A semi-empirical framework is developed to estimate the viscosity of binary brine systems (m-Pas) over temperatures from 293 to 323 K and molal concentrations between 0 and 4, using a continuous viscosity function constructed from experimental salt-water data. The modeling employs Machine Learning (ML) algorithms – Artificial Neural Network (ANN), Random Forest Regressor (RFR), and Gaussian Process Regressor (GPR) to optimize prediction accuracy with fewer fitting parameters. Comparative assessment shows that the AI-based approach achieves an average absolute deviation (%AAD) below 1%, outperforming conventional models while utilizing fewer parameters. Specifically, the GPR model yielded the best results with a %AAD of 0.96%, root mean square error (RMSE) of 0.0001, and an R2 score of 0.9979, surpassing RFR (%AAD 6.65%) and ANN (%AAD 18.67%). Robustness and model validity are confirmed through rigorous cross-validation and confidence intervals. These findings demonstrate that machine learning, particularly GPR, provides a highly accurate and practical approach for predicting physicochemical properties in aqueous electrolyte environments, enabling effective industrial applications in process optimization and resource management. The results underscore machine learning as a practical approach for modelling physicochemical properties within aqueous electrolyte environments.
{"title":"Non-linear AI based viscosity prediction for binary brine data","authors":"Vinita Sangwan , Rashmi Bhardwaj , Marco Alfaro , Andrés Soto-Bubert , Roberto Acevedo","doi":"10.1016/j.ctta.2025.100231","DOIUrl":"10.1016/j.ctta.2025.100231","url":null,"abstract":"<div><div>A semi-empirical framework is developed to estimate the viscosity of binary brine systems (m-Pas) over temperatures from 293 to 323 K and molal concentrations between 0 and 4, using a continuous viscosity function <span><math><mrow><mi>η</mi><mo>[</mo><mrow><mi>m</mi><mo>,</mo><mi>T</mi></mrow><mo>]</mo></mrow></math></span> constructed from experimental salt-water data. The modeling employs Machine Learning (ML) algorithms – Artificial Neural Network (ANN), Random Forest Regressor (RFR), and Gaussian Process Regressor (GPR) to optimize prediction accuracy with fewer fitting parameters. Comparative assessment shows that the AI-based approach achieves an average absolute deviation (%AAD) below 1%, outperforming conventional models while utilizing fewer parameters. Specifically, the GPR model yielded the best results with a %AAD of 0.96%, root mean square error (RMSE) of 0.0001, and an R<sup>2</sup> score of 0.9979, surpassing RFR (%AAD 6.65%) and ANN (%AAD 18.67%). Robustness and model validity are confirmed through rigorous cross-validation and confidence intervals. These findings demonstrate that machine learning, particularly GPR, provides a highly accurate and practical approach for predicting physicochemical properties in aqueous electrolyte environments, enabling effective industrial applications in process optimization and resource management. The results underscore machine learning as a practical approach for modelling physicochemical properties within aqueous electrolyte environments.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100231"},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145323882","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 : 2025-10-01DOI: 10.1016/j.ctta.2025.100236
Khairunnisa Waznah Baharin , Mohd Afzanizam Mohd Rosli , Mohd Nurazzi Norizan , Nor Ain Azeany Mohd Nasir , Nanthini Sridewi Appan , Noor Aisyah Ahmad Shah , Intan Juliana Shamsudin , Norherdawati Kasim , Mohd Haizal Mohd Husin , Norli Abdullah
This review article explores the promising applications and performance enhancements offered by nanofluids in modern cooling systems. Nanofluids an engineered colloidal suspension of nanoparticles within conventional base fluids demonstrates superior thermo-physical properties, such as increased thermal conductivity and improved convective heat transfer capabilities. These characteristics position nanofluids as highly effective alternatives to traditional coolants across a wide spectrum of engineering and industrial domains. The article presents an analysis of contemporary research on nanofluid-based cooling technologies, encompassing diverse applications such as heat pipe systems, automotive thermal management, heating, ventilation, and air conditioning (HVAC) systems, solar thermal collectors, electronic device cooling, and machining processes. Emphasis is placed on the potential of nanofluids to enhance energy efficiency, reduce thermal resistance, and improve overall system performance. In addition to highlighting the advantages, the review also addresses key challenges associated with nanofluid implementation, including nanoparticle stability, economic feasibility, and practical integration into existing systems. By synthesizing current findings and identifying future research directions, this article aims to serve as a valuable resource for researchers, engineers, and policymakers seeking to optimize cooling system performance through the strategic use of nanofluid-based technologies.
