Journal of Supercritical Fluids最新文献

{"title":"Structural compatibility-driven performance enhancement: PA6 in-situ microfibrillated Pebax composites with improved rheological, crystallization, and foaming properties","authors":"Lei Zhang,&nbsp;Ruyun Xu,&nbsp;Mingwei Guo,&nbsp;Genshi Liu,&nbsp;Zheng Shen,&nbsp;Guangxian Li,&nbsp;Xia Liao","doi":"10.1016/j.supflu.2025.106829","DOIUrl":"10.1016/j.supflu.2025.106829","url":null,"abstract":"<div><div>Polyamide 6 (PA6) is one of the most widely used synthetic fibers in the world, and its molecular structure is similar to that of the hard segments of polyether block amide (Pebax). Therefore, it is an ideal material for in-situ fiber formation to reinforce Pebax and its foams. In this work, Pebax/PA composites with excellent tensile properties were prepared through the combination of in-situ fibrillation and chain extension. The nano three-dimensional network structure constructed by PA6 improved the crystallization performance and rheological properties of Pebax. Its high specific surface area promoted heterogeneous nucleation of cells and reduced the average cell size. The cell nucleation density of the in-situ fibrillated Pebax composite foam (14.5 ×10⁸ nuclei/cm³) was 2.2 times that of the non-fibrillated one (6.7 ×10⁸ nuclei/cm³). Furthermore, the introduction of PA6 in-situ fibers enhanced the tensile properties and cyclic compression properties of the Pebax/PA foam. The tensile strength was increased by approximately 2.5 times at its maximum, and the compressive strength reached up to 1.41 MPa when the expansion ratio was approximately 6 times.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106829"},"PeriodicalIF":4.4,"publicationDate":"2025-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145434979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical investigations on transport properties for SCO2 flow in Gyroid structures with the pore-scale method","authors":"Wenpeng Hong,&nbsp;Jingwen Fan,&nbsp;Guilei Yue,&nbsp;Haoran Li,&nbsp;Xiaojuan Niu","doi":"10.1016/j.supflu.2025.106828","DOIUrl":"10.1016/j.supflu.2025.106828","url":null,"abstract":"<div><div>Supercritical CO₂ (SCO₂) has emerged as a promising coolant for transpiration cooling in combustion chamber liners. The cooling performance is strongly influenced by the transport properties of SCO₂ within porous media. However, the absence of accurate porosity-dependent correlations for customized porous structures has hindered the application of volume-averaged models, which are more appropriate for transpiration design. In this study, Gyroid porous structures with porosities ranging from 30 % to 42 % were reconstructed at the pore scale. Numerical simulations of heat and mass transfer were conducted to investigate the local transport behaviors of SCO₂. Porosity-dependent correlations for permeability, Forchheimer coefficient, convective heat transfer, and effective thermal conductivity were derived from the pore-scale simulation data. The permeability increased exponentially with porosity, while the Forchheimer coefficient decreased linearly from approximately 6.7171 × 10⁴ m⁻¹ to 3.4923 × 10³ m⁻¹ . The effective thermal conductivity was found to require correction factors between 0.57 and 0.78. An empirical correlation for the surface-averaged Nusselt number (<em>Nu</em>_sf) was also proposed, incorporating correction terms to account for temperature-dependent thermophysical properties. These correlations were implemented into a volume-averaged model and validated through conjugate simulations. Comparisons with pore-scale results demonstrated that the LTNE-based volume-averaged model accurately predicts both temperature and velocity fields. Overall, this study presents a multiscale modeling framework for SCO₂ transport in Gyroid porous media and validated empirical correlations, addressing a critical gap in transpiration cooling design using the volume-averaged method.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106828"},"PeriodicalIF":4.4,"publicationDate":"2025-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145404737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis of glycerol carbonate via direct carbonation of glycerol in CO2 over Pd/CeO2/TiO2 catalyst","authors":"Awais Khalid,&nbsp;Satam Alotibi","doi":"10.1016/j.supflu.2025.106827","DOIUrl":"10.1016/j.supflu.2025.106827","url":null,"abstract":"<div><div>We report herein the effect of Pd loading supported over CeO₂/TiO₂ nanocomposite for catalytic carbonation of glycerol with CO₂. The synthesized catalyst was thoroughly characterized using various spectroscopic and microscopic techniques and overserved uniformly dispersed 1.5 % Pd nanoparticles of 5–20 nm showed improved conversion of glycerol to 34 % with 60 % glycerol carbonate selectivity at 150°C. Reaction parameters, such as temperature, CO₂ pressure, mmol of 2-cyanopyridine, and the reaction time, were investigated. Sheldon’s hot filtration test confirmed the catalyst’s heterogeneity with no leaching up to five consecutive cycles.