Monometallic (Ni-, Co-, Cu-, and Fe-containing, Me25/Al2O3) and bimetallic (NixCo(50-x)/Al2O3) catalysts were synthesized via precipitation in supercritical carbon dioxide. The catalytic activity of these systems was evaluated in the transfer hydrodechlorination of chlorobenzene, employing supercritical isopropanol as a hydrogen donor, at temperatures ranging from 250 °C to 275 °C. The hydrodechlorination rates for monometallic catalysts followed the order: Ni25/Al2O3 > Co25/Al2O3 > Cu25/Al2O3 > > Fe25/Al2O3. For bimetallic catalysts (NixCo(50-x)/Al2O3), the hydrodechlorination rate increased with increasing nickel content. It was observed that significant coarsening of metal particle crystallites occurred during hydrodechlorination; however, this phenomenon did not demonstrably affect catalyst activity.
{"title":"Transfer hydrodechlorination of chlorobenzene in supercritical isopropanol using monometallic and bimetallic catalysts obtained by precipitation in a supercritical CO2","authors":"A.S. Romanov, N.S. Nesterov, V.P. Pakharukova, D.E. Nasokhov, O.A. Ukhterova, O.N. Martyanov","doi":"10.1016/j.supflu.2025.106846","DOIUrl":"10.1016/j.supflu.2025.106846","url":null,"abstract":"<div><div>Monometallic (Ni-, Co-, Cu-, and Fe-containing, Me25/Al<sub>2</sub>O<sub>3</sub>) and bimetallic (NixCo(50-x)/Al<sub>2</sub>O<sub>3</sub>) catalysts were synthesized via precipitation in supercritical carbon dioxide. The catalytic activity of these systems was evaluated in the transfer hydrodechlorination of chlorobenzene, employing supercritical isopropanol as a hydrogen donor, at temperatures ranging from 250 °C to 275 °C. The hydrodechlorination rates for monometallic catalysts followed the order: Ni25/Al<sub>2</sub>O<sub>3</sub> > Co25/Al<sub>2</sub>O<sub>3</sub> > Cu25/Al<sub>2</sub>O<sub>3</sub> > > Fe25/Al<sub>2</sub>O<sub>3</sub>. For bimetallic catalysts (NixCo(50-x)/Al<sub>2</sub>O<sub>3</sub>), the hydrodechlorination rate increased with increasing nickel content. It was observed that significant coarsening of metal particle crystallites occurred during hydrodechlorination; however, this phenomenon did not demonstrably affect catalyst activity.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106846"},"PeriodicalIF":4.4,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145559875","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}
Polyvinyl chloride (PVC) is extensively utilized due to its excellent flame retardancy, aging resistance, and chemical stability. In this work, environmentally friendly supercritical CO2 was employed as a blowing agent for PVC foaming. PVC samples with controlled gelation degrees were prepared by modulating the processing conditions. The results show that gelation degree significantly governs the dissolution and diffusion of CO2 in PVC, consequently dictating foaming behavior and mechanical properties. Elevated gelation degrees promote the development of additional cross-linking points and the formation of stronger network structures, which restrict melt fluidity while substantially increasing both storage and loss moduli, demonstrating enhanced viscoelastic properties of the polymer melt. Notably, as the gelation degree rises from 29.9 % to 74.2 %, the CO2 diffusion coefficient declines from 4.73 × 10−10 m2/s to 9.43 × 10−12 m2/s. This work achieves controlled regulation of the PVC gelation degree to modulate foaming behavior. Specifically, PVC with 63.2 % gelation degree exhibits optimal melt strength coupled with reduced CO2 diffusion rate, yielding the maximum expansion ratio of 11.
