Applied Clay Science最新文献_第10页

Hydrothermal vs. electrochemical synthesis of CaAl-layered double hydroxides smart pigments for steel corrosion protection 水热与电化学合成用于钢铁防腐的钙层双氢氧化物智能颜料

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2026-01-01 Epub Date: 2025-11-14 DOI: 10.1016/j.clay.2025.108045

Andrea Cristoforetti, Mitchell Tariro Harare, Michele Fedel

Intercalation efficiency and controlled release of organic molecules within CaAl-layered double hydroxides (LDHs) were investigated to develop smart pigments for corrosion protection of organic-coated steel. By systematically comparing hydrothermal and electrochemical syntheses, it is found that the electrochemical approach provides higher sebacate loading, whereas only autoclave post-treatment applied to either route leads to enhanced LDH crystallinity, smaller and more uniform particles, and greater inhibitor content (up to 40.9 wt%), and controlled release behavior. The improved structural features following autoclaving allow for a stronger link between release kinetics and overall corrosion protection performance. Hydrothermally prepared pigments display initially faster release and nobler corrosion potentials; however, post-treatment minimizes these differences and boosts the performance of electrochemical LDHs. The core novelty of this work lies in demonstrating that the interplay between tailored synthesis and post-synthesis treatment governs both the structure and function of LDH-based smart pigments. These findings provide practical guidance for the rational design of sustainable and effective inhibitors, highlighting the key relationships between LDH structure, inhibitor release, and protective efficacy on steel substrates.

研究了钙层双氢氧化物（calal -layered double hydroxides, LDHs）中有机分子的嵌入效率和控制释放，以开发用于有机涂层钢防腐的智能颜料。通过系统地比较水热合成和电化学合成，发现电化学方法提供了更高的脂酸负载，而仅采用高压灭菌后处理的任何一种方法都可以提高LDH的结晶度，更小更均匀的颗粒，更高的抑制剂含量（高达40.9 wt%），并具有可控的释放行为。经过改进的结构特征使得释放动力学和整体防腐性能之间的联系更加紧密。水热法制备的颜料最初表现出更快的释放速度和更高的腐蚀电位；然而，后处理可以最大限度地减少这些差异，并提高电化学LDHs的性能。这项工作的核心新颖之处在于证明了定制合成和合成后处理之间的相互作用决定了基于ldh的智能色素的结构和功能。这些发现为合理设计可持续和有效的抑制剂提供了实用指导，突出了LDH结构，抑制剂释放和对钢底物的保护效果之间的关键关系。

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引用次数: 0

Analysis of the energy and nature of bandgap in layered double hydroxides Mg-Al-X and Zn-Al-X (X= Cl−, OH−, CO32−, or NO3−) 层状双氢氧化物Mg-Al-X和Zn-Al-X （X= Cl−、OH−、CO32−或NO3−）带隙的能量和性质分析

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2026-01-01 Epub Date: 2025-11-20 DOI: 10.1016/j.clay.2025.108061

Márcio F. Santos , Pedro Ivo R. Moraes , Sérgio R. Tavares , A.S. Martins , Rodrigo B. Capaz , Fernando Wypych , Alexandre A. Leitão

Photocatalysts are materials activated by sunlight and are therefore in line with so-called “Green Chemistry”. However, ab initio calculations based on Density Functional Theory (DFT) fail to describe the bandgap, which is a fundamental parameter in photocatalysis. Therefore, more sophisticated tools were required to estimate the energy bandgap and construct the band structure of the materials studied. This study expanded the electron’s self-energy in terms of the single particle Green’s function and the screened Coulomb interaction (GW approximation), evaluating how the bandgap behaves when intercalated anions are exchanged and when the ratio M

^{I I}

and M

^{I I I}

cations in the structure of layered double hydroxides (LDH). The calculations demonstrated that the forbidden band in layered double hydroxides can be tuned by varying the composition of the layers, as well as of the intercalated anions. This study suggests that LDH can be designed with finely tuned bandgaps for environmental and economic goals, such as CO

_{2}

photoreduction by sunlight, as well as organic pollutant decomposition.

