Applied Clay Science最新文献

{"title":"Tuning the synthesis of aluminosilicates to enhance metal cation uptake for heavy metal immobilization","authors":"Alina Gawel ,&nbsp;Patrick Diehl ,&nbsp;Sven Westheimer ,&nbsp;Sarah Sühnholz ,&nbsp;Marc Greuel","doi":"10.1016/j.clay.2025.107728","DOIUrl":"10.1016/j.clay.2025.107728","url":null,"abstract":"<div><div>Many aluminosilicates are characterized by a pronounced ability to bind heavy metals from aqueous solutions. This work demonstrates the great potential and adaptability of clay materials for use in the emerging field of <em>in-situ</em> groundwater remediation of heavy metals. The synthesis of aluminosilicates was adapted to achieve the highest possible uptake affinity and capacity for Co²⁺, Cu²⁺ and Ni²⁺. This optimization enabled maximum loadings of up to 1.1 mol Me²⁺ kg⁻¹ and <em>K</em>_D values well above 3000 L kg⁻¹. Elevated temperatures during synthesis or drying lead to reduced uptake affinity for metals, <em>e.g.</em>, by the factor of 3 for Ni²⁺ when changing drying temperature from 100 °C to room temperature. On the one hand, metal uptake takes place <em>via</em> interaction with variable surface charges, which is strongly pH-dependent and more pronounced for Cu²⁺. On the other hand, there is also a certain degree of interaction with permanent surface charges through isomorphous substitution leading to more stable bonds. Individual experiments showed comparable uptake of the various metals with 0.6 mol kg⁻¹ at pH 3 up to 1.1 mol kg⁻¹ at pH 5. However, Ni²⁺ was preferably taken up in direct competition with the other metals. Thanks to the simple low-temperature synthesis, the high metal loadings and robust metal uptake achieved even at low pH, amorphous aluminosilicates represent a valuable alternative to other products for heavy metal removal from aqueous solution. Future research should focus on their interaction with different metals simultaneously and metal uptake in flow-through systems.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"268 ","pages":"Article 107728"},"PeriodicalIF":5.3,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rheology of aqueous suspensions of montmorillonite/ gum arabic /electrolyte","authors":"Fatou Guey ,&nbsp;Ousseynou M'bodj ,&nbsp;Aliou Barry ,&nbsp;Albert Magnin","doi":"10.1016/j.clay.2025.107745","DOIUrl":"10.1016/j.clay.2025.107745","url":null,"abstract":"<div><div>The rheological properties of purified Na-montmorillonite (Na-MTp)-Water-NaCl- Gum arabic (GA) mixture have been investigated. Montmorillonite and the GA from the south of Mauritania were purified and characterized by several physical and chemical methods: X-ray fluorescence (XRF), X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), and size exclusion chromatography (SEC). The results showed that both the plastic and elastic parameters increased with the clay fraction. The sol-gel transition was detected at the volume fraction between 0.012 and 0.016. These two parameters increased with the amount of NaCl added, at low NaCl concentrations, due to the decrease in the double layer thickness, before the system collapsed at NaCl concentrations above 20 mmol. L⁻¹. In the presence of GA, the variation of the yield stress and the elastic modulus shows a progressive reduction of both parameters as the amount of gum increased<strong>.</strong> The order of mixing of the different components used is also studied. The results of the MTp-NaCl-GA mixture, called the first order of the mixture, shows that the yield stress and the elastic modulus decreased as the concentration of NaCl increases. The MTp-GA-NaCl mixture, called the second order of the mixture, shows that the yield stress and the elastic modulus increased progressively with the increase in NaCl concentration. The connection between physicochemical interactions and the observed behaviors is detailed.