{"title":"Recent advances and ongoing challenges in nanofluids-enhanced cooling technologies","authors":"Khairunnisa Waznah Baharin , Mohd Afzanizam Mohd Rosli , Mohd Nurazzi Norizan , Nor Ain Azeany Mohd Nasir , Nanthini Sridewi Appan , Noor Aisyah Ahmad Shah , Intan Juliana Shamsudin , Norherdawati Kasim , Mohd Haizal Mohd Husin , Norli Abdullah","doi":"10.1016/j.ctta.2025.100236","DOIUrl":"10.1016/j.ctta.2025.100236","url":null,"abstract":"<div><div>This review article explores the promising applications and performance enhancements offered by nanofluids in modern cooling systems. Nanofluids an engineered colloidal suspension of nanoparticles within conventional base fluids demonstrates superior thermo-physical properties, such as increased thermal conductivity and improved convective heat transfer capabilities. These characteristics position nanofluids as highly effective alternatives to traditional coolants across a wide spectrum of engineering and industrial domains. The article presents an analysis of contemporary research on nanofluid-based cooling technologies, encompassing diverse applications such as heat pipe systems, automotive thermal management, heating, ventilation, and air conditioning (HVAC) systems, solar thermal collectors, electronic device cooling, and machining processes. Emphasis is placed on the potential of nanofluids to enhance energy efficiency, reduce thermal resistance, and improve overall system performance. In addition to highlighting the advantages, the review also addresses key challenges associated with nanofluid implementation, including nanoparticle stability, economic feasibility, and practical integration into existing systems. By synthesizing current findings and identifying future research directions, this article aims to serve as a valuable resource for researchers, engineers, and policymakers seeking to optimize cooling system performance through the strategic use of nanofluid-based technologies.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100236"},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145473680","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 : 2025-10-01DOI: 10.1016/j.ctta.2025.100227
Rongchun Shen , Yun Chen , Shi Zheng , Yunhai Shi , Jinghong Zhou , Wei Li
Isobaric vapor-liquid Equilibrium (VLE) data for dimethyl oxalate + methanol and methanol + 1,2-butanediol binary systems, as well as the VLE for dimethyl oxalate + methanol + 1,2-butanediol ternary system have been determined using an Ellis equilibrium distiller at 101.325 kPa. The vapor pressure of 1,2-butanol was measured with a Rose equilibrium apparatus under pressure of 0.34 kPa to atmospheric pressure. The thermodynamic consistency tests of the two binary experimental VLE data for dimethyl oxalate + methanol and methanol + 1,2-butanediol were performed according to a statistical method. The two binary experimental data were correlated by the Wilson, non-random two-liquid (NRTL) and universal quasi-chemical (UNIQUAC) activity coefficient models integrated in the authorized Aspen Plus software with the maximum average absolute deviations of 1.42 K for temperature and 0.0153 for vapor phase composition, the binary component interaction parameters were also obtained by this regression. On the basis of these calculated results, the corresponding binary interaction parameters of the dimethyl oxalate and 1,2-butanediol was then regressed from experimental ternary (dimethyl oxalate + methanol +1,2-butanediol) VLE data. These experimental and calculated data are valuable for the separation process design and optimization of dimethyl oxalate hydrogenation to ethylene glycol.
