Applied Clay Science最新文献

{"title":"A novel green approach for the synthesis of binder-free zeolite NaX foams by joint utilization of metakaolin and clinoptilolite as Si-Al precursors","authors":"Luowen Xiang ,&nbsp;Qiancheng Qiao ,&nbsp;Xiumei Qiu ,&nbsp;Sen Zhou ,&nbsp;Hongquan Wang ,&nbsp;Xiaoyan Zhu ,&nbsp;Chunjie Yan ,&nbsp;Yi Liu","doi":"10.1016/j.clay.2025.108060","DOIUrl":"10.1016/j.clay.2025.108060","url":null,"abstract":"<div><div>Binder-free zeolite NaX foams were successfully prepared through a novel one-step geopolymer-gels-conversion approach using H₂O₂ solution as a foaming agent. Unlike traditional methods that utilize clay materials combined with expensive chemical Si<img>Al reagents as precursors, metakaolin and natural clinoptilolite (mass ratio = 1:1) were selected as Si<img>Al sources for zeolite NaX synthesis. Zeolite foams were systematically characterized and their CO₂ adsorption performance was evaluated. Crystalline phases in natural clinoptilolite (clinoptilolite, albite, illite and quartz) and impurity phases in metakaolin (anatase and quartz) were found to be partially or completely dissolved during alkaline activation process. The resultant foam products exhibit hierarchical porosity, featuring macropores (∼1–2 mm) and zeolite micropores, with compressive strength of 0.83–2.6 MPa, bulk density of 0.51–0.84 g/cm³, BET surface area of 33.18–188.79 m²/g and CO₂ adsorption capacity of 0.24–1.84 mmol/g (1 bar). Pure phase binder-free zeolite NaX foam with the relatively high crystallinity, suitable compressive strength (1.48 MPa), and high BET surface area (188.79 m²/g) was synthesized at SiO₂/Al₂O₃ molar ratio = 3.4, SiO₂/Na₂O molar ratio = 3.8, NaOH activator concentration = 10 M, crystallization temperature of 80 °C and crystallization time of 24 h. This work presents an innovative perspective on developing clay materials as promising Si<img>Al sources for zeolite synthesis.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"280 ","pages":"Article 108060"},"PeriodicalIF":5.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145571116","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-polymer composite adsorbents for in situ uranium remediation in groundwater: Adsorption mechanism, reusability, and field-scale performance estimation","authors":"Subeen Kim ,&nbsp;Sanghee Park ,&nbsp;Donghye Heo ,&nbsp;Jimin Mun ,&nbsp;Minhee Lee ,&nbsp;Minjune Yang","doi":"10.1016/j.clay.2025.108043","DOIUrl":"10.1016/j.clay.2025.108043","url":null,"abstract":"<div><div>This study presents the development and evaluation of a montmorillonite–polysulfone sorbent (MPS) designed for the remediation of uranium-contaminated groundwater. The composite was synthesized by embedding montmorillonite (MMT) into a polysulfone (PSF) matrix to combine the high adsorption capacity of layered silicates with the mechanical stability of synthetic polymers. Batch experiments were conducted to investigate the effects of MMT content, pH, contact time, and uranium (U) concentration on adsorption behavior. Optimal performance was achieved with 4 wt% MMT, showing &gt;99 % adsorption efficiency at pH 7.0. Kinetic data were best described by the pseudo-first-order model (<span><math><msup><mi>R</mi><mn>2</mn></msup></math></span> = 0.969), while the Elovich model captured late-stage adsorption behavior, suggesting a two-phase mechanism involving rapid physisorption followed by slower chemisorption. Isotherm analysis indicated that both Langmuir and Freundlich models fitted the data well, with a maximum adsorption capacity of 453.7 μg/g. SEM-EDS characterization confirmed U penetration into both surface and internal pore structures of MPS. Reusability tests demonstrated sustained adsorption (≥95 %) and desorption (≥93 %) efficiencies over ten cycles using 0.1 M HNO₃. In continuous-flow permeable reactive barrier (PRB) system, MPS maintained U removal efficiencies &gt;95 % over 34 pore volumes, with minimal breakthrough. Field-scale modeling suggests that an MPS-based PRB can treat 3.27 × 10⁴ m³ of groundwater over 7 yr with ten regeneration cycles. These findings highlight the structural robustness and practical applicability of MPS for <em>in situ</em> U remediation under realistic hydrogeological conditions.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"280 ","pages":"Article 108043"},"PeriodicalIF":5.