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"268 ","pages":"Article 107745"},"PeriodicalIF":5.3,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Consequences of the calcination on the morphological, structural, optical, and catalytic properties of CuMgFe-layered double hydroxide for photo-fenton degradation","authors":"Nayara de Melo Costa Serge ,&nbsp;Rosembergue Gabriel Lima Gonçalves ,&nbsp;Karla Virgínia Leite Lima ,&nbsp;York Estewin Serge Correales ,&nbsp;João Maurício Beghetto Tomaz de Aquino ,&nbsp;Rogéria Rocha Gonçalves ,&nbsp;Peter Hammer ,&nbsp;Raquel Fernandes Pupo Nogueira","doi":"10.1016/j.clay.2025.107740","DOIUrl":"10.1016/j.clay.2025.107740","url":null,"abstract":"<div><div>This study explored the influence of calcination on Layered Double Hydroxides (LDH) applied as catalyst in Fenton and photo-Fenton processes evaluated during sulfamethoxazole (SMX) degradation. According to the findings, CuMgFe-layered double hydroxide underwent significant structural, optical, and catalytic transformations following thermal treatment at 400 °C and 650 °C. X-ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS) analyses showed the formation of pure cuprous delafossites and cupric spinels. The use of the CuMgFe-layered double hydroxide treated at 400 °C and CuMgFe-layered double hydroxide treated at 650 °C in the Fenton process caused an increase in the solution pH, which subsequently inhibited the degradation of SMX, in contrast to LDH without calcination. CuMgFe-layered double hydroxide treated at 400 °C achieved 13 % and 18 % SMX degradation in Fenton and photo-Fenton reaction, while CuMgFe-layered double hydroxide treated at 650 °C resulted in 18 % and 29 %, respectively. Compared to LDH without calcination (26 % and 36 %), the lower degradation values of calcined catalysts were found to be significantly influenced by the pH increase of the suspensions (9.0–9.6). Despite the reduced SMX removal, calcined LDH exhibited intriguing structural and optical modifications, suggesting potential applications beyond degradation processes.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"268 ","pages":"Article 107740"},"PeriodicalIF":5.3,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of on stereoisomers of lactic acids on microbially-mediated reductive dissolution of clay minerals: Insights from DFT and experimental studies","authors":"Jingjie Yang ,&nbsp;Liang Bian ,&nbsp;Aiqin Wang ,&nbsp;Xiaofeng Zhao ,&nbsp;Jianan Nie ,&nbsp;Temirlan Arslanov ,&nbsp;Bin Mu ,&nbsp;Hailiang Dong ,&nbsp;Mianxin Song ,&nbsp;Li Zeng ,&nbsp;Peng Liu ,&nbsp;Xiaobin Gu","doi":"10.1016/j.clay.2025.107725","DOIUrl":"10.1016/j.clay.2025.107725","url":null,"abstract":"<div><div>Interactions between microorganisms and clay minerals occur ubiquitously in nature. It has been established that various factors can affect the interactions between microorganisms and clay minerals, such as temperature, pressure, pH, surface area and electron shuttle compounds. Lactic acid has two stereoisomer forms (L-(+)-lactic acid (L-(+)-lac) and D-(−)-lactic (D-(−)-lac)) and has widely been recognized as an important biomolecule that can be utilized as an electronic donor and/or carbon source by dissimilatory iron-reducing bacteria. Furthermore, lactic acid (endogenous or exogenous) has been shown to result in the dissolution of metal impurities from clay minerals. However, the synergistic effect of different lactic acid stereoisomers on abiotic processes (clay mineral dissolution) and biotic processes (microbial reduction) remains unclear, as well as the fundamental principles governing this process. To examine the differences between the effects of both stereoisomers of lactic acid on the interactions between microorganisms and clay minerals, experiments on microbially mobilized elements in clay mineral dissolution (MMED) were carried out in the presence of either L-(+)-lac or D-(−)-lac. Experimental results showed that the interdependence between coupled abiotic and biotic processes, created a synergy between these processes. Furthermore, to investigate the molecular or atomic level interactions, such as electrostatic charges and bond formation, that occur during the attachment of L-(+)-lac and D-(−)-lac onto mineral surfaces. Molecular dynamics (MD) simulations were used to distinguish between the adsorption pathways of L-(+)-lac and D-(−)-lac on clay minerals. The results of density functional theory (DFT) calculations indicated that the presence of lactic acid affected the electron distribution profile of clay mineral templates. The finding of this study provide insights into the role of lactic acid stereoisomers in promoting mineral-microbe interactrions.