Applied Clay Science最新文献_第2页

Evolution of steel-bentonite interactions under hydrothermal gradients: Mineralogical and geochemical implications for nuclear waste disposal 热液梯度下钢-膨润土相互作用的演化：核废料处理的矿物学和地球化学意义

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-05 DOI: 10.1016/j.clay.2025.108084

Carlos Mota-Heredia, Jaime Cuevas, Raúl Fernández

Carbon steel and bentonite are chosen as engineered barriers for high-level radioactive waste containment in deep geological repositories, which requires an evaluation of their long-term interactions to ensure durability. Two laboratory experiments were conducted under hydrothermal gradients with steel-Ca-Mg-Na-bentonite and Na-bentonite unsaturated columns over 25 and 27 months, respectively. The experiments measured changes in the porewater distribution, the specific surface area, the cation exchange capacity of the bentonites, and the oxidation state of Fe. These were determined in different sections along the columns. Mineralogical analyses were performed using X-ray diffraction and scanning electron microscopy. The results obtained showed water saturation at the conclusion of the experimental time. The specific surface area of bentonites decreased near the steel interface, while the cation exchange capacity exhibited an overall increase. The corrosion rate decreased over time, with bentonite showing enriched Fe content within the first 3.5 mm from the steel interface. New Fe-bearing minerals, including ferri-chlorite, magnetite, hematite, maghemite, and siderite, were identified as reaction products at the steel-bentonite interface. Aqueous species are redistributed in the bentonite's porewater, increasing with time the concentrations of Na⁺, Ca²⁺, Mg²⁺ and SO₄²⁻ and decreasing those of Fe, due to the imposed hydraulic gradient and the precipitation reactions. This study compares the evolution of these bentonite properties with a previous study at short experimental times of 1 and 6 months of reaction. These findings are relevant to deep geological disposal conditions, where bentonite influences the formation and nature of iron clay minerals over time.

选择碳钢和膨润土作为深层地质储存库中高放射性废物围堵的工程屏障，这需要对它们的长期相互作用进行评估，以确保耐久性。在水热梯度条件下，用钢-钙-镁-钠-膨润土和钠-膨润土不饱和柱分别进行了25个月和27个月的室内实验。实验测量了膨润土孔隙水分布、比表面积、阳离子交换容量和铁氧化态的变化。这些是沿着柱子在不同的部分测定的。矿物学分析采用x射线衍射和扫描电镜进行。所得结果显示了实验结束时的含水饱和度。膨润土在靠近钢界面处的比表面积减小，而阳离子交换容量整体增大。随着时间的推移，腐蚀速率逐渐降低，膨润土在距钢界面3.5 mm范围内铁含量富集。铁-绿泥石、磁铁矿、赤铁矿、磁铁矿和菱铁矿等新的含铁矿物在钢-膨润土界面处被发现为反应产物。由于施加的水力梯度和沉淀反应，水相在膨润土孔隙水中重新分布，随着时间的推移，Na+、Ca2+、Mg2+和SO42−的浓度增加，Fe的浓度降低。本研究比较了这些膨润土性质的演变与先前的研究在短实验时间的1和6个月的反应。这些发现与深部地质处置条件有关，膨润土随着时间的推移影响了铁粘土矿物的形成和性质。

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引用次数: 0

Swelling behaviour of compacted Ca/Mg bentonite during hydration on different scales Ca/Mg膨润土在不同尺度水化过程中的膨胀行为

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-04 DOI: 10.1016/j.clay.2025.108067