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616299","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":"Metakaolin-based single-step engineered geopolymer composites: Design and performance characterization","authors":"Fei Wang ,&nbsp;Long Liang ,&nbsp;Yao Ding ,&nbsp;Xinjian Sun ,&nbsp;Jingming Cai ,&nbsp;Neven Ukrainczyk ,&nbsp;Kequan Yu","doi":"10.1016/j.clay.2025.108055","DOIUrl":"10.1016/j.clay.2025.108055","url":null,"abstract":"<div><div>Conventional one-part engineered geopolymer composite (EGC) facilitates the mixing process of EGC. However, this “one-part” only refers to the matrix of EGC, the reinforcing fiber as the second step should be separately added during mixing. In this study, through a careful multi-component design to regulate matrix rheology and fiber dispersion, we pioneer the development of a single-step metakaolin-based EGC, which requires only a single mixing step of adding water to achieve exceptional tensile performance, without dry pre-mixing process. This one-part EGC exhibits a density of approximately 1100 kg/m³ and a compressive strength of up to 40 MPa, outperforming conventional “one-part” geopolymers with similar densities. Remarkably, with only 0.5 % fiber volume fraction, about 1/4 of that in conventional EGC, the proposed single-step EGC achieves a high tensile strain capacity of 6 %. Further, the 28-day dry shrinkage remains below 300 με, setting a new benchmark for the lowest dry shrinkage in geopolymers (400–1000 με) and even rivaling ordinary concrete with similar strength grades. The current findings can address the production process shortcoming of conventional fiber-reinforced composite compared to ordinary concrete and facilitate the practical application of EGC.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"280 ","pages":"Article 108055"},"PeriodicalIF":5.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616300","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":"Swelling pressure response of Bentonil-WRK bentonite under thermal cycling up to 150°C","authors":"Deuk-Hwan Lee ,&nbsp;Seok Yoon ,&nbsp;Minhyeong Lee ,&nbsp;Seeun Chang ,&nbsp;Changsoo Lee ,&nbsp;Dong-Keun Cho ,&nbsp;Gi-Jun Lee","doi":"10.1016/j.clay.2025.108046","DOIUrl":"10.1016/j.clay.2025.108046","url":null,"abstract":"<div><div>This study investigates the thermal effects on the swelling pressure response of compacted Bentonil-WRK (Ca-type) bentonite. Swelling pressure tests were conducted under saturated conditions at dry densities ranging from 1.40 to 1.62 g/cm³ using a high-temperature load cell system capable of operation up to 160°C. To simulate repository thermal environments, the specimens were subjected to two controlled thermal cycles between 30°C and 150°C. Results revealed a temperature-dependent response, characterized by a gradual decrease in swelling pressure during heating. While the absolute pressure reduction was larger at higher dry densities, the swelling pressure normalized by its value at 30°C showed a more pronounced decrease at lower densities, indicating that the lower-density specimens exhibited greater relative thermal sensitivity. During the heating–cooling cycles, all specimens exhibited thermal hysteresis, characterized by partial recovery of swelling pressure upon cooling, whereas the magnitude of hysteresis was markedly reduced in the second thermal cycle. The swelling pressure did not reach equilibrium at temperatures above 90°C during the first heating stage and only at 150°C in the second heating stage. Although higher dry density specimens exhibited larger absolute pressure reductions, their smaller relative decreases indicate enhanced thermal stability, suggesting that such compaction levels are favorable for ensuring long-term barrier performance under repository-relevant thermal loads.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"280 ","pages":"Article 108046"},"PeriodicalIF":5.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145555248","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":"Preparation of composite material sodium dodecyl sulfonate/2-methylimidazole zinc MOF/ palygorskite and its high- efficiency adsorption for tetracycline","authors":"Xin Li ,&nbsp;Wen Chen ,&nbsp;Jin-Long Jiang ,&nbsp;Xia-ping Zhu ,&nbsp;Ping Zhao","doi":"10.1016/j.clay.2025.108057","DOIUrl":"10.1016/j.clay.2025.108057","url":null,"abstract":"<div><div>In this study, a one pot self-assembly strategy was adopted in aqueous solution to prepare a new material of sodium dodecyl sulfonate/2-methylimidazole zinc MOF/palygorskite (SDS/ZIF-8/PAL, abbreviated as SZP) with