Pub Date : 2025-11-07DOI: 10.1016/j.tca.2025.180178
Xiaoan Song , Lulu Teng , Ruina Zhang , Lijie Yin , Dezhen Chen , Shanping Chen
In the process of fuel pyrolysis, direct pyrolysis using high-temperature gas is currently the most economical method. For larger fuel particles, shape exerts a significant influence on the rate of temperature increase and the completion time of decomposition. In this study, an experimental apparatus for single-particle pyrolysis was designed, and a back propagation (BP) neural network model was constructed. Based on experimental and prediction results, the influences of the sphericity, characteristic length, and windward area ratio of the particles on the intra-particle temperature during the pyrolysis process were analysed. The rates of temperature increase and weight loss of near-spherical particles were higher than those of nonspherical particles; the weight loss ratios (mass loss per unit time divided by initial mass) of the cylinder and the quadrangular prism were 54.62 % and 44.67 % of those of the sphere. Additionally, the windward area ratio had the greatest impact on the intra-particle temperature and weight loss ratio.
{"title":"The influence of material shape on the intra-particle temperature during biomass pyrolysis under direct heating with high-temperature gas","authors":"Xiaoan Song , Lulu Teng , Ruina Zhang , Lijie Yin , Dezhen Chen , Shanping Chen","doi":"10.1016/j.tca.2025.180178","DOIUrl":"10.1016/j.tca.2025.180178","url":null,"abstract":"<div><div>In the process of fuel pyrolysis, direct pyrolysis using high-temperature gas is currently the most economical method. For larger fuel particles, shape exerts a significant influence on the rate of temperature increase and the completion time of decomposition. In this study, an experimental apparatus for single-particle pyrolysis was designed, and a back propagation (BP) neural network model was constructed. Based on experimental and prediction results, the influences of the sphericity, characteristic length, and windward area ratio of the particles on the intra-particle temperature during the pyrolysis process were analysed. The rates of temperature increase and weight loss of near-spherical particles were higher than those of nonspherical particles; the weight loss ratios (mass loss per unit time divided by initial mass) of the cylinder and the quadrangular prism were 54.62 % and 44.67 % of those of the sphere. Additionally, the windward area ratio had the greatest impact on the intra-particle temperature and weight loss ratio.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"754 ","pages":"Article 180178"},"PeriodicalIF":3.5,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526046","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}
Pub Date : 2025-10-31DOI: 10.1016/j.tca.2025.180174
Shuchang Zhang , Meiqian Chen , Bingyang Li , Yuelong Pan , Linjun Yang
The treatment of spent ion exchange resins (CERs) has become a major concern with the development of nuclear industry. The migration and transformation mechanism of Cs in CERs in both pyrolysis and gasification were evaluated based on chemical equilibrium and experimental analysis. The pyrolysis and gasification temperatures should be limited below 813.15 K and 873.15 K, respectively, but after adding the fixatives, ZrO2 or Nb2O5, the temperatures could be extended to 873.15 K, 1233.15 K (ZrO2) or 1153.15 K (Nb2O5). The kinetic and thermodynamic characteristics of CERs with metal ion catalysts in the gasification were evaluated based on thermogravimetric analysis. In 10 % O2/90 % N2, Fe2+ and Mn2+ metal nuclides would urge the decomposition of functional groups and polymer matrices, since they could promote the reaction in the second stage and the advance of the third stage. This study could provide basic data for the thermal treatment of CERs.