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"268 ","pages":"Article 107725"},"PeriodicalIF":5.3,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clay/GO asymmetric bilayer membrane with temperature and concentration dual-responsivity for enhanced ion transport properties","authors":"Nengwei Li ,&nbsp;Kang Cheng ,&nbsp;Yiwei Dong,&nbsp;Mingda Hu,&nbsp;Zhihong Yang,&nbsp;Jianmei Xu,&nbsp;Wei Zhou,&nbsp;Jian Sun","doi":"10.1016/j.clay.2025.107722","DOIUrl":"10.1016/j.clay.2025.107722","url":null,"abstract":"<div><div>The controllable ion transport in the membranes has attracted significant interest for water treatment, molecular sieving, energy storage and harvesting because of the molecular/ion sieving and selectivity of the nanofluidic channels. Here, we selected Li-exchanged montmorillonite (Mt) to prepare montmorillonite/graphene oxide (Mt/GO) bilayer membranes with two-dimensional (2D) nanofluidic channels and studied the ion transport across the nanofluidic membrane under the external stimuli of temperature and concentration. It is interesting that the ion transport is affected by the orientation of Mt./GO bilayer membrane between two electrolyte cells. The bilayer membrane with GO layer facing higher concentration electrolytes shows much higher ionic conductance than that with Mt. layer facing higher concentration electrolytes, also higher than Mt./GO homogenous monolayer membrane. The diffuse current, membrane potential and output power of the bilayer membrane are affected by the external temperature and electrolyte concentration, showing good thermoelectric conversion and abnormal temperature dependence. These asymmetric bilayer membranes with the integration of the cost-effective clay and high ion-selective GO show many advantages such as low cost, facile fabrication and high ion-transport performance. This work provides a new idea for designing clay based nanofluidic membrane for creating smart high-efficient membranes.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"268 ","pages":"Article 107722"},"PeriodicalIF":5.3,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Montmorillonite-alginate films for paraquat adsorption and fluorescent detection","authors":"Michelle D. Restivo,&nbsp;Danielle Silva do Nascimento,&nbsp;Yésica Sepúlveda,&nbsp;Mariana Etcheverry,&nbsp;Carolina V. Waiman,&nbsp;Graciela P. Zanini","doi":"10.1016/j.clay.2025.107746","DOIUrl":"10.1016/j.clay.2025.107746","url":null,"abstract":"<div><div>This study explores the ability of montmorillonite (Mt) encapsulated in alginate films (A) to retain and detect the herbicide paraquat (PQ) in situ by molecular fluorescence in aqueous solution. The synthesis of the films (Mt-A) was carried out using a biopolymer in aqueous solution, avoiding organic solvents and thus preventing toxic waste generation. Characterization techniques such as XRD, FTIR, SEM, and EDS demonstrated that Mt. is homogeneously distributed within the film, with only slight changes to its interlayer space. Before evaluating the fluorescence behavior of PQ adsorbed on the films, the robustness of the herbicide's fluorescence signal was confirmed in Mt. dispersions, showing independence from dissolved ions and pH. Fluorescence response as a function of initial herbicide concentration was evaluated under conditions where C_eq ∼ 0. Under these conditions, a linear fluorescence intensity response was observed for the initial PQ concentration in all studied scenarios. The Mt-A composite also exhibited a linear fluorescence response with the initial herbicide concentration within the range of concentrations highly toxic to humans and animals. The simplicity and sustainability of the films synthesis, the ability to preconcentrate the herbicide, the absence of sample preparation, the avoidance of organic solvents, and the simplicity of detection are noteworthy. These findings provide insights for the future development of simple detection systems for PQ in aqueous systems, with montmorillonite as the principal active component.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"268 ","pages":"Article 107746"},"PeriodicalIF":5.