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106827"},"PeriodicalIF":4.4,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145404738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A mechanistic model for X65 steel corrosion in supercritical CO2 flow and phase change pipeline transportation environment","authors":"Guangyu Liu ,&nbsp;Xinxin Fan ,&nbsp;Cailin Wang ,&nbsp;Junwen Chen ,&nbsp;Shengzhu Zhang ,&nbsp;Mingzhuo Li ,&nbsp;Qihui Hu ,&nbsp;Yuxing Li","doi":"10.1016/j.supflu.2025.106825","DOIUrl":"10.1016/j.supflu.2025.106825","url":null,"abstract":"<div><div>Phase transitions in long-distance CO₂ pipelines are inevitable, yet their coupled effects on corrosion under real pipeline flow conditions remain inadequately understood. This study systematically investigates the influence of phase transition and flow velocity on the corrosion mechanisms of X65 steel in CO₂ pipelines through corrosion experiments, microscopic characterization of corrosion product films, and theoretical modeling of droplet spreading and pit development. The findings reveal that flow conditions transform the dominant corrosion mode in the phase transition environment from pitting corrosion in static conditions to uniform corrosion in dynamic conditions. This shift primarily arises from variations in flow rate and CO₂ density, which alter droplet size distribution on the steel surface. Most droplets become smaller than the critical radius required for downward pit propagation, leading to lateral pit expansion rather than deepening. Consequently, uniform corrosion is intensified, while pitting corrosion is mitigated. Furthermore, changes in wall shear stress and droplet dynamics during phase transitions disrupt the structural integrity of corrosion products, further exacerbating uniform corrosion.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106825"},"PeriodicalIF":4.4,"publicationDate":"2025-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145383119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-phase constant phase fraction lines in binary isopleths: Computation method utilizing liquid-liquid-vapor information and resulting analysis","authors":"Matías J. Molina ,&nbsp;Martín Cismondi ,&nbsp;S. Belén Rodriguez-Reartes ,&nbsp;Marcelo S. Zabaloy","doi":"10.1016/j.supflu.2025.106826","DOIUrl":"10.1016/j.supflu.2025.106826","url":null,"abstract":"<div><div>In this work, a criterion is proposed, for binary systems, for detecting the segments, of already calculated liquid-liquid-vapor (LLV) equilibrium lines, which should be part of the heterogeneous region of a yet to be computed isopleth of set global composition <em>z</em>. This criterion is based on a system of equations corresponding to mass conservation constraints. Through the application of this criterion, it is also possible to automatically detect the LLV points that will be located on the phase envelope of the isopleth, i.e., the double saturation points. On the other hand, at specified <strong>z</strong> and specified phase mole fraction <span><math><msub><mrow><mi>Φ</mi></mrow><mrow><mi>x</mi></mrow></msub></math></span> of a given “<em>x”</em> phase, a two-phase line of constant <span><math><msub><mrow><mi>Φ</mi></mrow><mrow><mi>x</mi></mrow></msub></math></span> becomes defined. Such line will be made of one or more segments. Each segment has one or more origin/termination points (endpoints). The present criterion also identifies, of such endpoints, those of the LLV type. The detected endpoints are used by an algorithm, proposed also in this work, for computing two-phase constant phase mole fraction lines or segments for binary systems. The proposed methodology is here illustrated for the CO₂ (1) + n-tetradecane (2) binary system. The obtained results suggest the existence of complex phase behavior patterns in the heterogeneous regions of the isopleths, depending on the set global composition. The presence of critical points significantly contributes to the mentioned complexity.