光催化剂是由阳光激活的材料，因此符合所谓的“绿色化学”。然而，基于密度泛函理论（DFT）的从头计算无法描述光催化的基本参数带隙。因此，需要更复杂的工具来估计所研究材料的能带隙和构建能带结构。本研究从单粒子格林函数和筛选库仑相互作用（GW近似）的角度扩展了电子的自能，评估了层状双氢氧化物（LDH）结构中插入阴离子交换和MII和MIII阳离子比例时带隙的行为。计算表明，层状双氢氧化物中的禁带可以通过改变层的组成以及插入的阴离子来调节。这项研究表明，LDH可以被设计成具有精细调节的带隙，以实现环境和经济目标，如阳光下的二氧化碳光还原，以及有机污染物分解。

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引用次数: 0

3D-printed Zeolite–MgAl layered double oxides (3D-Ze/LDO) as a reusable adsorbent with dual functionality for effective anionic and cationic pollutant removal from water 3d打印沸石- mgal层状双氧化物（3D-Ze/LDO）作为可重复使用的吸附剂，具有双重功能，可有效去除水中的阴离子和阳离子污染物

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-15 Epub Date: 2025-10-06 DOI: 10.1016/j.clay.2025.108009

Tarmizi Taher , Sephia Amanda Muhtar , Audrey Giftie Natasha Sianturi , Rizky Aflaha , Kuwat Triyana , Aldes Lesbani , Muhamad F. Arif , Dian Ahmad Hapidin , Khairurrijal Khairurrijal , Zhongliang Yu , Aditya Rianjanu

Conventional powdered adsorbents often suffer from aggregation, difficult recovery, and poor reusability, limiting their practical application in wastewater treatment. In this study, a 3D-printed zeolite/MgAl layered double oxides (MgAl LDO) composite (3D-Ze/LDO) was successfully developed to overcome these challenges while offering dual-functional dye removal capabilities. Materials characterization, including scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectroscopy, confirmed the successful formation of zeolite - LDO composite in the 3D-printed structure. Adsorption experiments demonstrated that both 3D-Ze and 3D-Ze/LDO achieved high methylene blue (MB) removal at approximately 98 %, while the incorporation of LDO significantly enhanced congo red (CR) removal from 67 % (3D-Ze) to 79 % (3D-Ze/LDO) due to the introduction of anion-exchange sites. Kinetic studies revealed that PSO kinetics best described both MB and CR adsorption, indicating a chemisorption-dominated process. Additionally, 3D-Ze/LDO exhibited good reusability over four adsorption cycles, demonstrating its stability and potential for practical applications. These findings highlighted the advantages of 3D-printed adsorbents in addressing the limitations of powdered materials while leveraging the dual-functionality of zeolite and LDO for efficient cationic and anionic dye removal.

传统的粉状吸附剂存在结块、回收困难、可重复使用性差等问题，限制了其在废水处理中的实际应用。在这项研究中，成功开发了一种3d打印沸石/MgAl层状双氧化物（MgAl LDO）复合材料（3D-Ze/LDO），以克服这些挑战，同时提供双功能染料去除能力。材料表征，包括扫描电镜（SEM）、x射线衍射（XRD）和傅里叶变换红外（FTIR）光谱，证实了在3d打印结构中成功形成沸石- LDO复合材料。吸附实验表明，3D-Ze和3D-Ze/LDO均能达到98%的亚甲基蓝（MB）去除率，而由于引入阴离子交换位点，LDO的加入显著提高了刚果红（CR）的去除率，从67% （3D-Ze）提高到79% （3D-Ze/LDO）。动力学研究表明，PSO动力学最能描述MB和CR的吸附，表明这是一个化学吸附为主的过程。此外，3D-Ze/LDO在四个吸附循环中表现出良好的可重复使用性，证明了其稳定性和实际应用潜力。这些发现突出了3d打印吸附剂在解决粉状材料局限性方面的优势，同时利用沸石和LDO的双重功能高效去除阳离子和阴离子染料。

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引用次数: 0

The mutual interaction between geopolymerization and hydration in producing aluminosilicate geopolymer-OPC composites: Interface characterizations and mix-design regulation 铝硅酸盐地聚合物- opc复合材料中地聚合和水化的相互作用：界面表征和混合设计调节

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-15 Epub Date: 2025-10-14 DOI: 10.1016/j.clay.2025.108014

Zheng Chen , Tao Su , Jingwen Tang , Chaofan Yi , Jing Li , Shuai Zhang , Kaixuan Song

