Porcelain stone, composed of quartz, feldspar, kaolin, and mica, is used to produce white porcelain clay. Therefore, many countries, such as Arita, Japan, renowned for porcelain stone, are making significant efforts to reduce iron impurities like α-FeOOH and FeS2 in order to increase whiteness. In this study, the removal of iron impurities from Arita porcelain stone was investigated using citric acid (C6H8O7) as an eco-friendly iron-leaching agent. Stone samples were treated with 0.05–1 M citric acid at 50 and 100 °C to analyze the iron leaching rate and whiteness of fired stones by measuring the residual Fe2O3 content. The effectiveness of iron leaching with citric acid was evaluated and compared to conventional 10 % HCl treatment. Specifically, α-FeOOH and FeS2 iron residues were investigated; α-FeOOH was found to dissolve in acid, while FeS2 remained insoluble. To modulate the temperature conditions, treatment time and citric acid concentration were effective in enhancing leaching and whiteness. In the results, the leaching rate of citric acid increased to 67.2 % at 50 °C over 54 h. It is novel that citric acid presents a more sustainable and economically viable option for iron impurity removal in porcelain stone processing compared to HCl and other leaching agents.
{"title":"Production of clays for white porcelains from porcelain stone using eco-friendly iron impurity leaching with citric acid","authors":"Hiroaki Katsuki , Jin-Ho Kim , Masahiro Kugishima , Nobuaki Kamochi , Sridhar Komarneni , Jae-Hwan Pee","doi":"10.1016/j.clay.2025.108052","DOIUrl":"10.1016/j.clay.2025.108052","url":null,"abstract":"<div><div>Porcelain stone, composed of quartz, feldspar, kaolin, and mica, is used to produce white porcelain clay. Therefore, many countries, such as Arita, Japan, renowned for porcelain stone, are making significant efforts to reduce iron impurities like α-FeOOH and FeS<sub>2</sub> in order to increase whiteness. In this study, the removal of iron impurities from Arita porcelain stone was investigated using citric acid (C<sub>6</sub>H<sub>8</sub>O<sub>7</sub>) as an eco-friendly iron-leaching agent. Stone samples were treated with 0.05–1 M citric acid at 50 and 100 °C to analyze the iron leaching rate and whiteness of fired stones by measuring the residual Fe<sub>2</sub>O<sub>3</sub> content. The effectiveness of iron leaching with citric acid was evaluated and compared to conventional 10 % HCl treatment. Specifically, α-FeOOH and FeS<sub>2</sub> iron residues were investigated; α-FeOOH was found to dissolve in acid, while FeS<sub>2</sub> remained insoluble. To modulate the temperature conditions, treatment time and citric acid concentration were effective in enhancing leaching and whiteness. In the results, the leaching rate of citric acid increased to 67.2 % at 50 °C over 54 h. It is novel that citric acid presents a more sustainable and economically viable option for iron impurity removal in porcelain stone processing compared to HCl and other leaching agents.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"283 ","pages":"Article 108052"},"PeriodicalIF":5.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145881722","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}
Pub Date : 2026-04-01Epub Date: 2026-01-06DOI: 10.1016/j.clay.2026.108120
Tianqi Zhang , Qi Tao , Jinming Bao , Xinman Xu , Xiaorong Qin , Xiaoliang Liang , Hongping He
This study addresses the limitations of individual mineral phases for paleoenvironmental reconstruction on Mars, by investigating smectite-associated mineral assemblages formed across a broad pH range (pH = 4–13). Hydrothermal experiments reveal that aluminum content controls iron crystallization pathways under acidic conditions. Low aluminum content favors direct nontronite formation, while high aluminum content leads to iron (hydr)oxide precipitation. Under oxidizing environments, moderately acidic conditions enhance Fe/Mg enrichment, explaining the elevated Fe/Mg ratios observed in Martian smectites. With increasing pH toward alkaline conditions, zeolite species shift from gobbinsite to phillipsite, and analcime crystal morphology changes from purely cubic to a combination of cubic and tetragonal trisoctahedra between pH 10 and 13. These trends make smectite-zeolite assemblages promising diagnostic indicators of alkalinity. Raman spectroscopy reliably distinguishes zeolite species, overcoming visible and near-infrared reflectance (VNIR) technology limitations. Furthermore, evaporite minerals exhibit exquisite sensitivity to variations in temperature and humidity, undergoing structural transitions (e.g., Na2SO4-III → Na2SO4-V) and ionic substitution (e.g., hexahydrite → blödite; thermonatrite and sodium sulfate → burkeite). These pose challenges for reliable paleoenvironmental reconstruction and Mars sample return curation. These results provide a mineralogical framework for deciphering smectite-related aqueous environments on Mars.