certain mesopores and high adsorption capacity for tetracycline. The material was prepared using surfactants such as sodium dodecyl sulfonate (SDS), Zn(NO₃)₂·6H₂O, 2-methylimidazole (2-MI) (maintaining 2-MI: Zn²⁺ = 10: 1), and palygorskite (PAL), and was environmentally friendly in both preparation and application. The saturated adsorption capacity of SZP was 914 mg/g at pH 7.0, temperature 298 K, adsorption time 180 min and ionic strength 0.01 mol/L, which was much higher than that of unmodified PAL and TC adsorption materials in other reports. X-ray photoelectron spectroscopy (XPS) analysis showed that SZP mainly removes TC through hydrogen bonding and coordination. Furthermore, SZP had good adsorption selectivity for TC, and the interference of dissolved organic substances, coexisting inorganic anions, cations and antibiotics with high detection rate in environmental water was small. And the removal rate was still above 90 % after five times of reuse. When SZP was applied to adsorb TC simulated water samples with different environmental water as the background, the concentration was 2.5 times of the highest concentration (20 mg/L) in actual aquaculture water, and the removal rate was up to 97 %. It showed that SZP can not only remove all TC from environmental water, but also its adsorption capacity far exceeds the pollution capacity, which indicated that SZP has potential application value in removing TC from environmental water.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"279 ","pages":"Article 108057"},"PeriodicalIF":5.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145576383","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":"Swelling of Na-montmorillonite in the presence of dissolved gas molecules","authors":"Jerry Peprah Owusu ,&nbsp;Konstantinos Karalis ,&nbsp;Nikolaos I. Prasianakis ,&nbsp;Alessio Ferrari ,&nbsp;Sergey V. Churakov","doi":"10.1016/j.clay.2025.108058","DOIUrl":"10.1016/j.clay.2025.108058","url":null,"abstract":"<div><div>Various dissolved gases, such as CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, and CH<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>, may be present in the near-field geological repository due to metal corrosion or the degradation of organic waste. However, the influence of dissolved gases on the swelling behavior of bentonites, commonly used as backfill material, is still poorly understood. In this study, classical molecular dynamics simulations are conducted to investigate the swelling behavior of Na-Mt as a function of compaction and the presence of dissolved gas. The simulations revealed that the presence of gas molecules increases the swelling pressure of Na-Mt and can be quantitatively explained by Henry’s law, which describes the increase in the gas solubility with pressure. The magnitude of the effect is gas-specific, depending on the dry density of clay and the gas concentration in the external reservoir. Accordingly, a general equation describing the enhanced swelling pressure due to gas solubility is proposed. A detailed analysis of structural transformations in the clay interlayer provided a model-based explanation for the discrepancy between the experimentally measured swelling curves and the simulated curves at high compaction levels. These findings contribute to a better understanding of the fundamental mechanisms underlying the swelling behavior of clays used as barrier material in deep geological disposal.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"279 ","pages":"Article 108058"},"PeriodicalIF":5.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145576382","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":"Efficient Zn2+ transport and stable electrolyte/electrode interface achieved in acid-modified palygorskite-based quasi-solid-state electrolyte for high-performance zinc-ion batteries","authors":"Zhuo Zhang ,&nbsp;Jingyi Zeng ,&nbsp;Ming Liu ,&nbsp;Bing Xue","doi":"10.1016/j.clay.2025.108015","DOIUrl":"10.1016/j.clay.2025.108015","url":null,"abstract":"<div><div>The parasitic reactions induced by free water molecules in the electrolyte of aqueous zinc-ion batteries severely disrupt the stability of the electrolyte/electrode interface, significantly affecting the application performance of the batteries. To mitigate the adverse effects of free water molecules in the electrolyte of aqueous zinc-ion batteries, this paper utilized acid-treated palygorskite as the matrix and prepared a palygorskite-based