{"title":"VLE measurement of ternary system containing components of dimethyl oxalate, methanol and 1,2-butanediol under atmospheric pressure","authors":"Rongchun Shen , Yun Chen , Shi Zheng , Yunhai Shi , Jinghong Zhou , Wei Li","doi":"10.1016/j.ctta.2025.100227","DOIUrl":"10.1016/j.ctta.2025.100227","url":null,"abstract":"<div><div>Isobaric vapor-liquid Equilibrium (VLE) data for dimethyl oxalate + methanol and methanol + 1,2-butanediol binary systems, as well as the VLE for dimethyl oxalate + methanol + 1,2-butanediol ternary system have been determined using an Ellis equilibrium distiller at 101.325 kPa. The vapor pressure of 1,2-butanol was measured with a Rose equilibrium apparatus under pressure of 0.34 kPa to atmospheric pressure. The thermodynamic consistency tests of the two binary experimental VLE data for dimethyl oxalate + methanol and methanol + 1,2-butanediol were performed according to a statistical method. The two binary experimental data were correlated by the Wilson, non-random two-liquid (NRTL) and universal quasi-chemical (UNIQUAC) activity coefficient models integrated in the authorized Aspen Plus software with the maximum average absolute deviations of 1.42 K for temperature and 0.0153 for vapor phase composition, the binary component interaction parameters were also obtained by this regression. On the basis of these calculated results, the corresponding binary interaction parameters of the dimethyl oxalate and 1,2-butanediol was then regressed from experimental ternary (dimethyl oxalate + methanol +1,2-butanediol) VLE data. These experimental and calculated data are valuable for the separation process design and optimization of dimethyl oxalate hydrogenation to ethylene glycol.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100227"},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145262338","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}
To investigate the molecular interactions of L-alanine and L-valine with a cephalosporin antibiotic drug namely, ceftriaxone we have measured the densities and viscosities of L-alanine and L-valine in (0.01 and 0.02) mol. kg−1 ceftriaxone solutions over a temperature range of (305.15, 310.15 and 315.15) K at 0.1MPa pressure. The apparent molar volume, Vϕ, limiting apparent molar volume, V 0ϕ, the slope, Sv, limiting apparent molar volume of transfer, ΔtrV 0ϕ, limiting apparent molar expansivity, E 0ϕ, and Hepler’s constant, (∂2V 0ϕ /∂T2)P, have been calculated from density data. The viscosity data has been used to determine relative viscosity ƞr, viscosity B-coefficients, temperature derivative of B-coefficients, dB/dT and viscosity B-coefficients of transfer, ∆trB. The structure-making and structure-breaking behavior of the amino acids were analyzed using the signs and magnitude of Hepler’s constant, (∂2V 0ϕ /∂T2)P and dB/dT coefficients. The cosphere overlap model was used to interpret the positive transfer volume ΔtrV 0ϕ. The calculated parameters have been discussed in terms of various solute-solute and solute-solvent interactions prevailing in these solutions. The comparison of these effects on the amino acid hydration enables us to have a better understanding of the influence of drug on the protein stabilization.
{"title":"Intermolecular interactions of L-alanine and L-valine with the drug ceftriaxone in aqueous solution: A volumetric and viscometric approach","authors":"Ruby Rani , Daljeet Singh Manhas , Rajinder Kumar Bamezai , Saloni Panoch , Sakshi Sharma , Indu Sharma , Ruchi Salaria , Ruchi Sharma","doi":"10.1016/j.ctta.2025.100229","DOIUrl":"10.1016/j.ctta.2025.100229","url":null,"abstract":"<div><div>To investigate the molecular interactions of L-alanine and L-valine with a cephalosporin antibiotic drug namely, ceftriaxone we have measured the densities and viscosities of L-alanine and L-valine in (0.01 and 0.02) mol. kg<sup>−1</sup> ceftriaxone solutions over a temperature range of (305.15, 310.15 and 315.15) K at 0.1MPa pressure. The apparent molar volume, <em>V<sub>ϕ</sub></em>, limiting apparent molar volume, <em>V <sup>0</sup><sub>ϕ</sub></em>, the slope, <em>S<sub>v</sub>,</em> limiting apparent molar volume of transfer, <em>Δ<sub>tr</sub>V <sup>0</sup><sub>ϕ,</sub></em> limiting apparent molar expansivity, <em>E <sup>0</sup><sub>ϕ</sub></em>, and Hepler’s constant, (<em>∂</em><sup>2</sup><em>V <sup>0</sup><sub>ϕ</sub></em> /<em>∂T</em><sup>2</sup>)<em><sub>P</sub></em><sub>,</sub> have been calculated from density data. The viscosity data has been used to determine relative viscosity <em>ƞ<sub>r</sub></em>, viscosity <em>B</em>-coefficients, temperature derivative of <em>B</em>-coefficients, <em>dB/dT</em> and viscosity <em>B</em>-coefficients of transfer, <em>∆<sub>tr</sub>B</em>. The structure-making and structure-breaking behavior of the amino acids were analyzed using the signs and magnitude of Hepler’s constant, (<em>∂</em><sup>2</sup><em>V <sup>0</sup><sub>ϕ</sub></em> /<em>∂T</em><sup>2</sup>)<em><sub>P</sub></em> and d<em>B</em>/d<em>T</em> coefficients. The cosphere overlap model was used to interpret the positive transfer volume <em>Δ<sub>tr</sub>V <sup>0</sup><sub>ϕ</sub></em>. The calculated parameters have been discussed in terms of various solute-solute and solute-solvent interactions prevailing in these solutions. The comparison of these effects on the amino acid hydration enables us to have a better understanding of the influence of drug on the protein stabilization.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100229"},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145323884","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}
Thermophysical investigations have been carried out for uridine in water and water + lysine (0.01, 0.05 and 0.1 mol kg −1) solutions at different temperatures T=(303. 15, 308.15 and 313.15) K and 0.101 MPa. The measured density and speed of sound data were used to calculateapparent molar volume, and compatibility of solute uridine in aqueous solution of lysine. The partial molar volume and compressibility (and,) were computed using Masson’s and Gucker’s relation. The partial molar transfer volume and compressibility (and) has been calculated and discussed. The UV–VIS spectra of uridine in water and in aqueous-lysine solutions have been recorded in order to understand the molecular interactions. The results are interpreted in terms of solute-solvent/solute interactions. Hydration behavior of uridine nucleoside in aqueous solutions of lysine has also been evaluated.
