Journal of Supercritical Fluids最新文献_第7页

A novel extract of Dendrobium flexicaule flower: Volatile components and neuroprotective potential 一种新的石斛花提取物：挥发性成分及其神经保护作用

IF 4.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-11-12 DOI: 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.

近年来，石斛花具有显著的生物活性和营养价值，具有广阔的应用前景。然而，最佳的提取技术及其促进健康的效果仍未得到充分的探索。本研究研究了超临界流体提取DFF提取物（DFFE）的神经保护作用，确定了其关键成分，并通过体外和计算机集成方法阐明了其潜在机制。本文采用超临界流体萃取（SFE）获得提取物，与传统的乙醇回流萃取相比，超临界流体萃取在保存热不稳定性化合物和减少氧化降解方面表现出更高的效率，不饱和脂肪酸和甾醇的回收率也有所提高。气相色谱-质谱（GC-MS）分析鉴定出DFFE中共96种化学成分。值得注意的是，DFFE通过减少LDH释放、ROS生成和增强抗氧化酶活性，显著减轻了谷氨酸诱导的PC12细胞损伤。网络药理学发现亚油酸、十六烯酸和五烯酸是核心生物活性成分，靶向调节阿尔茨海默病和TNF信号通路的PPARG、GSK3β、IL6、PTGS2和MAPK3。分子对接表明，大多数生物活性成分与核心靶标之间通过氢键稳定相互作用，结合能主要小于−5 kcal/mol。最后，利用决策树模型对提取过程进行优化，其中温度和压力是关键参数。总的来说，这些发现强调了DFFE作为功能性食品或治疗开发的神经保护剂的潜力。

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引用次数: 0

The development of GelMA based hydrogels combined with acellular small intestinal submucosa for peripheral nerve injuries GelMA基水凝胶联合脱细胞小肠粘膜下层治疗周围神经损伤的研究

IF 4.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-11-12 DOI: 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.

周围神经损伤是一个主要的公共卫生问题。周围神经系统复杂结构的缓慢自我再生严重影响功能恢复。因此，神经组织工程修复周围神经的研究至关重要。在这里，我们构建了一个基于gelma的去细胞SIS混合结构来促进周围神经损伤后的功能再生。建立了牛小肠粘膜下层（SIS）脱细胞的超临界二氧化碳（scCO2）脱细胞方案。采用一种常规的方法，包括物理、化学和酶处理的组合，来评估scCO2技术对SIS脱细胞的效率。通过定性和定量分析对脱细胞方法的效率进行了评价。由此可见，scCO2技术是一种高效高产的SIS脱细胞方法。然后，将SIS与gelMA溶液孵育，得到混合水凝胶。利用傅里叶变换红外光谱（FT-IR）和扫描电镜（SEM）验证了杂交组织支架的成功合成，并对其结构变化进行了研究。研究了复合支架的保水性能、降解性能和机械强度，并与无细胞SIS进行了比较。最后，通过体外培养雪旺细胞，从细胞活力、增殖和形态变化等方面评价杂交膜诱导神经细胞粘附和增殖的能力。

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引用次数: 0

Preparation of drug-containing chitosan gels based on CO2-induced pH switching 基于co2诱导pH开关的含药壳聚糖凝胶的制备

IF 4.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-11-12 DOI: 10.1016/j.supflu.2025.106839

Hiroaki Matsukawa, Yasue Matsuoka, Yuko Nakamoto, Katsuto Otake

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.

水溶性差的药物的增溶是确保药物有效性的关键挑战。一种方法是将水溶性聚合物与药物复合。在这项研究中，我们重点研究了聚合物与药物之间的离子相互作用作为一种新的络合方法。以阳离子聚合物壳聚糖为聚合物，阴离子药物吲哚美辛为药物。壳聚糖在水中的溶解需要酸性条件。因此，我们利用引入二氧化碳诱导的pH转换，以对人体无害的方式调节pH值。这种方法可以减少对人体有害的有机溶剂的使用。利用该方法制备了一种负载吲哚美辛的壳聚糖凝胶。在本研究的制备条件下，约5.0 mg/mL的吲哚美辛与壳聚糖形成配合物分散。这相当于其在水中的原始饱和溶解度的2000倍。此外，改变制备温度改变了负载药物的分散性，并且在较高温度下壳聚糖与吲哚美辛之间形成酰胺键，导致凝胶不均匀。由于酰胺键已被证明抑制药物释放，在适当的制备温度下形成凝胶是必要的，以尽量减少酰胺键的形成。溶出度试验结果表明，与单独使用吲哚美辛相比，药物在配合物中的溶出率提高了约60-200 %。本研究提出了一种利用壳聚糖溶解难溶性阴离子药物的新方法。