{"title":"Effect of gelation degree of PVC on its supercritical CO2 foaming behavior and mechanical properties","authors":"Chenyang Niu, Xuelin Zhang, Xiulu Gao, Qiyuan He, Haonan Chen, Yichong Chen, Weizhen Sun, Ling Zhao, Dongdong Hu","doi":"10.1016/j.supflu.2025.106844","DOIUrl":"10.1016/j.supflu.2025.106844","url":null,"abstract":"<div><div>Polyvinyl chloride (PVC) is extensively utilized due to its excellent flame retardancy, aging resistance, and chemical stability. In this work, environmentally friendly supercritical CO<sub>2</sub> was employed as a blowing agent for PVC foaming. PVC samples with controlled gelation degrees were prepared by modulating the processing conditions. The results show that gelation degree significantly governs the dissolution and diffusion of CO<sub>2</sub> in PVC, consequently dictating foaming behavior and mechanical properties. Elevated gelation degrees promote the development of additional cross-linking points and the formation of stronger network structures, which restrict melt fluidity while substantially increasing both storage and loss moduli, demonstrating enhanced viscoelastic properties of the polymer melt. Notably, as the gelation degree rises from 29.9 % to 74.2 %, the CO<sub>2</sub> diffusion coefficient declines from 4.73 × 10<sup>−10</sup> m<sup>2</sup>/s to 9.43 × 10<sup>−12</sup> m<sup>2</sup>/s. This work achieves controlled regulation of the PVC gelation degree to modulate foaming behavior. Specifically, PVC with 63.2 % gelation degree exhibits optimal melt strength coupled with reduced CO<sub>2</sub> diffusion rate, yielding the maximum expansion ratio of 11.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"230 ","pages":"Article 106844"},"PeriodicalIF":4.4,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145559876","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}
Pub Date : 2025-11-14DOI: 10.1016/j.supflu.2025.106843
Ahmed lbrahim, Mohamed Tarek, Zhi-En Xin, Ardila Hayu Tiwikrama
Converting agricultural waste into useful materials through seeking effective and convenient routes is an important step toward shifting to sustainable energy. In this work, a deep eutectic solvent (DES) was prepared by mixing choline chloride (ChCl) as a hydrogen bond acceptor (HBA) and diethylene glycol (DEG) as a hydrogen bond donor (HBD) in a molar ratio of 1:8 to break down rice husk (RH) biomass. The RH was extracted using supercritical CO2 pretreatment at T = 80 °C and 120 °C during the reaction times ranging from (2−24) h to determine the composition of cellulose, hemicellulose and lignin in the RH. The ChCl-DEG achieved successful selective separation of lignin and hemicellulose from lignocellulosic RH biomass with a delignification value of over 66 % at 120 °C after 24 h. The effect of supercritical carbon dioxide (scCO2) was investigated during the fractionation process of the RH. The results show that the use of scCO2 decreased the delignification value, which can be attributed to the disturbance of the hydrogen bonds between the DES and the lignin composition structure, hindering the separation process. Morphological characterization using scanning electron microscopy (SEM) revealed significant changes on the surface of the treated RH, indicating the removal of lignin and hemicellulose from the biomass surface. Overall, the study demonstrates that ChCl-DEG is a promising, adaptable DES for environmentally friendly processing of plant materials.