废离子交换树脂的处理已成为核工业发展的一个重要问题。基于化学平衡和实验分析，评价了Cs在cer热解和气化过程中的迁移转化机理。热解和气化温度应分别控制在813.15 K和873.15 K以下，但加入固化剂ZrO2或Nb2O5后，温度可扩展到873.15 K、1233.15 K （ZrO2）或1153.15 K （Nb2O5）。基于热重分析，评价了金属离子催化剂在气化过程中的动力学和热力学特性。在10% o2 / 90% N2条件下，Fe2+和Mn2+金属核素会促进官能团和聚合物基体的分解，促进反应进入第二阶段和第三阶段。本研究可为CERs的热处理提供基础数据。
{"title":"Thermal degradation of spent cation exchange resin with fixatives or metal ion catalysts: Insights from experiments, thermodynamics and kinetics","authors":"Shuchang Zhang , Meiqian Chen , Bingyang Li , Yuelong Pan , Linjun Yang","doi":"10.1016/j.tca.2025.180174","DOIUrl":"10.1016/j.tca.2025.180174","url":null,"abstract":"<div><div>The treatment of spent ion exchange resins (CERs) has become a major concern with the development of nuclear industry. The migration and transformation mechanism of Cs in CERs in both pyrolysis and gasification were evaluated based on chemical equilibrium and experimental analysis. The pyrolysis and gasification temperatures should be limited below 813.15 K and 873.15 K, respectively, but after adding the fixatives, ZrO<sub>2</sub> or Nb<sub>2</sub>O<sub>5</sub>, the temperatures could be extended to 873.15 K, 1233.15 K (ZrO<sub>2</sub>) or 1153.15 K (Nb<sub>2</sub>O<sub>5</sub>). The kinetic and thermodynamic characteristics of CERs with metal ion catalysts in the gasification were evaluated based on thermogravimetric analysis. In 10 % O<sub>2</sub>/90 % N<sub>2</sub>, Fe<sup>2+</sup> and Mn<sup>2+</sup> metal nuclides would urge the decomposition of functional groups and polymer matrices, since they could promote the reaction in the second stage and the advance of the third stage. This study could provide basic data for the thermal treatment of CERs.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"754 ","pages":"Article 180174"},"PeriodicalIF":3.5,"publicationDate":"2025-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474759","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}
Pub Date : 2025-10-31DOI: 10.1016/j.tca.2025.180175
Shangpeng Pan , Hengbin Zhang , Rui Shan , Chengyu Li , Jun Zhang
This study systematically investigates the process of catalytic selective pyrolysis of epoxy resin to high-value aromatics over niobium phosphate-modified ZSM-5 and provides a detailed analysis of the pyrolysis reaction kinetics. The introduction of amorphous niobium phosphate resulted in abundant mesopores and strong acid sites, which enhanced the deoxygenation performance of the zeolite during high-temperature pyrolysis and significantly improved aromatic selectivity. Notably, the niobium phosphate-modified ZSM-5 achieving a maximum aromatic selectivity of 63.5 % at 650 °C significantly outperformed commercial HZSM-5 zeolite, where monocyclic aromatics account for 31.7 % of the total liquid products and polycyclic aromatics account for 31.8 %. Furthermore, the hierarchical pore structure and excellent anti-coking properties of the modified catalyst effectively reduced the activation energy required for epoxy resin pyrolysis, decreasing the apparent activation energy significantly from 325.6 kJ/mol to 240.4 kJ/mol. The findings of this study provide deep insights into metal-modified zeolite-catalyzed pyrolysis of epoxy resin and contribute to the valorization of waste epoxy resin.
{"title":"Hierarchical niobium phosphate-engineered ZSM-5 for selective pyrolysis of epoxy resin toward aromatics: Synergistic effects and kinetic elucidations","authors":"Shangpeng Pan , Hengbin Zhang , Rui Shan , Chengyu Li , Jun Zhang","doi":"10.1016/j.tca.2025.180175","DOIUrl":"10.1016/j.tca.2025.180175","url":null,"abstract":"<div><div>This study systematically investigates the process of catalytic selective pyrolysis of epoxy resin to high-value aromatics over niobium phosphate-modified ZSM-5 and provides a detailed analysis of the pyrolysis reaction kinetics. The introduction of amorphous niobium phosphate resulted in abundant mesopores and strong acid sites, which enhanced the deoxygenation performance of the zeolite during high-temperature pyrolysis and significantly improved aromatic selectivity. Notably, the niobium phosphate-modified ZSM-5 achieving a maximum aromatic selectivity of 63.5 % at 650 °C significantly outperformed commercial HZSM-5 zeolite, where monocyclic aromatics account for 31.7 % of the total liquid products and polycyclic aromatics account for 31.8 %. Furthermore, the hierarchical pore structure and excellent anti-coking properties of the modified catalyst effectively reduced the activation energy required for epoxy resin pyrolysis, decreasing the apparent activation energy significantly from 325.6 kJ/mol to 240.4 kJ/mol. The findings of this study provide deep insights into metal-modified zeolite-catalyzed pyrolysis of epoxy resin and contribute to the valorization of waste epoxy resin.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"754 ","pages":"Article 180175"},"PeriodicalIF":3.5,"publicationDate":"2025-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474764","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}
Pub Date : 2025-10-31DOI: 10.1016/j.tca.2025.180176
Yuzhen Cai , Xinkun Li , Yicheng Deng , Xiong Zhao , Xueyan Han , Fengjiao Wang , Xuefeng Wang
Impurities in alkali-metal vapor cells were investigated by differential scanning calorimetry (DSC). Comparative analysis of vapor cells fabricated with different types of glass and in various sizes suggests that the observed impurity originates from the formation of a rubidium-sodium alloy, which results from a reaction between rubidium and sodium precipitated from the inner surface of borosilicate glass. This conclusion is further supported by the intentional introduction of sodium atoms into the vapor cells. The presence of sodium precipitation is confirmed by the localized heating of the vapor cells. This study provides a method for characterizing the alkali metal impurities in atomic vapor cells and offers guidance for optimizing the rubidium filling process, thereby improving the performance of vapor cells.