Aiming to meet the demand for carbon peak and neutrality, the combination of alkali-activated metakaolin (AAMK) and Ordinary Portland cement (OPC) presents a promising solution. However, the lack of a comprehensive understanding of their synergistic effects poses challenges for the mix-design of geopolymer-OPC composites. This study investigated the macro-mechanical properties and microstructural characteristics of metakaolin-based geopolymer-OPC composites with varying compositional oxide ratios. The results demonstrate that adjusting the SiO₂/Al₂O₃ and H₂O/Na₂O ratios significantly affected the compressive strength alongside the initiation of plastic deformation. In contrast, the Na₂O/Al₂O₃ ratio modulated both the elastic modulus and the transition from elastic to plastic behaviour. Microstructural analysis reveals that the above oxide ratios may differentially influence the polycondensation of N-A-S-H at the interface compared to the geopolymer matrix alone, owing to the migration of mineral compounds and the variation of flowability at fresh state. Optimal compressive strength, surpassing that of pure OPC systems, was achieved at SiO₂/Al₂O₃ = 3.2, Na₂O/Al₂O₃ = 0.8–1.0, and H₂O/Na₂O = 8.75–10.75, highlighting the potential of these composites to reduce cement usage and carbon emissions in construction applications.

碱活化偏高岭土（AAMK）与普通硅酸盐水泥（OPC）的组合是一种很有前景的解决方案，旨在满足碳峰值和中性的需求。然而，缺乏对其协同效应的全面了解，为地聚合物- opc复合材料的混合设计带来了挑战。研究了不同氧化物配比的偏高岭土聚合物- opc复合材料的宏观力学性能和微观结构特征。结果表明，随着塑性变形的开始，SiO₂/Al₂O₃和H₂O/Na₂O的比例的调整对抗压强度有显著影响。相比之下，Na₂O/Al₂O₃比例调节了弹性模量和从弹性到塑性行为的转变。微观结构分析表明，由于矿物化合物的迁移和新鲜状态下流动性的变化，上述氧化物比例对界面处N-A-S-H缩聚的影响可能与单独的地聚合物基质不同。SiO₂/Al₂O₃= 3.2,Na₂O/Al₂O₃= 0.8-1.0,H₂O/Na₂O = 8.75-10.75，达到了优于纯OPC体系的最佳抗压强度，突出了这些复合材料在建筑应用中减少水泥使用量和碳排放的潜力。

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引用次数: 0

Effect of thermal aging at 165 °C–200 °C on bentonite performance 165℃- 200℃热老化对膨润土性能的影响

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-15 Epub Date: 2025-09-17 DOI: 10.1016/j.clay.2025.107994

Sirpa Kumpulainen , Jari Martikainen , Teemu Laurila , Florian Kober , Olivier Leupin

The engineered barrier system in the deep geological repository will encounter varying design loads (hydraulic, mechanical, thermal and chemical) over time. The bentonite buffer may remain dry for long periods of time locally, where access to water from the host rock is low, and consequently, heat may build up increasing the buffer temperature leading to dehydration of smectite. The temperature for complete removal of interlayer water on the smectite is within >150 °C and depends on among others exchangeable cation, smectite type and confining pressure. Although dehydration reactions can be considered reversible, complete dehydration may lead to irreversible alterations. The objective of this work was to determine the effect of thermal aging on bentonite buffer performance.

Bentonite from Wyoming was thermally aged at 165 °C, 180 °C or 200 °C for 4 weeks, 8 weeks or 20 weeks in a dry, unsaturated state. Thereafter, bentonite was cooled down to room temperature and its properties and performance were evaluated determining the mineralogy by X-ray diffraction (XRD), cation exchange capacity (CEC), swelling index, and performing swelling pressure and hydraulic conductivity tests. Swiss repository conditions were applied for this work using granular bentonite mixture (GBM) and a target dry density of 1450 kg/m³ and Opalinus Clay synthetic porewater (TDS of 16.92 g/l) in swelling pressure and hydraulic conductivity experiments.

Mineralogical changes observed include dehydration of gypsum and change in clay suspension color indicating small changes in iron oxide mineral phases or contents. No impact on the swelling pressure was noted due to thermal aging, but thermally aged samples had a factor of 1.8 higher hydraulic conductivity compared to references. In addition, up to 4 % decrease in apparent CEC, and up to 25 % decrease in swelling index and faster settling of clay suspensions were observed to occur with thermal aging time and temperature. One potential explanation for observed changes is partial fixation of exchangeable cations and consequent changes in particle size due to heat exposure.