Antonia Nitsch , Ali Asaad , Torsten Wichtmann , Katja Emmerich , Wiebke Baille

A mock-up test on decimetric scale in an innovative column test device and small-scale element tests were carried out on a German Ca/Mg bentonite, which is investigated as a suitable material for engineered barrier systems in nuclear waste disposal. Key hydro-mechanical parameters such as relative humidity, water content and swelling pressure were monitored and spatially resolved over the 30 cm height of the column in the mock-up test. The test was hydrated from the bottom and ran for 370 days. To compare the material behaviour at different scales, swelling pressure tests and water retention measurements were performed at the element-test scale. The results of the column test showed a heterogeneous evolution of swelling pressure and hydration state variables along the column height. Simultaneous measurement of vertical and radial swelling pressure indicated swelling anisotropy. Transient measurement of relative humidity and water content revealed a redistribution of porosity within the sample, which was confirmed by sampling after completion of the test. Comparison with the results of the element test showed that the two test scales are comparable in similar hydraulic states. The column test is therefore suitable as a precursor to the field test and provides valuable insights into the spatially and temporally resolved hydration behaviour of a buffer material, which helps for the design of in-situ experiments, the validation of numerical models and supports the overall process understanding.

对德国Ca/Mg膨润土作为核废料处理工程屏障材料的可行性进行了研究，并在新型柱式试验装置上进行了分米尺度的实体试验和小尺度单元试验。在模拟试验中，对相对湿度、含水量和膨胀压力等关键水力学参数进行了监测，并在30cm高度上进行了空间解析。该测试从底部加水，并运行了370天。为了比较材料在不同尺度下的性能，在单元试验尺度下进行了膨胀压力试验和保水性测量。柱试验结果表明，膨胀压力和水化状态变量沿柱高呈非均匀演化。同时测量垂直和径向膨胀压力表明膨胀各向异性。相对湿度和含水量的瞬时测量表明，样品内部孔隙度的重新分布，这在测试完成后通过采样得到了证实。与单元试验结果对比表明，在相似的水力状态下，两种试验尺度具有可比性。因此，柱试验适合作为现场试验的先导，并为缓冲材料的空间和时间分解水化行为提供有价值的见解，这有助于现场实验的设计，数值模型的验证，并支持整体过程的理解。

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引用次数: 0

The electrochemical sensor for sulfamerazine detection in water based on polypyrrole-decorated halloysite nanotubes 基于聚吡咯修饰的高岭土纳米管的水中磺胺嘧啶电化学传感器

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-02 DOI: 10.1016/j.clay.2025.108062

Balamurugan Senthil Kumar , Raja Nehru , Cheng-Di Dong

Sulfamerazine (SMR), a widely used sulfonamide antibiotic, has become a significant pollutant in surface water, posing risks to ecosystems and human health. This study presents the development of an innovative electrochemical sensor for detecting SMR in environmental water samples, addressing a critical need for sustainable water monitoring technologies. A composite material based on polypyrrole (PPy) and halloysite nanotubes (HNTs) was synthesized and characterized using comprehensive physicochemical and electrochemical analyses. The polypyrrole decorated halloysite nanotubes (HNT/PPy) composite demonstrated an exceptional electrochemically active surface area, enhanced charge transfer, and superior electrocatalytic performance. The glassy carbon electrode (GCE) modified composite enabled highly sensitive and selective detection of SMR across a broad linear range (0.005–601.985 μM) with a low detection limit (LOD) of 29 nM. The sensor exhibited excellent reproducibility, stability, and anti-interference properties in complex matrices, underscoring its robustness for practical applications. The affordability and scalability of the HNT/PPy composite offer a cost-effective solution for environmental monitoring.