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106826"},"PeriodicalIF":4.4,"publicationDate":"2025-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145383120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Infrared microspectroscopy with Bayesian inference for revealing spatiotemporal evolution of supercritical CO2 sorption in low-density polyethylene","authors":"Alex Eduardo Delhumeau,&nbsp;Amaël Obliger,&nbsp;Thierry Tassaing","doi":"10.1016/j.supflu.2025.106823","DOIUrl":"10.1016/j.supflu.2025.106823","url":null,"abstract":"<div><div>We demonstrate the application of Bayesian inference for the analysis of concentration profile data obtained with infrared microspectroscopy (IRM) for the adsorption of supercritical CO₂ in a semicrystalline polymer with simultaneous measurement of the adsorption-induced swelling. Low-density polyethylene (LDPE) is chosen as a model system in which Fick’s second law is expected to hold without any anomalous diffusion because the adsorption-induced swelling is negligible as confirmed by the present study. From fitting all of the spatiotemporal data of the adsorption process, the solubility and the Fickian diffusion coefficient of CO₂ in LDPE are obtained. The Bayesian method provides the statistical uncertainty of the best-fit parameters in addition to rigorously quantifying how closely the proposed model with optimal parameters can explain the experimental data. The sorptive–diffusive process is confirmed to proceed with Fickian kinetics as has been frequently assumed though not formally demonstrated.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106823"},"PeriodicalIF":4.4,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of drug loading onto MCM-48 via supercritical CO2 deposition: Effects of drug type, temperature, and silica structure","authors":"Yuto Asai,&nbsp;Ikuo Ushiki","doi":"10.1016/j.supflu.2025.106824","DOIUrl":"10.1016/j.supflu.2025.106824","url":null,"abstract":"<div><div>Mesoporous silica is a promising drug delivery carrier owing to its high surface area, tunable pores, and ability to stabilize amorphous drugs. In this study, supercritical fluid deposition (SCFD) using supercritical CO₂ (15 MPa) was employed to load ibuprofen and ketoprofen into MCM-48 mesoporous silica. The effects of drug type, temperature (313 K to 333 K), and silica framework were evaluated systematically. Transmission electron microscopy (TEM) and nitrogen adsorption confirmed that the three-dimensional cubic mesostructure of MCM-48 remained intact after impregnation. Fourier-transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA) verified the successful incorporation, with distinct thermal events indicating external and pore-confined adsorption. Ibuprofen consistently achieved higher loading than ketoprofen, driven by its greater solubility in supercritical CO₂, indicating that solubility is the dominant factor over surface affinity. Temperature had only a modest influence owing to the opposing effects of decreased CO₂ density and reduced competitive CO₂ adsorption at higher temperatures. Compared with SBA-15, MCM-48 exhibited superior uptake across all conditions, which was attributed to its larger surface area and interconnected pore network. These results demonstrate that SCFD enables the efficient, solvent-free incorporation of active compounds while preserving mesostructural integrity, offering guidance for the design of high-performance mesoporous carriers in pharmaceutical and related applications.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106824"},"PeriodicalIF":4.4,"publicationDate":"2025-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular dynamics simulation of lanthanum(III) chloride nucleation and growth mechanisms in supercritical water","authors":"Xiangyu Xu ,&nbsp;Shaokui Liu ,&nbsp;Liang He ,&nbsp;Shaohua Hu ,&nbsp;Xiaoping Ouyang ,&nbsp;Qingzhi Zhou","doi":"10.1016/j.supflu.2025.106822","DOIUrl":"10.1016/j.supflu.2025.106822","url":null,"abstract":"<div><div>Supercritical water oxidation (SCWO) is a highly efficient technology for treating radioactive organic waste. However, the deposition behavior of lanthanide salts in SCWO systems remains poorly understood. In this work, molecular dynamics simulations were performed to investigate the nucleation and growth mechanisms of LaCl₃ in supercritical water (SCW) across a wide range of temperatures (673–1073 K) and densities (0.1–0.3 g/cm³). The nucleation and growth process can be divided into three stages: ion pairs, small ion clusters, and large ion clusters. The nucleation process was completed within 40 ps. The nucleation rate was of the order of 10³⁰ cm⁻³·s⁻¹, which increased with increasing temperature and density. Under high temperature and low density conditions, the LaCl₃–H₂O binding energy decreased, the electrostatic interaction weakened, the hydrogen bond network was significantly destroyed, and the ion diffusion coefficient increased, which promoted the collisions and cluster formation of La³⁺ and Cl^- ions. The high charge and strong solvation effect of La³⁺ leads to the formation of a complex three-layer solvation shell structure, which is tightly associated with Cl^- ions, and the LaCl₃ clusters exhibit strong thermodynamic stability. This work provides a theoretical basis for solving the salt deposition problem in the treatment of radioactive organic wastewater and for the recovery of lanthanide metal elements.