{"title":"Mineral assemblages with smectites in simulated basalt alteration: implications for Martian aqueous environments","authors":"Tianqi Zhang , Qi Tao , Jinming Bao , Xinman Xu , Xiaorong Qin , Xiaoliang Liang , Hongping He","doi":"10.1016/j.clay.2026.108120","DOIUrl":"10.1016/j.clay.2026.108120","url":null,"abstract":"<div><div>This study addresses the limitations of individual mineral phases for paleoenvironmental reconstruction on Mars, by investigating smectite-associated mineral assemblages formed across a broad pH range (pH = 4–13). Hydrothermal experiments reveal that aluminum content controls iron crystallization pathways under acidic conditions. Low aluminum content favors direct nontronite formation, while high aluminum content leads to iron (hydr)oxide precipitation. Under oxidizing environments, moderately acidic conditions enhance Fe/Mg enrichment, explaining the elevated Fe/Mg ratios observed in Martian smectites. With increasing pH toward alkaline conditions, zeolite species shift from gobbinsite to phillipsite, and analcime crystal morphology changes from purely cubic to a combination of cubic and tetragonal trisoctahedra between pH 10 and 13. These trends make smectite-zeolite assemblages promising diagnostic indicators of alkalinity. Raman spectroscopy reliably distinguishes zeolite species, overcoming visible and near-infrared reflectance (VNIR) technology limitations. Furthermore, evaporite minerals exhibit exquisite sensitivity to variations in temperature and humidity, undergoing structural transitions (e.g., Na<sub>2</sub>SO<sub>4</sub>-III → Na<sub>2</sub>SO<sub>4</sub>-<em>V</em>) and ionic substitution (e.g., hexahydrite → blödite; thermonatrite and sodium sulfate → burkeite). These pose challenges for reliable paleoenvironmental reconstruction and Mars sample return curation. These results provide a mineralogical framework for deciphering smectite-related aqueous environments on Mars.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"283 ","pages":"Article 108120"},"PeriodicalIF":5.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922394","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}
Talc plays an essential role in transporting water into the mantle via subduction zones. The compressional behavior of triclinic (C) talc under high pressure was investigated by a combination of synchrotron X-ray diffraction (XRD), infrared (IR) spectroscopy, and density functional theory (DFT) calculations. Talc exhibited exceptional structural stability with no observable crystallographic phase transitions up to ∼20 GPa, as determined by synchrotron-based high-pressure XRD. However, a notable change occurs in the hydroxyl groups above ∼10 GPa: the OH bond length, which plateaus at ∼0.9687 Å below this pressure, shows a subsequent linear decrease. The structure of talc shows strong anisotropic compressibility: the decrease of a-, b-, and c-axis is 4.4 %, 5.0 %, and 9.0 % throughout the investigated pressure regime, respectively. Most of the compression is taken up by the weakly bonded interlayer regions below ∼10 GPa. The unit-cell volume changed continuously with pressure, but the F-fE plot indicates a change in compressibility around ∼10 GPa. The PV data below and above 10 GPa were fitted separately using the third-order Birch-Murnaghan equation of state. The derived parameters are as follows: K0 = 55.0(67) GPa and K′ = 11.0(52) below 10 GPa, and K0 = 59.2(19) GPa and K′ = 5.2(4) above 10 GPa for XRD results with V0 fitted as 455.5(9) Å3; V0 = 451.4(5) Å3, K0 = 41.2(18) GPa, and K′ = 8.2(8) below 10 GPa, and V0 = 445.2(8) Å3, K0 = 56.9(14) GPa, and K′ = 5.1(1) above 10 GPa for DFT results. Our findings contribute to a better understanding of hydroxyl groups in response to pressure in layered-structure silicates, offering insights into talc's roles in geological processes and the deep-Earth water cycle.