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引用次数: 0

Study on water hammer characteristics and protection measures of supercritical/dense CO2 pipelines 超临界/浓CO2管道水锤特性及防护措施研究

IF 4.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-11-10 DOI: 10.1016/j.supflu.2025.106837

Qian Chen , Jian Jiao , Xiaoqin Xiong , Wenhui Zhang , Jianwei Ge , Xinze Li , Liukang Zhao , Xiaokai Xing

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.

超临界致密相管道输送具有输送能力高、能耗低的优点，是二氧化碳（CO2）长距离输送的常用方法。在CO2管道系统中，当阀门意外关闭时，由于水锤效应，可能会出现相变或局部超压。本文提出了一种基于改进特征线算法的快速瞬态方法来模拟水锤情景下的动态行为，研究了水锤情景下CO2管道的相变特征。结果表明，该方法的求解速度比隐式差分法快4 ~ 10倍。水锤工况下，高差对CO2管道运行压力影响显著。由于水锤效应，CO2流体在大液滴向下倾斜的管道中更容易发生相变。当CO2管道中的上游阀门意外关闭时，可以同时关闭相应的下游阀门，延长管道中的流体相变。

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引用次数: 0

Effect of CO2-philic surfactant on adhesion behavior and foamability of thermoplastic polyurethane (TPU) in water-free foaming process 亲二氧化碳表面活性剂对热塑性聚氨酯（TPU）无水发泡过程中粘附性能和发泡性能的影响

IF 4.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-11-10 DOI: 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.

二氧化碳（CO2）水悬浮发泡可以生产具有微孔和低密度泡沫珠的复杂异形构件泡沫制品。传统的水悬浮发泡工艺存在废水、工艺复杂、能耗高、易水解聚合物降解等问题。针对上述问题，开发了工艺简单、效率高的喷床无水珠发泡工艺。然而，由于不同聚合物分子结构的差异以及CO2对聚合物的增塑性作用的不同，使得聚合物珠在发泡过程中的粘附行为存在差异。本文以热塑性聚氨酯（TPU）微球为原料，研究了不同的亲二氧化碳表面活性剂对TPU微球粘附和发泡性能的影响。分子动力学（MD）模拟和实验表明，全氟辛酸（PFOA）可以抑制TPU发泡珠的粘附。在4 wt% PFOA条件下，可制得膨胀比为10.75、孔尺寸为49.83 μm、孔密度为4.30 × 107个孔/cm3的无粘附TPU泡沫珠。然后，用氮气（N2）对收缩后的TPU泡沫珠进行二次发泡，膨胀率超过14倍，孔尺寸为60.06 μm，孔密度为5.23 × 107个孔/cm3。通过该方法，获得了具有高膨胀比、高孔密度、小孔尺寸等特点的非粘附TPU泡沫珠。最后，通过闪蒸对PFOA进行高效回收再利用，回收率达到97.69 %以上。值得注意的是，轻微的损失可能仍然会引起环境和健康问题。

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引用次数: 0

Silica-alumina aerogels functionalized with amino-groups for the adsorption of CO2 氨基功能化二氧化硅-氧化铝气凝胶吸附co2

IF 4.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-11-08 DOI: 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.

为了应对气候变化的挑战，新兴的二氧化碳捕获技术集中在创新的固体吸附剂上，如气凝胶。特别是二氧化硅气凝胶，尽管其对二氧化碳的吸附选择性、热性能和机械性能有限，但它已成为一类具有独特性能的特殊材料。在本研究中，制备了一种混合二氧化硅-氧化铝气凝胶，将二氧化硅典型的高表面积与氧化铝的基本特性（有利于CO2吸附）和高热阻和机械阻相结合。首次通过一锅法将这些二氧化硅-氧化铝气凝胶与3-氨基丙基三乙氧基硅烷（APTES）基团进行了官能化。选择这种方法是为了在凝胶形成过程中直接引入官能团，减少了合成后的步骤。氨基功能化旨在通过酸碱相互作用加强与CO₂分子的相互作用，从而提高吸附能力和选择性。制备了三种APTES含量增加的样品和未官能化的参比样品，并对其理化性质和吸附性质进行了表征。CO2和N2吸附测试以及原位FTIR的结果表明，低功能化并不会赋予CO2捕获的显着优势。相反，较高的APTES含量会导致吸附CO2总量的显著增加，并且比N2具有更高的选择性（根据理想吸附溶液理论计算）。此外，相互作用的强度也增加了，因为不仅发生了物理吸附，而且发生了化学吸附。