随着时间的推移，深层地质储存库中的工程屏障系统将遇到不同的设计载荷（水力、机械、热和化学）。膨润土缓冲层可能在局部保持干燥很长一段时间，因为从宿主岩石中获得的水分很少，因此，热量可能会积聚，增加缓冲层的温度，导致蒙脱石脱水。完全去除蒙脱石层间水的温度在150℃以内，这取决于交换阳离子、蒙脱石类型和围压等因素。虽然脱水反应可以被认为是可逆的，但完全脱水可能导致不可逆的改变。本工作的目的是确定热老化对膨润土缓冲性能的影响。怀俄明州的膨润土在165°C， 180°C或200°C下在干燥，不饱和状态下热老化4周，8周或20周。随后，将膨润土冷却至室温，通过x射线衍射（XRD）、阳离子交换容量（CEC）、溶胀指数、溶胀压力和水导率测试等方法对膨润土的矿物学特征进行评价。本研究采用瑞士储库条件，采用颗粒状膨润土混合物（GBM），目标干密度为1450 kg/m3， Opalinus Clay合成孔隙水（TDS为16.92 g/l）进行膨胀压力和水力导率实验。观察到的矿物学变化包括石膏脱水和粘土悬浮液颜色的变化，表明氧化铁矿物相或含量的微小变化。热老化对膨胀压力没有影响，但热老化样品的水力导率比参考样品高1.8倍。此外，随着热老化时间和温度的增加，表观CEC降低了4%，膨胀指数降低了25%，粘土悬浮物的沉降速度加快。对观察到的变化的一个可能的解释是，由于热暴露，可交换阳离子的部分固定和随之而来的颗粒大小变化。

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引用次数: 0

Large-area hybrid silver/nickel-iron layer double hydroxide on metallic tube array for highly sensitive surface-enhanced Raman scattering (SERS) application 金属管阵列上大面积混合银/镍铁层双氢氧化物用于高灵敏度表面增强拉曼散射（SERS）

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-15 Epub Date: 2025-09-13 DOI: 10.1016/j.clay.2025.107986

Balasubramanian Sriram , Alfreda Krisna Altama , Elaiyappillai Elanthamilan , Yi-Le Liao , Sea-Fue Wang , Jinn P. Chu

This paper presented a novel method for the preparation of hybrid metallic tube arrays (MeTA) with Ag coated nickel‑iron layered double hydroxide (LDH) as highly sensitive surface-enhanced Raman scattering (SERS) substrates for the detection of toxic dyes. Nickel‑iron LDH was used as a two-dimensional material with a brucite-like structure featured a large surface area and excellent adsorption capacity. This study leveraged the sharp edges of the array structures in conjunction with the plasmonic properties of silver (a noble metal) to amplify local electromagnetic fields to create plasmonic hot spots. A hybrid heterojunction composed of Ag and LDH on MeTA enhanced the capacity of the substrate to absorb target analytes such as rhodamine 6G (R6G) and malachite green (MG). The substrate demonstrated enhanced SERS performance, as indicated by high enhancement factors in the detection of R6G (2.6 × 10⁸) and MG (1.8 × 10⁶). The arrays exhibited a broad linear dynamic range (R6G: 10⁻⁴ to 10⁻¹⁴ mol L⁻¹; MG: 10⁻⁴ to 10⁻¹⁰ mol L⁻¹), exceeded the ranges reported in previous studies. The structure of the array also revealed good reproducibility and variability. In addition, the limit of detection for R6G was determined to be 6.0 × 10⁻⁹ mol L⁻¹ based on band height calibration and 2.57 × 10⁻⁹ mol L⁻¹ based on band height ratio calibration, respectively. These results underscored the importance of adsorption capacity in developing advanced SERS substrates.