{"title":"Temperature dependent thermophysical investigations of uridine nucleoside in aqueous-lysine solutions at different temperatures","authors":"S.B. Waghmare , H.N. Pawar , R.V. Dudhate , A.D. Arsule , S.D. Deosarkar","doi":"10.1016/j.ctta.2025.100239","DOIUrl":"10.1016/j.ctta.2025.100239","url":null,"abstract":"<div><div>Thermophysical investigations have been carried out for uridine in water and water + lysine (0.01, 0.05 and 0.1 mol kg <sup>−1</sup>) solutions at different temperatures <em>T</em>=(303. 15, 308.15 and 313.15) K and 0.101 MPa. The measured density and speed of sound data were used to calculateapparent molar volume,<span><math><msub><mi>V</mi><mrow><mn>2</mn><mo>,</mo><mi>ϕ</mi></mrow></msub></math></span> and compatibility <span><math><msub><mi>κ</mi><mrow><mi>S</mi><mo>,</mo><mn>2</mn><mo>,</mo><mi>ϕ</mi></mrow></msub></math></span>of solute uridine in aqueous solution of lysine. The partial molar volume and compressibility (<span><math><msubsup><mi>V</mi><mrow><mn>2</mn><mo>,</mo><mi>φ</mi></mrow><mi>o</mi></msubsup></math></span>and,<span><math><msubsup><mi>κ</mi><mrow><mi>S</mi><mo>,</mo><mn>2</mn><mo>,</mo><mi>ϕ</mi></mrow><mn>0</mn></msubsup></math></span>) were computed using Masson’s and Gucker’s relation. The partial molar transfer volume and compressibility (<span><math><mrow><msub><mstyle><mi>Δ</mi></mstyle><mi>t</mi></msub><msubsup><mi>V</mi><mrow><mn>2</mn><mo>,</mo><mi>φ</mi></mrow><mi>o</mi></msubsup></mrow></math></span>and<span><math><mrow><msub><mstyle><mi>Δ</mi></mstyle><mi>t</mi></msub><msubsup><mi>κ</mi><mrow><mi>S</mi><mo>,</mo><mn>2</mn><mo>,</mo><mi>φ</mi></mrow><mn>0</mn></msubsup></mrow></math></span>) has been calculated and discussed. The UV–VIS spectra of uridine in water and in aqueous-lysine solutions have been recorded in order to understand the molecular interactions. The results are interpreted in terms of solute-solvent/solute interactions. Hydration behavior of uridine nucleoside in aqueous solutions of lysine has also been evaluated.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100239"},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145473681","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}
Present research work examines the physicochemical interactions of calcium propionate (a widely used food preservative) with two different imidazolium-based ionic liquids (ILs) i.e. 1-Ethyl-3-methylimidazolium ethyl sulphate ([C₂mim][EtSO₄]) and 1-Butyl-3-methylimidazolium chloride ([C₄mim][Cl]) in aqueous systems. Measurements were conducted across three molal concentrations (0.05, 0.10, 0.15 mol kg⁻¹) of the ILs, spanning a temperature range of 293.15 to 313.15 K at p = 0.1 MPa. Viscosity and refractive index measurements were used to probe molecular interactions as a function of temperature and concentration. The resulting data were analyzed to determine key parameters, viscosity coefficients {Falkenhagen coefficient (A), Jones-Dole coefficient (B)}, viscosity B-coefficients of transfer (ΔtrB) and dB/dT values. The obtained data definitively suggest effective solute-cosolute interactions between calcium propionate and the aqueous ionic liquid media. Notably, the positive ΔtrB values indicate that calcium propionate interacts more strongly in the IL-water mixtures than in pure water. Furthermore, the positive dB/dT values inferred a structure-breaking (chaotropic) effect of the media on the solvent structure. These comprehensive physicochemical insights are vital for formulating more effective hybrid preservative systems and advancing the role of these materials in green chemistry applications.
