high sediment permeability does not compensate for the thermodynamic constraints of liquid CO<sub>2</sub>, redefining site selection and phase criteria for large-scale carbon sequestration in continental margins.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"21 ","pages":"Article 100267"},"PeriodicalIF":0.0,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034690","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 alliance of four anti-tubercular drugs, namely rifampicin (RIF), isoniazid (INH), pyrazinamide (PZA) and ethambutol (EMB), is considered incompatible in tablet formulation. Several mechanistic investigations have been proposed to interpret this complex interplay in the literature. We employed isothermal titration calorimetry (ITC) to map the self-, hetero-, and catalytically modulated interactions among rifampicin (RIF), isoniazid (INH), pyrazinamide (PZA), and ethambutol (EMB). Each drug displayed distinct thermodynamic signatures during self-association (KD ≈ 5.16 × 10-7), primarily governed by enthalpy–entropy compensation. The self-association strength followed the order of PZA > INH > EMB > RIF, with PZA showing the strongest, entropy-driven aggregation via π–π stacking and RIF exhibiting the weakest. In binary systems, hetero-association patterns revealed strong, spontaneous complexation between INH–EMB and RIF–PZA, followed by RIF–INH, RIF–EMB ≈ INH–PZA, and weak PZA–EMB interactions. These differences stemmed from variations in hydrogen bonding, desolvation, and hydrophobic reorganization. Ternary mixtures demonstrated catalytic modulation of RIF–INH interaction, where PZA enhanced (positive catalyst) and EMB reduced (negative catalyst) their association. In the quaternary system, these opposing effects balanced to yield a weakly bound, entropy-dominated multicomponent network, representing a thermodynamic compromise among all four drugs. Overall, ITC provided a direct, quantitative insight into molecular compatibility and reactivity under isothermal conditions, thereby circumventing the confounding effects of decomposition typically observed in DSC or TGA. The calorimetric mapping approach, as explained in the manuscript, establishes a powerful strategy for identifying favourable and adverse small-molecule interactions in complex drug combinations.
{"title":"Calorimetric mapping of complex interplay between rifampicin, isoniazid, pyrazinamide and ethambutol: Identifying Thermodynamic signatures of interaction between small molecules in an Alliance","authors":"Saurabh B. Pawar, Pavankumar Sathala, Arindam Senapati, Laltanpuii Chenkual, Madhuri Divate, Pawan Kumar Porwal","doi":"10.1016/j.ctta.2026.100266","DOIUrl":"10.1016/j.ctta.2026.100266","url":null,"abstract":"<div><div>The alliance of four anti-tubercular drugs, namely rifampicin (RIF), isoniazid (INH), pyrazinamide (PZA) and ethambutol (EMB), is considered incompatible in tablet formulation. Several mechanistic investigations have been proposed to interpret this complex interplay in the literature. We employed isothermal titration calorimetry (ITC) to map the self-, hetero-, and catalytically modulated interactions among rifampicin (RIF), isoniazid (INH), pyrazinamide (PZA), and ethambutol (EMB). Each drug displayed distinct thermodynamic signatures during self-association (K<sub>D</sub> ≈ 5.16 × 10<sup>-7</sup>), primarily governed by enthalpy–entropy compensation. The self-association strength followed the order of PZA > INH > EMB > RIF, with PZA showing the strongest, entropy-driven aggregation via π–π stacking and RIF exhibiting the weakest. In binary systems, hetero-association patterns revealed strong, spontaneous complexation between INH–EMB and RIF–PZA, followed by RIF–INH, RIF–EMB ≈ INH–PZA, and weak PZA–EMB interactions. These differences stemmed from variations in hydrogen bonding, desolvation, and hydrophobic reorganization. Ternary mixtures demonstrated catalytic modulation of RIF–INH interaction, where PZA enhanced (positive catalyst) and EMB reduced (negative catalyst) their association. In the quaternary system, these opposing effects balanced to yield a weakly bound, entropy-dominated multicomponent network, representing a thermodynamic compromise among all four drugs. Overall, ITC provided a direct, quantitative insight into molecular compatibility and reactivity under isothermal conditions, thereby circumventing the confounding effects of decomposition typically observed in DSC or TGA. The calorimetric mapping approach, as explained in the manuscript, establishes a powerful strategy for identifying favourable and adverse small-molecule interactions in complex drug combinations.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"21 ","pages":"Article 100266"},"PeriodicalIF":0.0,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973299","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 : 2026-01-06DOI: 10.1016/j.ctta.2026.100265
JA Cobos-Murcia