{"title":"High-pressure structural evolution of talc investigated by X-ray diffraction, infrared spectroscopy, and density functional theory calculations","authors":"Bingxu Hou , Jingjing Niu , Lili Zhang , Hongrui Ding , Fei Qin , Yanzhang Li , Shan Qin , Anhuai Lu , Hongyan Zuo","doi":"10.1016/j.clay.2026.108119","DOIUrl":"10.1016/j.clay.2026.108119","url":null,"abstract":"<div><div>Talc plays an essential role in transporting water into the mantle via subduction zones. The compressional behavior of triclinic (<em>C</em><span><math><mover><mn>1</mn><mo>¯</mo></mover></math></span>) talc under high pressure was investigated by a combination of synchrotron X-ray diffraction (XRD), infrared (IR) spectroscopy, and density functional theory (DFT) calculations. Talc exhibited exceptional structural stability with no observable crystallographic phase transitions up to ∼20 GPa, as determined by synchrotron-based high-pressure XRD. However, a notable change occurs in the hydroxyl groups above ∼10 GPa: the O<img>H bond length, which plateaus at ∼0.9687 Å below this pressure, shows a subsequent linear decrease. The structure of talc shows strong anisotropic compressibility: the decrease of <em>a</em>-, <em>b</em>-, and <em>c</em>-axis is 4.4 %, 5.0 %, and 9.0 % throughout the investigated pressure regime, respectively. Most of the compression is taken up by the weakly bonded interlayer regions below ∼10 GPa. The unit-cell volume changed continuously with pressure, but the <em>F</em>-<em>f</em><sub>E</sub> plot indicates a change in compressibility around ∼10 GPa. The <em>P</em><img><em>V</em> data below and above 10 GPa were fitted separately using the third-order Birch-Murnaghan equation of state. The derived parameters are as follows: <em>K</em><sub>0</sub> = 55.0(67) GPa and <em>K</em>′ = 11.0(52) below 10 GPa, and <em>K</em><sub>0</sub> = 59.2(19) GPa and <em>K</em>′ = 5.2(4) above 10 GPa for XRD results with <em>V</em><sub>0</sub> fitted as 455.5(9) Å<sup>3</sup>; <em>V</em><sub>0</sub> = 451.4(5) Å<sup>3</sup>, <em>K</em><sub>0</sub> = 41.2(18) GPa, and <em>K</em>′ = 8.2(8) below 10 GPa, and <em>V</em><sub>0</sub> = 445.2(8) Å<sup>3</sup>, <em>K</em><sub>0</sub> = 56.9(14) GPa, and <em>K</em>′ = 5.1(1) above 10 GPa for DFT results. Our findings contribute to a better understanding of hydroxyl groups in response to pressure in layered-structure silicates, offering insights into talc's roles in geological processes and the deep-Earth water cycle.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"283 ","pages":"Article 108119"},"PeriodicalIF":5.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922393","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}
Pub Date : 2026-04-01Epub Date: 2026-01-02DOI: 10.1016/j.clay.2025.108106
Xiuqiong Fu , Qian Wan , Yong Fan , Yimin Zhang , Ruobing Zhang
Temperature has an important influence on geopolymerization. While existing studies have mainly focused on curing temperature effects, research on the influence of mixing temperature remains limited. This study investigated the effects of mixing temperature between alkali activators and metakaolin (MK) on the physical properties, microstructure, and reaction kinetics of metakaolin-based geopolymers (MKGs). The results demonstrated that different mixing temperatures led to distinct geopolymerization processes and had significant impacts on mechanical performance. With increasing mixing temperature, compressive strength first increased and then decreased. Geopolymers prepared at 50 °C (MKG50) exhibited a denser structure and the highest compressive strength, reaching 46.47 MPa at 7 days. Elevated mixing temperatures accelerated geopolymerization, promoting rapid dissolution of raw materials and coagulation of the paste. As the temperature increased from 25 °C to 90 °C, the final setting time was shortened from 351 to 6 min. Extreme mixing temperatures (5 °C and 90 °C) both induced rapid setting within 15 min but through distinct mechanisms. At 90 °C, excessively accelerated geopolymerization produced gel structures encapsulating incompletely decomposed raw materials, hindering subsequent reactions and deteriorating the structure and strength. In contrast, at 5 °C, rapid setting was caused by hydrated sodium silicate crystal inclusions, which did not negatively affect the final structure or performance, as the final setting was only 15 min, with an initial compressive strength of 2.66 MPa and achieved 36.80 MPa after 7 days. This suggests that low-temperature reaction can be used as an effective method for preparing rapid-setting geopolymers.
