Chengze Wu, Sai Zhang, Aymen Bourezgui, Ahmad Bilal Ahmadullah, Mohammad Almasi, Mustafa Bayram
{"title":"Thermophysical Properties and Barker–Henderson Perturbation Modeling of 2-(Dimethylamino)ethanol + 1-Alkanol (C5–C10) Mixtures","authors":"Chengze Wu, Sai Zhang, Aymen Bourezgui, Ahmad Bilal Ahmadullah, Mohammad Almasi, Mustafa Bayram","doi":"10.1007/s10765-026-03813-8","DOIUrl":"10.1007/s10765-026-03813-8","url":null,"abstract":"<div><p>Densities and viscosities of binary mixtures comprising 2-(dimethylamino)ethanol (DMAE) and a homologous series of 1-alkanols (1-pentanol to 1-decanol) were investigated to elucidate their molecular interactions and non-ideal thermophysical behavior. The derived properties, including excess molar volumes (<i>V</i><sup><i>E</i></sup>) and viscosity deviations (Δ<i>η</i>), exhibit positive and negative deviations from ideality, respectively. The magnitudes of both <i>V</i><sup><i>E</i></sup> and Δ<i>η</i> increase systematically with the elongation of the alkyl chain, indicating that the disruption of the alcohol’s self-associated hydrogen-bonded networks and steric hindrance dominate over specific cross-interactions. Furthermore, the Barker–Henderson (BH) perturbation theory was successfully applied to model the volumetric behavior of these complex mixtures. The BH framework demonstrated reasonable accuracy in predicting mixture densities, yielding average absolute deviations (AAD) ranging from 0.033 % to 0.088 %, with maximum absolute deviations not exceeding 1.227 kg/m<sup>3</sup>. The optimized binary interaction parameter (<i>k</i><sub>12</sub>) increased progressively from 0.02 to 0.09 as the carbon chain lengthened, mathematically capturing the growing structural asymmetry and non-ideality of the systems. These findings confirm that the BH perturbation theory is a highly robust and reliable tool for correlating the thermodynamic properties of associating fluid mixtures, providing valuable insights for chemical process design and thermodynamic modeling.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"47 9","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148662029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Thermal and Drying Performance of a Double Pass Solar Air Heater Assisted by Graphene and Hexagonal Boron Nitride-Doped Eutectic Phase Change Material","authors":"Nergiz Ulker, Hüsamettin Bulut, Naciye Unver, Gokhan Demircan","doi":"10.1007/s10765-026-03820-9","DOIUrl":"10.1007/s10765-026-03820-9","url":null,"abstract":"<div><p>Solar dryers are challenged to maintain a homogeneous drying air temperature because cloud cover and rapid fluctuations in solar radiation disrupt heat supply, reducing efficiency and process reliability. Integrating phase change materials (PCMs) provides thermal energy storage that reduces these variations and limits temperature drops during low solar radiation periods. In this work, a double pass solar air heater (DPSAH) drying system was developed and tested under real outdoor conditions to achieve more stable and effective drying of agricultural products. An eco-friendly eutectic PCM doped with hexagonal boron nitride (hBN) and graphene (GN) nanoparticles was incorporated into the DPSAH and connected to a drying cabinet to promote uniform drying. Field experiments were performed on Urfa pepper in Şanlıurfa, Türkiye, a hot climate region locally. Experiments were performed at inlet air velocities of 3 m·s<sup>−1</sup>, 6 m·s<sup>−1</sup>, and 9 m·s<sup>−1</sup> using a two-step charging-discharging process. At each air velocity, four DPSAH dryers were compared against open sun drying. The results showed that GN-doped PCM significantly improved the drying performance. At an inlet air velocity of 6 m·s<sup>−1</sup>, the PCM-GN integrated DPSAH (DG) configuration delivered the highest performance, achieving a useful heat gain of 462.6 W and an average thermal efficiency of 83.4 %. In addition, the lowest moisture and water activity, as well as the best color preservation and highest antioxidant values, were obtained for the DG configuration at an inlet air velocity of 6 m·s<sup>−1</sup>. Results confirmed that improved heat transfer in nanoparticle-doped PCM directly improved overall system performance significantly.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"47 9","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148661976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vladimir Diky, Tausif Altamash, Marc J. Assael, Ala Bazyleva, Ralf Dohrn, Peter Dvorak, José M. S. Fonseca, Johan Jacquemin, Georgios M. Kontogeorgis, Jörg Krafczyk, Herbert Loria, Demian Riccardi, Bastian Schmid, Vojtěch Štejfa, Jadran Vrabec, Thorsten Windmann
