Thermochimica Acta最新文献

{"title":"How to correctly evaluate kinetics based on experimental data of reaction calorimetry","authors":"Arcady Kossoy,&nbsp;Yury Akhmetshin,&nbsp;Elena Koludarova","doi":"10.1016/j.tca.2025.179947","DOIUrl":"10.1016/j.tca.2025.179947","url":null,"abstract":"<div><div>Reaction calorimetry (RC) is a powerful experimental technique with a wide range of applications. A significant advantage of RC is the ability to simultaneously measure the heat generated by the reaction and the current composition of the reacting mixture, which provides more complete information about the reaction and its kinetics. This makes it a useful tool for studying reaction kinetics, although this method is rather complicated and requires a thorough elaboration of the methodology of experimentation and data processing.</div><div>The literature on RC theory is extensive, yet there is a lack of recognition regarding some methodical aspects of utilizing RC data to construct kinetic models. This paper aims to draw attention to these aspects. In particular:</div><div>the need for careful analysis of experimental data is emphasized and demonstrated,</div><div>the importance of applying the concept of key species to obtain unique kinetics is shown, as is the need to consider the effects of feed rate and reactants’ ratios to properly plan kinetic experiments,</div><div>the usefulness of kinetic modeling for better understanding of reaction progress is demonstrated.</div><div>The material is based on the results of a study of the well-known methanol - acetic anhydride esterification reaction taken from the literature.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"745 ","pages":"Article 179947"},"PeriodicalIF":3.1,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143103938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Review of supercooling suppression of phase change materials based on nanoparticles","authors":"Yuguo Gao ,&nbsp;Yanan Zhao ,&nbsp;Xinyu Wang ,&nbsp;Mohammaderfan Mohit ,&nbsp;Minghan Xu ,&nbsp;Agus P. Sasmito","doi":"10.1016/j.tca.2025.179936","DOIUrl":"10.1016/j.tca.2025.179936","url":null,"abstract":"<div><div>The phenomenon of supercooling in phase change materials has been a major obstacle to the effective use of these materials in thermal energy storage systems. Numerous studies have shown that nanoparticles display significant advantages over other methods of supercooling inhibition in terms of increased nucleation rate, enhanced thermal conductivity, reduced supercooling, and improved cycling stability. Yet, the mechanism of supercooling inhibition by nanoparticles has not been comprehensively discussed or reviewed in published articles. The objective of this review is to provide a comprehensive analysis of the mechanisms by which nanoparticles promote nucleation and reduce supercooling in phase change materials, as well as to discuss the most influential factors such as the type, concentration, and size of the nanoparticles, as well as ultrasonic and synergistic effects. Additionally, the paper focuses on an overview of recent advances in the application of machine learning to control the supercooling of nanofluid phase change materials. The potential for practical applications of machine learning techniques to enhance the thermophysical properties of phase change materials and suppress phase change material supercooling is one of our major findings.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"745 ","pages":"Article 179936"},"PeriodicalIF":3.1,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143170461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermoanalytical and kinetic degrees of conversion in the application of general rate equation","authors":"Peter Šimon ,&nbsp;Peter J. Skrdla ,&nbsp;Tibor Dubaj ,&nbsp;Zuzana Cibulková","doi":"10.1016/j.tca.2025.179933","DOIUrl":"10.1016/j.tca.2025.179933","url":null,"abstract":"<div><div>Kinetics of condensed-phase processes are routinely studied by methods based on the general rate equation. It is demonstrated here that, for the kinetic analysis, two degrees of conversion should be employed: (i) the degree of conversion used in classical kinetics, <em>α</em>_kin, conventionally defined as the reacted amount of a reactant normalized to its initial amount; (ii) the thermoanalytical degree of conversion, <em>α</em>, defined as the thermoanalytical effect observed at temperature <em>T</em> (or at time <em>t</em> for isothermal measurements) divided by the total thermoanalytical effect. For elementary reactions, <em>α</em>_kin = <em>α</em> so