{"title":"Impact of different mixing temperature on the microstructural evolution and properties of metakaolin-based geopolymers","authors":"Xiuqiong Fu , Qian Wan , Yong Fan , Yimin Zhang , Ruobing Zhang","doi":"10.1016/j.clay.2025.108106","DOIUrl":"10.1016/j.clay.2025.108106","url":null,"abstract":"<div><div>Temperature has an important influence on geopolymerization. While existing studies have mainly focused on curing temperature effects, research on the influence of mixing temperature remains limited. This study investigated the effects of mixing temperature between alkali activators and metakaolin (MK) on the physical properties, microstructure, and reaction kinetics of metakaolin-based geopolymers (MKGs). The results demonstrated that different mixing temperatures led to distinct geopolymerization processes and had significant impacts on mechanical performance. With increasing mixing temperature, compressive strength first increased and then decreased. Geopolymers prepared at 50 °C (MKG50) exhibited a denser structure and the highest compressive strength, reaching 46.47 MPa at 7 days. Elevated mixing temperatures accelerated geopolymerization, promoting rapid dissolution of raw materials and coagulation of the paste. As the temperature increased from 25 °C to 90 °C, the final setting time was shortened from 351 to 6 min. Extreme mixing temperatures (5 °C and 90 °C) both induced rapid setting within 15 min but through distinct mechanisms. At 90 °C, excessively accelerated geopolymerization produced gel structures encapsulating incompletely decomposed raw materials, hindering subsequent reactions and deteriorating the structure and strength. In contrast, at 5 °C, rapid setting was caused by hydrated sodium silicate crystal inclusions, which did not negatively affect the final structure or performance, as the final setting was only 15 min, with an initial compressive strength of 2.66 MPa and achieved 36.80 MPa after 7 days. This suggests that low-temperature reaction can be used as an effective method for preparing rapid-setting geopolymers.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"283 ","pages":"Article 108106"},"PeriodicalIF":5.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145881724","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}
Pub Date : 2026-04-01Epub Date: 2026-01-12DOI: 10.1016/j.clay.2026.108127
Haizhen Li , Mengqian Qi , Wensheng Yang , Jiateng Hu , Mengjiao Niu , Yongshuai Xie , Tianliang Wang , Gang Yu
The deep activation process of natural clay minerals, which leads to surface modification and optimization of pore structures, plays a critical role in enhancing their practical applicability in composite phase change materials. In this study, a novel ultrasound-assisted acidification approach was developed to produce activated sepiolite fibers for the fabrication of paraffin/sepiolite composite PCMs, exhibiting superior thermal stability and energy storage performance. The ultrasonic-assisted acidification method enables effective fiber dissociation and removal of associated mineral impurities in sepiolite fibers, thereby preserving structural integrity, generating optimal porous channels, and increasing surface areas up to 308.82 m2/g. The activated sepiolite fiber with specific surface area and pore size of 142.2 m2/g and 9.1 nm, enables the paraffin/sepiolite composite phase change material (UHP/S3–1) to achieve the highest latent heat of fusion and crystallization, reaching 106.72 J/g and 107.86 J/g, respectively. Moreover, the mechanical oscillation and cavitation effects generated by ultrasound strengthened the synergistic interaction between the acidification process and ultrasound irradiation, enabling the effective use of weak organic acids, such as acetic acid (HAc), as the acidifying agent. UAP/S5–1 prepared using HAc-acidified sepiolite fibers with ultrasound irradiation, exhibits excellent structural stability, thermal reliability, and reusability at temperatures below 80 °C after 100 thermal cycles, resulting in strong chemical binding interactions (COO- group) between paraffin and activated sepiolite fibers. This work provides a prospective strategy for constructing stable mineral-based composite PCMs with excellent energy storage performance for their practical application thermal management.
