Jintao Guo , Ying Xu , Gang Liu , Xin Nie , Tao Sun , Xiaoyan Liu
{"title":"A molecular dynamics-based study on the microstructural phase transition mechanisms of novel paraffin composite phase change materials","authors":"Jintao Guo , Ying Xu , Gang Liu , Xin Nie , Tao Sun , Xiaoyan Liu","doi":"10.1016/j.tca.2025.180018","DOIUrl":"10.1016/j.tca.2025.180018","url":null,"abstract":"<div><div>The thermodynamic mechanisms and properties of paraffin-based composite phase change materials at microscopic scale directly influence their potential applications in energy storage and conversion. This study employs molecular dynamics simulations to construct two models of composite phase change materials. Both experimental and simulation results demonstrate that, compared to two pure alkanes (n-octadecane and n-eicosane), thermal conductivity increases from 0.14 W/(m·K) to 0.31 W/(m·K) for the MOT (n-octadecane mixed with glycerol trimyristate) system and from 0.13 W/(m·K) to 0.27 W/(m·K) for the MET(n-eicosane mixed with glycerol trimyristate) system, indicating a twofold increase. Further investigation into thermodynamic properties, such as van der Waals energy, phase change temperature, and specific heat capacity, reveals microscopic interactions governing the phase transitions in the two binary composite systems. These findings enhance understanding of the molecular structural mechanisms during the phase change process in composite phase change material systems.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"749 ","pages":"Article 180018"},"PeriodicalIF":3.1,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143916740","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}
Wenke Zhang , Longjin Du , Yu Zhao , Haiyang Wang , Fan Zhang , Jianzhong Liu
{"title":"Ignition and combustion performance of TKX-50 solid propellant under extreme conditions","authors":"Wenke Zhang , Longjin Du , Yu Zhao , Haiyang Wang , Fan Zhang , Jianzhong Liu","doi":"10.1016/j.tca.2025.180020","DOIUrl":"10.1016/j.tca.2025.180020","url":null,"abstract":"<div><div>To expand the applications of dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50), a novel TKX-50 solid propellant (TP) was prepared using a TKX-50/AP/GAP composite system. The ignition and combustion performance under extreme conditions was investigated using thermogravimetric analysis and differential scanning calorimetry and a custom-designed low-temperature negative-pressure laser ignition system. The results indicated that TP samples exhibited earlier thermal decomposition onset temperatures than their individual components, with their ignition and combustion properties highly sensitive to ambient pressure and temperature. The TKX-50/AP/GAP system exhibited complex interactions that enhanced ignition performance. The incorporation of Ni and Fe catalysts further improved performance. Fe outperformed Ni under most conditions; however, Ni was more effective at low temperatures. As a result, the Ni-containing TP sample demonstrated superior ignition stability under extreme low-temperature conditions, whereas the Fe-containing TP sample proved to be more suitable for extreme low-pressure conditions.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"749 ","pages":"Article 180020"},"PeriodicalIF":3.1,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143928042","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}
Zhong-xuan Han , Hao Liu , Zhan-jun Yang , Yi-fan Guo , Shu-na Zhao , Mi Li , Lin Jiang , Andrei Rotaru
{"title":"A comparative structural and combustion study of Al-MO/PVDF (MO=ZnO & ZnFe2O4) thermites synthesised by electrospraying and mechanical mixing","authors":"Zhong-xuan Han , Hao Liu , Zhan-jun Yang , Yi-fan Guo , Shu-na Zhao , Mi Li , Lin Jiang , Andrei Rotaru","doi":"10.1016/j.tca.2025.180019","DOIUrl":"10.1016/j.tca.2025.180019","url":null,"abstract":"<div><div>Aluminised thermites show strong potential for energy-intensive applications, but ensuring stable nanoscale dispersion and optimising combustion performance is challenging. This study prepared Al–MO/PVDF thermites (MO = ZnO, ZnFe₂O₄) by electrospraying and mechanical mixing to compare how particle morphology and compositional uniformity affect reactivity. Electrosprayed samples formed near-spherical, submicron particles with homogeneous distributions of reactants, whereas mechanically mixed samples aggregated