that the general rate equation is a true rate equation describing the mechanism of the reaction. For complex processes, <em>α</em>_kin and <em>α</em> differ considerably in general; they are equivalent for some special cases only. In this case, the general rate equation represents the single-step approximation. The values of <em>α</em> thus describe the kinetics of heat exchange (for DSC) or mass loss (for TG) and so do the kinetic parameters obtained from the treatment of experimental data. Even though no mechanistic conclusions should be drawn from such kinetic parameters, they still enable us to model the kinetics of complex processes from the point of view of the quantity measured.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"745 ","pages":"Article 179933"},"PeriodicalIF":3.1,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143170460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase equilibria and phase diagrams of the ternary system NaNO3 + Sr(NO3)2 + H2O: Experimental insights and industrial applications at 298.15 and 338.15 K","authors":"Xinru Li,&nbsp;Jiaqi Wang,&nbsp;Linxue Yan,&nbsp;Can Liu,&nbsp;Yafei Guo,&nbsp;Tianlong Deng","doi":"10.1016/j.tca.2025.179937","DOIUrl":"10.1016/j.tca.2025.179937","url":null,"abstract":"<div><div>In this study, the isothermal dissolution and wet solid phase methods (Schreinemarkers rule) were applied to systematically investigate (NaNO₃ + Sr(NO₃)₂ + H₂O) ternary system at 298.15 and 338.15 K, to develop a green separation of Sr(NO₃)₂. The phase diagrams and thermodynamic models were designed on the basis of experimental data to elucidate the system's behavior under varying conditions. The phase diagram and physicochemical property diagrams indicate that no complex salts or solid solutions are formed, confirming the system's classification as a simple type. The invariant point (E), consisting solely of NaNO₃ and Sr(NO₃)₂ crystals, was identified using the REFLEX module in Material Studio. An optimized separation process for mixed NaNO₃ and Sr(NO₃)₂ solutions was established, reaching a 96.76 % separation efficiency for Sr(NO₃)₂. This study offers an eco-friendly and efficient approach for recovery of Sr(NO₃)₂ from sodium nitrate eluate, providing a reliable solution for industrial applications.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"745 ","pages":"Article 179937"},"PeriodicalIF":3.1,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143103937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electromotive force measurements of U-Zr alloys in LiCl-KCl-UCl3 melt","authors":"Gurudas Pakhui,&nbsp;Soja. K. Vijay,&nbsp;Ashish Jain,&nbsp;Suddhasattwa Ghosh","doi":"10.1016/j.tca.2025.179924","DOIUrl":"10.1016/j.tca.2025.179924","url":null,"abstract":"<div><div>Electromotive force measurements of U-60Zr (79.6 <em>at.</em>% Zr) and U-77Zr (89.7 <em>at.</em>% Zr) alloys in LiCl-KCl-UCl₃ melt were carried out in temperature range 670-800 K for determining <span><math><mrow><msub><mrow><mi>Δ</mi></mrow><mrow><mtext>f</mtext></mrow></msub><msubsup><mrow><mi>G</mi></mrow><mrow><msub><mrow><mi>UZr</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow><mrow><mo>∘</mo></mrow></msubsup></mrow></math></span>, the temperature dependence of which was expressed as</div><div><span><math><mrow><msub><mrow><mi>Δ</mi></mrow><mrow><mtext>f</mtext></mrow></msub><msubsup><mrow><mi>G</mi></mrow><mrow><msub><mrow><mi>UZr</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow><mrow><mo>∘</mo></mrow></msubsup></mrow></math></span> <span><math><mrow><mrow><mo>(</mo><mtext>kJ/mol-atom</mtext><mo>)</mo></mrow><mo>=</mo><mrow><mo>(</mo><mo>−</mo><mn>59</mn><mo>.</mo><mn>29</mn><mo>±</mo><mn>1</mn><mo>.</mo><mn>37</mn><mo>)</mo></mrow><mo>+</mo><mrow><mo>(</mo><mn>32</mn><mo>.</mo><mn>0</mn><mo>±</mo><mn>1</mn><mo>.</mo><mn>9</mn><mo>)</mo></mrow><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup><mi>T</mi><mrow><mo>(</mo><mtext>K</mtext><mo>)</mo></mrow></mrow></math></span></div><div>Correlation suggested stability of <span><math><mi>δ</mi></math></span>-UZr₂ to be higher than what is currently accepted in literature, which is based on its enthalpy of formation at 298.15 K. Cyclic voltammetry with U-Zr alloys as working electrode was also performed in potential range −1.50 to −0.50 V in LiCl-KCl-UCl₃ melt for exploring onset potential of dissolution of uranium and zirconium to address consequences of higher stability of UZr₂ on spent metal fuel dissolution.