Xiaoyu Zhang , Chunquan Li , Liqiu He , Yujiao Zhang , Fang Yuan , Shuilin Zheng , Zhiming Sun
{"title":"Synergistic antibacterial material of cetylpyridinium/Cu2+/sepiolite and its application in thermoplastic polyurethane films","authors":"Xiaoyu Zhang , Chunquan Li , Liqiu He , Yujiao Zhang , Fang Yuan , Shuilin Zheng , Zhiming Sun","doi":"10.1016/j.clay.2024.107604","DOIUrl":"10.1016/j.clay.2024.107604","url":null,"abstract":"<div><div>Seeking non-antibiotic solutions against bacterial infections has become a global priority. Therefore, this work employs sepiolite as the carrier to load cetylpyridinium (CP<sup>+</sup>) and Cu<sup>2+</sup>, constructing a CP<sup>+</sup>/Cu<sup>2+</sup>/sepiolite (PCS) system with excellent antibacterial and application properties. Sepiolite, serving as a micro-container for storing antibacterial agents, enhances their thermal stability and realizes their “burst + sustained” release. Antibacterial agents improve the organic compatibility of sepiolite and provide a synergistic antibacterial effect. With the released antibacterial agents and contact inactivation effect, PCS at 10 mg/L and 75 mg/L achieve 100 % inactivation of <em>Staphylococcus aureus</em> and <em>Escherichia coli</em> within 120 min, respectively. Furthermore, the sepiolite carrier with an intact fibrous structure facilitates the loading-release and antibacterial activity of agents in PCS. The obtained PCS disperses uniformly in thermoplastic polyurethane and binds tightly with it, improving its mechanical properties. Film of ST-10wt%PCS with 10 wt% PCS inactivates 100 % of <em>Staphylococcus aureus</em> and 93.0 % of <em>Escherichia coli</em> in 4 h, while exhibiting superior elongation at break (263 %) and tensile strength (35 MPa) compared to the pure film (242 % and 30 MPa). Thus, it is evident that the resulting PCS holds promise for the direct use or manufacture of functional products to combat bacterial infections.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"262 ","pages":"Article 107604"},"PeriodicalIF":5.3,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531188","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":"Predicting the diffusion of CeEDTA− and CoEDTA2− in bentonite using decision tree hybridized with particle swarm optimization algorithms","authors":"Zhengye Feng, Jiaxing Feng , Junlei Tian, Xiaoqiong Shi, Dongchen Shao, Tao Wu, Qiang Shen","doi":"10.1016/j.clay.2024.107596","DOIUrl":"10.1016/j.clay.2024.107596","url":null,"abstract":"<div><div>The diffusion of radionuclide anionic complexes in bentonite barriers is of great concern in assessing the safety of repositories for high-level radioactive waste due to their high diffusivity. This study investigated the diffusion behaviors of CeEDTA<sup>−</sup> (as surrogate to <sup>241</sup>AmEDTA<sup>−</sup> and <sup>239</sup>PuEDTA<sup>−</sup>) and CoEDTA<sup>2−</sup> (as surrogate to <sup>60</sup>CoEDTA<sup>2−</sup>) in compacted bentonite using a through-diffusion method, a multi-porosity model (MP), and various decision tree algorithms hybridized with Particle Swarm Optimization (PSO). The algorithms included PSO-Light Gradient Boosting Machine (LightGBM), PSO-Categorical Gradient Boosting (CatBoost), PSO-EXtreme Gradient Boosting (XGBoost), and PSO-Random Forest (RF). The effective diffusion coefficients of these species in compacted Wyoming bentonite were determined utilizing the through-diffusion method to assess the reliability of machine learning (ML) models. The accuracy of cross validation ranked as follows: PSO-LightGBM (R<sub>CV</sub><sup>2</sup> = 0.91) > PSO-XGBoost (R<sub>CV</sub><sup>2</sup> = 0.86) > PSO-CatBoost (R<sub>CV</sub><sup>2</sup> = 0.85) > PSO-RF (R<sub>CV</sub><sup>2</sup> = 0.81). Shapley additive explanation (SHAP) and feature importance (FI) with PSO-LightGBM identified the ion diffusion coefficient in water, total porosity, and rock capacity factor as the top three features. The MP model confirmed the reliability of partial dependence plots (PDP) method, highlighting the good interpretability of ML models. This work provides an accurate, generalizable, and interpretable ML method for analyzing the adsorptive radionuclide anionic complexes diffusion in bentonite barriers.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"262 ","pages":"Article 107596"},"PeriodicalIF":5.3,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531199","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}
