Applied Clay Science最新文献

{"title":"Sorption mechanism of europium(III) onto metakaolin-based geopolymers","authors":"Anıl C. Yıldırım ,&nbsp;Huiyang Mei ,&nbsp;Kanako Toda ,&nbsp;Noboru Aoyagi ,&nbsp;Takumi Saito","doi":"10.1016/j.clay.2025.107853","DOIUrl":"10.1016/j.clay.2025.107853","url":null,"abstract":"<div><div>Metakaolin-based geopolymers (MKGPs) are ceramic-like materials used for nuclear waste stabilization. Therefore, understanding the sorption of ions on MKGPs is crucial where the cation exchange is considered as the main mechanism, yet the studies based on pH are limited. Thus, this study evaluates the effect of pH on the sorption mechanism of Eu(III) onto Na- and K-MKGPs. Here, time-resolved laser fluorescence spectroscopy (TRLFS) combined with parallel factor analysis, TRLFS in mixed D₂O/H₂O matrices, and extended X-ray absorption fine structure analysis. Eu(III) predominantly forms surface complexes with both MKGPs in the pH range of 4–11 at the open air environment, where three distinct surface species were identified at different pH values. The Eu(III) sorption mechanisms of both MKGPs are similar, involving ternary edge-sharing bidentate or monodentate inner-sphere surface complexation of Eu(III) with MKGP and silicate ions released from the MKGP up to pH 8, followed by the precipitation of Eu(OH)_3(S) within the pores of MKGP. The insights gained from this study will enhance the knowledge on MKGP for pollutant immobilization, thereby mitigating the spread of contaminants in the environment and expanding the potential application areas.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"274 ","pages":"Article 107853"},"PeriodicalIF":5.3,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071785","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":"Uranium coordination on clay surface at nanoscale: Integration of EXAFS data and Ab initio molecular dynamics","authors":"Anna D. Krot ,&nbsp;Evgeny V. Tararushkin ,&nbsp;Alexander L. Trigub ,&nbsp;Irina E. Vlasova ,&nbsp;Stepan N. Kalmykov","doi":"10.1016/j.clay.2025.107863","DOIUrl":"10.1016/j.clay.2025.107863","url":null,"abstract":"<div><div>Understanding the interactions between uranium and clay minerals at the molecular level is crucial for addressing environmental contamination and nuclear waste management. In this work we are focusing on the determination the molecular-level structure of uranium (VI) surface species on smectite using a combination of EXAFS spectroscopy and ab initio molecular dynamics simulations (AIMD). A set of samples was prepared with uranyl cation adsorbed on bentonite clay of three deposits at various pH and uranium concentrations. To elucidate the structure of the adsorbed species at nanoscale, AIMD simulations were carried out for uranyl coordination models at basal surface and on edge sites of clay mineral. Linear combination fitting of experimental EXAFS spectra with those calculated from AIMD trajectories allowed us to specify the fractions of each adsorbed complex configuration present at pH 3, 5 and 8. At low pH, the speciation of the adsorbed uranyl cation is mainly comprised of outer-sphere basal complex. When pH is increased to 5, edge complexes at (110) surface become predominant, and at pH 8 uranyl cation is mainly localized at (010) surface of clay mineral. With the implementation of advanced molecular dynamics simulations and spectroscopic techniques, the obtained results for the first time reveal the structure of the adsorbed uranyl complexes on clay mineral surfaces at nanoscale.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"274 ","pages":"Article 107863"},"PeriodicalIF":5.3,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071784","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":"Partial substitution of TEOS with pyridyl-silanes: A route to functionalizing inner wall of imogolite nanotubes","authors":"Cristóbal Flores ,&nbsp;Karen Manquián-Cerda ,&nbsp;Carlos P. Silva ,&nbsp;Jorge Pavez ,&nbsp;Nicolás Arancibia-Miranda","doi":"10.1016/j.clay.2025.107861","DOIUrl":"10.1016/j.clay.2025.107861","url":null,"abstract":"<div><div>A new imogolite isostructure (Imo-Py) was obtained and characterized structurally and superficially, where 5 % of the TEOS was replaced by 2-(4-pyridylethyl)triethoxysilane. Incorporating the new organosilane did not cause significant inhibitions to nanotubular formation. However, an increase in the diameter and reactivity of the internal cavity of Imo-Py compared to imogolite was evidenced, attributable to the differences in charge and acidity properties of the incorporated functional groups. This study expands the family of imogolite-based nanostructures and could contribute to new technological applications.