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"745 ","pages":"Article 179924"},"PeriodicalIF":3.1,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143171559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Theoretical study on the thermodynamic and transition properties of the interstellar molecule: FeC","authors":"Nan Fang ,&nbsp;Chuan-Yu Zhang ,&nbsp;Ming-Jie Wan ,&nbsp;Xiao-Peng Huang","doi":"10.1016/j.tca.2025.179938","DOIUrl":"10.1016/j.tca.2025.179938","url":null,"abstract":"<div><div>As an interstellar molecule, the thermodynamic properties and transition characteristics of FeC hold significant importance. In this study, high-precision ab initio methods were employed to obtain the potential energy functions of the five Λ-S states of FeC. Based on these results, the Partition functions, proportions of each molecular and thermodynamic properties were calculated for temperatures from 50 K to 10,000 K. In addition, the spin orbit coupling effects on the ground state (<em>X</em> ³Δ) split it into three Ω states (Ω = 3, 2, 1), with Ω = 3 being the lowest. The rotational spectrum for Ω = 3 at 298.15 K shows significantly higher transition intensity for the <em>v</em>′ = 0 and <em>v</em>′′ = 0 band. Moreover, this paper presents the ultraviolet spectrum of two transitions: <em>X</em> ³Δ ↔ 1³Π and 1³Π ↔ 1³Σ⁻, at a temperature of 298.15 K, with the 1³Π ↔ 1³Σ⁻ transition having stronger absolute intensity.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"745 ","pages":"Article 179938"},"PeriodicalIF":3.1,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143170446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Demicellization thermodynamics of amphiphilic carbon dots via isothermal titration calorimetry","authors":"Chang-Qing Xiao ,&nbsp;Juan Wu ,&nbsp;Lu Lai","doi":"10.1016/j.tca.2025.179935","DOIUrl":"10.1016/j.tca.2025.179935","url":null,"abstract":"<div><div>Amphiphilic carbon dots C₁₂₁₄-ACDs were synthesized from alkyl glucoside APG1214, and had shown good surface activity and high oil removal efficiency. In this study, we have employed ITC to study the demicellization processes of C₁₂₁₄-ACDs and its precursor APG1214 within the temperature range from 288 K to 313 K. The enthalpy change of demicellization Δ<em>H</em>_demic for C₁₂₁₄-ACDs is negative at the lower temperatures as -7.37 J g⁻¹ at 288 K and -4.31 J g⁻¹ at 293 K, gradually decreases to approximate zero around the room temperature, and becomes positive with the increase of temperature as 5.02 J g⁻¹ at 303 K, 10.18 J g⁻¹ at 308 K and 16.68 J g⁻¹ at 313 K. The temperature dependence of Δ<em>H</em>_demic demonstrates that the micellization processes of C₁₂₁₄-ACDs are dominated by the hydrophobic force. The Δ<em>H</em>_demic for APG1214 is more negative than C₁₂₁₄-ACDs below room temperature as -17.20 J g⁻¹ at 288 K and -8.90 J g⁻¹ at 293 K, but becomes more positive than C₁₂₁₄-ACDs above room temperature as 20.97 J g⁻¹ at 313 K. The heat capacity changes Δ<em>C</em>_p,demic for APG1214 and C₁₂₁₄-ACDs have been calculated as the values of 1.517±0.027 J g⁻¹ K⁻¹ and 0.958±0.056 J g⁻¹ K⁻¹ respectively. The smaller value of Δ<em>C</em>_p,demic for C₁₂₁₄-ACDs indicates that the relatively hydrophobic surface is reduced after polymerization of APG1214. The effects of NaCl and CaCl₂ on the demicellization processes of C₁₂₁₄-ACDs have also been investigated. The values of CMC increase slightly, but the values of Δ<em>H</em>_demic decrease significantly in the saline solutions. The results indicate that the effects of NaCl and CaCl₂ are mainly attributed to the reduction of water activity and disturbance on the hydration of hydrophobic groups by ions.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"745 ","pages":"Article 179935"},"PeriodicalIF":3.1,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143170459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Al2O3-modified EG/CH3COONa·3H2O form-stable composite phase change materials for medium and low-temperature waste heat recovery","authors":"Zhiqiang Zhu ,&nbsp;Qi Xu ,&nbsp;Dongliang Chen ,&nbsp;Xiang Li ,&nbsp;Shengde Dong ,&nbsp;Yanxia Sun ,&nbsp;Luxiang Ma ,&nbsp;Xin He ,&nbsp;Chunxi Hai ,&nbsp;Yuan Zhou","doi":"10.1016/j.tca.2025.179934","DOIUrl":"10.1016/j.tca.2025.179934","url":null,"abstract":"<div><div>In this study, a novel form-stable composite phase change material (MFCPCM) was synthesized using Al₂O₃ hydrophilic modified expanded graphite (MEG) as the supporting carrier and CH₃COONa·3H₂O (SAT) as the phase change material. By coating Al₂O₃ on the surface of expanded graphite, the water contact angle decreased from 85° to 56°, significantly improving the hydrophilicity of MEG. The