Wemerson D.C. Santos , Jhonatam P. Mendonça , Mayara M. Teixeira , Alan S. de Menezes , Alex Rojas , Marco A.S. Garcia , Ana C.S. Alcântara
{"title":"ZIF-8/magadiite layered silicate heterostructure for battery-type supercapacitors","authors":"Wemerson D.C. Santos , Jhonatam P. Mendonça , Mayara M. Teixeira , Alan S. de Menezes , Alex Rojas , Marco A.S. Garcia , Ana C.S. Alcântara","doi":"10.1016/j.clay.2024.107594","DOIUrl":"10.1016/j.clay.2024.107594","url":null,"abstract":"<div><div>By a in situ co-precipitation approach was created a novel heterostructured material by assembling the ZIF-8 zeolitic imidazolate framework on unmodified magadiite layered silicate (Na-MAG). ZIF-8 was successfully associated with the Na-MAG, as demonstrated by the Rietveld refinement, which also revealed the existence of two phases in the heterostructure. In addition to SEM and thermal analysis, <sup>13</sup>C and <sup>29</sup>Si NMR and FT-IR investigations also corroborate the formation of a new compound. Nitrogen adsorption-desorption isotherms indicated a notable increase in surface area to 842 m<sup>2</sup>/g and enhanced pore volume for the heterostructure, suggesting its potential for enhanced energy storage capabilities. Electrochemical analyses, such as Galvanostatic Charge-Discharge (GCD) tests and Cyclic Voltammetry (CV) studies, indicated a distinct hybrid electrochemical behavior integrating capacitive and Faradaic battery-type processes was identified by the CV study. Based on the GCD curves, the specific charge capacities showed that ZIF-8/Na-MAG outperformed its separate components, particularly at lower current densities, achieving a capacity of 291.3 mAh g<sup>−1</sup> at 1 A g<sup>−1</sup>. Charge balancing calculations and CV curves demonstrated this supercapacitor's balanced and effective functioning, highlighting the potential of these materials in high-performance energy storage applications.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"262 ","pages":"Article 107594"},"PeriodicalIF":5.3,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531198","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}
Fulong Cheng , Jie Pan , Changxin Zhao , Wei Li , Yuting Peng , Zuo Zhang , Yanjuan Lin , Guowen Chen
{"title":"Blocking endogenous phosphorus release in sediments by a hydrotalcite mixture synthesized with natural sepiolite and discarded cans","authors":"Fulong Cheng , Jie Pan , Changxin Zhao , Wei Li , Yuting Peng , Zuo Zhang , Yanjuan Lin , Guowen Chen","doi":"10.1016/j.clay.2024.107599","DOIUrl":"10.1016/j.clay.2024.107599","url":null,"abstract":"<div><div>Pure hydrotalcite (LDH) materials prepared from chemical reagents have been investigated as solid-phase phosphorus (P) inactivation materials (SPIM) to manage endogenous P loading in sediments. However, the efficacy and mechanism of LDH mixtures prepared by natural minerals and solid wastes in controlling sediment P release are unclear. Therefore, a Ca/Mg-Al-LDH (CMA-LDH) material was synthesized using sepiolite and cans, and its efficacy, mechanism, and ecological impact in controlling sediment P release were investigated. CMA-LDH-p was prepared as a control material using pure chemical reagents. The CMA-LDH and CMA-LDH-p were both composed of hydrotalcite and hydrocalumite. The maximum P adsorption capacity of CMA-LDH was 123.01 mg/g, comparable to that of CMA-LDH-p. The adsorbed P by CMA-LDH was mostly in the stable P form, accounting for 87.2 % of the total P. The adsorption capacity and immobilization ability of CMA-LDH for P were superior to other reported LDH-based SPIM. Both the CMA-LDH addition and capping successfully blocked sediment P release under anaerobic conditions. Passivation of mobile P in the sediment and DGT-labile P in the interstitial water was critical to preventing sediment P release by the CMA-LDH addition. The CMA-LDH capping inhibited sediment P release through the effective adsorption of CMA-LDH on DGT-labile P at the sediment/overlying water interface. The CMA-LDH addition and capping affected the abundance of microbial communities associated with iron and sulfur cycling, which might affect the stability of endogenous P. These results confirmed that CMA-LDH addition and capping treatments were effective methods for managing sediment P loading.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"261 ","pages":"Article 107599"},"PeriodicalIF":5.3,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445238","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}