{"title":"Green sustainable eutectic solvent using supercritical CO2 for extraction composition from rice husk","authors":"Ahmed lbrahim, Mohamed Tarek, Zhi-En Xin, Ardila Hayu Tiwikrama","doi":"10.1016/j.supflu.2025.106843","DOIUrl":"10.1016/j.supflu.2025.106843","url":null,"abstract":"<div><div>Converting agricultural waste into useful materials through seeking effective and convenient routes is an important step toward shifting to sustainable energy. In this work, a deep eutectic solvent (DES) was prepared by mixing choline chloride (ChCl) as a hydrogen bond acceptor (HBA) and diethylene glycol (DEG) as a hydrogen bond donor (HBD) in a molar ratio of 1:8 to break down rice husk (RH) biomass. The RH was extracted using supercritical CO<sub>2</sub> pretreatment at <em>T</em> = 80 °C and 120 °C during the reaction times ranging from (2−24) h to determine the composition of cellulose, hemicellulose and lignin in the RH. The ChCl-DEG achieved successful selective separation of lignin and hemicellulose from lignocellulosic RH biomass with a delignification value of over 66 % at 120 °C after 24 h. The effect of supercritical carbon dioxide (scCO<sub>2</sub>) was investigated during the fractionation process of the RH. The results show that the use of scCO<sub>2</sub> decreased the delignification value, which can be attributed to the disturbance of the hydrogen bonds between the DES and the lignin composition structure, hindering the separation process. Morphological characterization using scanning electron microscopy (SEM) revealed significant changes on the surface of the treated RH, indicating the removal of lignin and hemicellulose from the biomass surface. Overall, the study demonstrates that ChCl-DEG is a promising, adaptable DES for environmentally friendly processing of plant materials.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106843"},"PeriodicalIF":4.4,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145536504","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}
Pub Date : 2025-11-12DOI: 10.1016/j.supflu.2025.106841
Iván Navarro-Cárdenas, Andreas Kilzer, Eckhard Weidner, Marcus Petermann
Conventional catalytic hydrogenation of oils is essentially constrained by mass-transfer resistance because of the poor solubility of hydrogen in liquid-phase substrates. Supercritical fluids (SCFs) offer a solution by creating a single, homogeneous reaction medium that dissolves both hydrogen and high-molecular-weight oils, thus overcoming the interfacial transport limitations. This review synthesizes several research to establish a unified framework for the supercritical hydrogenation of different feedstocks, including heavy oils, vegetable oils, and emerging streams like bio- and plastic-derived pyrolysis oils. The central goal of this work is to provide a deep understanding of phase behavior which is a critical aspect of the process design, directly influencing reaction rates, selectivity, and overall efficiency. By integrating principles of thermodynamics, heat and mass transfer, catalysis selection, and reactor design, this review provides applicable design metrics for developing a more suitable upgrading technology with higher space yield times for a wide spectrum of complex oils.
{"title":"Phase behavior in heterogeneous catalytic hydrogenation of oils in supercritical fluids","authors":"Iván Navarro-Cárdenas, Andreas Kilzer, Eckhard Weidner, Marcus Petermann","doi":"10.1016/j.supflu.2025.106841","DOIUrl":"10.1016/j.supflu.2025.106841","url":null,"abstract":"<div><div>Conventional catalytic hydrogenation of oils is essentially constrained by mass-transfer resistance because of the poor solubility of hydrogen in liquid-phase substrates. Supercritical fluids (SCFs) offer a solution by creating a single, homogeneous reaction medium that dissolves both hydrogen and high-molecular-weight oils, thus overcoming the interfacial transport limitations. This review synthesizes several research to establish a unified framework for the supercritical hydrogenation of different feedstocks, including heavy oils, vegetable oils, and emerging streams like bio- and plastic-derived pyrolysis oils. The central goal of this work is to provide a deep understanding of phase behavior which is a critical aspect of the process design, directly influencing reaction rates, selectivity, and overall efficiency. By integrating principles of thermodynamics, heat and mass transfer, catalysis selection, and reactor design, this review provides applicable design metrics for developing a more suitable upgrading technology with higher space yield times for a wide spectrum of complex oils.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106841"},"PeriodicalIF":4.4,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145509466","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}
Pub Date : 2025-11-12DOI: 10.1016/j.supflu.2025.106840
Xu Lu , Xicheng Yang , Jia Zhang , Pengpeng Zhang , Qian Liu , Feng Zhou , Yanpei Sun , Hongjuan Zhang , Dongyin Chen , Yang Jin , Lina Chen
In recent years, the remarkable bioactivities and nutritional value of Dendrobium flexicaule flowers have become increasingly evident, underscoring their potential for broad applications. However, optimal extraction techniques and their health-promoting effects remain inadequately unexplored. This study investigated the neuroprotective effects of supercritical fluid-extracted DFF extract (DFFE), identified its key constituents, and elucidated underlying mechanisms via integrated in vitro and in silico approaches. Herein, the extract was obtained using supercritical fluid extraction (SFE), which demonstrated superior efficiency in preserving thermo-labile compounds and minimizing oxidative degradation compared to conventional ethanol reflux extraction, as evidenced by enhanced recovery of unsaturated fatty acids and sterols. Gas chromatography-mass spectrometry (GC-MS) analysis identified a total of 96 chemical constituents in DFFE. Notably, DFFE significantly mitigated glutamate-induced damage in PC12 cells by reducing LDH release, ROS generation, and enhancing antioxidant enzyme activity. Network pharmacology revealed linoleic acid, hexadecenoic acid, and pentadecanoic acid as core bioactive components, targeting PPARG, GSK3β, IL6, PTGS2, and MAPK3, which modulate Alzheimer’s and TNF signaling pathways. Molecular docking demonstrated stable interactions between most bioactive components and core targets through hydrogen bonds, with binding energies predominantly less than −5 kcal/mol. Ultimately, the extraction process was optimized using a decision tree model, which highlighted temperature and pressure as crucial parameters. Overall, these findings underscore DFFE’s potential as a neuroprotective agent for functional food or therapeutic development.