磺胺嘧啶（SMR）是一种广泛使用的磺胺类抗生素，已成为地表水中的重要污染物，对生态系统和人类健康构成威胁。本研究提出了一种用于检测环境水样中SMR的创新电化学传感器的开发，解决了对可持续水监测技术的迫切需求。合成了以聚吡咯（PPy）和高岭土纳米管（HNTs）为基材的复合材料，并用理化和电化学方法对其进行了表征。聚吡咯修饰的高岭土纳米管（HNT/PPy）复合材料具有优异的电化学活性表面积、增强的电荷转移和优异的电催化性能。玻璃碳电极（GCE）修饰的复合材料在宽线性范围（0.005-601.985 μM）内实现了SMR的高灵敏度和选择性检测，检测限（LOD）低至29 nM。该传感器在复杂矩阵中表现出优异的再现性、稳定性和抗干扰性能，强调了其在实际应用中的鲁棒性。HNT/PPy复合材料的可负担性和可扩展性为环境监测提供了经济高效的解决方案。

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引用次数: 0

Measuring piping erosion rate in bentonite using spectrophotometry and X-ray computed tomography 用分光光度法和x射线计算机断层扫描法测量膨润土中管道侵蚀率

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-11-29 DOI: 10.1016/j.clay.2025.108065

Norihisa Osawa , Tomoko Ishii , Kenji Ishii , Yuichi Niibori

For the geological disposal of high-level radioactive waste (HLW), maintaining a buffer density after emplacement in a disposal pit is crucial. Given the abundance of groundwater in Japan, it is necessary to estimate the amount of eroded bentonite from the buffer due to groundwater inflows. Previous quantitative evaluations have been based on the cumulative amount of eroded bentonite, making it difficult to generalize the results.

In this study, bentonite piping erosion was directly measured and quantitatively evaluated using spectrophotometry and X-ray computed tomography (CT). Piping erosion tests were performed by placing the simulated buffer block samples in polycarbonate cells, with deionized water injected from the bottom to the top. After piping developed and stabilized, X-ray CT measurements were conducted to obtain density distribution information and extract piping geometry. Furthermore, the concentration of eroded bentonite in outlet solutions was determined using spectrophotometry. The apparent erosion rate constant (i.e., specific erosion rate) of bentonite was calculated based on X-ray CT measurements and analysis of outlet solutions.

The tests confirmed a strong correlation between water flow rate and actual arc length of piping in the horizontal cross-section, as well as a negative correlation between water flow rate and effluent bentonite concentration. Based on these test results, the apparent erosion rate constants of bentonite remained nearly constant regardless of the water flow rate. Additionally, similar results were obtained when using samples with different montmorillonite content ratios. These findings suggest that the apparent erosion rate constant can be used to estimate the amount of bentonite erosion. Furthermore, this study demonstrates that X-ray CT is a highly effective non-destructive tool for understanding bentonite behavior in buffer materials and providing time-dependent data.

对于高放射性废物（HLW）的地质处置，在放置处置坑后保持缓冲密度是至关重要的。考虑到日本丰富的地下水，有必要估计由于地下水流入而从缓冲区中侵蚀的膨润土的数量。以往的定量评价都是基于侵蚀膨润土的累积量，很难对结果进行概括。在这项研究中，使用分光光度法和x射线计算机断层扫描（CT）直接测量和定量评估了膨润土管道侵蚀。通过将模拟缓冲块样品放置在聚碳酸酯电池中，从底部到顶部注入去离子水，进行管道侵蚀测试。在管道发育并稳定后，进行x射线CT测量以获得密度分布信息并提取管道几何形状。此外，用分光光度法测定了出口溶液中侵蚀膨润土的浓度。基于x射线CT测量和出口溶液分析，计算了膨润土的表观侵蚀速率常数（即比侵蚀速率）。试验结果表明，水流量与管道水平截面实际弧长呈较强的相关关系，出水膨润土浓度与水流量呈负相关关系。试验结果表明，无论水流速率如何，膨润土的表观侵蚀速率常数基本保持不变。此外，不同蒙脱土含量比的样品也得到了相似的结果。这些结果表明，表观侵蚀速率常数可以用来估计膨润土的侵蚀量。此外，该研究表明，x射线CT是一种非常有效的非破坏性工具，可用于了解缓冲材料中膨润土的行为，并提供随时间变化的数据。