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引用次数: 0

Technoeconomic analysis of biofuel production from spent coffee grounds using supercritical ethyl acetate 用超临界乙酸乙酯从废咖啡渣中生产生物燃料的技术经济分析

IF 4.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-11-08 DOI: 10.1016/j.supflu.2025.106834

Wirasinee Supang , Somkiat Ngamprasertsith , Winatta Sakdasri , Ruengwit Sawangkeaw

This study is a techno-economic analysis of biodiesel production from spent coffee grounds (SCGs) using ethyl acetate as an extracting solvent and a reactant through interesterification under supercritical conditions—a process called SCEA. Aspen Plus V12 was employed to simulate the SCEA process compared to the conventional biodiesel production process. Both processes operated at an original feed rate of 24,225 tonnes per year, but the production capacities of the conventional and SCEA processes were 1000 tonnes per year and 1800 tonnes per year, respectively. Because of the simplicity of SCEA, the fixed capital investment costs were lower than those of the conventional process. However, at the original feed rate, neither process was profitable within a project lifetime of 20 years. The production capacity of SCEA was increased to 4 times, 8 times, and 16 times its original size to identify the most effective scale for the production facility. The SCEA process commenced successfully with a production capacity of 7500 tonnes per year, but the payback period of 19.5 years was deemed unsatisfactory. The production capacities of 15,000 tonnes per year and 30,000 tonnes per year provided the payback periods of 7.67 years and 6.08 years, respectively. Nonetheless, the 15,000-ton plant requires 193,798 tonnes SCGs per year as feedstock, which is 12 times the annual coffee production in Thailand. Hence, this project is well-suited for large coffee producers when utilizing SCGs as a singular feedstock. Combining other feedstocks, such as microalgae, non-edible seeds, and waste fruit seeds, with SCGs presents an optional pathway for future research on biodiesel production.

这项研究是对用废咖啡渣（scg）生产生物柴油的技术经济分析，使用乙酸乙酯作为萃取溶剂和在超临界条件下进行交换反应的反应物，这一过程被称为SCEA。采用Aspen Plus V12模拟SCEA过程，并与传统生物柴油生产过程进行比较。这两种工艺的原始进料量均为每年24 225吨，但常规工艺和SCEA工艺的生产能力分别为每年1000吨和每年1800吨。由于SCEA工艺简单，固定资本投资成本低于常规工艺。然而，在最初的进料速度下，这两种工艺在20年的项目生命周期内都没有盈利。将SCEA的生产能力分别提高到原来的4倍、8倍和16倍，以确定生产设施的最有效规模。SCEA过程成功地开始，每年的生产能力为7500吨，但19.5年的投资回收期被认为是不令人满意的。年产15000吨和30000吨的生产能力，投资回收期分别为7.67年和6.08年。尽管如此，这个15000吨的工厂每年需要193798吨scg作为原料，这是泰国年咖啡产量的12倍。因此，当使用scg作为单一原料时，该项目非常适合大型咖啡生产商。将微藻、非食用种子和废弃水果种子等其他原料与scg相结合，为未来生物柴油生产的研究提供了一条可选的途径。

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引用次数: 0

Preparation and formation mechanism of bimodal cell structure in TPU/PVDF foam using microwave heating foaming 微波加热发泡TPU/PVDF泡沫材料双峰胞孔结构的制备及形成机理

IF 4.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-11-05 DOI: 10.1016/j.supflu.2025.106833

Yichong Chen , Yao Peng , Wenyu Zhong , Boda Du , Jiayang Sun , Xuwei Li , Xiaojia Wang , Dongdong Hu , Ling Zhao