目前的研究工作考察了丙酸钙（一种广泛使用的食品防腐剂）与两种不同的咪唑基离子液体（il），即1-乙基-3-甲基咪唑乙酯硫酸盐（[C₂mim][EtSO₄]）和1-丁基-3-甲基咪唑氯（[C₄mim][Cl]）在水体系中的物理化学相互作用。在三种摩尔浓度（0.05,0.10,0.15 mol kg⁻¹）下进行测量，温度范围为293.15至313.15 K, p = 0.1 MPa。粘度和折射率测量用于探测分子相互作用作为温度和浓度的函数。对得到的数据进行分析，确定关键参数，粘度系数{Falkenhagen系数(A)， Jones-Dole系数(B)}，粘度B-传递系数（ΔtrB）和dB/dT值。所得数据明确表明丙酸钙和水离子液体介质之间存在有效的溶质-溶质相互作用。值得注意的是，ΔtrB正值表明丙酸钙在il -水混合物中的相互作用比在纯水中更强。此外，正dB/dT值推断介质对溶剂结构的破坏（混沌）效应。这些全面的物理化学见解对于制定更有效的混合防腐剂系统和推进这些材料在绿色化学应用中的作用至关重要。
{"title":"Physicochemical investigations of calcium propionate with 1-Ethyl-3-methylimidazolium ethyl sulphate and 1-Butyl-3-methylimidazolium chloride in aqueous systems","authors":"Vrinda Sharma, Himani Singh, Umeshwari, Ashwani Kumar","doi":"10.1016/j.ctta.2025.100241","DOIUrl":"10.1016/j.ctta.2025.100241","url":null,"abstract":"<div><div>Present research work examines the physicochemical interactions of calcium propionate (a widely used food preservative) with two different imidazolium-based ionic liquids (ILs) i.e. 1-Ethyl-3-methylimidazolium ethyl sulphate ([C₂mim][EtSO₄]) and 1-Butyl-3-methylimidazolium chloride ([C₄mim][Cl]) in aqueous systems. Measurements were conducted across three molal concentrations (0.05, 0.10, 0.15 mol kg⁻¹) of the ILs, spanning a temperature range of 293.15 to 313.15 K at <em>p</em> = 0.1 MPa. Viscosity and refractive index measurements were used to probe molecular interactions as a function of temperature and concentration. The resulting data were analyzed to determine key parameters, viscosity coefficients {Falkenhagen coefficient (<em>A)</em>, Jones-Dole coefficient (<em>B</em>)}, viscosity <em>B</em>-coefficients of transfer (<em>Δ<sub>tr</sub>B</em>) and <em>dB/dT</em> values. The obtained data definitively suggest effective solute-cosolute interactions between calcium propionate and the aqueous ionic liquid media. Notably, the positive <em>Δ<sub>tr</sub>B</em> values indicate that calcium propionate interacts more strongly in the IL-water mixtures than in pure water. Furthermore, the positive <em>dB/dT</em> values inferred a structure-breaking (chaotropic) effect of the media on the solvent structure. These comprehensive physicochemical insights are vital for formulating more effective hybrid preservative systems and advancing the role of these materials in green chemistry applications.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100241"},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145525442","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 : 2025-10-01DOI: 10.1016/j.ctta.2025.100223
M.K. Binkar, R.B. Ramteke, J.N. Ramteke
The ultrasonic velocity (U) and density (ρ) of pure components and binary liquid mixtures, including xylene and 1,4-dioxane with tetra butyl ammonium chloride, have been determined as functions of composition at different temperatures (T = 301.15 K, 305.15 K, 309.15 K, and 313.15 K) at a fixed frequency of 5 MHz for different concentration ranges. The values of adiabatic compressibility (βs), intermolecular free length (Lf), acoustic impedance (Z), free volume (Vf), relaxation time (τ), coefficient of thermal expansion (αP), excess adiabatic compressibility (βEs), excess intermolecular free length (LEf), excess acoustic impedance (ZE), excess free volume (VEf), excess relaxation time (τE) and excess molar volume (VEm) were computed using experimental data. The increase or decrease of βs, Lf, Z, Vf, τ and αP with composition indicates the presence of interaction between the component molecules in the mixtures. While excess acoustic impedance and excess free volume consistently show negative variation, excess adiabatic compressibility (βEs), excess intermolecular free length (LEf), and excess relaxation time (τE) show mixed deviation. In the xylene + tetrabutylammonium chloride system, the observed trends suggest weak to moderate interactions, predominantly π–cation and dipole–induced dipole forces, which become more pronounced at higher concentrations. In contrast, the 1,4-dioxane + tetrabutylammonium chloride system exhibits comparatively stronger ion–dipole interactions, leading to greater structural rearrangement and compact molecular association across the entire composition range. These results emphasize the value of excess parameters in describing solute–solvent interactions by confirming that the degree and kind of departures from ideality are significantly impacted by the polarity and structural features of the constituents involved.