{"title":"Research on impurity in alkali-metal vapor cells by use of differential scanning calorimetry","authors":"Yuzhen Cai , Xinkun Li , Yicheng Deng , Xiong Zhao , Xueyan Han , Fengjiao Wang , Xuefeng Wang","doi":"10.1016/j.tca.2025.180176","DOIUrl":"10.1016/j.tca.2025.180176","url":null,"abstract":"<div><div>Impurities in alkali-metal vapor cells were investigated by differential scanning calorimetry (DSC). Comparative analysis of vapor cells fabricated with different types of glass and in various sizes suggests that the observed impurity originates from the formation of a rubidium-sodium alloy, which results from a reaction between rubidium and sodium precipitated from the inner surface of borosilicate glass. This conclusion is further supported by the intentional introduction of sodium atoms into the vapor cells. The presence of sodium precipitation is confirmed by the localized heating of the vapor cells. This study provides a method for characterizing the alkali metal impurities in atomic vapor cells and offers guidance for optimizing the rubidium filling process, thereby improving the performance of vapor cells.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"754 ","pages":"Article 180176"},"PeriodicalIF":3.5,"publicationDate":"2025-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474762","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}
Pub Date : 2025-10-29DOI: 10.1016/j.tca.2025.180173
Zhanlin Gong , Xing Liu , Sumei Liu , Jianqing Zhao
The development of polyurethane phase change materials (PUPCMs) integrating high latent heat and good elasticity is a major challenge for thermal management interface materials. Herein, a diol containing octadecyl side groups (MGAE) was synthesized via the thiol-ene click reaction and used to prepare PUPCMs, with the expectation of resolving the inherent contradiction between high latent heat and good elasticity. The effects of MGAE on the chemical structure, thermal stability, thermal reliability, phase change properties, elasticity, thermal conductivity and thermal contact resistance (TCR) of PUPCMs were investigated. All PUPCMs exhibit the excellent leakage resistance characteristic, particularly under pressure conditions. Compared with PUPCMs without MGAE, PUPCMs containing 2.7 wt% MGAE showed a 11.5 % increase in latent heat, a 10.1 °C decrease in phase change temperature, a 26.8 % decrease in Shore hardness, a 147.0 % increase in elongation at break and a 38 % reduction in TCR. These improvements were attributed to the plasticizing effect and heterogeneous nucleation effect of MGAE with octadecyl side groups. This study provides a viable route for the synthesis of PUPCMs with simultaneously enhanced latent heat and elasticity through the introduction of long alkyl side chains, and the resulting PUPCMs have the potential to be used as thermal management interface materials.