{"title":"Ultrasonic-assisted acidification of sepiolite fibers towards highly stable paraffin-based phase change composites with enhanced thermal energy storage performance","authors":"Haizhen Li , Mengqian Qi , Wensheng Yang , Jiateng Hu , Mengjiao Niu , Yongshuai Xie , Tianliang Wang , Gang Yu","doi":"10.1016/j.clay.2026.108127","DOIUrl":"10.1016/j.clay.2026.108127","url":null,"abstract":"<div><div>The deep activation process of natural clay minerals, which leads to surface modification and optimization of pore structures, plays a critical role in enhancing their practical applicability in composite phase change materials. In this study, a novel ultrasound-assisted acidification approach was developed to produce activated sepiolite fibers for the fabrication of paraffin/sepiolite composite PCMs, exhibiting superior thermal stability and energy storage performance. The ultrasonic-assisted acidification method enables effective fiber dissociation and removal of associated mineral impurities in sepiolite fibers, thereby preserving structural integrity, generating optimal porous channels, and increasing surface areas up to 308.82 m<sup>2</sup>/g. The activated sepiolite fiber with specific surface area and pore size of 142.2 m<sup>2</sup>/g and 9.1 nm, enables the paraffin/sepiolite composite phase change material (UHP/S3–1) to achieve the highest latent heat of fusion and crystallization, reaching 106.72 J/g and 107.86 J/g, respectively. Moreover, the mechanical oscillation and cavitation effects generated by ultrasound strengthened the synergistic interaction between the acidification process and ultrasound irradiation, enabling the effective use of weak organic acids, such as acetic acid (HAc), as the acidifying agent. UAP/S5–1 prepared using HAc-acidified sepiolite fibers with ultrasound irradiation, exhibits excellent structural stability, thermal reliability, and reusability at temperatures below 80 °C after 100 thermal cycles, resulting in strong chemical binding interactions (COO- group) between paraffin and activated sepiolite fibers. This work provides a prospective strategy for constructing stable mineral-based composite PCMs with excellent energy storage performance for their practical application thermal management.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"283 ","pages":"Article 108127"},"PeriodicalIF":5.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973492","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}
Pub Date : 2026-04-01Epub Date: 2026-01-07DOI: 10.1016/j.clay.2025.108101
Axel Neißer-Deiters, Sebastian Scherb, Nancy Beuntner, Karl-Christian Thienel
Calcined clays (CCs) are a promising supplementary cementitious material to advance decarbonization of cement, even though they are a challenge in rheology. The study focuses on the interaction of CCs, pore solution ions, and superplasticizer to improve rheology with CC. This was done with four illitic and smectitic dominated CCs in cement-free aqueous solutions. Rheometry, infrared spectroscopy, electroacoustic measurements, X-ray diffraction, and water absorption capacity measurements were conducted to investigate superplasticizer intercalation and adsorption, hydration, surface charge, ion adsorption, and rheology. Yield stress increased in synthetic cement pore solution in comparison to deionized water. This was not attributed to hydration products or a change in pH value, but explained by Derjaguin–Landau–Verwey–Overbeek theory (DLVO) due to changed zeta potential and ion concentration. CCs can adsorb anionic superplasticizers onto their negatively charged surface. With calcium addition, their surface charge polarity was reversed, and superplasticizer adsorption increased drastically. Superplasticizer demand seemed independent of sulfate addition, which is contradictory with cement systems. Superplasticizer demand was twice as high for illitic CCs compared to smectitic CCs. Intercalation of superplasticizers and swelling of calcined smectite can be excluded. The results confirmed BET specific surface area as a generally good indicator for superplasticizer demand of CCs, but it is not sufficient for differentiation within similar mineralogy. These findings help to further establish CCs further as an eco-friendly but also workable supplementary cementitious material.
{"title":"Rheology of calcined illitic and smectitic clays in cement-free aqueous solutions with a focus on ion adsorption and superplasticizer interaction","authors":"Axel Neißer-Deiters, Sebastian Scherb, Nancy Beuntner, Karl-Christian Thienel","doi":"10.1016/j.clay.2025.108101","DOIUrl":"10.1016/j.clay.2025.108101","url":null,"abstract":"<div><div>Calcined clays (CCs) are a promising supplementary cementitious material to advance decarbonization of cement, even though they are a challenge in rheology. The study focuses on the interaction of CCs, pore solution ions, and superplasticizer to improve rheology with CC. This was done with four illitic and smectitic dominated CCs in cement-free aqueous solutions. Rheometry, infrared spectroscopy, electroacoustic measurements, X-ray diffraction, and water absorption capacity measurements were conducted to investigate superplasticizer intercalation and adsorption, hydration, surface charge, ion adsorption, and rheology. Yield stress increased in synthetic cement pore solution in comparison to deionized water. This was not attributed to hydration products or a change in pH value, but explained by Derjaguin–Landau–Verwey–Overbeek theory (DLVO) due to changed zeta potential and ion concentration. CCs can adsorb anionic superplasticizers onto their negatively charged surface. With calcium addition, their surface charge polarity was reversed, and superplasticizer adsorption increased drastically. Superplasticizer demand seemed independent of sulfate addition, which is contradictory with cement systems. Superplasticizer demand was twice as high for illitic CCs compared to smectitic CCs. Intercalation of superplasticizers and swelling of calcined smectite can be excluded. The results confirmed BET specific surface area as a generally good indicator for superplasticizer demand of CCs, but it is not sufficient for differentiation within similar mineralogy. These findings help to further establish CCs further as an eco-friendly but also workable supplementary cementitious material.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"283 ","pages":"Article 108101"},"PeriodicalIF":5.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922396","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}