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引用次数: 0

Control of phosphorus release from sediment by multiple applications of lanthanum-modified palygorskite in the presence of suspended particulate matter input 在存在悬浮颗粒物输入的情况下，镧改性坡缕石的多种应用控制沉积物中磷的释放

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-11-27 DOI: 10.1016/j.clay.2025.108063

Chunyu Tian, Jianwei Lin, Yanhui Zhan

This study explored the performance and underlying mechanisms of multiple applications of lanthanum-modified palygorskite (LMP) for mitigating phosphorus (P) release from sediment to the overlying water under the condition of suspended particulate matter (SPM) input, with a further analysis of the impact of LMP dosing frequency on the control efficiency. The findings revealed that LMP possessed a strong phosphate adsorption capacity in water (maximum adsorption capacity at pH 7: 22.5 mg/g), with significantly higher lanthanum utilization efficiency than pure lanthanum hydroxide (LH) and commercial lanthanum-modified bentonite (LMB). Multiple applications of LMP effectively inhibited the release of sediment-derived P to the overlying water under SPM input conditions, with superior control efficiency compared to multiple applications of LMB. Average reduction efficiencies of SRP in the overlying water of 72.8 %, 76.2 %, and 76.5 % were achieved with six, eleven, and thirty-one applications of LMP, respectively. These multiple LMP applications also effectively suppressed internal P release from the upper sediment layer into the pore water, achieving higher control efficiency than LMB. Even with LMP application, the release of sedimentary P to the pore water continued through mechanisms involving iron-reducing bacteria (IRB)-driven dissimilatory Fe(III) reduction and chemical Fe(III) reduction mediated by sulfate-reducing bacteria (SRB)-driven sulfate reduction products. However, LMP effectively eliminated soluble reactive phosphorus (SRP) in the pore water through two pathways: adsorbing pore water SRP, and inactivating diffusive gradients in thin films (DGT)-labile P and mobile P in the upper sediment. This dual-pathway action constitutes the key mechanism by which multiple LMP applications control the release of sediment-derived P to the overlying water under SPM input conditions. Additionally, the frequency of LMP dosing in the multiple additions affected its efficacy in controlling sediment P release. Overall, multiple applications of LMP represent a highly promising method for controlling sediment P release in the presence of SPM inputs.

本研究探讨了在悬浮颗粒物（SPM）输入条件下，镧改性坡缕石（LMP）多种应用对沉积物上覆水体磷释放的抑制作用及其机制，并进一步分析了LMP投加频率对控制效果的影响。结果表明，LMP在水中具有较强的磷酸盐吸附能力（pH = 7时吸附量最大，为22.5 mg/g），镧的利用率明显高于纯氢氧化镧（LH）和工业镧改性膨润土（LMB）。在SPM输入条件下，多次施用LMP有效地抑制了沉积物源磷向上覆水体的释放，与多次施用LMB相比，控制效率更高。在LMP的6次、11次和31次应用中，SRP在上覆水中的平均还原效率分别达到72.8%、76.2%和76.5%。这些多重LMP应用也有效地抑制了上层沉积物向孔隙水中的内部磷释放，达到了比LMB更高的控制效果。即使使用了LMP，沉积态磷仍通过铁还原细菌（IRB）驱动的异构化Fe（III）还原和硫酸盐还原细菌（SRB）驱动的硫酸盐还原产物介导的化学Fe（III）还原机制继续向孔隙水中释放。然而，LMP通过吸附孔隙水中的可溶性活性磷（SRP）和使上层沉积物中薄膜(DGT)-不稳定P和流动P的扩散梯度失活两种途径有效地消除了孔隙水中的可溶性活性磷（SRP）。这种双途径作用构成了多个LMP应用在SPM输入条件下控制沉积物源磷向上覆水体释放的关键机制。此外，在多次添加中，LMP的添加频率影响其控制沉积物P释放的效果。总的来说，LMP的多种应用代表了在SPM输入存在的情况下控制沉积物P释放的一种非常有前途的方法。