{"title":"Synthesis of reliable polyurethane phase change materials with good thermal storage properties and elasticity by introducing long alkyl side chains","authors":"Zhanlin Gong , Xing Liu , Sumei Liu , Jianqing Zhao","doi":"10.1016/j.tca.2025.180173","DOIUrl":"10.1016/j.tca.2025.180173","url":null,"abstract":"<div><div>The development of polyurethane phase change materials (PUPCMs) integrating high latent heat and good elasticity is a major challenge for thermal management interface materials. Herein, a diol containing octadecyl side groups (MGAE) was synthesized via the thiol-ene click reaction and used to prepare PUPCMs, with the expectation of resolving the inherent contradiction between high latent heat and good elasticity. The effects of MGAE on the chemical structure, thermal stability, thermal reliability, phase change properties, elasticity, thermal conductivity and thermal contact resistance (TCR) of PUPCMs were investigated. All PUPCMs exhibit the excellent leakage resistance characteristic, particularly under pressure conditions. Compared with PUPCMs without MGAE, PUPCMs containing 2.7 wt% MGAE showed a 11.5 % increase in latent heat, a 10.1 °C decrease in phase change temperature, a 26.8 % decrease in Shore hardness, a 147.0 % increase in elongation at break and a 38 % reduction in TCR. These improvements were attributed to the plasticizing effect and heterogeneous nucleation effect of MGAE with octadecyl side groups. This study provides a viable route for the synthesis of PUPCMs with simultaneously enhanced latent heat and elasticity through the introduction of long alkyl side chains, and the resulting PUPCMs have the potential to be used as thermal management interface materials.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"754 ","pages":"Article 180173"},"PeriodicalIF":3.5,"publicationDate":"2025-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474760","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}
Pub Date : 2025-10-26DOI: 10.1016/j.tca.2025.180171
Jianjie Wang , Yifan Li , Wenzhe Zhang , Dahai Zhu , Naici Bing , Huaqing Xie , Wei Yu
The development of passive, energy-efficient thermal regulation materials is crucial for improving the cold chain logistics of perishable foods. By mixing tetradecane (TD), decyl alcohol (DOL), and styrene-ethylene-butylene-styrene (SEBS) triblock copolymer, a eutectic phase change gel was prepared. The optimized TD/DOL eutectic composition (molar ratio = 0.3) exhibits a high melting enthalpy of 205.1 J/g and a crystallization enthalpy of 201.2 J/g, indicating excellent reversible phase change performance. SEBS forms a continuous three-dimensional elastic network, effectively preventing leakage and providing mechanical reinforcement. Under conditions where SEBS content is 30 wt.%, the gel maintains a melting enthalpy value of 94.4 J/g after 100 thermal cycles, with a decrease of only 10.7 %, demonstrating good thermal stability. When the SEBS content is increased to 30 wt.%, the tensile strength reaches 3.0 MPa and the compressive strength reaches 0.727 MPa, which are 15 times and 60 times higher than those at 10 wt.%, respectively, confirming the reinforcing effect of the SEBS network. The 30 wt.% formulation achieves the optimal balance between thermal performance and structural integrity. In actual testing, 500 g of TD/DOL-SEBS-30 maintains a stable cooling range of 6–10 °C for an extended period without external power in an insulated container. Compared to the no-cooling-source group and the semiconductor-cooling group, the phase-change material group better preserved the appearance and freshness of strawberries, with minimal weight loss and no spoilage. The TD/DOL-SEBS gel thus combines high latent heat, thermal reliability, shape stability, and strong mechanical properties, demonstrating significant potential in cold chain food transportation, wearable thermal management, and other low-energy refrigeration applications.
{"title":"A SEBS-stabilized eutectic phase change gel for passive cold chain preservation of perishable produce","authors":"Jianjie Wang , Yifan Li , Wenzhe Zhang , Dahai Zhu , Naici Bing , Huaqing Xie , Wei Yu","doi":"10.1016/j.tca.2025.180171","DOIUrl":"10.1016/j.tca.2025.180171","url":null,"abstract":"<div><div>The development of passive, energy-efficient thermal regulation materials is crucial for improving the cold chain logistics of perishable foods. By mixing tetradecane (TD), decyl alcohol (DOL), and styrene-ethylene-butylene-styrene (SEBS) triblock copolymer, a eutectic phase change gel was prepared. The optimized TD/DOL eutectic composition (molar ratio = 0.3) exhibits a high melting enthalpy of 205.1 J/g and a crystallization enthalpy of 201.2 J/g, indicating excellent reversible phase change performance. SEBS forms a continuous three-dimensional elastic network, effectively preventing leakage and providing mechanical reinforcement. Under conditions where SEBS content is 30 wt.%, the gel maintains a melting enthalpy value of 94.4 J/g after 100 thermal cycles, with a decrease of only 10.7 %, demonstrating good thermal stability. When the SEBS content is increased to 30 wt.%, the tensile strength reaches 3.0 MPa and the compressive strength reaches 0.727 MPa, which are 15 times and 60 times higher than those at 10 wt.%, respectively, confirming the reinforcing effect of the SEBS network. The 30 wt.% formulation achieves the optimal balance between thermal performance and structural integrity. In actual testing, 500 g of TD/DOL-SEBS-30 maintains a stable cooling range of 6–10 °C for an extended period without external power in an insulated container. Compared to the no-cooling-source group and the semiconductor-cooling group, the phase-change material group better preserved the appearance and freshness of strawberries, with minimal weight loss and no spoilage. The TD/DOL-SEBS gel thus combines high latent heat, thermal reliability, shape stability, and strong mechanical properties, demonstrating significant potential in cold chain food transportation, wearable thermal management, and other low-energy refrigeration applications.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"754 ","pages":"Article 180171"},"PeriodicalIF":3.5,"publicationDate":"2025-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474758","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}