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"274 ","pages":"Article 107861"},"PeriodicalIF":5.3,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947218","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 elevated temperature on Wyoming bentonite and its implications for sorption of radioactive strontium","authors":"Gianni F. Vettese ,&nbsp;Xiaodong Li ,&nbsp;Afrida Fairuz ,&nbsp;Taavi Vierinen ,&nbsp;Lilia Sirén ,&nbsp;Damien Prieur ,&nbsp;Nina Huittinen ,&nbsp;Kathleen A. Law ,&nbsp;René Bes ,&nbsp;Mika Niskanen ,&nbsp;Noora Pakkanen ,&nbsp;Markus Olin ,&nbsp;Marja Siitari-Kauppi","doi":"10.1016/j.clay.2025.107865","DOIUrl":"10.1016/j.clay.2025.107865","url":null,"abstract":"<div><div>Bentonite is a key barrier material in deep geological facilities for spent nuclear fuel, where it may be exposed to temperatures &gt;100 °C because of radiogenic heating. Understanding how prolonged heating affects its physicochemical properties and radionuclide retention capacity is critical for ensuring long-term repository safety. This study investigated the impacts of dry heating (unconfined, evaporation allowed) at 150 °C for 36 months on the mineralogical and geochemical stability of a Wyoming bentonite, chosen for the Finnish geological disposal facility, and its subsequent sorption behavior with ⁹⁰Sr. Although the bentonite mineralogy remained mostly stable, combined X-ray diffraction, cation exchange capacity, titrations, demonstrated partial Na to Ca exchange within montmorillonite's interlayer following heating, and specific surface area analyses revealed a &gt; 50 % reduction in specific surface area (30 to 14 m²/g). Colloid stability tests revealed that bentonite colloids did not form under repository-relevant saline conditions (<em>I</em> = 0.2 M), and heat treatment did not significantly impact colloid formation in reduced ionic-strength systems. Sorption isotherms demonstrated that Sr sorption was strongly pH-dependent, increasing from ∼40 % at pH 8 to ∼90 % at pH 13, and heating slightly enhanced Sr retention at pH 8. Two-site protolysis non-electrostatic surface complexation and cation exchange modelling suggested that in unheated bentonite, Sr was bound via a combination of surface complexation (∼30 %) and cation exchange (∼70 %) at pH 8, while at pH 13, sorption shifted towards surface complexation. However, after heating, cation exchange dominated at both pH values. Extended X-ray absorption fine structure analysis confirmed outer-sphere Sr sorption at pH 8 and increasing inner-sphere complexation at pH 13. Together, these findings highlight that despite minor physicochemical alterations, bentonite retained its Sr sorption potential, supporting its continued suitability as a buffer material in the ONKALO® repository.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"274 ","pages":"Article 107865"},"PeriodicalIF":5.3,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067996","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":"Biogrouting and bio-clay grouting: Regulating biocement location with clay","authors":"Guo-Liang Ma ,&nbsp;Yang Xiao ,&nbsp;Qingyun Fang ,&nbsp;Xiang He","doi":"10.1016/j.clay.2025.107860","DOIUrl":"10.1016/j.clay.2025.107860","url":null,"abstract":"<div><div>Biogrouting has been proposed for improving mechanical properties of soils and rocks, whose performance greatly depends on the location of biocement at pore-scale. To enhance the performance of biogrouting, many strategies were proposed, including the addition of assistants, controlling curing moisture degree, and flocculation of bacteria. Clay is one such assistant which has been proven to be effective, with an assumption of increasing active biocement, i.e. those located between soil particles. In this work, we employed microfluidics to directly observe whether clay minerals can certainly control the location of precipitates and how they function. First of all, the capacity of bentonite and kaolin for adsorbing bacteria were investigated. Then, the location of CaCO₃ crystals with and without clay minerals were visually observed using microfluidics. Pore-filling ratios and CaCO₃ ratios, which are closely related to permeability and strength of biocemented soils, were quantitatively analyzed from collected images. Finally, the effects of bentonite and kaolin and their dosages on the location of biocement were comprehensively discussed. The results demonstrated that the performance of bentonite and kaolin on adsorbing bacteria and regulating biocement location is distinct due to differences in the morphologies of clays. These findings can help us to improve biogrouting performance on soil stabilization and propose new strategies in various practical applications, such as CO₂ sequestration, heavy metal remediation, and oil recovery enhancement, all with a foundational understanding of their mechanisms.