本文提出了一种以镀银镍铁层状双氢氧化物（LDH）作为高灵敏度表面增强拉曼散射（SERS）底物制备杂化金属管阵列（MeTA）的新方法，用于检测有毒染料。镍铁LDH作为一种二维材料，具有类似水镁石的结构，具有较大的表面积和优异的吸附能力。这项研究利用阵列结构的尖锐边缘和银（一种贵金属）的等离子体特性来放大局部电磁场，从而产生等离子体热点。在MeTA上由Ag和LDH组成的杂化异质结增强了底物吸收目标分析物如罗丹明6G （R6G）和孔雀石绿（MG）的能力。通过检测R6G （2.6 × 108）和MG （1.8 × 106）的高增强因子，表明该底物具有增强的SERS性能。该阵列具有较宽的线性动态范围（R6G: 10−4 ~ 10−14 mol L−1;MG: 10−4 ~ 10−10 mol L−1），超出了以往研究的范围。该阵列的结构也显示出良好的再现性和可变性。此外，基于带高校正R6G的检出限为6.0 × 10−9 mol L−1，基于带高比校正R6G的检出限为2.57 × 10−9 mol L−1。这些结果强调了吸附能力在开发先进SERS底物中的重要性。

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引用次数: 0

Ab initio calculations of the structural, electronic and mechanical properties of palygorskite under high pressure 高压下坡缕石结构、电子和力学性能的从头计算

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-15 Epub Date: 2025-10-09 DOI: 10.1016/j.clay.2025.108010

Changhui Song , Jinchong Gan , Jing Zou , Man Mo , Zhijie Fang , Haitao Wang

To further expand the applications of palygorskite (Pal) in materials science, this research employs density functional theory (DFT) to systematically investigate the alterations of its structural, electronic and mechanical properties under high pressure. This finding reveal that the MgO bonds, particularly those associated with ring oxygen atoms, undergo significant contraction under high pressure, which is indicative of the high compressibility of Pal. Meanwhile, the volume of Pal decreases substantially within the pressure interval of 10–20 GPa. Moreover, at 20 GPa, the band gap of Pal diminishes from 4.58 eV at ambient pressure to 4.39 eV, resulting in an increase in conductivity. Subsequent density of states (DOS) analysis corroborates that the reduction in Pal's band gap is predominantly ascribed to the increased contribution of Si 3 s orbitals at 20 GPa. Additionally, the examination of elastic constants reveals a substantial augmentation in shear rigidity along the a-c and b-c planes, which further facilitates the narrowing of the band gap. The Gibbs free energy of adsorbed hydrogen (ΔG_H⁎) DFT calculation results further confirm that the bandgap-narrowed Pal at 20 GPa displays enhanced catalytic performance for hydrogen evolution. Notably, despite significant structural reconfigurations under high pressure, Pal maintains negative binding energies and shows no phase transition, demonstrating exceptional structural stability. This study offers theoretical insights and guidance for optimizing the performance of Pal in a plethora of sophisticated technological applications.

为了进一步拓展斜晶石（Pal）在材料科学中的应用，本研究采用密度泛函理论（DFT）系统地研究了其结构、电子和力学性能在高压下的变化。这一发现表明，在高压下，MgO键，特别是与环状氧原子相关的MgO键发生了明显的收缩，这表明Pal具有较高的可压缩性，同时，Pal的体积在10-20 GPa的压力区间内大幅减小。此外，在20gpa时，Pal的带隙从环境压力下的4.58 eV减小到4.39 eV，导致电导率增加。随后的态密度（DOS）分析证实了Pal带隙的减小主要归因于si3s轨道在20gpa下的贡献增加。此外，弹性常数的测试表明，沿a-c和b-c平面的剪切刚度大幅增加，这进一步促进了带隙的缩小。吸附氢的吉布斯自由能（ΔGH ） DFT计算结果进一步证实，在20gpa下，带隙缩小的Pal具有增强的析氢催化性能。值得注意的是，尽管在高压下发生了明显的结构重构，Pal仍然保持负结合能，没有发生相变，表现出优异的结构稳定性。本研究为优化Pal在众多复杂技术应用中的性能提供了理论见解和指导。

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引用次数: 0

Soil particle size and Hofmeister effects on soil colloidal aggregation 土壤粒径和霍夫迈斯特效应对土壤胶体聚集的影响

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-15 Epub Date: 2025-10-15 DOI: 10.1016/j.clay.2025.108018