The formulation of general principles governing energy degradation and transformation remains an open problem in thermodynamics, particularly for irreversible and coupled processes. In this work, the Principle of Energy Quality is introduced as a unified thermodynamic formulation that characterizes how energy is transformed, degraded, and partially regenerated across physical, chemical, informational, and ecological systems. Within this framework, total energy is partitioned into two complementary components: exergy (E), the convertible fraction into useful work; anergy (A), the fraction degraded through entropy generation; and Onsager coupling potentials (O), which describe the redistribution and partial recovery of degraded energy through coupled irreversible processes. Building on classical exergy–anergy analysis and Onsager’s flux–force formalism, the principle establishes a direct link between entropy production and energy quality loss, while recognizing the structured and potentially regenerative character of degraded energy. The formulation is discussed within the modern enumeration of thermodynamic laws, which includes the zeroth law and acknowledges the historically non-canonical nature of their numbering. In this context, the proposed principle may be regarded as a step toward a fourth law of thermodynamics. The zeroth law defines the reference environment T0; the first law enforcers energy conservation with explicit partitioning into useful and degraded components; the second law quantifies irreversibility; the third law bounds exergy as T→0; and the proposed fourth law generalizes efficiency and dissipation by identifying anergy as the fundamental measure of energy degradation and regenerative potential.
{"title":"Formulation of the Principle of Energy Quality: Toward a Fourth Law of Thermodynamics","authors":"JA Cobos-Murcia","doi":"10.1016/j.ctta.2026.100265","DOIUrl":"10.1016/j.ctta.2026.100265","url":null,"abstract":"<div><div>The formulation of general principles governing energy degradation and transformation remains an open problem in thermodynamics, particularly for irreversible and coupled processes. In this work, the Principle of Energy Quality is introduced as a unified thermodynamic formulation that characterizes how energy is transformed, degraded, and partially regenerated across physical, chemical, informational, and ecological systems. Within this framework, total energy is partitioned into two complementary components: exergy (<em>E</em>), the convertible fraction into useful work; anergy (<em>A</em>), the fraction degraded through entropy generation; and Onsager coupling potentials (<em>O</em>), which describe the redistribution and partial recovery of degraded energy through coupled irreversible processes. Building on classical exergy–anergy analysis and Onsager’s flux–force formalism, the principle establishes a direct link between entropy production and energy quality loss, while recognizing the structured and potentially regenerative character of degraded energy. The formulation is discussed within the modern enumeration of thermodynamic laws, which includes the zeroth law and acknowledges the historically non-canonical nature of their numbering. In this context, the proposed principle may be regarded as a step toward a fourth law of thermodynamics. The zeroth law defines the reference environment <em>T<sub>0</sub></em>; the first law enforcers energy conservation with explicit partitioning into useful and degraded components; the second law quantifies irreversibility; the third law bounds exergy as <em>T→0</em>; and the proposed fourth law generalizes efficiency and dissipation by identifying anergy as the fundamental measure of energy degradation and regenerative potential.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"21 ","pages":"Article 100265"},"PeriodicalIF":0.0,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973298","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 : 2026-01-03DOI: 10.1016/j.ctta.2026.100264
Zahra Ghafourian , Mohammad Fani Kheshti , Mojtaba Saei Maghaddam
A new thermodynamic model for predicting solid–liquid equilibria (SLE) of paraffinic hydrocarbons in binary and multicomponent systems has been developed. The model employs the ideal solution theory for the liquid phase and the predictive Wilson activity model for the solid phase, thereby avoiding the use of cubic equations of state. The model accurately predicts the wax disappearance temperature (WDT) over a wide pressure range (from atmospheric pressure up to 300 MPa). Validation against more than 320 experimental data points, including pure components, binary mixtures, and multicomponent systems, shows excellent agreement, with average absolute deviations of 1.56 K for binary mixtures and 0.81 K for light–heavy hydrocarbon systems. The approach offers a reliable tool for modeling wax formation in pipeline and reservoir conditions.