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引用次数: 0

Condensation of chromate into dichromate within magnesium/aluminum layered double hydroxide: An experimental and theoretical study 镁/铝层状氢氧化物中铬酸盐缩合成重铬酸盐的实验与理论研究

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-11-26 DOI: 10.1016/j.clay.2025.108064

Abdelhak Fezraoui , Damien Cornu , Gwladys Steciuk , Jaafar Ghanbaja , Marc Hebrant

This study investigated the speciation of hexavalent chromium (Cr(VI)) anion when inserted in layered double hydroxides (LDH). Nitrated magnesium/aluminum (Mg/Al-NO₃) LDH nanoparticles (NP) were synthesized via fast coprecipitation followed by hydrothermal treatment with a Mg/Al molar ratio of 2. The saturation with hexavalent chromium (Cr(VI)) was easily performed by mixing the colloidal dispersion of LDH NP and a solution of chromate ion. Comprehensive characterization using powder X-ray diffraction (PXRD), Raman, Fourier-transform infrared (FTIR), and X-ray photoelectron spectroscopies, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), thermogravimetric analysis (TGA) were performed on LDH nanoparticles in dry state. Ultraviolet-visible spectroscopy (UV–vis) captured the evolution of the Cr(VI) speciation during the hydration of the solid into colloidal aqueous suspension. The structural characterization data of both hydrated CrO₄²⁻-LDH in colloidal state and dried Cr₂O₇²⁻-LDH nanoparticles in the solid state was interpreted with the help of density functional theory (DFT) calculation.

Cr(VI) was demonstrated to keep its oxidation state and remain in the interlamellar space and not inserted in the cationic layer. The existence of Cr₂O₇²⁻ along with CrO₄²⁻ in the dry state was unexpected, particularly when it was surrounded by hydroxide molecules in the interlamellar space of LDH, as this species is known to exist only in acidic solution. CrO₄²⁻ became fully predominant upon hydration, indicating that study only on the dry solid, usually performed, could not be used to explain phenomenon in wet conditions such as the ionic exchange in LDH.

本研究研究了六价铬（Cr(VI)）阴离子插入层状双氢氧化物（LDH）时的形态。采用快速共沉淀法和水热法合成了硝酸镁/铝（Mg/Al- no3） LDH纳米颗粒（NP）， Mg/Al摩尔比为2。将LDH NP胶体分散体与铬酸盐离子溶液混合，可以很容易地实现六价铬（Cr(VI)）的饱和。采用粉末x射线衍射（PXRD）、拉曼光谱（Raman）、傅里叶变换红外光谱（FTIR）、x射线光电子能谱、扫描电镜（SEM）、透射电镜（TEM）、热重分析（TGA）对干燥状态下的LDH纳米颗粒进行了综合表征。紫外可见光谱（UV-vis）捕捉到了固体水化成胶体水悬浮液过程中Cr（VI）形态的演变过程。利用密度泛函理论（DFT）计算对胶体状态下水合cr42−-LDH和固体状态下干燥Cr2O72−-LDH纳米颗粒的结构表征数据进行了解释。结果表明，Cr（VI）保持其氧化态，并停留在层间空间而不插入到阳离子层中。Cr2O72−和CrO42−在干燥状态下的存在是出乎意料的，特别是当它们在LDH的层间空间被氢氧化物分子包围时，因为这种物质已知只存在于酸性溶液中。在水化作用下，CrO42−完全占主导地位，这表明通常只对干燥固体进行研究，不能用于解释湿条件下的现象，如LDH中的离子交换。

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引用次数: 0

Weathering-induced lithium mineralization on granite in South China: Li-rich muscovite accumulation and cookeite neoformation 华南花岗岩风化锂成矿作用：富锂白云母富集与库克岩新形成

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-11-26 DOI: 10.1016/j.clay.2025.108050