Linqiao Yu, Aizhou He, Hang Li

Soil aggregates play a vital role in maintaining soil structure. In this study, soil colloid particles (<2000 nm) were further divided into three size fractions (<500 nm, 500–1000 nm, and 1000–2000 nm) to investigate the coupled effects of particle size and cation specificity (Li⁺, Na⁺, K⁺, Cs⁺) on soil colloid aggregation. The results showed: (1) For each size fraction, the aggregation rate and critical coagulation concentration (CCC) exhibited consistent ion-specific effects that was originated from the asymmetric hybridization of cation outer electron orbitals. (2) Among all size fractions, <500 nm soil colloid particles showed the fastest aggregation rate and required the lowest electrolyte concentration for rapid aggregation, while 1000–2000 nm particles not only had the slowest aggregation rate but also completely failed to achieve rapid aggregation. Although <500 nm colloid particles carried the highest charge quantity, their large specific surface area resulted in the lowest actual surface charge density and weakest interparticle electrostatic repulsion. Moreover, the Brownian motion of <500 nm particles was nearly 100 times that of 1000–2000 nm particles. (3) The main clay mineral affecting charge quantity and specific surface area across different size fractions was montmorillonite, <500 nm particles contained the highest montmorillonite content. Based on these findings, three key conclusions are drawn: (1) <500 nm particles play a crucial role in overall soil particle aggregation, as their rapid Brownian motion enables active collisions with >1000 nm particles, driving collective particle coagulation. (2) Effective soil aggregation occurs exclusively when <500 nm particles interact with cations exhibiting asymmetric outer electron orbital hybridization. (3) For constant-charge soil, montmorillonite-type clay minerals serve as essential material foundations promoting soil particle aggregation.

土壤团聚体对维持土壤结构起着至关重要的作用。本研究将土壤胶体颗粒（2000 nm）进一步划分为500 nm、500 - 1000 nm和1000-2000 nm三个粒径段，研究粒径和阳离子特异性（Li+、Na+、K+、Cs+）对土壤胶体聚集的耦合影响。结果表明：(1)对于不同粒径的组分，聚集率和临界凝聚浓度（CCC）均表现出一致的离子特异性效应，这种效应源于阳离子外电子轨道的不对称杂化。(2)在所有粒径组分中，500 nm土壤胶体颗粒的聚集速度最快，需要最低的电解质浓度才能快速聚集，而1000-2000 nm颗粒不仅聚集速度最慢，而且完全无法实现快速聚集。虽然500 nm的胶体粒子携带的电荷量最大，但其较大的比表面积导致实际表面电荷密度最低，粒子间静电斥力最弱。500 nm粒子的布朗运动是1000 ~ 2000 nm粒子的近100倍。(3)影响不同粒径组分电荷量和比表面积的主要粘土矿物是蒙脱土，其中500 nm颗粒蒙脱土含量最高。基于这些发现，得出了三个关键结论：(1)500 nm颗粒在整体土壤颗粒聚集中起着至关重要的作用，因为它们的快速布朗运动使它们能够与1000 nm颗粒主动碰撞，从而驱动集体颗粒凝聚。(2)有效的土壤团聚只发生在<；500 nm粒子与表现不对称外电子轨道杂化的阳离子相互作用时。(3)对于恒荷土，蒙脱石型粘土矿物是促进土壤颗粒聚集的重要物质基础。

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引用次数: 0

Compressive strength of clay-based geopolymers: A concise review of the influencing factors and underlying mechanisms 粘土基地聚合物的抗压强度：影响因素和潜在机制的简要综述

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-15 Epub Date: 2025-09-26 DOI: 10.1016/j.clay.2025.107985

Shoaib Hassan , Mineesha Sivakumar , Ayokunle Odunayo Alade , Shangeetha Ganesan , Mazidatulakmam Miskam

Geopolymer is a green inorganic polymer that is produced by using aluminosilicate materials, such as clay materials and industrial by-products in a highly alkaline environment. In recent years, clay had been widely used in the manufacturing of ceramics and building construction. The use of clay in geopolymer production not only reduces the environmental impact of traditional cement production, but also provides a sustainable alternative for various construction applications. Its versatility and cost-effectiveness make it an attractive option for industries looking to reduce their carbon footprint. This review is mainly focused on factors that influence the strength of clay-based geopolymers. Several factors, such as clay type, alkaline activator solution, aggregates, system ratio, curing temperature and time were discussed. The review also included mechanism of geopolymerization reaction. Overall, a combination of the appropriate clay type, aggregates, curing conditions, and activator solution is essential in achieving a high strength in geopolymers. Additionally, emerging reinforcement strategies such as nanomaterials, hybrid binders and fiber reinforcements are also discussed in context of mechanical behaviour of clay-based geopolymer.