{"title":"Challenges and Research Opportunities in Chemical Thermodynamics, Thermophysics, and Materials Property Science","authors":"Vladimir Diky, Tausif Altamash, Marc J. Assael, Ala Bazyleva, Ralf Dohrn, Peter Dvorak, José M. S. Fonseca, Johan Jacquemin, Georgios M. Kontogeorgis, Jörg Krafczyk, Herbert Loria, Demian Riccardi, Bastian Schmid, Vojtěch Štejfa, Jadran Vrabec, Thorsten Windmann","doi":"10.1007/s10765-026-03814-7","DOIUrl":"10.1007/s10765-026-03814-7","url":null,"abstract":"<div><p>There is robust industrial demand for thermodynamic and thermophysical property data for chemical substances and materials. Unresolved inconsistencies and unexplained anomalies in the data are frequently revealed by data users. Inconsistency appears when either multiple measurements significantly deviate from each other beyond reasonable uncertainties or different reported properties do not obey thermodynamic relations between them. Anomaly here means a reported value or behavior significantly deviating from expectation based on theory or correlation. To address such issues, we have launched the new Thermodynamics Research Center (TRC) Research Challenge Search website. The goals of this service are to encourage researchers to address these problems, identify the need for additional theoretical and experimental development, support the justification of related research proposals, and ultimately provide users with reliable data. This publication provides an overview of the service, presents the current collection of cases, and describes the procedures for user feedback and contribution.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"47 8","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10765-026-03814-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148614739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Enhanced Thermophysical Properties of a Quaternary Molten Salt NaNO3–KNO3–NaNO2–Ca(NO3)2 Doped with Al2O3 Nanoparticles","authors":"Yan Li, Lantu Tian, Shuo Wang, Qunzhi Zhu","doi":"10.1007/s10765-026-03819-2","DOIUrl":"10.1007/s10765-026-03819-2","url":null,"abstract":"<div><p>As the key heat storage and transfer medium in concentrated solar power (CSP) systems, molten salts’ thermophysical properties, such as thermal conductivity, specific heat capacity, and thermal stability, critically determine the systems energy conversion efficiency and economic viability. However, conventional molten salts suffer from low thermal conductivity and limited energy storage density, restricting their application in high-temperature thermal energy storage. Recent advances show that doping with nanoparticles, such as Al<sub>2</sub>O<sub>3</sub>, CuO, and SiO<sub>2</sub>, can significantly improve these properties. Nevertheless, systematic studies on quaternary molten salt systems remain scarce. In this work, we focus on the quaternary eutectic salt H15 (15 wt% Ca(NO<sub>3</sub>)<sub>2</sub>–5.95 wt% NaNO<sub>3</sub>–45.05 wt% KNO<sub>3</sub>–34 wt% NaNO<sub>2</sub>), which demonstrates a high decomposition temperature of 597.4 °C alongside a relatively low melting point of 84.4 °C and high thermal energy storage density of 1052.41 kJ/kg. To overcome its thermal performance limitations, Al<sub>2</sub>O<sub>3</sub> nanoparticles (0.1 wt% to 3 wt%) were introduced to form a nanocomposite molten salt. The influence of varying nanoparticle loadings was assessed <i>via</i> DSC, HotDisk, SEM, and XRD to examine corresponding changes in phase transition behavior, thermal conductivity, viscosity, and material microstructure. This study provides theoretical and experimental support for developing high-performance, wide temperature-range thermal energy storage materials for advanced CSP systems.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"47 8","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148614738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Derui Li, Qiang Zheng, Fuxin Yang, Houzhang Tan, Xiaopo Wang
{"title":"Diethylamine Hydrochloride-Based Deep Eutectic Solvents for CO2 Capture: Experimental Characterization and soft-SAFT Thermodynamic Modeling","authors":"Derui Li, Qiang Zheng, Fuxin Yang, Houzhang Tan, Xiaopo Wang","doi":"10.1007/s10765-026-03800-z","DOIUrl":"10.1007/s10765-026-03800-z","url":null,"abstract":"<div><p>Deep eutectic solvents (DESs) are promising green CO<sub>2</sub> absorbents due to their low vapor pressure, high designability, and environmental friendliness. In this work, diethylamine hydrochloride (DH) was used as the hydrogen bond acceptor (HBA), and ethylene glycol (EG) and diethylene glycol (DEG) as the hydrogen bond donors (HBDs). Six homogeneous, room-temperature-stable DESs were synthesized at HBA: HBD molar ratios from 1:4 to 1:6. Their densities and viscosities were measured at 303.15–333.15 K, and CO<sub>2</sub> solubilities were determined at pressures of 0.206–2.310 MPa. A soft‑SAFT thermodynamic model was established to correlate the densities, and a temperature–dependent binary interaction parameter was introduced to correlate CO<sub>2</sub> solubilities. The improved free volume theory (FVT) was coupled to achieve accurate viscosity calculation. The average absolute relative deviations for density, CO<sub>2</sub> phase equilibrium, and viscosity were 0.028%, 2.15%, and 0.77%, respectively, demonstrating excellent predictive accuracy and extrapolation capability. All DESs exhibited mass losses below 1% below 100 °C, and the capacity decay of the optimal absorbents after three cycles was less than 7%, indicating both excellent thermal stability and cyclic stability.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"47 8","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148613828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Noor Alam, Sheikh Ahmad Zaki, Chong Jia Yi, Ng Wai Tuck, Manoj Kumar Singh, Hom Bahadur Rijal, Nor’azizi Othman