into larger, irregular clusters. Differential scanning calorimetry revealed sharper, staged exothermic peaks in the electrosprayed thermites, indicating enhanced reactant contact, while the mechanically mixed thermites produced broad, overlapping exotherms. X-ray diffraction showed partial amorphisation and core-shell formation under rapid solvent evaporation. Laser ignition tests demonstrated faster ignition, higher flame temperatures, and more intense combustion in electrosprayed formulations, particularly Al–ZnFe₂O₄/PVDF, which exhibited a secondary heat release (micro-explosion). Electrospray-assisted fabrication improved homogeneity and promoted rapid, high-temperature reactions for enhanced combustion performance.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"749 ","pages":"Article 180019"},"PeriodicalIF":3.1,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143903736","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}
Xueqin Liao , Binghong Chen , Qiaoyu Zhang , Zehao Li , Jianzhong Liu
{"title":"Heat release behavior of aluminum particles under pure nitrogen atmosphere","authors":"Xueqin Liao , Binghong Chen , Qiaoyu Zhang , Zehao Li , Jianzhong Liu","doi":"10.1016/j.tca.2025.180014","DOIUrl":"10.1016/j.tca.2025.180014","url":null,"abstract":"<div><div>Herein, a thermal analysis system and a laser combustion diagnostic system were employed to comparatively investigate the reaction behavior differences of Al particles in N<sub>2</sub> and oxidizing atmospheres. The results show that Al particles have higher mass gain and heat release in N<sub>2</sub> compared to air and carbon dioxide at low heating rates. When the temperature is increased to 1000 °C, the reaction efficiency of Al in nitrogen is as high as 56.68%, much higher than that of 16.02% for air and 17.41% for carbon dioxide. Broken particles and large-sized agglomerates are found in the intermediate nitride products, and the particle surfaces become loose and porous. Combustion test results show that the combustion performance of Al particles in air is better than that in N<sub>2</sub>. Nanoscale smooth spherical alumina particles are found in the condensed combustion products of Al particles under air. Whisker-like aluminum nitride (AlN) is observed under nitrogen.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"749 ","pages":"Article 180014"},"PeriodicalIF":3.1,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887038","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":"Global atomic and group contribution models for prediction of the thermal conductivities of deep eutectic solvents","authors":"Fatemeh Soltani , Reza Haghbakhsh , Sona Raeissi","doi":"10.1016/j.tca.2025.180017","DOIUrl":"10.1016/j.tca.2025.180017","url":null,"abstract":"<div><div>Deep Eutectic Solvents (DESs) are often categorized as novel green solvents. Knowledge of the thermal conductivity of a solvent in an industrial process is vital for the optimization of energy utilization. Considering the vast number of DESs introduced to date, it is practically impossible to measure all their thermal conductivities. Thus, it is vital to have predictive models that can predict the thermal conductivities of various DESs, and at different temperatures. For this purpose, a large data bank was collected, including 338 data points from 56 DESs of various natures. The data were used to develop a group contribution (GC) model and an atomic contribution (AC) model to predict the thermal conductivities of DESs. The calculated <em>AARD%</em> values of 7.62 % and 9.52 % for the proposed GC and AC models, respectively, indicated reliable performance and promising predictions for both models. The models were also compared to well-known literature models.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"749 ","pages":"Article 180017"},"PeriodicalIF":3.1,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143898883","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}
Sheng-song Li , Shuai Hou , Yong Liu , Ying Wu , Shuai Zou , De-wen Jiao , Tian Xue