地聚合物是一种在高碱性环境下，利用粘土等铝硅酸盐材料和工业副产品生产的绿色无机聚合物。近年来，粘土被广泛应用于陶瓷制造和建筑施工中。在地聚合物生产中使用粘土不仅减少了传统水泥生产对环境的影响，而且为各种建筑应用提供了可持续的替代方案。它的多功能性和成本效益使其成为寻求减少碳足迹的行业的一个有吸引力的选择。本文主要综述了影响粘土基地聚合物强度的因素。讨论了粘土类型、碱性活化剂溶液、集料、体系比、养护温度和养护时间等因素。综述了地聚合反应的机理。总的来说，适当的粘土类型、骨料、养护条件和活化剂溶液的组合对于实现高强度地聚合物是必不可少的。此外，新兴的增强策略，如纳米材料，杂化粘合剂和纤维增强也在粘土基地聚合物的力学行为的背景下进行了讨论。

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引用次数: 0

Clostridium pasteurianum in kaolin bioleaching: Iron reduction and whitening mechanisms 高岭土生物浸出中的巴氏梭菌：铁还原和增白机制

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-15 Epub Date: 2025-09-22 DOI: 10.1016/j.clay.2025.107998

Kaiqiang Li , Jiajiang Lin , Gary Owens , Zuliang Chen

Previous studies have shown that microbial consortia outperform single strains in bioleaching processes. However, gaps remain in understanding the microbial community structure and functional interactions between key species and critical metabolic genes. This study addressed these questions through iron-reducing microbe-mediated bioleaching experiments combined with multi-omic approaches. The study found four major findings: (1) Bioleaching significantly enhanced the whiteness of kaolin from 60.8 to 90.4 % by selectively removing Fe (III), reducing the Fe (III) content from 1.5 % to 1.2 % without altering the kaolin structure. This process was accompanied by the solubilization of Fe (II). (2) Community succession identified Clostridium (87.7 %), Lysinibacillus (5.9 %), and Bacillus (0.7 %) as the dominant populations. Spearman analysis confirmed strong positive correlations between Clostridium abundance, Fe²⁺ concentration, and whiteness (p < 0.05), suggesting that together with Fe (III) content in kaolin Clostridium plays a key role in whitening. (3) Metagenomic reconstruction revealed Clostridium pasteurianum (50.8 %) was the core functional species. Its complete glycolysis/pyruvate metabolism pathways and acidogenesis gene clusters (lactic/formic/butyric acids) synergistically facilitated Fe (III) dissolution. Notably, this strain exhibited enriched ferredoxin-coding genes and membrane-bound electron transport chain components, suggesting it had a pivotal role in dissimilatory iron reduction. This work provides the first elucidation of structure-function relationships and metabolic networks within iron-reducing consortia, offering both theoretical foundations and practical strategies for sustainable mineral bio-processing.

以前的研究表明，微生物联合体优于单一菌株在生物浸出过程。然而，在了解微生物群落结构和关键物种与关键代谢基因之间的功能相互作用方面仍然存在空白。本研究通过结合多组学方法的铁还原微生物介导的生物浸出实验解决了这些问题。研究发现了四个主要发现：(1)生物浸出通过选择性地去除Fe (III)，将高岭土的白度从60.8%显著提高到90.4%，在不改变高岭土结构的情况下，将Fe （III）含量从1.5%降低到1.2%。(2)群落演替结果表明，优势菌群分别为Clostridium（87.7%）、Lysinibacillus（5.9%）和Bacillus（0.7%）。Spearman分析证实Clostridium丰度、Fe2+浓度与白度呈正相关（p < 0.05），说明Clostridium与高岭土中Fe （III）含量一起对白度起关键作用。(3)宏基因组重建显示巴氏梭菌（50.8%）为核心功能种。其完整的糖酵解/丙酮酸代谢途径和产酸基因簇（乳酸/甲酸/丁酸）协同促进铁（III）的溶解。值得注意的是，该菌株表现出丰富的铁氧化还原蛋白编码基因和膜结合电子传递链组分，表明它在异化铁还原中起关键作用。这项工作首次阐明了铁还原联合体中的结构-功能关系和代谢网络，为可持续矿物生物处理提供了理论基础和实践策略。

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引用次数: 0