{"title":"A novel extract of Dendrobium flexicaule flower: Volatile components and neuroprotective potential","authors":"Xu Lu , Xicheng Yang , Jia Zhang , Pengpeng Zhang , Qian Liu , Feng Zhou , Yanpei Sun , Hongjuan Zhang , Dongyin Chen , Yang Jin , Lina Chen","doi":"10.1016/j.supflu.2025.106840","DOIUrl":"10.1016/j.supflu.2025.106840","url":null,"abstract":"<div><div>In recent years, the remarkable bioactivities and nutritional value of <em>Dendrobium flexicaule</em> flowers have become increasingly evident, underscoring their potential for broad applications. However, optimal extraction techniques and their health-promoting effects remain inadequately unexplored. This study investigated the neuroprotective effects of supercritical fluid-extracted DFF extract (DFFE), identified its key constituents, and elucidated underlying mechanisms via integrated <em>in vitro</em> and <em>in silico</em> approaches. Herein, the extract was obtained using supercritical fluid extraction (SFE), which demonstrated superior efficiency in preserving thermo-labile compounds and minimizing oxidative degradation compared to conventional ethanol reflux extraction, as evidenced by enhanced recovery of unsaturated fatty acids and sterols. Gas chromatography-mass spectrometry (GC-MS) analysis identified a total of 96 chemical constituents in DFFE. Notably, DFFE significantly mitigated glutamate-induced damage in PC12 cells by reducing LDH release, ROS generation, and enhancing antioxidant enzyme activity. Network pharmacology revealed linoleic acid, hexadecenoic acid, and pentadecanoic acid as core bioactive components, targeting PPARG, GSK3β, IL6, PTGS2, and MAPK3, which modulate Alzheimer’s and TNF signaling pathways. Molecular docking demonstrated stable interactions between most bioactive components and core targets through hydrogen bonds, with binding energies predominantly less than −5 kcal/mol. Ultimately, the extraction process was optimized using a decision tree model, which highlighted temperature and pressure as crucial parameters. Overall, these findings underscore DFFE’s potential as a neuroprotective agent for functional food or therapeutic development.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106840"},"PeriodicalIF":4.4,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145509479","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}
Pub Date : 2025-11-12DOI: 10.1016/j.supflu.2025.106842
Zeynep Caglar , Busra Kilic , Halil Murat Aydin
Peripheral nerve injuries are a major public health concern. The slow self-regeneration of the complex structure of the peripheral nervous system significantly impacts functional recovery. For this reason, studies on nerve tissue engineering for peripheral nerve repair are critical. Here, we constructed a gelMA-based decellularized SIS hybrid construct to promote functional regeneration after peripheral nerve injury. A supercritical carbon dioxide (scCO2) decellularization protocol was developed for bovine small intestinal submucosa (SIS) decellularization. A conventional method involving the combinations of physical, chemical, and enzymatic treatments was used for evaluating the efficiency of the scCO2 technology for SIS decellularization. The efficiency of decellularization methods was evaluated using both qualitative and quantitative analyses. In this regard, it was shown that the scCO2 technology was an efficient and high-yielding method for the decellularization of SIS. Then, SIS was incubated with gelMA solutions to obtain hybrid hydrogels. FT-IR and SEM were used to prove the success of hybrid tissue scaffold synthesis as well as to investigate structural changes. The water retention capacity, degradation properties and mechanical strength of the hybrid scaffolds were investigated and compared with the acellular SIS. Lastly the ability of hybrid membranes to induce neural cell adhesion and proliferation was evaluated via in vitro cell culture of Schwann cells in terms of cell viability, proliferation and morphological changes.