{"title":"Study on pyrolysis behaviors and mechanism of N-(4-hydroxy-3-methoxybenzyl)nonanamide","authors":"Sheng-song Li , Shuai Hou , Yong Liu , Ying Wu , Shuai Zou , De-wen Jiao , Tian Xue","doi":"10.1016/j.tca.2025.180016","DOIUrl":"10.1016/j.tca.2025.180016","url":null,"abstract":"<div><div><em>N</em>-(4‑hydroxy-3-methoxybenzyl)nonanamide (PAVA) exhibits a broad spectrum of applications as a capsaicinoid in fields such as medicine, marine engineering, and riot control. Investigating its thermal stability and thermal decomposition properties is crucial for assessing the service life of PAVA-containing products, optimizing their efficiency, and evaluating the toxicity of the decomposition products. In this study, thermogravimetry/differential scanning calorimetry-Fourier transform infrared spectroscopy (TGA/DSC-FTIR) and pyrolysis-gas chromatography/mass spectrometry (PY-GC/MS) techniques were employed to investigate the pyrolysis behaviors of PAVA. A melting endotherm was observed at approximately 335.15 K (62 °C) and the extrapolated onset decomposition temperature was determined to be 534.15 K (261 °C) related to the heating rate in thermal analysis experiments. The most probable mechanism function for the thermal decomposition of PAVA was identified as G(<em>α</em>)=[(1+<em>α</em>)<sup>1/3</sup>–1]<sup>2</sup>. Furthermore, thermal pyrolysis results indicated that only pyrolysis reactions were found below 923.15 K (650 °C) under an aerobic environment, initiating between 523.15 K (250 °C) and 623.15 K (350 °C).</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"749 ","pages":"Article 180016"},"PeriodicalIF":3.1,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902466","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}
Baichao Zang , Baoshu Chen , Xiping Gao , Dahu Yao , Jing Chen , Chang Lu
{"title":"Synergistic flame retardant mechanism of MoO₃ and intumescent flame retardants: Insights from real-time char layer resistance monitoring","authors":"Baichao Zang , Baoshu Chen , Xiping Gao , Dahu Yao , Jing Chen , Chang Lu","doi":"10.1016/j.tca.2025.180013","DOIUrl":"10.1016/j.tca.2025.180013","url":null,"abstract":"<div><div>This study explores the synergistic flame retardant mechanism of molybdenum trioxide (MoO₃) and intumescent flame retardants (IFRs) in a styrene-butadiene-styrene (SBS) matrix using real-time resistance monitoring. By tracking the char layer resistance during combustion and combining multiple characterization techniques, we examined MoO₃’s impact on the char layer morphology. The results demonstrate that the incorporation of MoO₃ enhances the flame-retardant performance of IFR. At 1 wt % MoO₃, the UL-94 rating improves from non-classified to V-1. Thermogravime tric Analysis reveals that MoO₃ lowers the initial decomposition temperature of the material from 240 °C to 231 °C while increasing the char residue. X-ray Photoelectron Spectroscopy and Fourier transform infrared analyses confirm that MoO₃ acts as a catalyst, promoting ammonium polyphosphate decomposition and facilitating the formation of phosphate esters, which enhance the char layer's viscosity and compactness. While MoO₃ does not directly participate in char crosslinking, it accelerates char formation, improves expansion, and strengthens flame retardancy. Real-time resistance data further indicate that MoO₃ reduces char formation time and slows char layer cracking, thereby enhancing flame resistance. This study provides new insights into the MoO₃/IFR synergy and introduces a novel approach for monitoring char layer changes during combustion.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"749 ","pages":"Article 180013"},"PeriodicalIF":3.1,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887037","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}
Pedro Jesús Rodríguez de Rivera , Miriam Rodríguez de Rivera , Fabiola Socorro , Manuel Rodríguez de Rivera
{"title":"Modelling of heat conduction calorimeters. Case of a non-differential skin calorimeter","authors":"Pedro Jesús Rodríguez de Rivera , Miriam Rodríguez de Rivera , Fabiola Socorro , Manuel Rodríguez de Rivera","doi":"10.1016/j.tca.2025.180015","DOIUrl":"10.1016/j.tca.2025.180015","url":null,"abstract":"<div><div>In non-differential calorimeters, the ambient temperature, the thermostat temperature, and the thermostat cooling system affect the measured heat flux. For this reason, the modelling and calibration procedures should take into account all the variables that affect the heat flux transmitted through the calorimeter. In this work, we present the complete calibration of three non-differential skin calorimeters designed to measure the heat flux, the heat capacity and the thermal resistance of a localized skin surface. In addition, the incorporation of the skin into the calorimetric model allows the determination of the core temperature of the tissue where the measurement is performed. The electrical calibration is validated with measurements with the three calorimeters on the volar and dorsal areas of the wrist of a healthy 30-year-old male subject.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"749 ","pages":"Article 180015"},"PeriodicalIF":3.1,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143879156","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}