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"274 ","pages":"Article 107860"},"PeriodicalIF":5.3,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948080","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":"Fast hydrothermal and microwave synthesis of high purity methylated imogolite nanotubes","authors":"Y. Zhang ,&nbsp;F. Alfadel Raad ,&nbsp;P. Picot ,&nbsp;F. Gobeaux ,&nbsp;A. Thill ,&nbsp;X. Sun ,&nbsp;D. Schaming ,&nbsp;L. Sicard","doi":"10.1016/j.clay.2025.107851","DOIUrl":"10.1016/j.clay.2025.107851","url":null,"abstract":"<div><div>To take advantage of the many potential applications of hybrid imogolites, a one-pot reproducible and fast synthesis route is desirable. However, the current protocols are time consuming, necessitating heating for several days to temperatures of around 90 °C, and often lead to turbid solutions. Here, a new synthesis is developed at higher temperature that produces a purer nanotube dispersion within a few hours. In this work, we increased the reaction temperature from 90 °C to 150 °C and even 200 °C, using either a conventional resistive oven or a microwave. Characterization of the suspensions obtained after different thermal treatment durations using several characterization techniques, including FTIR spectroscopy, SAXS, XRD, UV–visible spectroscopy and TEM microscopy, we show that high purity limpid methyl-imogolite suspensions can be obtained within 3 h at 150 °C and 1 h at 200 °C. We also evidence that nanotubes are intermediate species that are obtained in a limited time window that varies with temperature and heating mode. At low heating duration, their precursor, metastable proto-imogolite, is predominant while at high heating duration, imogolite decomposes to form aluminum hydroxides. Increasing the temperature within the corresponding time window results in an increase of the nanotube length.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"274 ","pages":"Article 107851"},"PeriodicalIF":5.3,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143943520","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":"Physical and mechanical properties of ceramics: insights into raw material selection in prehistoric pottery production in Croatia","authors":"Natali Neral ,&nbsp;Andreja Kudelić ,&nbsp;Ana Maričić ,&nbsp;Biljana Kovačević Zelić","doi":"10.1016/j.clay.2025.107859","DOIUrl":"10.1016/j.clay.2025.107859","url":null,"abstract":"<div><div>This study investigates the physical and mechanical properties of ceramics, with a particular emphasis on the influence of clay composition and tempering materials on ceramic point load strength and the technological process involved in ancient ceramic production. A combination of analytical methods was employed, including X-ray diffraction (XRD), optical microscopy, laser granulometry, Atterberg limits, shrinkage evaluation, and the point load index test. Two clay types; sandy clay and inclusion-poor clay, alongside four tempering materials; calcite, sand, grog, and vegetal material, all commonly used during prehistory in Croatia, were analysed. The results show that the inclusion-poor clay requires more complex preparation and firing but results in stronger ceramics. In contrast, sandy clay, which is easier to process and fire, produces ceramics with lower strength. The effect of tempering materials is clay-dependent, with a more significant impact observed in inclusion-poor clay. These results emphasize the critical role of clay in shaping the production process and ceramic properties, highlighting the need to adapt technological process to clay characteristics. Communities selecting sandy clay prioritized ease of preparation, while those using inclusion-poor clay valued its superior functionality despite greater technological demands.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"274 ","pages":"Article 107859"},"PeriodicalIF":5.3,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143943519","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":"Deposition and release of clay colloids on alumina and natural organic matter surfaces via heterogeneous pathways","authors":"Yuanqi Fu ,&nbsp;Heng Wang ,&nbsp;Zhenyu Yang ,&nbsp;Liangke Liu ,&nbsp;Xiaohu Jin ,&nbsp;Yajing Huang ,&nbsp;Xiaoyao Wang ,&nbsp;Xiaoyun Yi ,&nbsp;Zhi Dang","doi":"10.1016/j.clay.2025.107856","DOIUrl":"10.1016/j.clay.2025.107856","url":null,"abstract":"<div><div>Clay colloids are ubiquitous on land and in aquatic environments. Because of their overall negative surface charge, the impact of surface charge heterogeneity has long been overlooked. In this work, we demonstrate that both the deposition and the release of montmorillonite colloids (MONTs) are influenced by surface charge heterogeneity, both on positively charged metal oxide (alumina) surfaces and negatively charged natural organic matter (NOM: humic acid and alginate) surfaces. Deposition trends show that MONTs has the highest attachment on alginate, due to the positive charge and rich hydroxyl functional groups at the edges of MONTs, as