{"title":"Thermodynamic model for predicting the precipitation temperature of waxes using the activity model at high pressures","authors":"Zahra Ghafourian , Mohammad Fani Kheshti , Mojtaba Saei Maghaddam","doi":"10.1016/j.ctta.2026.100264","DOIUrl":"10.1016/j.ctta.2026.100264","url":null,"abstract":"<div><div>A new thermodynamic model for predicting solid–liquid equilibria (SLE) of paraffinic hydrocarbons in binary and multicomponent systems has been developed. The model employs the ideal solution theory for the liquid phase and the predictive Wilson activity model for the solid phase, thereby avoiding the use of cubic equations of state. The model accurately predicts the wax disappearance temperature (WDT) over a wide pressure range (from atmospheric pressure up to 300 MPa). Validation against more than 320 experimental data points, including pure components, binary mixtures, and multicomponent systems, shows excellent agreement, with average absolute deviations of 1.56 K for binary mixtures and 0.81 K for light–heavy hydrocarbon systems. The approach offers a reliable tool for modeling wax formation in pipeline and reservoir conditions.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"21 ","pages":"Article 100264"},"PeriodicalIF":0.0,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921096","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 : 2025-12-30DOI: 10.1016/j.ctta.2025.100263
Dhirendra Kumar Sharma , Chandra pal Prajapati , Suneel Kumar
Experimental densities (ρ), viscosities (η), refractive indices (n), and sound velocities (u) were measured at 298.15 K and atmospheric pressure for binary liquid mixtures of isopropyl benzene (cumene) with ethylbenzene, toluene, mesitylene, n-propylbenzene, tert‑butylbenzene, and biphenyl. Based on these experimental results, various thermodynamic excess functions and deviation properties were subsequently evaluated. Physical properties such as density, viscosity, speed of sound, and refractive index play a crucial role in determining the excess thermodynamic properties of chemical mixtures. These properties provide valuable insight into molecular interactions and help predict the behaviour of complex chemical systems. However, comprehensive experimental data for these parameters are not always available for all mixtures, which limit the accuracy of thermodynamic modelling and analysis. The study provides new sets of experimental data, and the results indicate that the intermolecular interactions in the binary systems of isopropyl benzene (cumene) with the investigated aromatic hydrocarbons (ethylbenzene, toluene, mesitylene, n-propylbenzene, tert‑butylbenzene, and biphenyl) are relatively weak.