{"title":"Ultrasonic investigation of binary liquid mixture's excess thermodynamic characteristics at various temperatures","authors":"M.K. Binkar, R.B. Ramteke, J.N. Ramteke","doi":"10.1016/j.ctta.2025.100223","DOIUrl":"10.1016/j.ctta.2025.100223","url":null,"abstract":"<div><div>The ultrasonic velocity (<em>U</em>) and density (<em>ρ</em>) of pure components and binary liquid mixtures, including xylene and 1,4-dioxane with tetra butyl ammonium chloride, have been determined as functions of composition at different temperatures (<em>T</em> = 301.15 K, 305.15 K, 309.15 K, and 313.15 K) at a fixed frequency of 5 MHz for different concentration ranges. The values of adiabatic compressibility (<em>β<sub>s</sub></em>), intermolecular free length (<em>L<sub>f</sub></em>), acoustic impedance <em>(Z</em>), free volume (<em>V<sub>f</sub></em>), relaxation time (<em>τ</em>), coefficient of thermal expansion (<em>α<sub>P</sub></em>), excess adiabatic compressibility (<em>β<sup>E</sup><sub>s</sub></em>), excess intermolecular free length (L<sup>E</sup><sub>f</sub>), excess acoustic impedance (<em>Z<sup>E</sup></em>), excess free volume (<em>V<sup>E</sup><sub>f</sub>),</em> excess relaxation time (<em>τ<sup>E</sup></em>) and excess molar volume (<em>V<sup>E</sup><sub>m</sub></em>) were computed using experimental data. The increase or decrease of <em>β<sub>s</sub>, L<sub>f</sub>, Z, V<sub>f</sub>, τ and α<sub>P</sub></em> with composition indicates the presence of interaction between the component molecules in the mixtures. While excess acoustic impedance and excess free volume consistently show negative variation, excess adiabatic compressibility (<em>β<sup>E</sup><sub>s</sub></em>), excess intermolecular free length (<em>L<sup>E</sup><sub>f</sub></em>), and excess relaxation time (<em>τ<sup>E</sup></em>) show mixed deviation. In the xylene + tetrabutylammonium chloride system, the observed trends suggest weak to moderate interactions, predominantly π–cation and dipole–induced dipole forces, which become more pronounced at higher concentrations. In contrast, the 1,4-dioxane + tetrabutylammonium chloride system exhibits comparatively stronger ion–dipole interactions, leading to greater structural rearrangement and compact molecular association across the entire composition range. These results emphasize the value of excess parameters in describing solute–solvent interactions by confirming that the degree and kind of departures from ideality are significantly impacted by the polarity and structural features of the constituents involved.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100223"},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145216619","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 : 2025-10-01DOI: 10.1016/j.ctta.2025.100233
Chakanaka P. Mungwari , Babatunde Abiodun Obadele , Cecil K. King’ondu
This study evaluates the thermodynamic behavior and adsorption mechanism of methanolic Acacia mearnsii bark extract (MAMBE) as a green corrosion inhibitor for stainless steel (SS304) in synergy with KI in 1 M HCl solution. Using weight loss measurements, thermodynamic calculations, and adsorption studies, the study assesses both the individual and combined effectiveness of MAMBE and potassium iodide (KI). MAMBE alone achieved a maximum inhibition efficiency of 62.2 % at 1.2 g/L, which dramatically increased to 98.2% when supplemented with 0.3 g/L KI, indicating a strong synergistic effect (s > 1). Thermodynamic parameters, including activation energy (Ea), enthalpy change (ΔH°), entropy change (ΔS°), and Gibbs free energy change (ΔG°), were analyzed to understand the nature of adsorption and spontaneity. MAMBE and KI alone showed Ea values below 80 kJ/mol with positive ΔH°, indicating endothermic adsorption. The MAMBE and KI combination presented a higher Ea of 105 kJ/mol, suggesting a more robust corrosion barrier. The ΔG° values (-6.653 to −21.765 kJ/mol) confirmed spontaneous, predominantly physical adsorption. Adsorption followed the Langmuir isotherm model, and thermogravimetric analysis revealed MAMBE's thermal stability up to 110°C, highlighting its excellent thermal resistance and potential as an effective eco-friendly corrosion inhibitor.