Haonan Zhao , Kunyue Ling , Yi Cao , Xuefei Liu , Lin Xu , Shuilong Wang , Wenbin Yu , Hanjie Wen

Granite-type lithium deposits are an important global Li resource and occur widely in South China. Thick regolith layers on Li-rich granites enrich Li to industrial-grade levels, with some containing up to 1.0 wt% Li₂O, double the content of the underlying granite. Lithium is highly mobile in the supergene environment, commonly leaching from primary minerals during weathering. However, the mechanism of Li enrichment in granite regolith is enigmatic. Lithium-rich muscovite is the predominant Li-bearing mineral in granite and its weathered regolith in the Xikeng Li deposit in northwest Jiangxi, South China. High resolution techniques (time-of-fight secondary-ion mass spectrometry and high resolution transmission electron microscopy) reveal that the higher Li content in the regolith relative to that in the granite is attributed to the strong resistance of Li-rich muscovite to weathering and the neoformation of cookeite (Li-bearing chlorite) under moderate weathering conditions. Cookeite was formed from muscovite alteration through solid-state transformation during granite weathering. These findings highlight the importance of weathering-induced Li mineralization on Li-rich granites, driven by the different weathering behaviours of the main granite minerals. The principal Li-bearing minerals in granites of South China, such as muscovite and lepidolite, have structures and weathering resistance similar to those of Li-rich muscovite. It follows that moderately weathered regolith developed on Li-rich granites has significant potential as an exploration target for regolith-hosted Li deposits.

花岗岩型锂矿床是全球重要的锂资源，广泛分布于华南地区。富锂花岗岩上的厚风化层将锂富集到工业级水平，其中一些含有高达1.0 wt%的Li2O，是下伏花岗岩含量的两倍。锂在表生环境中具有高度的流动性，通常在风化过程中从原生矿物中浸出。然而，花岗岩风化层中Li富集的机理尚不清楚。富锂白云母是赣西北西坑里矿床花岗岩及其风化表土中的主要含锂矿物。高分辨技术（战斗时间二次离子质谱和高分辨透射电镜）显示，风化层中Li含量高于花岗岩，这是富锂白云母具有较强的抗风化能力和中等风化条件下新形成的含锂绿泥石所致。库克岩是在花岗岩风化过程中由白云母蚀变经过固态转化形成的。这些发现强调了风化作用对富锂花岗岩的重要性，主要花岗岩矿物的不同风化行为驱动了富锂花岗岩的风化作用。华南花岗岩中主要含锂矿物白云母和锂云母的结构和耐风化性与富锂白云母相似。由此可见，在富锂花岗岩上发育的中等风化风化层具有较大的找矿潜力。

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引用次数: 0

Metakaolin-based single-step engineered geopolymer composites: Design and performance characterization 基于偏高岭土的单步工程地聚合物复合材料：设计和性能表征

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-11-24 DOI: 10.1016/j.clay.2025.108055

Fei Wang , Long Liang , Yao Ding , Xinjian Sun , Jingming Cai , Neven Ukrainczyk , Kequan Yu

Conventional one-part engineered geopolymer composite (EGC) facilitates the mixing process of EGC. However, this “one-part” only refers to the matrix of EGC, the reinforcing fiber as the second step should be separately added during mixing. In this study, through a careful multi-component design to regulate matrix rheology and fiber dispersion, we pioneer the development of a single-step metakaolin-based EGC, which requires only a single mixing step of adding water to achieve exceptional tensile performance, without dry pre-mixing process. This one-part EGC exhibits a density of approximately 1100 kg/m³ and a compressive strength of up to 40 MPa, outperforming conventional “one-part” geopolymers with similar densities. Remarkably, with only 0.5 % fiber volume fraction, about 1/4 of that in conventional EGC, the proposed single-step EGC achieves a high tensile strain capacity of 6 %. Further, the 28-day dry shrinkage remains below 300 με, setting a new benchmark for the lowest dry shrinkage in geopolymers (400–1000 με) and even rivaling ordinary concrete with similar strength grades. The current findings can address the production process shortcoming of conventional fiber-reinforced composite compared to ordinary concrete and facilitate the practical application of EGC.