{"title":"Thermal Performance Simulation of Attic Roof Retrofitting Strategies in Hot and Humid Malaysian Climate","authors":"Noor Alam, Sheikh Ahmad Zaki, Chong Jia Yi, Ng Wai Tuck, Manoj Kumar Singh, Hom Bahadur Rijal, Nor’azizi Othman","doi":"10.1007/s10765-026-03815-6","DOIUrl":"10.1007/s10765-026-03815-6","url":null,"abstract":"<div><p>The present research comprehensively explored the thermal performance of various roof retrofitting strategies, including insulation, solar reflectance, and their combination, to avoid high temperatures in the attic and thus improve indoor thermal conditions in the master bedroom in a typical terrace house in Malaysia’s hot and humid climate. In this study, 17 strategies were simulated in DesignBuilder to evaluate their effects on indoor temperature and heat flux in the master bedroom and the attic. The innovation lies in modeling a bio-based phase change material (Bio-PCM) panel as a roof component, both as a standalone strategy and in combination with other strategies. The heat-reflective paint strategy excelled at managing indoor temperatures by reflecting solar radiation, lowering temperatures by 1.3 °C and 2.0 °C in the master bedroom and the attic, respectively. However, the combined strategy of single-sided aluminum woven foil, heat-reflective paint, and Bio-PCM panel is the most effective in minimizing conductive and radiant heat transfer. The reduction in heat flux in the master bedroom by 67 % and in the attic by 49 % compared to the baseline heat flux of 3.67 W/m<sup>2</sup> in the master bedroom and − 5.09 W/m<sup>2</sup> in the attic, leading to an improvement in the overall thermal environment.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"47 8","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148613681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hubert P. Blabus, Pranay K. Chittem, Dena Mombeini, Thomas M. Koller, Michael H. Rausch, Junxiang Lei, Kakeru Ninomiya, Maiko Nishibori, Suhendro Purbo Prakoso, Tadafumi Adschiri, Akira Yoko, Patrick S. Schmidt, Andreas P. Fröba
{"title":"Effective Thermal Conductivity of Various Surface-Modified Cerium Dioxide Nanoparticles Dispersed in Cyclohexane","authors":"Hubert P. Blabus, Pranay K. Chittem, Dena Mombeini, Thomas M. Koller, Michael H. Rausch, Junxiang Lei, Kakeru Ninomiya, Maiko Nishibori, Suhendro Purbo Prakoso, Tadafumi Adschiri, Akira Yoko, Patrick S. Schmidt, Andreas P. Fröba","doi":"10.1007/s10765-026-03804-9","DOIUrl":"10.1007/s10765-026-03804-9","url":null,"abstract":"<div><p>Nanofluids with ultrasmall nanoparticles below 10 nm stabilized in organic liquids lack a deeper characterization with respect to the effective thermal conductivity λ<sub>eff</sub>. This study investigates nanofluids consisting of cerium dioxide (CeO<sub>2</sub>) nanoparticles and cyclohexane. To elaborate the influence of particle size, surface modification, and particle volume fraction <i>φ</i><sub>p</sub>, nearly spherical nanoparticles with very small core sizes <i>d</i><sub>core</sub> from (3 to 6) nm covered by modifiers of varying chain length were examined at <i>φ</i><sub>p</sub> of up to 0.045. <i>λ</i><sub>eff</sub> was measured using a guarded parallel-plate instrument at temperatures from (283.15 to 313.15) K and at atmospheric pressure with an expanded uncertainty of 2.5%. All samples were characterized using transmission electron microscopy, thermogravimetric differential thermal analysis, small-angle X-ray scattering, and dynamic light scattering to determine <i>d</i><sub>core</sub>, the mass and size of the modifier shell, the effective particle size and <i>d</i><sub>core</sub>, and the hydrodynamic diameter, respectively. The thorough analysis allowed for a better understanding of the influence of the particle characteristics on <i>λ</i><sub>eff</sub>. The enhancement of <i>λ</i><sub>eff</sub> shows no temperature dependence and an increase as a function of <i>φ</i><sub>p</sub>. With increasing <i>d</i><sub>core</sub> and chain length of the modifier, <i>λ</i><sub>eff</sub> exhibits the tendency to decrease and increase, respectively. The comparison of the experimental <i>λ</i><sub>eff</sub> data with empirical prediction models shows agreement, especially with the geometric mean model that accounts for an interfacial resistance between the core particle and cyclohexane. This work demonstrates a novel multi-method approach for investigating <i>λ</i><sub>eff</sub> together with particle morphology in nanofluids with ultrasmall surface-modified nanoparticles relevant for colloid science and technology.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"47 8","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10765-026-03804-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148613623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fang Xie, Chuanqing Zhu, Xiaoxue Jiang, Yuanjin Sun, Fuhao Zheng, Simeng Yin, Wenxuan Tao, Hem B. Motra