{"title":"Synergistic corrosion inhibition of 304 stainless steel in 1 M HCl by methanolic Acacia mearnsii bark extract and KI: Thermodynamic, kinetic, and thermal analysis","authors":"Chakanaka P. Mungwari , Babatunde Abiodun Obadele , Cecil K. King’ondu","doi":"10.1016/j.ctta.2025.100233","DOIUrl":"10.1016/j.ctta.2025.100233","url":null,"abstract":"<div><div>This study evaluates the thermodynamic behavior and adsorption mechanism of methanolic Acacia mearnsii bark extract (MAMBE) as a green corrosion inhibitor for stainless steel (SS304) in synergy with KI in 1 M HCl solution. Using weight loss measurements, thermodynamic calculations, and adsorption studies, the study assesses both the individual and combined effectiveness of MAMBE and potassium iodide (KI). MAMBE alone achieved a maximum inhibition efficiency of 62.2 % at 1.2 g/L, which dramatically increased to 98.2% when supplemented with 0.3 g/L KI, indicating a strong synergistic effect (s > 1). Thermodynamic parameters, including activation energy (Ea), enthalpy change (ΔH°), entropy change (ΔS°), and Gibbs free energy change (ΔG°), were analyzed to understand the nature of adsorption and spontaneity. MAMBE and KI alone showed E<sub>a</sub> values below 80 kJ/mol with positive ΔH°, indicating endothermic adsorption. The MAMBE and KI combination presented a higher E<sub>a</sub> of 105 kJ/mol, suggesting a more robust corrosion barrier. The ΔG° values (-6.653 to −21.765 kJ/mol) confirmed spontaneous, predominantly physical adsorption. Adsorption followed the Langmuir isotherm model, and thermogravimetric analysis revealed MAMBE's thermal stability up to 110°C, highlighting its excellent thermal resistance and potential as an effective eco-friendly corrosion inhibitor.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100233"},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145323883","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 : 2025-10-01DOI: 10.1016/j.ctta.2025.100238
Peter J. Skrdla
Thermal measurements employing differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) are frequently utilized in the study of chemical reactions and phase transformations involving the solid state. Given that these techniques typically involve heating (and occasionally cooling), it is essential to comprehend how the kinetics are influenced in comparison to isothermal measurements obtained using the same instrumentation. This matter has recently re-emerged due to an article published in the thermoanalytical literature that provided substantial evidence of unexpected linear correlations between the activation energy, E, and the reaction temperature, T, across diverse classes of conversions investigated with non-isothermal kinetic methods. This work provides a rationalization for the physical origin of that finding and proposes why, under isothermal conditions, the corresponding E values should remain temperature-invariant. In contrast to the Kissinger method, isoconversional methods are anticipated to remain unaffected when processing non-isothermal kinetic data.