quasi-solid-state electrolyte by adsorbing liquid electrolyte. This approach reduced the reactivity of water molecules in the electrolyte while enhancing the conductivity of zinc ions. The acid treatment with hydrochloric acid achieved fine-tuning of the palygorskite structure, increasing the number of surface -OH groups and enhancing the specific surface area of palygorskite to 199.16 m² g⁻¹. The plastic limit-liquid limit test results of the palygorskite-salt-water system showed that acid treatment improved the plastic limit (52.6 %) and liquid limit (68.4 %) of palygorskite, confirming that acid treatment could enhance the electrolyte adsorption capacity of palygorskite. Furthermore, acid treatment reduced the Zeta potential of palygorskite (−38.25 mV), strengthening the electrostatic attraction field of palygorskite in the palygorskite-salt-water system. This significantly improved the “relay-style” transmission efficiency of zinc ions in the palygorskite diffusion layer, promoting uniform deposition of zinc ions and inhibiting the growth of zinc dendrites. Simultaneously, it effectively suppressed the transmission of sulfate ions in this diffusion layer, thereby inhibiting the occurrence of side reactions and stabilizing the electrolyte/electrode interface. Based on the unique effect of acid treatment on the microstructure adjustment of palygorskite, the quasi-solid-state electrolyte prepared from acid-treated palygorskite exhibited an ionic conductivity of 20.84 mS cm⁻¹ and an ionic transference number of 0.87. The Zn//Zn symmetric cell assembled with this quasi-solid-state electrolyte demonstrated stable cycling for 3000 h at a current density of 0.2 mA cm⁻², with a polarization voltage less than 40 mV. The assembled Zn//MnO₂ full cell exhibited an initial discharge specific capacity of 240.57 mAh g⁻¹ at a current density of 0.33 A g⁻¹, and the average coulombic efficiency after 500 cycles was approximately 100 %.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"279 ","pages":"Article 108015"},"PeriodicalIF":5.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145360844","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":"Construction of superhydrophobic CoZnAl-LDH coating on anodized aluminum surfaces to enhance corrosion and wear resistance","authors":"Guixiang Wang ,&nbsp;Qizi Wu ,&nbsp;Maomao Guo ,&nbsp;Shilong Zhang ,&nbsp;Qiuyan Luo ,&nbsp;Hao Yu ,&nbsp;Xuyan Guo ,&nbsp;Fuqiu Ma ,&nbsp;Haining Feng ,&nbsp;Ruizhi Wu ,&nbsp;Boris Krit","doi":"10.1016/j.clay.2025.108025","DOIUrl":"10.1016/j.clay.2025.108025","url":null,"abstract":"<div><div>In this study, a novel CoZnAl-LDH coating was synthesized in-situ on anodized aluminum through a hydrothermal method without introducing trivalent metal salts. Subsequently, a vanadate-intercalated LDH-VS coating was fabricated via ion exchange and hexadecyltrimethoxysilane (HDTMS) self-assembly, which integrated long-term corrosion resistance, friction reduction, and superhydrophobicity into a single coating. The morphology and structure of the coatings were investigated using SEM, EDS, XRD, FT-IR, and XPS. The coating performance was evaluated through scratch tests, contact angle, electrochemical, and friction wear tests. The results demonstrated that the contact angle of the LDH-VS increased from 26° to 154° and remained above 120° even after prolonged immersion, exhibiting outstanding self-cleaning and antifouling properties. After 28 days of immersion in 3.5 wt% NaCl solution, the corrosion current density of LDH-VS decreased by four orders of magnitude to 8.09 × 10⁻⁹ A·cm⁻² compared to bare aluminum alloy and the microstructure remained intact, indicating excellent long-term corrosion resistance. Friction tests confirmed the superior friction reduction of the modified coating, with the average friction coefficient of LDH-VS decreasing to 0.28, significantly lower than that of the aluminum alloy. Scratch tests also verified the coating's excellent adhesion strength. This study provides new insights into the development and application of LDH in superhydrophobicity, long-term corrosion protection, and wear resistance.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"279 ","pages":"Article 108025"},"PeriodicalIF":5.