Pub Date : 2026-04-01Epub Date: 2026-01-02DOI: 10.1016/j.clay.2025.108110
Renzheng Guan , Xinyan Hao , Chuyang Chen , Guangqi Cheng , Qianchen Huang , Shuang Wang , Fang Wang , Jiwei Li , Aihua Cui , Shaohua Zhang
This study presents the development of chitosan sutures functionalized with copper-loaded halloysite nanotubes (Cu@HNTs-CS) to achieve synergistically enhanced antibacterial efficacy, mechanical performance, and biocompatible properties. Alkali-treated halloysite nanotubes (NHNTs), characterized by hollow tubular structures with an inner diameter of 17 ± 2 nm, serve as nanoscale reservoirs for Cu2+. The dispersion of Cu@HNTs on chitosan fibers, facilitated by hydrogen bonding and electrostatic interactions between functional groups on chitosan and the hydroxyl/siloxy groups of HNTs, leads to improved tensile strength and an optimized friction coefficient, thereby balancing tissue penetration and knot security within the optimal surgical range. Furthermore, Cu@HNTs enable the sustained release of Cu2+, effectively preventing burst toxicity while maintaining antibacterial activity against S. aureus and E. coli. Moreover, the Cu@HNTs-CS sutures exhibit excellent biocompatibility, as evidenced by high cell viability and low hemolysis rate (<5 %). By harnessing the dual functionality of HNTs as both Cu2+ stabilizers and mechanical reinforcers, this study offers a scalable solution to address burst-release toxicity and poor mechanical properties inherent in chitosan sutures.
{"title":"Copper-loaded halloysite nanotube-coated chitosan sutures: Enhanced antibacterial activity, mechanical strength, and reduced burst-release toxicity","authors":"Renzheng Guan , Xinyan Hao , Chuyang Chen , Guangqi Cheng , Qianchen Huang , Shuang Wang , Fang Wang , Jiwei Li , Aihua Cui , Shaohua Zhang","doi":"10.1016/j.clay.2025.108110","DOIUrl":"10.1016/j.clay.2025.108110","url":null,"abstract":"<div><div>This study presents the development of chitosan sutures functionalized with copper-loaded halloysite nanotubes (Cu@HNTs-CS) to achieve synergistically enhanced antibacterial efficacy, mechanical performance, and biocompatible properties. Alkali-treated halloysite nanotubes (NHNTs), characterized by hollow tubular structures with an inner diameter of 17 ± 2 nm, serve as nanoscale reservoirs for Cu<sup>2+</sup>. The dispersion of Cu@HNTs on chitosan fibers, facilitated by hydrogen bonding and electrostatic interactions between functional groups on chitosan and the hydroxyl/siloxy groups of HNTs, leads to improved tensile strength and an optimized friction coefficient, thereby balancing tissue penetration and knot security within the optimal surgical range. Furthermore, Cu@HNTs enable the sustained release of Cu<sup>2+</sup>, effectively preventing burst toxicity while maintaining antibacterial activity against <em>S. aureus</em> and <em>E. coli</em>. Moreover, the Cu@HNTs-CS sutures exhibit excellent biocompatibility, as evidenced by high cell viability and low hemolysis rate (<5 %). By harnessing the dual functionality of HNTs as both Cu<sup>2+</sup> stabilizers and mechanical reinforcers, this study offers a scalable solution to address burst-release toxicity and poor mechanical properties inherent in chitosan sutures.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"283 ","pages":"Article 108110"},"PeriodicalIF":5.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145881723","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}
Pub Date : 2026-03-15Epub Date: 2025-12-22DOI: 10.1016/j.clay.2025.108094
Mingshuai Wang, Joel Fabregat-Palau, Stefan B. Haderlein
Although competitive interactions between glyphosate (Gly) and phosphate (PO4) in soils were previously confirmed, systematic investigations of their behavior on homo-ionic phyllosilicate clay minerals remain limited. This study employed adsorption edge experiments at different pH conditions to derive solid/liquid distribution coefficients (Kd) and evaluated Gly and PO4 species-specific adsorption contributions on potassium- and calcium-saturated homo-ionic kaolinite (K-, Ca-kao) and montmorillonite (K-, Ca-mont), alongside elucidating related adsorption mechanisms. The results identified H2Gly− as the dominant Gly species driving adsorption on K-clays. For PO4, H2PO4− governed adsorption on K-kao, while its enhanced uptake on K-mont under alkaline conditions was reflected in the model by PO43− species. In contrast, both Gly and PO4 exhibited Ca2+-bridged co-adsorption mechanisms on Ca-clays, yielding enhanced adsorption capacities compared to K-clays. At alkaline pH, removal of aqueous PO4 was primarily attributed to Ca2+-PO4 precipitation. Competitive adsorption data, combined with single-system results, resolved the interplay of surface complexation, interlayer adsorption, and hydrogen bonding under co-adsorption conditions. Notably, Ca2+ played a dual role by promoting Gly release under competition yet enhancing Gly adsorption in single scenarios. The sorption comparison of Gly and PO4 with Fe/Al oxides revealed preferential PO4 adsorption at oxides, while Gly showed comparable adsorption affinity, validating previous kinetic competition analyses. This study elucidates the distinct roles of adsorbate speciation, cation type, and mineral structure, thereby providing a conceptual framework essential for advancing predictions of contaminant behavior in complex environmental systems.