传统的单组分工程地聚合物复合材料（EGC）有利于EGC的混合过程。但是，这里的“一部分”仅指EGC的基体，作为第二步的增强纤维应在混合时单独添加。在这项研究中，通过精心的多组分设计来调节基体流变和纤维分散，我们率先开发了一种基于偏高岭土的单步EGC，它只需要一个混合步骤，即加水就可以达到优异的拉伸性能，而不需要干燥的预混合过程。这种单组分EGC的密度约为1100 kg/m3，抗压强度高达40 MPa，优于类似密度的传统“单组分”地聚合物。值得注意的是，当纤维体积分数仅为0.5%，约为常规EGC的1/4时，单步EGC的拉伸应变容量达到6%。此外，28天干收缩率保持在300 με以下，为地聚合物中最低干收缩率（400-1000 με）设定了新的基准，甚至可以与类似强度等级的普通混凝土相媲美。本研究结果可以解决传统纤维增强复合材料相对于普通混凝土的生产工艺缺陷，促进纤维增强复合材料的实际应用。

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引用次数: 0

Clay-polymer composite adsorbents for in situ uranium remediation in groundwater: Adsorption mechanism, reusability, and field-scale performance estimation 用于地下水铀原位修复的粘土-聚合物复合吸附剂：吸附机制、可重复使用性和现场规模性能评估

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-11-22 DOI: 10.1016/j.clay.2025.108043

Subeen Kim , Sanghee Park , Donghye Heo , Jimin Mun , Minhee Lee , Minjune Yang

This study presents the development and evaluation of a montmorillonite–polysulfone sorbent (MPS) designed for the remediation of uranium-contaminated groundwater. The composite was synthesized by embedding montmorillonite (MMT) into a polysulfone (PSF) matrix to combine the high adsorption capacity of layered silicates with the mechanical stability of synthetic polymers. Batch experiments were conducted to investigate the effects of MMT content, pH, contact time, and uranium (U) concentration on adsorption behavior. Optimal performance was achieved with 4 wt% MMT, showing >99 % adsorption efficiency at pH 7.0. Kinetic data were best described by the pseudo-first-order model (

R^{2}

 = 0.969), while the Elovich model captured late-stage adsorption behavior, suggesting a two-phase mechanism involving rapid physisorption followed by slower chemisorption. Isotherm analysis indicated that both Langmuir and Freundlich models fitted the data well, with a maximum adsorption capacity of 453.7 μg/g. SEM-EDS characterization confirmed U penetration into both surface and internal pore structures of MPS. Reusability tests demonstrated sustained adsorption (≥95 %) and desorption (≥93 %) efficiencies over ten cycles using 0.1 M HNO₃. In continuous-flow permeable reactive barrier (PRB) system, MPS maintained U removal efficiencies >95 % over 34 pore volumes, with minimal breakthrough. Field-scale modeling suggests that an MPS-based PRB can treat 3.27 × 10⁴ m³ of groundwater over 7 yr with ten regeneration cycles. These findings highlight the structural robustness and practical applicability of MPS for in situ U remediation under realistic hydrogeological conditions.