Polymer foams offer advantages including lightweight, high resilience, excellent thermal insulation, superior sound absorption, and effective energy dissipation. Those with bimodal cell structures exhibit outstanding cyclic compression performance and comprehensive properties, garnering significant research attention. Microwave heating, as a non-conventional technique, enables rapid and uniform heating with minimal thermal gradients. Introducing materials with differential microwave energy absorption capabilities into a polymer matrix, combined with microwave heating foaming after supercritical CO₂ saturation at 40 ℃, 8 MPa for 8 h and slow depressurization, provides an effective route to achieve polymer foams with bimodal cells. This work utilized incompatible TPU and PVDF as the matrix. A phase separated structure was formed within the TPU/PVDF composite system due to the inherent immiscibility of the two polymers, leveraging the inherent difference in microwave energy absorption between the two polymers to create a TPU/PVDF foam with a bimodal cell structure. The extent of phase separation in the TPU/PVDF composite was investigated using SEM and EDS. Subsequently, the influence of PVDF content on the melting and crystallization behavior, rheological properties, and uniaxial tensile behavior of the TPU/PVDF composites was examined. By controlling microwave radiation power and time, various bimodal cell structures were successfully fabricated within the TPU/PVDF composites. Finally, COMSOL Multiphysics simulations were employed to model the microwave heating effects in both TPU and TPU/PVDF. These simulations demonstrated the formation mechanism of the bimodal cell structure during the foaming process of the TPU/PVDF composite. This work establishes a novel processing strategy for designing high-performance polymer foams.

聚合物泡沫具有重量轻、回弹性高、隔热性能好、吸声效果好、耗能效果好等优点。具有双峰胞结构的复合材料具有优异的循环压缩性能和综合性能，引起了人们的广泛关注。微波加热作为一种非传统的技术，能够以最小的热梯度实现快速均匀的加热。在聚合物基体中引入具有不同微波能量吸收能力的材料，并在40℃、8 MPa、8 h的超临界CO2饱和条件下进行微波加热发泡，缓慢降压，为实现具有双峰电池的聚合物泡沫提供了有效途径。这项工作利用不兼容的TPU和PVDF作为矩阵。由于两种聚合物固有的不混溶性，在TPU/PVDF复合体系中形成了相分离结构，利用两种聚合物之间固有的微波能量吸收差异来创建具有双峰细胞结构的TPU/PVDF泡沫。利用扫描电镜和能谱仪研究了TPU/PVDF复合材料的相分离程度。随后，研究了PVDF含量对TPU/PVDF复合材料熔融结晶行为、流变性能和单轴拉伸性能的影响。通过控制微波辐射功率和时间，在TPU/PVDF复合材料内部成功制备了多种双峰胞元结构。最后，采用COMSOL多物理场模拟方法对TPU和TPU/PVDF的微波加热效应进行了模拟。模拟结果揭示了TPU/PVDF复合材料发泡过程中双峰胞结构的形成机理。本工作为设计高性能聚合物泡沫材料建立了一种新的加工策略。

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引用次数: 0

Comparison of LC3 and traditional SCM-blended cement pastes under supercritical CO2 exposure 超临界CO2作用下LC3与传统scm混合水泥浆的比较

IF 4.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-11-04 DOI: 10.1016/j.supflu.2025.106832

Kristína Compeľová , Jiří Másilko , Jozef Švorec , Peter Peciar , Eva Kuzielová

Carbonation of cementitious materials is a critical issue affecting the long-term performance of geothermal wells. This study compares the resistance of limestone calcined clay cements (LC³) and traditional SCM-based (silica fume and metakaolin) cement pastes exposed to supercritical CO₂ for 7 days. The extent of carbonation and the associated phase transformations resulting from carbonation reactions were assessed using TGA, XRD, FTIR, and SEM-EDX analyses. Additionally, bulk density and compressive strength tests were conducted to evaluate the mechanical properties. The results demonstrated that the LC³ composition exhibited superior resistance to carbonation compared to the mixtures incorporating silica fume and metakaolin at an equivalent level of cement replacement. Higher carbonation penetration in traditional SCM-based systems is evidenced by up to 52 % higher carbonate contents in the middle part of the samples. This enhanced carbonation is attributed to the limited portlandite buffering capacity. In the middle part of the sample, LC3–70 contained up to 55 % more portlandite, indicating both reduced carbonation and lower pozzolanic reactivity of the calcined clay and limestone compared to SF/MK mixtures. Higher portlandite content in LC³ favoured more extensive carbonation-induced densification of the pore structure, effectively impeding CO₂ ingress. In addition, this process contributed to an increase in compressive strength, which reached 53 MPa, approximately 34 % higher than that of the corresponding composition cured under standard water-hydration conditions. For highly carbonated SF/MK samples, compressive strength increased by 77 % reaching up to 93 MPa.