{"title":"Effects of pH and cations on adsorption of glyphosate and phosphate at clay minerals","authors":"Mingshuai Wang, Joel Fabregat-Palau, Stefan B. Haderlein","doi":"10.1016/j.clay.2025.108094","DOIUrl":"10.1016/j.clay.2025.108094","url":null,"abstract":"<div><div>Although competitive interactions between glyphosate (Gly) and phosphate (PO<sub>4</sub>) in soils were previously confirmed, systematic investigations of their behavior on homo-ionic phyllosilicate clay minerals remain limited. This study employed adsorption edge experiments at different pH conditions to derive solid/liquid distribution coefficients (K<sub>d</sub>) and evaluated Gly and PO<sub>4</sub> species-specific adsorption contributions on potassium- and calcium-saturated homo-ionic kaolinite (K-, Ca-kao) and montmorillonite (K-, Ca-mont), alongside elucidating related adsorption mechanisms. The results identified H<sub>2</sub>Gly<sup>−</sup> as the dominant Gly species driving adsorption on K-clays. For PO<sub>4</sub>, H<sub>2</sub>PO<sub>4</sub><sup>−</sup> governed adsorption on K-kao, while its enhanced uptake on K-mont under alkaline conditions was reflected in the model by PO<sub>4</sub><sup>3−</sup> species. In contrast, both Gly and PO<sub>4</sub> exhibited Ca<sup>2+</sup>-bridged co-adsorption mechanisms on Ca-clays, yielding enhanced adsorption capacities compared to K-clays. At alkaline pH, removal of aqueous PO<sub>4</sub> was primarily attributed to Ca<sup>2+</sup>-PO<sub>4</sub> precipitation. Competitive adsorption data, combined with single-system results, resolved the interplay of surface complexation, interlayer adsorption, and hydrogen bonding under co-adsorption conditions. Notably, Ca<sup>2+</sup> played a dual role by promoting Gly release under competition yet enhancing Gly adsorption in single scenarios. The sorption comparison of Gly and PO<sub>4</sub> with Fe/Al oxides revealed preferential PO<sub>4</sub> adsorption at oxides, while Gly showed comparable adsorption affinity, validating previous kinetic competition analyses. This study elucidates the distinct roles of adsorbate speciation, cation type, and mineral structure, thereby providing a conceptual framework essential for advancing predictions of contaminant behavior in complex environmental systems.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"282 ","pages":"Article 108094"},"PeriodicalIF":5.8,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838211","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}
Pub Date : 2026-03-15Epub Date: 2025-12-15DOI: 10.1016/j.clay.2025.108090
Weihua Meng , Da Yang , Shengnan Wang , Chenyang Liu , Pengyang Zou , Yuan Li , Jixing Xie , Jianzhong Xu
Epoxy resin (EP) is a high-performance polymer whose broader application is restricted by inherent flammability. In this work, a novel core-shell ILA@ATMEL was synthesized by coating natural illite with melamine-based aminotrimethylene phosphonate (ATMEL). The resulting hybrid was incorporated into EP to simultaneously improve flame retardancy and mechanical properties. With the addition of 9 phr ILA@ATMEL, the limiting oxygen index of EP composite reached 28.8 %, and the char residue at 800 °C increased from 17.82 % to 29.57 %. Cone calorimetry tests revealed notable reductions in peak heat release rate (33.57 %), total heat release (20.89 %), peak smoke production rate (29.37 %), and total smoke production (14.17 %) compared to those of pore EP. These improvements are attributed to synergistic flame-retardant mechanisms both in the condensed phase and the gas phase with Si, Al, P, and N elements. Moreover, ILA@ATMEL acts as a reinforcing filler at low loadings. The composite with 3 phr additive exhibited increases in elongation at break and tensile strength by 10.57 % and 18.86 %, respectively. This study demonstrates a feasible strategy for designing eco-friendly, high-performance EP composites with enhanced fire safety and mechanical durability via mineral-based core-shell flame retardants.