{"title":"The development of GelMA based hydrogels combined with acellular small intestinal submucosa for peripheral nerve injuries","authors":"Zeynep Caglar , Busra Kilic , Halil Murat Aydin","doi":"10.1016/j.supflu.2025.106842","DOIUrl":"10.1016/j.supflu.2025.106842","url":null,"abstract":"<div><div>Peripheral nerve injuries are a major public health concern. The slow self-regeneration of the complex structure of the peripheral nervous system significantly impacts functional recovery. For this reason, studies on nerve tissue engineering for peripheral nerve repair are critical. Here, we constructed a gelMA-based decellularized SIS hybrid construct to promote functional regeneration after peripheral nerve injury. A supercritical carbon dioxide (scCO<sub>2</sub>) decellularization protocol was developed for bovine small intestinal submucosa (SIS) decellularization. A conventional method involving the combinations of physical, chemical, and enzymatic treatments was used for evaluating the efficiency of the scCO<sub>2</sub> technology for SIS decellularization. The efficiency of decellularization methods was evaluated using both qualitative and quantitative analyses. In this regard, it was shown that the scCO<sub>2</sub> technology was an efficient and high-yielding method for the decellularization of SIS. Then, SIS was incubated with gelMA solutions to obtain hybrid hydrogels. FT-IR and SEM were used to prove the success of hybrid tissue scaffold synthesis as well as to investigate structural changes. The water retention capacity, degradation properties and mechanical strength of the hybrid scaffolds were investigated and compared with the acellular SIS. Lastly the ability of hybrid membranes to induce neural cell adhesion and proliferation was evaluated via <em>in vitro</em> cell culture of Schwann cells in terms of cell viability, proliferation and morphological changes.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106842"},"PeriodicalIF":4.4,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145509470","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}
The solubilization of poorly water-soluble drugs is a key challenge for ensuring drug effectiveness. One approach is to complex water-soluble polymers with drugs. In this study, we focused on ionic interactions between a polymer and a drug as a novel complexation method. A cationic polymer, chitosan, was used as the polymer, and an anionic drug, indomethacin, was used as the drug. The solubilization of chitosan in water requires acidic conditions. Therefore, we utilized pH switching induced by the introduction of carbon dioxide to adjust the pH in a manner harmless to the human body. This method made it possible to reduce the use of organic solvents harmful to the human body. Using this strategy, a chitosan gel loaded with indomethacin was obtained. Under the preparation conditions of this study, approximately 5.0 mg/mL of indomethacin was dispersed by forming a complex with chitosan. This represents approximately 2000 times greater dispersion compared to its original saturation solubility in water. Furthermore, changing the preparation temperature altered the dispersibility of the loaded drug, and amide bonds were formed between chitosan and indomethacin at higher temperatures, resulting in an uneven gel. As amide bonds have been shown to inhibit drug release, gel formation at an appropriate preparation temperature is necessary to minimize amide bond formation. The dissolution test results showed that the dissolution rate of the drug in the complex increased by approximately 60–200 % compared to that of indomethacin alone. This study demonstrates a new method for solubilizing poorly water-soluble anionic drugs using chitosan.