T.B. Musso , G. Pettinari , A.B. Galán , G.A. Martinez , M. Pozo
{"title":"Compositional and textural evidences of Na-bentonite authigenesis in the Pellegrini lake deposit (Neuquen basin, Argentina)","authors":"T.B. Musso , G. Pettinari , A.B. Galán , G.A. Martinez , M. Pozo","doi":"10.1016/j.clay.2024.107598","DOIUrl":"10.1016/j.clay.2024.107598","url":null,"abstract":"<div><div>Textural and compositional variations of Na-bentonites from the Pellegrini Lake deposit (Neuquén Basin) have been established, with special emphasis on petrographic features in order to better understand the genetic pathways in their formation. In this region, two bentonite beds named “white bentonite” and “green bentonite” are mined mainly for the oil and foundry industries. The genesis of these beds was studied using petrological (petrography, SEM and TEM), mineralogical (DRX, FT-IR, DTA-TGA, <sup>27</sup>Al MAS NMR) and geochemical (ICP-AES) data from two quarries named COR and CA. The bentonites mainly consist of Na-montmorillonite, with lesser amounts of quartz, plagioclase, potassium feldspar, illite, zeolite, barite and gypsum. Mineralogical and petrographical evidence indicates that the authigenic smectite was formed by devitrification of unstable glass shards in a shallow coastal marine environment. Green bentonite would be the result of several episodes of volcanic ash-fall input from multiple eruptions with a higher degree of alteration uppermost in the bed. In this case, the alteration would have occurred in a reducing environment as evidenced by the greenish colouration of these bentonites, the Ce anomaly and the presence of pyrite. Meanwhile, white bentonite would have formed in a less restricted environment than green bentonite, as evidenced by the existence of intercalations of silt-sized grains and a higher amount of detrital grains in the clay groundmass transported probably by fresher waters. The presence of celestine, barite, halite and gypsum indicates evaporitic conditions after smectite formation. The observed secondary gypsum and iron staining of surfaces are much later processes. Green bentonite samples indicate a trachyandesite composition of the parent material, while the white bentonite suggests a parent material most related to a rhyodacite/dacite composition showing that the characteristics of the volcanism might have changed with time.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"261 ","pages":"Article 107598"},"PeriodicalIF":5.3,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445239","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}
Yu-Cheng Li , Yong-Gui Chen , Li Liu , Guo-Ping Zhang , Wei-Min Ye , Qiong Wang
{"title":"Extracting hydromechanical properties of montmorillonite quasi-crystals via nanoindentation of oriented thin films","authors":"Yu-Cheng Li , Yong-Gui Chen , Li Liu , Guo-Ping Zhang , Wei-Min Ye , Qiong Wang","doi":"10.1016/j.clay.2024.107595","DOIUrl":"10.1016/j.clay.2024.107595","url":null,"abstract":"<div><div>This paper presents the first effort to extract the hydromechanical properties of montmorillonite quasi-crystals via nanoindentation testing of highly oriented montmorillonite thin films with varying degrees of water intercalation. By preparing highly preferentially oriented montmorillonite thin films, the evolution of basal spacing, isothermal adsorption of water, microstructure, and mechanical properties of montmorillonite quasi-crystals equilibrated with different relative humidity (RH) was examined by the grazing incidence X-ray diffraction (GIXRD), sorptometry, environmental scanning electron microscopy (ESEM), and nanoindentation, respectively. Results indicate that the montmorillonite thin films exhibit depth-dependent mechanical properties across different RH. At a 40 % RH, the Young's modulus and hardness of a montmorillonite quasi-crystal consisting of ∼60 platelets are 4.85 and 0.20 GPa, which remain relatively stable upon increasing the RH to 50 % but experienced a remarkable decrease to 3.31 and 0.12 GPa when the RH reaches 65 %. Simultaneous GIXRD and isothermal adsorption results reveal the interlayer swelling as the key factor contributing to the mechanical property variation of montmorillonite quasi-crystal, while the capillarity dominates the mechanical behavior at high RH. This study shed light on the hydromechanical behavior of montmorillonite upon hydration and swelling, and paves a solid foundation for the multiscale modeling of unsaturated compacted bentonites.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"261 ","pages":"Article 107595"},"PeriodicalIF":5.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442298","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}