well as the coarser surface produced by the extended conformation of alginate macromolecules. At very low ionic strength (IS), MONTs can deposit onto alumina in a face-face adsorption manner due to electrostatic attraction, while no deposition occurs on NOM because of electrostatic repulsion. At high IS, the compression of the basal surface electrical double layer (EDL) exposes the edge EDL of the MONTs, leading to significant deposition on the NOM via the edge. In addition, on the MONT layer already deposited on the alumina surface, small particles of MONT also further deposit via the edge adsorption. When divalent ions are present, in addition to the EDL compression a cation bridge effect between the edges of the MONTs and the NOM surface occurs, thereby reducing release. These findings provide new insights into the study of the deposition behavior of charge-heterogeneous colloids, such as MONTs, in the environment.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"274 ","pages":"Article 107856"},"PeriodicalIF":5.3,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936871","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":"Interlayer cation effects on optical and dielectric properties of montmorillonite in terahertz frequency band","authors":"Lixian Hao ,&nbsp;Shusen Zhou ,&nbsp;Zhiyuan Zheng ,&nbsp;Chutong Gao ,&nbsp;Mingrui Zhang ,&nbsp;Tong Zhang ,&nbsp;Haochong Huang ,&nbsp;Bingcheng Luo ,&nbsp;Hao Liu","doi":"10.1016/j.clay.2025.107857","DOIUrl":"10.1016/j.clay.2025.107857","url":null,"abstract":"<div><div>This study investigates the optical and dielectric properties of montmorillonite through terahertz time-domain spectroscopy. The results reveal that the absorption coefficient, refractive index, dielectric constant, and conductivity increase with montmorillonite content. Notably, differences were observed between Na-type and Ca-type montmorillonite, particularly in dielectric constants, with Na-type exhibiting a stronger dielectric response. Additionally, humidity significantly affects these properties, with both optical and dielectric characteristics increasing with moisture content. Molecular dynamics simulations analyzed and compared self-diffusion coefficients and radial distributions of both montmorillonite types, revealing conductivity peaks at 0.59 (Na-type) and 0.44 (Ca-type), which are supporting experimental results. These findings suggest that montmorillonite type and humidity significantly influence their optical and dielectric properties, providing a framework for understanding montmorillonite behavior in the terahertz frequency range.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"274 ","pages":"Article 107857"},"PeriodicalIF":5.3,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936771","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":"Water-in-water pickering emulsions stabilized by talc or kaolinite layered particles","authors":"Vitor Vianna de Souza Machado ,&nbsp;Bianca Hazt ,&nbsp;Anne Raquel Sotiles ,&nbsp;Rilton Alves de Freitas ,&nbsp;Fernando Wypych","doi":"10.1016/j.clay.2025.107858","DOIUrl":"10.1016/j.clay.2025.107858","url":null,"abstract":"<div><div>Kaolinite (Kaol) - Al₂Si₂O₅(OH)₄ and talc - Mg₃Si₄O₁₀(OH)₂ (Talc) are abundant clay minerals, with layered particles characterized by nanometric thicknesses and few micrometers in length. Such characteristics are interesting attributes when considering the stabilization of emulsions with low interfacial tension, like in water-in-water emulsions. Here, Kaol and Talc layered particles were characterized by several instrumental techniques. Then, we evaluated the effect of Kaol and Talc addition on water-in-water emulsions, formed by aqueous colloidal dispersions of amylopectin (AMP) and xyloglucan (XG) polymers. The emulsions were evaluated macroscopically and by means of droplet size distributions. The apparent contact angle (ACA) of a water droplet in atmospheric air was also measured on Kaol and Talc pressed pellets. Due to a larger droplet size (D50 = 2.01 ± 0.20 μm) when compared to Kaol (D50 = 0.34 ± 0.02 μm), Talc particles did not create complete coverage on the droplet surfaces. The droplets were also dragged down faster, increasing coalescence and the average droplet size after 24 h of preparation. In both cases, the difference in densities between the solids and the aqueous phases led to particle sedimentation, even when adsorbed to the interface of the droplets, generating a concentrated emulsion at the bottom of the flasks. While talc particles sedimented completely after 72 h, Kaol ones remained at the droplets interface, creating Pickering emulsions with enhanced stability.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"274 ","pages":"Article 107858"},"PeriodicalIF":5.3,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936770","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}