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145414419","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":"Steel-bentonite interaction at elevated temperatures","authors":"Šárka Šachlová ,&nbsp;Vlastislav Kašpar ,&nbsp;Michaela Matulová ,&nbsp;Petr Bezdička ,&nbsp;Zbyněk Veselka ,&nbsp;Petr Večerník","doi":"10.1016/j.clay.2025.108011","DOIUrl":"10.1016/j.clay.2025.108011","url":null,"abstract":"<div><div>The long-term durability of carbon steel, proposed as the outer layer of waste disposal packages in the Czech deep geological repository concept, is influenced by anaerobic conditions, elevated temperatures, irradiation, bentonite composition and water content. These factors were examined in a small-scale laboratory experiment within the European Joint Programme on Radioactive Waste Management, project CONtainer CORrosion under Disposal conditions (EURAD CONCORD). Carbon steel coupons were embedded in compacted (1600 kg⋅m^-3) bentonite of Ca/Mg-type (BCV) and reference bentonite of Na-type (MX-80), subjected to water saturation under a pressure of 5 MPa, heated to 90 °C and 150 °C, and irradiated with a ⁶⁰Co source at 0.4 Gy·h⁻¹ for 6 to 18 months.</div><div>Corrosion rates were primarily affected by temperature and saturation level. Similar rates were observed for both bentonites at 150 °C over 18 months, while lower rates were recorded for MX-80 at 90 °C and at ambient temperature. Irradiation had a negligible effect. Corrosion product composition strongly depended on temperature. At 90 °C, Fe-Ca‑carbonates formed in both bentonites, along with Fe-Ca(Mn-Mg)‑carbonates in BCV. At 150 °C, Fe-Si-O-rich layers and Fe-oxides developed, probably linked to the dissolution of amorphous silica and its incorporation into alteration products.</div><div>Elevated temperatures altered the mineralogy and chemistry of the bentonite. Changes included shifts in smectite basal spacing, enrichment with Fe^x+ and Mn²⁺, and modifications to exchangeable cation composition, including reduced Mg²⁺ content. Increased SO₄²⁻ and Cl⁻ concentrations in bentonite water leachates, particularly in BCV at 90 °C and MX-80 at 150 °C, partially correlated with higher corrosion rates. These results highlight the interconnected influence of temperature, bentonite type, and chemical interactions on carbon steel corrosion in repository-relevant environments.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"279 ","pages":"Article 108011"},"PeriodicalIF":5.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145360843","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":"Injection moulded biodegradable hydroxyapatite–kaolin geopolymer scaffolds with enhanced mechanical strength, biocompatibility, and antibacterial activity for bone regeneration","authors":"Zaid Kareem ,&nbsp;Ersan Eyiler","doi":"10.1016/j.clay.2025.108051","DOIUrl":"10.1016/j.clay.2025.108051","url":null,"abstract":"<div><div>This study explored the synthesis and optimization of biodegradable scaffolds composed of bovine-derived hydroxyapatite (HA) and uncalcined kaolin, specifically formulated for extrusion-based injection moulding. The mixture contained geopolymeric solids (kaolin and silica sand, GP) activated with varying concentrations of sodium hydroxide (NaOH) to form a paste compatible with low-temperature curing processes. Characterizations included X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy- energy dispersive X-ray spectroscopy (SEM-EDS), the specific surface area and porosity analysis, and mechanical testing, alongside evaluations of biodegradability, cytotoxicity, and antimicrobial activity. Results demonstrated that a composition of 15 % GP and 1.5 % NaOH achieved an optimal balance of mechanical strength (7 MPa), porosity (55 %), Young's modulus (5.6 GPa), and acceptable biocompatibility. The materials also exhibited effective antimicrobial activity, with the strongest inhibition observed against <em>Staphylococcus aureus</em> (31 mm zone at 1000 μg/mL) and the weakest against <em>Pseudomonas aeruginosa</em> (7 mm at 125 μg/mL). In addition, they demonstrated a suitable degradation behavior over 21 days in both phosphate buffer solution (PBS) and simulated body fluid (SBF) media. The cytotoxicity results showed a dose-dependent cytotoxic response; however, all tested concentrations maintained cell viability above 70 %, suggesting moderate biocompatibility. These findings suggested promising applications in bone tissue engineering, particularly for trabecular bone regeneration.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"279 ","pages":"Article 108051"},"PeriodicalIF":5.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145576433","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}