Pub Date : 2025-10-26DOI: 10.1016/j.tca.2025.180172
Hui-Sheng Peng
To reveal the relationship between anion structure and thermal decomposition property, an experimental system integrating comprehensive thermal analysis and Fourier-transform infrared spectroscopy is constructed to investigate the thermal decomposition mechanisms of four 1-ethyl-3-methyl imidazolium-based ([EMIM]+) ionic liquids with anion structures of thiocyanate ([SCN]-), dicyanamide ([DCA]-), tetrafluoroborate ([BF4]-), and bis(trifluoromethylsulfonyl)imine ([NTF2]-). Results show that the thermal stability follows the order of [EMIM][NTF2] > [EMIM][BF4] > [EMIM][DCA] > [EMIM][SCN] by decomposition temperature. Spectrum analyses reveal that the anion structures are thoroughly disrupted, forming different gas products, while the cation structure only undergoes substitution and elimination reactions on the imidazole ring. Due to the differences in anion structure, methyl isothiocyanate, trifluoromethanesulfonamide and sulfur dioxide, ammonia, and boron trifluoride are found as key products during the decomposition of [EMIM][SCN], [EMIM][NTF2], [EMIM][DCA], and [EMIM][BF4], respectively. Following designs of anion structure for propellant may start from [SCN]- and [DCA]- to obtain better decomposition property.
{"title":"Experimental investigation on the influence of anion structure on the thermal decomposition properties of EMIM-based ionic liquids","authors":"Hui-Sheng Peng","doi":"10.1016/j.tca.2025.180172","DOIUrl":"10.1016/j.tca.2025.180172","url":null,"abstract":"<div><div>To reveal the relationship between anion structure and thermal decomposition property, an experimental system integrating comprehensive thermal analysis and Fourier-transform infrared spectroscopy is constructed to investigate the thermal decomposition mechanisms of four 1-ethyl-3-methyl imidazolium-based ([EMIM]<sup>+</sup>) ionic liquids with anion structures of thiocyanate ([SCN]<sup>-</sup>), dicyanamide ([DCA]<sup>-</sup>), tetrafluoroborate ([BF<sub>4</sub>]<sup>-</sup>), and bis(trifluoromethylsulfonyl)imine ([NTF<sub>2</sub>]<sup>-</sup>). Results show that the thermal stability follows the order of [EMIM][NTF<sub>2</sub>] > [EMIM][BF<sub>4</sub>] > [EMIM][DCA] > [EMIM][SCN] by decomposition temperature. Spectrum analyses reveal that the anion structures are thoroughly disrupted, forming different gas products, while the cation structure only undergoes substitution and elimination reactions on the imidazole ring. Due to the differences in anion structure, methyl isothiocyanate, trifluoromethanesulfonamide and sulfur dioxide, ammonia, and boron trifluoride are found as key products during the decomposition of [EMIM][SCN], [EMIM][NTF<sub>2</sub>], [EMIM][DCA], and [EMIM][BF<sub>4</sub>], respectively. Following designs of anion structure for propellant may start from [SCN]<sup>-</sup> and [DCA]<sup>-</sup> to obtain better decomposition property.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"754 ","pages":"Article 180172"},"PeriodicalIF":3.5,"publicationDate":"2025-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474757","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}
Pub Date : 2025-10-22DOI: 10.1016/j.tca.2025.180169
Pouya Rouhollahi , Newsha Moghoufe , Ana Rita C. Duarte , Reza Haghbakhsh
Deep eutectic solvents (DESs) are gaining attention as sustainable alternatives to conventional solvents due to their tunable properties and environmental advantages. Yet, predicting their physical behavior, particularly acoustic properties like the speed of sound, remains limited, especially in approaches that consider chemical structure. This study introduces a hybrid machine learning framework that incorporates molecular-level information to predict the speed of sound in DES systems with high accuracy and interpretability. A dataset of 1001 experimental data points, collected from 92 distinct DESs under atmospheric pressure and varying temperatures, was used to train and evaluate the models. Instead of relying solely on bulk experimental parameters, the models integrate structural descriptors based on group and atomic contributions, capturing detailed chemical features of both hydrogen bond donors and acceptors. These structure-based inputs were embedded into machine learning algorithms to develop robust and generalizable predictive tools. The resulting models demonstrated excellent performance, achieving average absolute relative deviations below 1 %. In addition to strong predictive power, the framework allows for interpretation of how specific molecular characteristics influence acoustic behavior, offering a transparent view into the structure–property relationship. This work advances the application of machine learning in solvent science by uniting chemical intuition with data-driven modeling. The hybrid approach not only enhances predictive capability but also provides mechanistic insight, making it a valuable tool for the rational design and selection of DESs in green chemistry, materials processing, and related fields.