{"title":"Preparation of drug-containing chitosan gels based on CO2-induced pH switching","authors":"Hiroaki Matsukawa, Yasue Matsuoka, Yuko Nakamoto, Katsuto Otake","doi":"10.1016/j.supflu.2025.106839","DOIUrl":"10.1016/j.supflu.2025.106839","url":null,"abstract":"<div><div>The solubilization of poorly water-soluble drugs is a key challenge for ensuring drug effectiveness. One approach is to complex water-soluble polymers with drugs. In this study, we focused on ionic interactions between a polymer and a drug as a novel complexation method. A cationic polymer, chitosan, was used as the polymer, and an anionic drug, indomethacin, was used as the drug. The solubilization of chitosan in water requires acidic conditions. Therefore, we utilized pH switching induced by the introduction of carbon dioxide to adjust the pH in a manner harmless to the human body. This method made it possible to reduce the use of organic solvents harmful to the human body. Using this strategy, a chitosan gel loaded with indomethacin was obtained. Under the preparation conditions of this study, approximately 5.0 mg/mL of indomethacin was dispersed by forming a complex with chitosan. This represents approximately 2000 times greater dispersion compared to its original saturation solubility in water. Furthermore, changing the preparation temperature altered the dispersibility of the loaded drug, and amide bonds were formed between chitosan and indomethacin at higher temperatures, resulting in an uneven gel. As amide bonds have been shown to inhibit drug release, gel formation at an appropriate preparation temperature is necessary to minimize amide bond formation. The dissolution test results showed that the dissolution rate of the drug in the complex increased by approximately 60–200 % compared to that of indomethacin alone. This study demonstrates a new method for solubilizing poorly water-soluble anionic drugs using chitosan.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106839"},"PeriodicalIF":4.4,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145515656","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}
Pipeline transportation under supercritical and dense phases is commonly adopted for carbon dioxide (CO2) long-distance transportation due to its high transportation capacity and low energy consumption. When valves are accidentally shut off in CO2 pipeline systems, there might exist phase transitions or local overpressure due to water hammer effects. In this paper, a rapid transient method is proposed by improved characteristic line algorithm to simulate dynamic behaviors of water hammer scenarios, and characteristics of phase transitions in CO2 pipelines under water hammer scenarios are investigated. It was found that time-consuming by proposed method is about 4–10 times faster than that by implicit difference methods. Elevation differences have significant effects on operating pressure of CO2 pipelines under water hammer scenarios. CO2 fluids in downward sloping pipelines with a large drop is more likely to undergo phase transitions due to water hammer effects. Corresponding downstream valve can be closed simultaneously to extend fluid phase transitions in pipelines when a upstream valve in CO2 pipelines is accidentally shut off.
{"title":"Study on water hammer characteristics and protection measures of supercritical/dense CO2 pipelines","authors":"Qian Chen , Jian Jiao , Xiaoqin Xiong , Wenhui Zhang , Jianwei Ge , Xinze Li , Liukang Zhao , Xiaokai Xing","doi":"10.1016/j.supflu.2025.106837","DOIUrl":"10.1016/j.supflu.2025.106837","url":null,"abstract":"<div><div>Pipeline transportation under supercritical and dense phases is commonly adopted for carbon dioxide (CO<sub>2</sub>) long-distance transportation due to its high transportation capacity and low energy consumption. When valves are accidentally shut off in CO<sub>2</sub> pipeline systems, there might exist phase transitions or local overpressure due to water hammer effects. In this paper, a rapid transient method is proposed by improved characteristic line algorithm to simulate dynamic behaviors of water hammer scenarios, and characteristics of phase transitions in CO<sub>2</sub> pipelines under water hammer scenarios are investigated. It was found that time-consuming by proposed method is about 4–10 times faster than that by implicit difference methods. Elevation differences have significant effects on operating pressure of CO<sub>2</sub> pipelines under water hammer scenarios. CO<sub>2</sub> fluids in downward sloping pipelines with a large drop is more likely to undergo phase transitions due to water hammer effects. Corresponding downstream valve can be closed simultaneously to extend fluid phase transitions in pipelines when a upstream valve in CO<sub>2</sub> pipelines is accidentally shut off.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106837"},"PeriodicalIF":4.4,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145485489","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}