{"title":"Thermodynamic properties of isopropyl benzene (cumene) with aromatic hydrocarbons at temperature 298.15 K and under atmospheric pressure","authors":"Dhirendra Kumar Sharma , Chandra pal Prajapati , Suneel Kumar","doi":"10.1016/j.ctta.2025.100263","DOIUrl":"10.1016/j.ctta.2025.100263","url":null,"abstract":"<div><div>Experimental densities (ρ), viscosities (η), refractive indices (n), and sound velocities (u) were measured at 298.15 K and atmospheric pressure for binary liquid mixtures of isopropyl benzene (cumene) with ethylbenzene, toluene, mesitylene, n-propylbenzene, tert‑butylbenzene, and biphenyl. Based on these experimental results, various thermodynamic excess functions and deviation properties were subsequently evaluated. Physical properties such as density, viscosity, speed of sound, and refractive index play a crucial role in determining the excess thermodynamic properties of chemical mixtures. These properties provide valuable insight into molecular interactions and help predict the behaviour of complex chemical systems. However, comprehensive experimental data for these parameters are not always available for all mixtures, which limit the accuracy of thermodynamic modelling and analysis. The study provides new sets of experimental data, and the results indicate that the intermolecular interactions in the binary systems of isopropyl benzene (cumene) with the investigated aromatic hydrocarbons (ethylbenzene, toluene, mesitylene, n-propylbenzene, tert‑butylbenzene, and biphenyl) are relatively weak.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"21 ","pages":"Article 100263"},"PeriodicalIF":0.0,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880391","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}
In this work, the thermodynamic properties of the GeTe-rich layered ternary compounds Ge2Sb2Te5, Ge3Sb2Te6, and Ge4Sb2Te7 were investigated using electromotive-force (EMF) measurements in the temperature interval 300–450 K. To ensure correct electrode selection, the solid-phase equilibria in the were first examined, and the corresponding equilibrium diagram for the GeTe-rich compositional region was refined using powder X-ray diffraction. Based on these results, concentration cells of the type (–) GeTe (solid) │ glycerol-KCl │ Ge-Sb-Te (solid) (+) were assembled, and linear EMF-temperature dependences were obtained for the three phase regions. The partial molar Gibbs free energies, enthalpies, and entropies of Ge in the corresponding equilibrated alloys were calculated from the EMF data, and the standard thermodynamic functions of formation of Ge2Sb2Te5, Ge3Sb2Te6, and Ge4Sb2Te7 were derived using the method of virtual-cell reactions. The obtained values were compared with available literature data, including experimental results and theoretical calculation data. The results provide a consistent and experimentally validated thermodynamic dataset essential for accurate phase-diagram construction, assessment of phase stability, and predictive modeling of Ge-Sb-Te materials.
{"title":"Thermodynamic study of GeTe-rich germanium antimony tellurides using electromotive force measurements","authors":"E.N. Orujlu , A.N. Mammadov , A.M. Orujlu , M.B. Babanly","doi":"10.1016/j.ctta.2025.100262","DOIUrl":"10.1016/j.ctta.2025.100262","url":null,"abstract":"<div><div>In this work, the thermodynamic properties of the GeTe-rich layered ternary compounds Ge<sub>2</sub>Sb<sub>2</sub>Te<sub>5</sub>, Ge<sub>3</sub>Sb<sub>2</sub>Te<sub>6</sub>, and Ge<sub>4</sub>Sb<sub>2</sub>Te<sub>7</sub> were investigated using electromotive-force (EMF) measurements in the temperature interval 300–450 K. To ensure correct electrode selection, the solid-phase equilibria in the were first examined, and the corresponding equilibrium diagram for the GeTe-rich compositional region was refined using powder X-ray diffraction. Based on these results, concentration cells of the type (–) GeTe (solid) │ glycerol-KCl │ Ge-Sb-Te (solid) (+) were assembled, and linear EMF-temperature dependences were obtained for the three phase regions. The partial molar Gibbs free energies, enthalpies, and entropies of Ge in the corresponding equilibrated alloys were calculated from the EMF data, and the standard thermodynamic functions of formation of Ge<sub>2</sub>Sb<sub>2</sub>Te<sub>5</sub>, Ge<sub>3</sub>Sb<sub>2</sub>Te<sub>6</sub>, and Ge<sub>4</sub>Sb<sub>2</sub>Te<sub>7</sub> were derived using the method of virtual-cell reactions. The obtained values were compared with available literature data, including experimental results and theoretical calculation data. The results provide a consistent and experimentally validated thermodynamic dataset essential for accurate phase-diagram construction, assessment of phase stability, and predictive modeling of Ge-Sb-Te materials.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"21 ","pages":"Article 100262"},"PeriodicalIF":0.0,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880394","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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