Yulu Chen , Li Huang , Jusheng Gao , Shuo Zhao , Lei Huang , Mingjian Geng , Yangbo He , Huimin Zhang , Jing Huang
{"title":"Clay minerals transformation in soil particles of Udic Ferrisols under 36-year Chinese milk vetch application in southern China","authors":"Yulu Chen , Li Huang , Jusheng Gao , Shuo Zhao , Lei Huang , Mingjian Geng , Yangbo He , Huimin Zhang , Jing Huang","doi":"10.1016/j.clay.2024.107593","DOIUrl":"10.1016/j.clay.2024.107593","url":null,"abstract":"<div><div>To elucidate the impact of green manure application on soil clay minerals, surface soil samples (0–20 cm) were collected from Udic Ferrisols developed from Quaternary clay sediments, under no fertilization (CK) and Chinese milk vetch (MV) application treatments, based on a 36-year long-term experiment in southern China. Synchrotron X-ray diffraction (XRD), thermogravimetric analysis (TG), <sup>27</sup>Al and <sup>29</sup>Si nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), and high-resolution transmission electron microscopy (HRTEM) were employed to investigate the composition and structural characteristics of clay minerals in soil particles (100–2000 nm and 25–100 nm). The clay minerals in the 100–2000 nm and 25–100 nm particles were mainly kaolinite and illite, containing a minor amount of vermiculite. As the particle size decreased to the nanoscale (25–100 nm), the kaolinite content increased, the vermiculite content decreased, and the crystallinity of the clay minerals weakened. Aluminum (Al) in the structure of the clay minerals mainly existed as octahedral coordinated Al (<sup>VI</sup>Al), with a small proportion of tetrahedral coordinated Al (<sup>IV</sup>Al) (5.8 %–18.4 %) predominantly as Q3(1Al) (where silicon (Si) in the tetrahedron was connected to three neighboring Si atoms through oxygen to form a framework structure). The abundance of <sup>IV</sup>Al decreased significantly with decreasing particle size, and the structure of the clay minerals gradually shifted from a 2:1 to a 1:1 type. In the 100–2000 nm particles, MV application reduced illite content and increased <sup>IV</sup>Al abundance. HRTEM observation revealed a transition of lattice fringes from 1.0 nm to 1.38 nm. Conversely, in the 25–100 nm particles, MV application decreased <sup>IV</sup>Al abundance and increased kaolinite content, with the 1.38 nm lattice fringes gradually transformed into 0.71 nm. These findings indicate that long-term MV incorporation promoted the transformation of illite to vermiculite in the 100–2000 nm particles and vermiculite to kaolinite in the 25–100 nm particles to a certain extent.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"261 ","pages":"Article 107593"},"PeriodicalIF":5.3,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142437847","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}
Judith Granados-Reyes, Angie C. Rueda, Yolanda Cesteros
{"title":"Synthesis of NiCuMgAl-layered double hydroxides using advanced microwave and ultrasound methods","authors":"Judith Granados-Reyes, Angie C. Rueda, Yolanda Cesteros","doi":"10.1016/j.clay.2024.107590","DOIUrl":"10.1016/j.clay.2024.107590","url":null,"abstract":"<div><div>The effect of using ultrasound vs magnetic stirring, microwaves vs conventional heating, and autoclave vs refluxing on the synthesis of NiCuMgAl-layered double hydroxides (LDH) was widely studied. The use of ultrasounds during coprecipitation resulted in lower LDH crystallinity, difficulted the incorporation of the divalent cations in the layer and led to low specific surface area and low basicity. This could be attributed to smaller crystallization nuclei formed under ultrasound; that is, more efficient agitation due to cavitation phenomena, led to less crystal growth. The use of microwaves refluxing during the aging step instead of conventional heating resulted in higher crystallinity, allowing a better incorporation of the cations in the layer, obtaining higher specific surface area and higher amount of stronger basic sites. Interestingly, the use of autoclave at higher temperature (180 °C) but at shorter time (1 h) improved the crystallinity of the LDH samples, especially in the stacking direction and applying microwaves, favoring the incorporation of the cations in the layer. Autoclave under microwaves led to higher amount of basic sites but lower surface area than autoclave by conventional heating at the same conditions. This suggests that microwaves favored a better incorporation of the hydroxyl groups into the layers and/or the appearance of surface-defective sites.