Pub Date : 2025-11-10DOI: 10.1016/j.supflu.2025.106836
Yao Peng , Wenyu Zhong , Weizhong Zheng , Dongdong Hu , Xiaojia Wang , Jiayang Sun , Xinyu Zhuo , Yichong Chen , Ling Zhao
Carbon dioxide (CO2) water suspension foaming can produce complex special-shaped components foamed products with microcellular and low-density bead foams. The traditional water suspension foaming process has wastewater, complexity, high energy consumption, and hydrolysable polymer degradation. Based on the above problems, the water-free bead foaming process in spouted bed is developed, which has simple process and high efficiency. However, due to the differences in molecular structure of different polymers and the different plasticization effect of CO2 on polymers, there are differences in the adhesion behavior of polymer beads in the foaming process. In this work, thermoplastic polyurethane (TPU) beads were selected as raw materials, and the effects of different CO2-philic surfactants on the adhesion and foaming behavior of TPU beads were investigated. Molecular dynamics (MD) simulations and experiments showed perfluorooctanoic acid (PFOA) can inhibit the adhesion of TPU foamed beads. Under 4 wt% PFOA, non-adhered TPU foamed beads with expansion ratio is 10.75, cell size is 49.83 μm and cell density is 4.30 × 107 cells/cm3 can be prepared. Then, the shrinking TPU foamed beads are foamed twice by nitrogen (N2), and expansion ratio is over 14 times, cell size is 60.06 μm, and cell density is 5.23 × 107 cells/cm3. Through this method, achieving non-adhered TPU foamed beads characterized by high expansion ratio, high cell density, and small cell size. Finally, PFOA was efficiently recovered and reused via flash evaporation, achieving a recovery ratio exceeding 97.69 %. It’s worthy that minor losses may still present environmental and health concerns.
{"title":"Effect of CO2-philic surfactant on adhesion behavior and foamability of thermoplastic polyurethane (TPU) in water-free foaming process","authors":"Yao Peng , Wenyu Zhong , Weizhong Zheng , Dongdong Hu , Xiaojia Wang , Jiayang Sun , Xinyu Zhuo , Yichong Chen , Ling Zhao","doi":"10.1016/j.supflu.2025.106836","DOIUrl":"10.1016/j.supflu.2025.106836","url":null,"abstract":"<div><div>Carbon dioxide (CO<sub>2</sub>) water suspension foaming can produce complex special-shaped components foamed products with microcellular and low-density bead foams. The traditional water suspension foaming process has wastewater, complexity, high energy consumption, and hydrolysable polymer degradation. Based on the above problems, the water-free bead foaming process in spouted bed is developed, which has simple process and high efficiency. However, due to the differences in molecular structure of different polymers and the different plasticization effect of CO<sub>2</sub> on polymers, there are differences in the adhesion behavior of polymer beads in the foaming process. In this work, thermoplastic polyurethane (TPU) beads were selected as raw materials, and the effects of different CO<sub>2</sub>-philic surfactants on the adhesion and foaming behavior of TPU beads were investigated. Molecular dynamics (MD) simulations and experiments showed perfluorooctanoic acid (PFOA) can inhibit the adhesion of TPU foamed beads. Under 4 wt% PFOA, non-adhered TPU foamed beads with expansion ratio is 10.75, cell size is 49.83 μm and cell density is 4.30 × 10<sup>7</sup> cells/cm<sup>3</sup> can be prepared. Then, the shrinking TPU foamed beads are foamed twice by nitrogen (N<sub>2</sub>), and expansion ratio is over 14 times, cell size is 60.06 μm, and cell density is 5.23 × 10<sup>7</sup> cells/cm<sup>3</sup>. Through this method, achieving non-adhered TPU foamed beads characterized by high expansion ratio, high cell density, and small cell size. Finally, PFOA was efficiently recovered and reused via flash evaporation, achieving a recovery ratio exceeding 97.69 %. It’s worthy that minor losses may still present environmental and health concerns.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106836"},"PeriodicalIF":4.4,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145485488","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}