{"title":"Learning to hear: Predicting speed of sound in deep eutectic solvents via molecular signatures","authors":"Pouya Rouhollahi , Newsha Moghoufe , Ana Rita C. Duarte , Reza Haghbakhsh","doi":"10.1016/j.tca.2025.180169","DOIUrl":"10.1016/j.tca.2025.180169","url":null,"abstract":"<div><div>Deep eutectic solvents (DESs) are gaining attention as sustainable alternatives to conventional solvents due to their tunable properties and environmental advantages. Yet, predicting their physical behavior, particularly acoustic properties like the speed of sound, remains limited, especially in approaches that consider chemical structure. This study introduces a hybrid machine learning framework that incorporates molecular-level information to predict the speed of sound in DES systems with high accuracy and interpretability. A dataset of 1001 experimental data points, collected from 92 distinct DESs under atmospheric pressure and varying temperatures, was used to train and evaluate the models. Instead of relying solely on bulk experimental parameters, the models integrate structural descriptors based on group and atomic contributions, capturing detailed chemical features of both hydrogen bond donors and acceptors. These structure-based inputs were embedded into machine learning algorithms to develop robust and generalizable predictive tools. The resulting models demonstrated excellent performance, achieving average absolute relative deviations below 1 %. In addition to strong predictive power, the framework allows for interpretation of how specific molecular characteristics influence acoustic behavior, offering a transparent view into the structure–property relationship. This work advances the application of machine learning in solvent science by uniting chemical intuition with data-driven modeling. The hybrid approach not only enhances predictive capability but also provides mechanistic insight, making it a valuable tool for the rational design and selection of DESs in green chemistry, materials processing, and related fields.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"754 ","pages":"Article 180169"},"PeriodicalIF":3.5,"publicationDate":"2025-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145418647","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}
Pub Date : 2025-10-21DOI: 10.1016/j.tca.2025.180170
Seungtaek Lee , Hakduck Kim , Donghyeok Park , Heechang Lim , Juhun Song
Coal dewatering using liquid carbon dioxide (LCO2) or supercritical CO₂ (ScCO2) has been regarded as more effective than conventional thermal drying methods. This is because coal properties such as pore structure, surface area, and surface chemical groups are not significantly altered at relatively low temperatures associated with LCO2 treatment. In this application, understanding the precise mechanism by which LCO₂ interacts with water confined within coal pores is essential. However, direct evidence demonstrating the relationship between the water-dissolution kinetics and coal dewatering has been lacking.
In this study, the extent of water removal from coal was measured under LCO₂ and ScCO₂. A shadowgraph technique was employed to observe the time-dependent behavior of water dissolution in LCO₂ under coal-free condition. The water removal from coal showed an exponential increase with increasing CO₂ saturation pressures, reaching a maximum of approximately 40 %-equivalent to 0.4 g of water removed per 1 g of coal-under ScCO₂. The similar time-dependent trend in water removal was also observed for single water droplet under coal-free condition. This similarity was observed because the water confined within coal pores was exposed to LCO2 and subsequently dissolved into it. This finding indicates that water dissolution into LCO2 predominantly governs the desorption of water molecules from coal.