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106822"},"PeriodicalIF":4.4,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145418276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dense carbon dioxide technologies applied to the conservation of cultural heritage: A review","authors":"Inês Soares ,&nbsp;Angelica Bartoletti ,&nbsp;Carolina Viana ,&nbsp;Isabel Pombo Cardoso ,&nbsp;Teresa Casimiro ,&nbsp;Joana Lia Ferreira","doi":"10.1016/j.supflu.2025.106821","DOIUrl":"10.1016/j.supflu.2025.106821","url":null,"abstract":"<div><div>Cultural heritage conservation is a complex and challenging field, involving a wide variety of materials with distinct properties, degradation behaviours and specific requirements, often demanding non-standardised methodologies. Conventional treatments frequently rely on hazardous products, raising concerns about user safety and environmental impact. In response, green chemistry principles have gained prominence, advocating for safer and more sustainable practices by replacing toxic products with less harmful alternatives, thereby mitigating risks to conservators, the environment, and heritage assets. Carbon dioxide (CO₂), owing to its tuneable and non-toxic properties, has emerged as a green solvent alternative to traditional solvent-based methods in the conservation field. Therefore, this research reviews the application of dense CO₂ technologies (liquid and supercritical) in conservation processes including cleaning, decontamination, degreasing, hydration, stabilisation, and consolidation, across a wide array of materials like textiles, wood, leather, metal, glass, paper and plastics. Drawing on experimental trials and case studies, key achievements, challenges, and emerging trends are highlighted, encouraging further research into these promising and sustainable CO₂-based technologies.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106821"},"PeriodicalIF":4.4,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerically stable determination of mixture critical points and loci with PC-SAFT Equation of State","authors":"Mustajab Safarov,&nbsp;Vishnu Jayaprakash,&nbsp;Changxu Wu,&nbsp;Huazhou Li","doi":"10.1016/j.supflu.2025.106817","DOIUrl":"10.1016/j.supflu.2025.106817","url":null,"abstract":"<div><div>Compositional simulations are important for understanding, analyzing, and optimizing multiphase flows, especially in the petrochemical industry. These simulations are dependent on an accurate Equation of State (EOS) to model the relationships between phases under changing conditions. While cubic EOS (CEOS) models are widely used in the industry due to their simplicity and efficiency, the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) EOS offers a more physically accurate representation of molecular interactions. Despite the potential of PC-SAFT EOS, the application to predict mixture critical points remains underexplored. These challenges primarily arise from computational complexities and spurious stationary points that have long limited the practical use of PC-SAFT EOS for mixture criticality.</div><div>This study performs a systematic evaluation of two critical point computational methods using PC-SAFT EOS. The critical point calculation methods are applied to compute mixture critical temperatures and pressures, vapor–liquid equilibrium phase envelopes, and to trace full critical loci. Furthermore, the evaluation covers many distinct multicomponent mixtures ranging from two to eleven components. By directly comparing our results against experimental data and the results yielded by CEOS, we provide an evaluation of the performance of PC-SAFT EOS in predicting the critical points of pure compounds and mixtures.</div><div>For pure compounds in the tested mixtures, the results show that Global Optimization (GO) method demonstrates slightly better performance than the Newton–Raphson (NR) method for critical temperature (<span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>) predictions with Average Absolute Relative Deviations (AARD%) of 1.538%, while both show nearly identical performance for critical pressure (<span><math><msub><mrow><mi>P</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>) predictions. For mixtures, PC-SAFT-based NR demonstrates superior performance in predicting critical points with AARD% of 1.687% for <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> predictions and 4.623% for <span><math><msub><mrow><mi>P</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> predictions. In contrast, GO demonstrates higher deviations, particularly for some heavier mixtures. When calculating critical loci of mixtures, both methods produce root mean square error values with typical errors below 10 K for <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> predictions and 0.5 MPa for <span><math><msub><mrow><mi>P</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> predictions.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106817"},"PeriodicalIF":4.4,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}