胶结材料的碳酸化是影响地热井长期性能的关键问题。本研究比较了石灰石煅烧粘土水泥（LC3）和传统的scm基水泥（硅灰和偏高岭土）在超临界二氧化碳环境下暴露7天的耐磨性。通过TGA， XRD， FTIR和SEM-EDX分析来评估碳化程度和碳化反应引起的相关相变。此外，还进行了堆积密度和抗压强度试验来评估其力学性能。结果表明，在同等水平的水泥替代下，与含有硅灰和偏高岭土的混合物相比，LC3组成具有更强的抗碳化性。在传统的基于scm的体系中，较高的碳化渗透证明了样品中部的碳酸盐含量高达52. %。这种增强的碳酸化作用归因于有限的波特兰岩缓冲能力。在样品的中间部分，LC3-70含有高达55% %的波特兰铁矿，这表明与SF/MK混合物相比，煅烧粘土和石灰石的碳化作用降低，火山灰反应性降低。LC3中较高的波特兰岩含量有利于孔隙结构更广泛的碳化致密化，有效地阻碍了CO2的进入。此外，该工艺还提高了抗压强度，达到53 MPa，比标准水水化条件下固化的相应组合物的抗压强度提高了约34 %。对于高碳化的SF/MK样品，抗压强度提高了77 %，达到93 MPa。

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引用次数: 0

Multi-physics coupling simulation and sealing performance optimization of supercritical CO2 stepped T-groove dry gas seals 超临界CO2阶梯t型槽干气密封多物理场耦合仿真及密封性能优化

IF 4.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-11-04 DOI: 10.1016/j.supflu.2025.106830

Andi Jiang , Junhua Ding , Xuexing Ding , Shipeng Wang , Haitao Jiang , Ning Ling

This study examines the thermal hydrodynamic lubrication and thermodynamic performance of stepped T-groove dry gas seals operating with supercritical carbon dioxide (S-CO₂). A stepped T-groove end-face structure is proposed through the optimization of dynamic pressure groove depth. A bidirectional thermal-fluid-solid coupling model is established using finite element analysis to comprehensively examine microscale gas film flow characteristics, critical sealing performance parameters, and the interplay between sealing rings deformation and gas film behavior. Furthermore, temperature distributions and flow evolution within the sealing clearance are compared across various groove depth ratios, and the influence of operational conditions and groove geometric parameters on sealing performance is thoroughly evaluated. Results indicate that an increase in groove depth ratio enhances gas film pressure by 0.50 MPa and improves the opening force, albeit at the expense of greater leakage. Elevated operational parameters intensify turbulence and centrifugal inertia effects, significantly affecting overall seal performance. Sealing performance parameters exhibit varying sensitivity to groove geometry: opening force, leakage rate, and frictional force increase with a higher circumferential groove ratio but decrease with a higher radial groove ratio, while the opening-to-leakage ratio shows an opposite trend. Optimal sealing performance occurs at circumferential and radial groove ratios ranging from 0.4 to 0.6 under the studied conditions. These findings provide essential theoretical support for the design and optimization of stepped T-groove dry gas seal under S-CO₂ operating conditions.

本研究考察了在超临界二氧化碳（S-CO2）环境下运行的阶梯t型槽干气密封的热流体动力润滑和热力学性能。通过对动压槽深度的优化，提出了一种阶梯式t型槽端面结构。通过有限元分析，建立了双向热-流-固耦合模型，全面考察了微尺度气膜流动特性、密封关键性能参数以及密封圈变形与气膜行为的相互作用。对比了不同槽深比下密封间隙内的温度分布和流动演化，全面评估了工况和槽形参数对密封性能的影响。结果表明：沟槽深度比的增加使气膜压力提高0.50 MPa，开启力提高，但泄漏量增加；升高的操作参数加剧了湍流和离心惯性效应，显著影响了整体密封性能。密封性能参数对沟槽几何形状的敏感性不同：开口力、泄漏率和摩擦力随周向沟槽比的增大而增大，随径向沟槽比的增大而减小，而开漏比则相反。在研究条件下，当周向沟槽比和径向沟槽比在0.4 ~ 0.6之间时，密封性能最佳。这些研究结果为S-CO2工况下阶梯t槽干气密封的设计与优化提供了重要的理论支持。

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引用次数: 0