{"title":"Estimating Effective Thermal Conductivity of Unconsolidated Materials by Quartz-Cell-Assisted Thermal Conductivity Scanner Measurements","authors":"Fang Xie, Chuanqing Zhu, Xiaoxue Jiang, Yuanjin Sun, Fuhao Zheng, Simeng Yin, Wenxuan Tao, Hem B. Motra","doi":"10.1007/s10765-026-03811-w","DOIUrl":"10.1007/s10765-026-03811-w","url":null,"abstract":"<div><p>Reliable thermal conductivity data for unconsolidated geological materials are essential for accurate geothermal resource assessment and subsurface thermal modeling, particularly when utilizing drilling cuttings for thermophysical characterization. However, conventional needle-probe methods are often impractical for high-throughput analysis due to lengthy measurement cycles and the uncertainty arising from random probe-sample contact variability. To address this limitation, we developed a novel quartz-cell-assisted protocol for the Thermal Conductivity Scanner (TCS), enabling rapid estimation of thermal conductivity in unconsolidated samples. Six calibration models were rigorously evaluated using paired measurements from 30 block reference materials; model selection was optimized via leave-one-out cross-validation (LOOCV) and subsequently validated using independent powder samples. The power-law function was identified as the most robust empirical conversion equation for this specific TCS configuration. Application of this function to 20 powder samples yielded calibrated values consistent with independent transient needle-probe measurements, demonstrating negligible bias (0.000569 W·m<sup>−1</sup>·K<sup>−1</sup>), low mean absolute error (MAE = 0.0326 W·m<sup>−1</sup>·K<sup>−1</sup>), and minimal root mean square error (RMSE = 0.0394 W·m<sup>−1</sup>·K<sup>−1</sup>), with a mean absolute percentage error (MAPE) of 8.74 %. This study establishes a calibrated, non-contact TCS-based workflow that significantly enhances the efficiency and reliability of effective thermal conductivity estimation for unconsolidated geological materials.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"47 8","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Physics-Constrained Symbolic Regression of Collision Integrals for Dilute-Gas Viscosity","authors":"Zhuo Li, Yuanyuan Duan, Xiaoxian Yang","doi":"10.1007/s10765-026-03809-4","DOIUrl":"10.1007/s10765-026-03809-4","url":null,"abstract":"<div><p>Dilute-gas viscosity is a fundamental transport property governed by binary molecular collisions and is widely used as a reference term in dense-fluid viscosity models. In this work, a physics-constrained symbolic regression framework is developed for predicting dilute-gas viscosity through the conventional Chapman–Enskog framework and a new reduced Boyle-scaled collision integral. Instead of correlating viscosity directly, the viscosity data are transformed into a dimensionless collision integral using the Boyle temperature and Boyle length derived from the second virial coefficient. A comprehensive database containing 87 fluids and 11,263 dilute-gas viscosity data points was constructed by combining high-accuracy <i>ab initio</i> data with carefully screened and zero-density-extrapolated experimental data. The collision-integral model was formulated as a decomposed correlation consisting of a spherical reference term, a nonpolar correction term, and a polar correction term, with additional empirical extensions for quantum and associating fluids. Symbolic regression was used to identify the analytical expression of each term considering accuracy, numerical stability, and physical consistency. The resulting model gives an overall AARD of 2.00 % for the complete database and maintains good accuracy across different fluid classes. Analysis of the final expressions shows that the dominant temperature dependence is captured by the spherical reference term, while molecular nonsphericity mainly acts through a coupled acentric factor-temperature effect. The polar correction provides a coarse but systematic empirical adjustment for polar fluids. To facilitate reproducible use, a Python implementation of the final correlation is provided in the Supporting Information.</p></div>","PeriodicalId":598,"journal":{"name":"International Journal of Thermophysics","volume":"47 8","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10765-026-03809-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148466209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}