Pub Date : 2025-11-08DOI: 10.1016/j.supflu.2025.106835
Marta Gallo, Marco Armandi, Fabiana Mangano, Silvia Ronchetti, Mauro Banchero, Luigi Manna
To overcome climate challenges, emerging CO2 capture technologies focus on innovative solid sorbents, like aerogels. Silica aerogels, in particular, have emerged as an exceptional class of materials with unique properties even though their adsorption selectivity towards CO2, and their thermal and mechanical properties are limited. In this research, a hybrid silica-alumina aerogel has been prepared, to merge the elevated surface area typical of silica with the basic character (favorable to CO2 adsorption) and the high thermal and mechanical resistance typical of alumina. For the first time, these silica-alumina aerogels were functionalized with 3-aminopropyltriethoxysilane (APTES) amino groups through a one-pot process. This approach was chosen to directly introduce functional groups during gel formation, reducing the number of post-synthesis steps. The functionalization with amino groups aims to strengthen the interactions with CO₂ molecules via acid–base interactions, thus enhancing adsorption capacity and selectivity. Three samples with increasing APTES content as well as a reference without any functionalization were prepared and characterized in terms of physico-chemical and adsorption properties. The results of CO2 and N2 adsorption tests as well as in situ FTIR suggest that low functionalization does not confer a significant advantage in CO2 capture. Higher APTES contents, instead, lead to a significant increase in the total quantity of adsorbed CO2 and in higher selectivity over N2 (calculated according to the Ideal Adsorbed Solution Theory). Moreover, also the strength of interaction increases, since not only physisorption, but also chemisorption takes place.
{"title":"Silica-alumina aerogels functionalized with amino-groups for the adsorption of CO2","authors":"Marta Gallo, Marco Armandi, Fabiana Mangano, Silvia Ronchetti, Mauro Banchero, Luigi Manna","doi":"10.1016/j.supflu.2025.106835","DOIUrl":"10.1016/j.supflu.2025.106835","url":null,"abstract":"<div><div>To overcome climate challenges, emerging CO<sub>2</sub> capture technologies focus on innovative solid sorbents, like aerogels. Silica aerogels, in particular, have emerged as an exceptional class of materials with unique properties even though their adsorption selectivity towards CO<sub>2</sub>, and their thermal and mechanical properties are limited. In this research, a hybrid silica-alumina aerogel has been prepared, to merge the elevated surface area typical of silica with the basic character (favorable to CO<sub>2</sub> adsorption) and the high thermal and mechanical resistance typical of alumina. For the first time, these silica-alumina aerogels were functionalized with 3-aminopropyltriethoxysilane (APTES) amino groups through a one-pot process. This approach was chosen to directly introduce functional groups during gel formation, reducing the number of post-synthesis steps. The functionalization with amino groups aims to strengthen the interactions with CO₂ molecules via acid–base interactions, thus enhancing adsorption capacity and selectivity. Three samples with increasing APTES content as well as a reference without any functionalization were prepared and characterized in terms of physico-chemical and adsorption properties. The results of CO<sub>2</sub> and N<sub>2</sub> adsorption tests as well as <em>in situ</em> FTIR suggest that low functionalization does not confer a significant advantage in CO<sub>2</sub> capture. Higher APTES contents, instead, lead to a significant increase in the total quantity of adsorbed CO<sub>2</sub> and in higher selectivity over N<sub>2</sub> (calculated according to the Ideal Adsorbed Solution Theory). Moreover, also the strength of interaction increases, since not only physisorption, but also chemisorption takes place.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"229 ","pages":"Article 106835"},"PeriodicalIF":4.4,"publicationDate":"2025-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145473167","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}
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