adsorption rate of MEG for PCM also increased from 14.6 % to 67.9 % within 40 min. The addition of 12 % MEG effectively prevented the leakage of PCM. The corresponding composite phase change material (MFCPCM-12) exhibited a phase change enthalpy of 239.90 J/g, which remained at 235.33 J/g even after 50 cycles. Compared to pure SAT, the thermal conductivity of MFCPCM-12 was enhanced by 88 %, reaching 3.607 W/(m·K). These findings highlight the superior thermal stability and enhanced thermal conductivity of the MFCPCM based on Al₂O₃-modified EG, indicating that it is a promising candidate for medium and low-temperature thermal energy storage. Future research could focus on optimizing the coating process of Al₂O₃ to further enhance the uniformity and stability of the modification, as well as exploring its compatibility with other PCM to develop more efficient multi-component phase change composites for broader application scenarios.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"745 ","pages":"Article 179934"},"PeriodicalIF":3.1,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143171518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tailored group contribution methods designed using machine learning to predict enthalpies in carboxylic acids and anhydrides","authors":"Jesús A. Arzola-Flores ,&nbsp;José A. Alvarado-García ,&nbsp;Miguel A. García-Castro ,&nbsp;Fausto Díaz-Sánchez ,&nbsp;Ximena Limón-Aguilar ,&nbsp;Ma. Fernanda Saviñon-Flores","doi":"10.1016/j.tca.2024.179923","DOIUrl":"10.1016/j.tca.2024.179923","url":null,"abstract":"<div><div>This research details a methodology to obtain the enthalpy of formation in gas and crystalline phase, as well as the enthalpy of combustion and sublimation for 4methylphthalic acid (4MPAc) and 4-methylphthalic anhydride (4MPAn), using Machine Learning (ML), the prediction of these properties was achieved by Ridge Regression. The predicted values of 4MPAc were compared to the experimental data obtained from differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and combustion calorimetry. The aforementioned properties were used to determine the equilibrium constant of the interconversion reaction between 4MPAc and its corresponding anhydride.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"745 ","pages":"Article 179923"},"PeriodicalIF":3.1,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143170447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of powder characteristics on thermal oxidation of boron","authors":"Mysha Momtaz,&nbsp;Jonathan L. McNanna,&nbsp;Mirko Schoenitz,&nbsp;Edward L. Dreizin","doi":"10.1016/j.tca.2024.179917","DOIUrl":"10.1016/j.tca.2024.179917","url":null,"abstract":"<div><div>Boron has been widely studied as an attractive fuel for air-breathing propulsion due to its high oxidation enthalpy. However, the metrics from many relevant published ignition and combustion experiments with different boron powders cannot be compared with one another because of variations in experimental methods and conditions. Conversely, thermoanalytical measurements performed with different powders used consistent procedures and thus are suitable for direct comparisons. Here, the effects of characteristics of boron powders on their oxidation are elucidated based on the available reports. The oxidation metrics included temperatures for oxidation onset and peaks of differential scanning calorimetry (DSC) and differential thermogravimetry (DTG) traces, mass gain at a certain temperature and an integrated oxidation heat release. The oxidation metrics were correlated with data on particle size, purity, and crystallinity. The experimental heating rates, gas flowrates, and oxygen partial pressures were also considered. All characteristic temperatures recovered from the thermal analysis exhibit a minimum for 0.5 – 1.5 µm particles. The identified oxidation metrics/powder parameter trends are distinct for the amorphous and crystalline boron. Generally, both the particle size and crystallinity affect the oxidation. The effect of the boron purity remains unclear. In the future, it is recommended to specify the type of impurity, which might clarify the influence of the composition of boron-based powders on their oxidation. The observed trends are interpreted semi-quantitatively assuming each boron particle is an aggregate with a reactive shell and an inert core.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"743 ","pages":"Article 179917"},"PeriodicalIF":3.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143154573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}