{"title":"Kinetics of water dissolution in liquid carbon dioxide and its role in coal dewatering","authors":"Seungtaek Lee , Hakduck Kim , Donghyeok Park , Heechang Lim , Juhun Song","doi":"10.1016/j.tca.2025.180170","DOIUrl":"10.1016/j.tca.2025.180170","url":null,"abstract":"<div><div>Coal dewatering using liquid carbon dioxide (LCO<sub>2</sub>) or supercritical CO₂ (ScCO<sub>2</sub>) has been regarded as more effective than conventional thermal drying methods. This is because coal properties such as pore structure, surface area, and surface chemical groups are not significantly altered at relatively low temperatures associated with LCO<sub>2</sub> treatment. In this application, understanding the precise mechanism by which LCO₂ interacts with water confined within coal pores is essential. However, direct evidence demonstrating the relationship between the water-dissolution kinetics and coal dewatering has been lacking.</div><div>In this study, the extent of water removal from coal was measured under LCO₂ and ScCO₂. A shadowgraph technique was employed to observe the time-dependent behavior of water dissolution in LCO₂ under coal-free condition. The water removal from coal showed an exponential increase with increasing CO₂ saturation pressures, reaching a maximum of approximately 40 %-equivalent to 0.4 g of water removed per 1 g of coal-under ScCO₂. The similar time-dependent trend in water removal was also observed for single water droplet under coal-free condition. This similarity was observed because the water confined within coal pores was exposed to LCO<sub>2</sub> and subsequently dissolved into it. This finding indicates that water dissolution into LCO<sub>2</sub> predominantly governs the desorption of water molecules from coal.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"754 ","pages":"Article 180170"},"PeriodicalIF":3.5,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145418648","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}
Pub Date : 2025-10-21DOI: 10.1016/j.tca.2025.180168
Pin Wang , Jie Wang , Neng-weng Chen , Li-heng Lu , Jie Xing , Bo Yuan , Ai-guo Wu , Juan Li
Introducing multiple iodine atoms into a heptamethine cyanine scaffold harnesses the heavy-atom effect to promote non-radiative decay, thereby achieving a remarkably high photothermal conversion efficiency (η = 61.0%) while retaining intense fluorescence in the near-infrared II (NIR-II) window. This structural optimization enables efficient light-to-heat conversion and enhanced photoacoustic contrast, making the system suitable for dual-modality imaging. Upon encapsulation into biocompatible nanomicelles, the resulting probes form stable, tumor-targeting colloids that exhibit concentration-dependent photothermal heating and superior photoacoustic responses compared with conventional cyanine analogues. In vivo studies confirm efficient tumor accumulation, low systemic toxicity, and optimal photothermal ablation. Collectively, these findings highlight heavy-atom-engineered heptamethine cyanines as a quantitatively optimized and mechanistically innovative platform for NIR-II fluorescence/photoacoustic dual imaging and image-guided photothermal cancer therapy.
{"title":"A novel near-infrared fluoro-photoacoustic probe for NIR/PA dual-model imaging and photothermal therapy in breast cancer","authors":"Pin Wang , Jie Wang , Neng-weng Chen , Li-heng Lu , Jie Xing , Bo Yuan , Ai-guo Wu , Juan Li","doi":"10.1016/j.tca.2025.180168","DOIUrl":"10.1016/j.tca.2025.180168","url":null,"abstract":"<div><div>Introducing multiple iodine atoms into a heptamethine cyanine scaffold harnesses the heavy-atom effect to promote non-radiative decay, thereby achieving a remarkably high photothermal conversion efficiency (η = 61.0%) while retaining intense fluorescence in the near-infrared II (NIR-II) window. This structural optimization enables efficient light-to-heat conversion and enhanced photoacoustic contrast, making the system suitable for dual-modality imaging. Upon encapsulation into biocompatible nanomicelles, the resulting probes form stable, tumor-targeting colloids that exhibit concentration-dependent photothermal heating and superior photoacoustic responses compared with conventional cyanine analogues. In vivo studies confirm efficient tumor accumulation, low systemic toxicity, and optimal photothermal ablation. Collectively, these findings highlight heavy-atom-engineered heptamethine cyanines as a quantitatively optimized and mechanistically innovative platform for NIR-II fluorescence/photoacoustic dual imaging and image-guided photothermal cancer therapy.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"754 ","pages":"Article 180168"},"PeriodicalIF":3.5,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474763","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}
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