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143376555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Halloysite modulated MoC-MoN heterojunction for high-performance LiS Batteries","authors":"Yihui Li ,&nbsp;Chenyu Yan ,&nbsp;Xiongbo Dong ,&nbsp;Aidong Tang ,&nbsp;Huaming Yang","doi":"10.1016/j.clay.2025.107709","DOIUrl":"10.1016/j.clay.2025.107709","url":null,"abstract":"<div><div>Transition metal carbide-nitride heterojunctions have gained great attention in Li<img>S batteries for overcoming the issues such as polysulfide dissolution, poor electrical conductivity of the cathode, and sluggish electrode reaction kinetics. However, precisely designing and synthesizing these potentially important materials is still challenging. Herein, a novel strategy that employs halloysite for MoC-MoN heterojunction with a precisely regulated interface (HNT/MoC-MoN) is proposed. The results show that halloysite surfaces abundant in hydroxyl groups can induce the formation of MoC-MoN heterojunction via enhancing charge transfer at the interface between halloysite and MoC-MoN. The optimized formation of the MoC-MoN heterojunction accelerates the electron migration and the conversion kinetics of lithium polysulfide (LiPSs). By optimizing the design, the synthesized HNT/MoC-MoN composite demonstrates excellent electrochemical performance in Li<img>S batteries, achieving an initial specific capacity of 1100 mAh g⁻¹ at 0.2C and maintaining a capacity of 605 mAh g⁻¹ after 300 cycles. This work may provide valuable insights for the application of natural minerals in Li<img>S batteries.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"267 ","pages":"Article 107709"},"PeriodicalIF":5.3,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergistic role of pillared bentonite with single and binary Fe/Al-polyoxocations on Pb(II) adsorption recovery from hard water under competitive and non-competitive effects","authors":"Samira M. Abdel-Azim ,&nbsp;Noha A.K. Aboul-Gheit ,&nbsp;Sherif A. Younis ,&nbsp;Sahar M. Ahmed","doi":"10.1016/j.clay.2025.107716","DOIUrl":"10.1016/j.clay.2025.107716","url":null,"abstract":"<div><div>This study investigates the post-pillarization of bentonite clay using Fe/Al-polyoxocations—both singular and mixed—to enhance its surface and textural properties for improved adsorption-desorption recovery of Pb(II) ions from hard water. The adsorption-desorption capabilities of the pillared bentonites (referred to as Fe-, Al-, and Fe/Al-PILBCs) are investigated and optimized, taking into account the interactions between water components and operational conditions in both competitive and non-competitive scenarios. The incorporation of mixed Fe/Al pillars significantly increases the surface area, reactivity, and interlayer spacing of the clay, leading to improved pore diffusivity and enhanced interactions between Pb(II) and the Brönsted/Lewis acid sites in Fe/Al-PILBC. Consequently, the adsorption capability of Fe/Al-PILBC for Pb(II) ions is enhanced by 1.33 to 1.53 times compared to single-pillared clay adsorbents. Optimization using response surface methodology demonstrates that the interaction between solution pH and other operational factors is crucial for maximizing the Pb(II) adsorption capacity of Fe/Al-PILBC. This capacity can reach 67.85 mg/g at a pH of 4.5 after 10 min by adjusting the Pb(II) speciation and the surface charge density of Fe/Al-PILBC.Thermodynamic, kinetic, and isotherm studies indicate that the physisorption of Pb(II) onto Fe/Al-PILBC is facilitated by heat energy input (Ea = 21.22 kJ/mol and ΔH^ο = 20.32 kJ/mol), allowing for endothermic adsorption with sustained adsorption-desorption recovery of Pb over 10 cycles. In practical applications involving groundwater and petroleum wastewater, higher ionic strength enhances electrostatic interactions and ion exchange between Ca(II)/Mg(II) cations and the active sites of Fe/Al-PILBC, leading to changes in Pb(II) adsorption thermodynamics due to competitive effects at the solid/liquid interface. Nonetheless, the overall adsorption capacity of Fe/Al-PILBC for divalent metal cations increases by 2.9 times in hard water compared to single Pb adsorption in a non-competitive environment, underscoring the promising potential of Fe/Al-PILBCs for water-softening applications.