研究了一种用于铀污染地下水修复的蒙脱石-聚砜吸附剂（MPS）的研制与评价。将蒙脱土（MMT）包埋在聚砜（PSF）基体中，结合层状硅酸盐的高吸附能力和合成聚合物的机械稳定性，合成了该复合材料。通过批量实验考察了MMT含量、pH、接触时间和铀浓度对吸附行为的影响。4 wt% MMT的吸附效果最佳，在pH 7.0时的吸附效率为99 %。拟一阶模型（R2 = 0.969）最能描述动力学数据，而Elovich模型捕获了后期吸附行为，表明两相吸附机制包括快速物理吸附和缓慢化学吸附。等温线分析表明，Langmuir和Freundlich模型拟合较好，最大吸附量为453.7 μg/g。SEM-EDS表征证实了U在MPS表面和内部孔隙结构中均有渗透。可重用性测试表明，使用0.1 M HNO₃，在10个循环中，持续的吸附（≥95 %）和解吸（≥93 %）效率。在连续渗流反应性屏障（PRB）体系中，MPS在34个孔隙体积内保持了95% %的U去除效率，并且几乎没有突破。现场尺度模拟表明，基于mps的PRB在7 年的10个再生周期内可以处理3.27 × 104 m3的地下水。这些发现突出了MPS的结构稳健性和在现实水文地质条件下的原位U修复的实用性。

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引用次数: 0

Development of a novel hydrogel formulation containing caffeic acid and ZnAl layer double hydroxide intercalated nanohybrid with wound healing performance 具有伤口愈合性能的咖啡酸- ZnAl层双氢氧化物嵌层纳米杂化物水凝胶配方的研制

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-11-21 DOI: 10.1016/j.clay.2025.108059

Zahra Rezanejad-Gatabi , Vajihe Alinezhad , Fatemeh Asadi , Ghazal Mollaeian , Hamidreza Mohammadi , Rezvan Yazdian-Robati , Mehri Mirhoseini

This study presents the development of a novel hydrogel formulation containing caffeic acid (CA) and Zinc‑aluminum layered double hydroxide (Zn-Al-LDH) nanohybrid, aimed at enhancing wound healing performance. The intricate process of wound healing involves various cellular interactions and the supply of essential metal ions, with hydrogels emerging as promising materials due to their ability to maintain a moist environment, absorb exudate, and facilitate painless dressing changes. The synthesized CA-LDH nanohybrid exhibited an average particle size of 345.43 ± 5.12 nm and a polydispersity index (PDI) of 0.41 ± 0.03, indicating a uniform size distribution. The encapsulation efficiency (EE %) was found to be 93.06 ± 3.64 %, with a drug loading (DL %) of 32.80 ± 1.10 %. In vivo studies using Wistar rats demonstrated that the CA-LDH/hydrogel significantly accelerated wound closure, achieving 96.57 % closure by day 14, compared to control groups. Histological assessments revealed enhanced collagen deposition and fibroblast maturation in the CA-LDH/hydrogel group. These findings suggest that the incorporation of CA into the hydrogel matrix not only improves the physicochemical properties but also significantly enhances its biological performance, highlighting the potential of CA-LDH-loaded hydrogels as innovative therapeutic options for wound management.

本研究提出了一种含有咖啡酸（CA）和锌铝层状双氢氧化物（Zn-Al-LDH）纳米杂化物的新型水凝胶配方，旨在提高伤口愈合性能。复杂的伤口愈合过程涉及各种细胞相互作用和必需金属离子的供应，水凝胶因其保持潮湿环境、吸收渗出液和促进无痛换药的能力而成为有前途的材料。合成的CA-LDH纳米杂化物平均粒径为345.43±5.12 nm，多分散性指数（PDI）为0.41±0.03，粒径分布均匀。包封率（EE %）为93.06±3.64%，载药量（DL %）为32.80±1.10%。Wistar大鼠的体内研究表明，CA-LDH/水凝胶显著加速伤口愈合，与对照组相比，第14天伤口愈合率达到96.57%。组织学评估显示CA-LDH/水凝胶组胶原沉积和成纤维细胞成熟增强。这些研究结果表明，将CA掺入水凝胶基质中不仅可以改善其物理化学特性，还可以显著提高其生物性能，突出了CA- ldh负载水凝胶作为伤口管理创新治疗选择的潜力。

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引用次数: 0