{"title":"Isothermal and non-isothermal measurements can yield different activation energies from thermoanalytical data","authors":"Peter J. Skrdla","doi":"10.1016/j.ctta.2025.100238","DOIUrl":"10.1016/j.ctta.2025.100238","url":null,"abstract":"<div><div>Thermal measurements employing differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) are frequently utilized in the study of chemical reactions and phase transformations involving the solid state. Given that these techniques typically involve heating (and occasionally cooling), it is essential to comprehend how the kinetics are influenced in comparison to isothermal measurements obtained using the same instrumentation. This matter has recently re-emerged due to an article published in the thermoanalytical literature that provided substantial evidence of unexpected linear correlations between the activation energy, <em>E</em>, and the reaction temperature, <em>T</em>, across diverse classes of conversions investigated with non-isothermal kinetic methods. This work provides a rationalization for the physical origin of that finding and proposes why, under isothermal conditions, the corresponding <em>E</em> values should remain temperature-invariant. In contrast to the Kissinger method, isoconversional methods are anticipated to remain unaffected when processing non-isothermal kinetic data.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100238"},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145473677","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 : 2025-09-11DOI: 10.1016/j.ctta.2025.100221
Anders M. Schade , Sascha Louring , Morten M. Smedskjaer , Donghong Yu
Transparent hybrid materials that combine organic and inorganic components offer the possibility to obtain properties not found in conventional materials, such as simultaneous high toughness and high strength. Covalent bonding between the organic and inorganic phases is crucial to the performance and stability of sol-gel-based hybrid materials, which in turn can be achieved by using coupling agents. However, quantifying chemical coupling in hybrids is challenging due to the similarity between the reactive groups in the coupling agent and those in the organic components. Investigating the thermal stability of hybrid materials offers an alternative to assess chemical coupling, as polymers typically exhibit enhanced thermal stability when covalently bonded to stable inorganic entities such as silica. In this study, we evaluate the thermal stability of sol-gel hybrid materials based on tetraethylorthosilicate (TEOS), polyethylene glycol 200 (PEG200), and (3-Glycidyloxypropyl)-trimethoxysilane (GPTMS). The materials were analysed using thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) to determine the extent of interfacial covalent bonding between the polymer and silica networks as facilitated by the coupling agent GPTMS. The TGA results indicate a systematic increase in thermal stability with increasing GPTMS content, which is due to the covalent bonding of PEG200 to the silica network according to the FTIR results. We find that a 1:1:1 molar ratio of GPTMS, TEOS, and PEG200 yields the highest thermal stability enhancement for PEG200, where 36.8% of the organics decompose at a higher temperature compared to the native organic species. These findings demonstrate the link between the chemical structure of hybrid materials and their thermal properties as characterised using TGA.
{"title":"Characterising the interfacial bonding in organic-inorganic hybrid materials from their thermal stability","authors":"Anders M. Schade , Sascha Louring , Morten M. Smedskjaer , Donghong Yu","doi":"10.1016/j.ctta.2025.100221","DOIUrl":"10.1016/j.ctta.2025.100221","url":null,"abstract":"<div><div>Transparent hybrid materials that combine organic and inorganic components offer the possibility to obtain properties not found in conventional materials, such as simultaneous high toughness and high strength. Covalent bonding between the organic and inorganic phases is crucial to the performance and stability of sol-gel-based hybrid materials, which in turn can be achieved by using coupling agents. However, quantifying chemical coupling in hybrids is challenging due to the similarity between the reactive groups in the coupling agent and those in the organic components. Investigating the thermal stability of hybrid materials offers an alternative to assess chemical coupling, as polymers typically exhibit enhanced thermal stability when covalently bonded to stable inorganic entities such as silica. In this study, we evaluate the thermal stability of sol-gel hybrid materials based on tetraethylorthosilicate (TEOS), polyethylene glycol 200 (PEG200), and (3-Glycidyloxypropyl)-trimethoxysilane (GPTMS). The materials were analysed using thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) to determine the extent of interfacial covalent bonding between the polymer and silica networks as facilitated by the coupling agent GPTMS. The TGA results indicate a systematic increase in thermal stability with increasing GPTMS content, which is due to the covalent bonding of PEG200 to the silica network according to the FTIR results. We find that a 1:1:1 molar ratio of GPTMS, TEOS, and PEG200 yields the highest thermal stability enhancement for PEG200, where 36.8% of the organics decompose at a higher temperature compared to the native organic species. These findings demonstrate the link between the chemical structure of hybrid materials and their thermal properties as characterised using TGA.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"20 ","pages":"Article 100221"},"PeriodicalIF":0.0,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105575","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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