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"267 ","pages":"Article 107716"},"PeriodicalIF":5.3,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143220288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Occurrence and genesis of hectorite and mixed-layer-illite/hectorite in argillaceous sediments interlayered with Neogene borate deposits, Emet, Türkiye","authors":"Selahattin Kadir ,&nbsp;Hülya Erkoyun ,&nbsp;Tacit Külah ,&nbsp;Muhsin Eren ,&nbsp;Cahit Helvacı ,&nbsp;Burak Demiral","doi":"10.1016/j.clay.2025.107737","DOIUrl":"10.1016/j.clay.2025.107737","url":null,"abstract":"<div><div>The Li-rich claystone was formed within the Miocene volcano-sedimentary units in Emet borate deposits, in western Anatolia. This research identified hectorite and mixed-layer-illite/hectorite-abundant claystone that have technological and economic potential and have not been studied to date. The claystone was formed through the diagenetic alteration of rhyolitic and zeolitic tuffaceous units in a shallow lacustrine playa lake environment under arid climatic conditions. The parent rocks comprise altered and sericitized plagioclase and sanidine, opacited and chloritized biotite/muscovite, zeolite, quartz, and rock fragments cemented by argillizied, sericitized, and carbonatized matrix. Abundant hectoritic smectite and mixed-layer-illite/hectorite accompanied by accessory feldspar, quartz, locally calcite/dolomite, gypsum, and orpiment/realgar. The Li concentration reaches a max of 2200 ppm in the hectorite-abundant claystone and 218 ppm in the tuffaceous units. Smectite flakes are associated with illite fiber, feldspar, and amphibole. The degradation of sanidine, plagioclase, biotite/muscovite, and hornblende contributed to the positive correlation of SiO₂ vs. Al₂O₃, K₂O, TiO₂, and total rare-earth elements (ΣREE) vs. SiO₂, Al₂O₃, and K₂O; MgO vs. Li values, and enhancement of MgO + CaO, Li, Sr + Rb, and ΣREE values, and LREE/HREE ratio; negative Eu anomaly and high concentration of S and As. These physicochemical compositions favored the formation of hectorite and mixed-layer-illite/hectorite. The δD and δ¹⁸O values of hectorite and mixed-layer-illite/hectorite samples and the formation temperatures range from 98 to 119 °C reveal a burial diagenetic alteration process. The δ¹⁸O and δ¹³C values of the calcite samples suggest the mixing of thermal and fresh waters. The high ⁸⁷Sr/⁸⁶Sr ratios of calcite and gypsum reveal the consumption of Sr during the alteration processes. Additionally, the negative δ³⁴S values of realgar and orpiment suggest formation under acidic-neutral conditions via sulfate reduction or microbial cycling.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"267 ","pages":"Article 107737"},"PeriodicalIF":5.3,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143220289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of silicas and aluminosilicate synthesized by sol-gel process on the structural properties of metakaolin-based geopolymers","authors":"Leonardo Martins Costa ,&nbsp;Tarcizo da Cruz Costa de Souza ,&nbsp;Raquel Kenya Ferreira Gonçalves de Oliveira ,&nbsp;Natanael Geraldo Silva Almeida ,&nbsp;Manuel Houmard","doi":"10.1016/j.clay.2025.107743","DOIUrl":"10.1016/j.clay.2025.107743","url":null,"abstract":"<div><div>This study synthesized two silicas and an aluminosilicate (AlS, Al₂O₃.2SiO₂) via the sol-gel process to evaluate their effects on metakaolin-based geopolymers. Two geopolymer dosages were prepared with metakaolin and 0, 1, 2, and 10 %wt. sol-gel materials, using metakaolin and silica-rich byproducts (rice husk ash and silica fume) as references. The results revealed that sol-gel silicas above 2 %wt. led to particle aggregation and alkalis entrapment, worsening efflorescence. Geopolymers with 10 % sol-gel silicas exhibited 3-day compressive strengths of approximately 10 MPa, compared to ∼35 MPa for geopolymers with 10 % sol-gel aluminosilicate or pure metakaolin. This indicates that AlS particles dissolved more readily during geopolymerization, forming binder structures at early ages. Furthermore, AlS-based structures inhibited Na⁺ diffusion in the hardened matrix, reducing efflorescence compared to reference samples. However, this effect was less noticeable at the more porous dosage of geopolymers. AlS-derived structures were more porous than the metakaolin-based structures, limiting strength gain up to 28 days.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"267 ","pages":"Article 107743"},"PeriodicalIF":5.3,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143220290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}