Mohammad Saleh Sedighi , Hassan Pahlavanzadeh , Mehdi Ardjmand , Mahdi Goharrokhi
{"title":"Solubility of CO2 in aqueous solution of MDEA promoted by K2CO3 Experimental investigation and thermodynamic modeling","authors":"Mohammad Saleh Sedighi , Hassan Pahlavanzadeh , Mehdi Ardjmand , Mahdi Goharrokhi","doi":"10.1016/j.tca.2025.179988","DOIUrl":"10.1016/j.tca.2025.179988","url":null,"abstract":"<div><div>The main objective of this study is to experimentally investigate the CO<sub>2</sub> solubility in an aqueous solution of N-methyldiethanolamine (MDEA) promoted by Potassium carbonate (K<sub>2</sub>CO<sub>3</sub>) at 303, 313, 323 Kelvin and atmospheric pressure, and to model the behavior of this system. Therefore, it comprises two main sections: experimental and modeling. The experimental section examines and compares the solubility of CO<sub>2</sub> into pure MDEA, pure K<sub>2</sub>CO<sub>3</sub>, and their mixtures. The results showed that mixed solutions (MDEA 10–30 % promoted by K<sub>2</sub>CO<sub>3</sub> 5–10 %) have higher CO<sub>2</sub> solubility compared to pure MDEA and K<sub>2</sub>CO<sub>3</sub> at most points. The experiments were carried out using an apparatus for determining gas solubility in liquid (introduced by Pahlavanzadeh et al., 2006, 2009). Based on the data obtained in the experimental section, modeling of the CO<sub>2</sub> solubility into MDEA promoted by K<sub>2</sub>CO<sub>3</sub> was performed. The CTS model (introduced by Medeiros et al., 2008, 2013) was used in this study after improvement in the electrolytic section. This model, called CTS<sup>DH</sup>, includes three parts: physical, association, and electrolyte. Using the adjustable parameters obtained in this work, the CTS<sup>DH</sup> EoS was able to provide relatively good CO<sub>2</sub> loading in a wide range of operating conditions. The average absolute deviation of model results compared to experimental data was determined to be 3.4 %.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"749 ","pages":"Article 179988"},"PeriodicalIF":3.1,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838215","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}
Xingang Meng , Zhiqiang Wang , Jianping Song , Yuting Tao , Haobin Zhang , Shiliang Huang , Jie Sun , Xiong Cao , Jinjiang Xu
{"title":"Size-dependent phase transition dynamics in HMX crystals: Mechanistic insights from defect-mediated transformation","authors":"Xingang Meng , Zhiqiang Wang , Jianping Song , Yuting Tao , Haobin Zhang , Shiliang Huang , Jie Sun , Xiong Cao , Jinjiang Xu","doi":"10.1016/j.tca.2025.180012","DOIUrl":"10.1016/j.tca.2025.180012","url":null,"abstract":"<div><div>The size effects of energetic materials (EMs) particles has a profound influence on their solid-state phase transition (PT) and structural damage. In this study, the PT behavior of large-sized 1,3,5,7-tetranitro-1,3,5,7-tetrazole (HMX) was studied by a series of characterization methods. It has been demonstrated that both internal defects and surface damage of large-size HMX occur approximately 20 °C earlier than that of small-size HMX. The kinetic analysis demonstrates that the PT of large-size HMX is comprised of two distinct steps. The initial step is characterised by fragmentation, while the subsequent step represents the PT in its strict sense. This makes the PT process appear more clearer in comparison to the powder form of HMX. Additionally, it was determined that varying humidity levels exert an influence on the HMX phase recover. This provides fundamental support for a correct understanding of HMX solid-state PT.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"749 ","pages":"Article 180012"},"PeriodicalIF":3.1,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143856022","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}