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"261 ","pages":"Article 107590"},"PeriodicalIF":5.3,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Montmorillonite modification and chromate adsorption mechanisms of organo-montmorillonite: A multiscale study","authors":"Xueying Liu , Wei Yang , Renpeng Chen","doi":"10.1016/j.clay.2024.107592","DOIUrl":"10.1016/j.clay.2024.107592","url":null,"abstract":"<div><div>Cetyltrimethylammonium bromide modified montmorillonite (CTMAB-Mt) demonstrates effective removal of hexavalent chromium. It is crucial to understand the mechanisms by which changes in the microstructure of montmorillonite affect its adsorption capacity. This study combines molecular dynamic simulation, microscopic detection, and column/batch tests to reconstruct the microstructure of CTMAB-Mt at various loading levels and to investigate its chromate adsorption behavior. The results indicate that the primary modification mechanism of CTMAB-Mt involves ligand binding between the head group N(CH<sub>3</sub>)<sub>3</sub> of the organic modifier and the surface oxygen of the siloxane layer in the clay. Compared to capture by CTMA<sup>+</sup>, CrO<sub>4</sub><sup>2−</sup> prefers to form aqueous complexes, resulting in limited enhancement of CTMAB-Mt's adsorption capacity at low loading levels (<1.00 CEC). Notably, Molecular dynamics simulations reveal that the adsorption capacity of 1.00 CTMAB-Mt is exceptionally high, reaching 7.87 mg/L. This finding is consistent with results from column and batch tests, providing a novel method for calculating the heavy metal adsorption capacity. The enhanced adsorption capacity is primarily due to electrostatic attraction and van der Waals forces between the head groups of CTMA<sup>+</sup> and CrO<sub>4</sub><sup>2−</sup>. A comprehensive understanding of chromate adsorption by modified montmorillonite is essential for developing modified clay and preventing chromium pollution.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"261 ","pages":"Article 107592"},"PeriodicalIF":5.3,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142419526","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}
Emily Maulden , Elizabeth Gager , An T. Ta , Rachel F. Wood , Daria Boglaienko , Juan C. Nino , Carolyn I. Pearce , Simon R. Phillpot , James E. Szecsody , Nathalie A. Wall
{"title":"Organometallic functionalized clays for technetium immobilization","authors":"Emily Maulden , Elizabeth Gager , An T. Ta , Rachel F. Wood , Daria Boglaienko , Juan C. Nino , Carolyn I. Pearce , Simon R. Phillpot , James E. Szecsody , Nathalie A. Wall","doi":"10.1016/j.clay.2024.107588","DOIUrl":"10.1016/j.clay.2024.107588","url":null,"abstract":"<div><div>Nuclear waste repository designs require backfill materials to contain long-lived radionuclides, including technetium-99, present as the pertechnetate anion (TcO<sub>4</sub><sup>−</sup>) under oxic repository conditions and mobile in the environment. Bentonite has been proposed as a suitable backfill material, and it is composed of montmorillonite clay, which can be functionalized to optimize its performance for TcO<sub>4</sub><sup>−</sup> sorption. In the current work, bentonite clay is functionalized with organic and inorganic moieties, and the impact of dual functionalization on TcO<sub>4</sub><sup>−</sup> sorption is investigated. The results show that the ordering of the functionalization is essential and that adding metal to an organoclay improves TcO<sub>4</sub><sup>−</sup> sorption compared to either the reverse ordering or the organic/inorganic clay alone. Furthermore, the TcO<sub>4</sub><sup>−</sup> sorption to the organometallic clays was consistent with either chemisorption or cooperative sorption, with a multi-step mechanism determining the kinetics of sorption.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"261 ","pages":"Article 107588"},"PeriodicalIF":5.3,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142419524","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}