{"title":"Synthesis of modified illite coated with melamine and aminotrimethylene phosphonic acid and study on its flame-retardant properties for epoxy resin","authors":"Weihua Meng , Da Yang , Shengnan Wang , Chenyang Liu , Pengyang Zou , Yuan Li , Jixing Xie , Jianzhong Xu","doi":"10.1016/j.clay.2025.108090","DOIUrl":"10.1016/j.clay.2025.108090","url":null,"abstract":"<div><div>Epoxy resin (EP) is a high-performance polymer whose broader application is restricted by inherent flammability. In this work, a novel core-shell ILA@ATMEL was synthesized by coating natural illite with melamine-based aminotrimethylene phosphonate (ATMEL). The resulting hybrid was incorporated into EP to simultaneously improve flame retardancy and mechanical properties. With the addition of 9 phr ILA@ATMEL, the limiting oxygen index of EP composite reached 28.8 %, and the char residue at 800 °C increased from 17.82 % to 29.57 %. Cone calorimetry tests revealed notable reductions in peak heat release rate (33.57 %), total heat release (20.89 %), peak smoke production rate (29.37 %), and total smoke production (14.17 %) compared to those of pore EP. These improvements are attributed to synergistic flame-retardant mechanisms both in the condensed phase and the gas phase with Si, Al, P, and N elements. Moreover, ILA@ATMEL acts as a reinforcing filler at low loadings. The composite with 3 phr additive exhibited increases in elongation at break and tensile strength by 10.57 % and 18.86 %, respectively. This study demonstrates a feasible strategy for designing eco-friendly, high-performance EP composites with enhanced fire safety and mechanical durability via mineral-based core-shell flame retardants.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"282 ","pages":"Article 108090"},"PeriodicalIF":5.8,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753892","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}
Pub Date : 2026-03-15Epub Date: 2025-12-23DOI: 10.1016/j.clay.2025.108107
Batuhan Özakın , Kürşat Gültekin , Özgür Aygür
Developing bio-based and high-performance lubricants for sustainable metal forming processes is an increasing necessity in the industry. This study systematically investigated the cold rolling performance of palm nanolubricant doped with oleic acid-modified kaolin nanoparticles. The nanolubricants were prepared at different particle sizes (350 nm and 650 nm) and concentrations (0.125, 0.25, and 0.5 wt%). Cold-rolling experiments were then performed on AISI 304 stainless steel strips using reduction ratios of 1.5 % and 7.5 %. The results indicate that, at a 1.5 % reduction ratio, the doping of 0.5 wt% kaolin nanoparticles with a size of 350 nm to the lubricant reduced the rolling force by 28 % compared to pure palm oil and by 40 % under dry conditions. Furthermore, surface roughness values showed significant improvement, with enhancements of 35 % and 51 %, respectively. Small particles (350 nm) were found to effectively fill surface micro-voids to form a protective tribo-film layer, reducing friction and wear and significantly improving surface quality. Two-dimensional (2D) roughness measurements, three-dimensional (3D) area scanning analyses, and material ratio curves (MRC) support each other, confirming this mechanism. The study demonstrates that doping surface-modified kaolin nanoparticles suitable for vegetable-based lubricants is a promising approach for developing new-generation nanolubricants. Under the tested laboratory-scale conditions, these nanolubricants showed potential to reduce friction and wear in cold rolling applications, which may contribute to lower energy consumption and longer roll life, while supporting sustainable manufacturing objectives.
{"title":"Investigation of tribological performance of bio-based palm oil reinforced with oleic acid modified kaolin nanoparticles in cold rolling","authors":"Batuhan Özakın , Kürşat Gültekin , Özgür Aygür","doi":"10.1016/j.clay.2025.108107","DOIUrl":"10.1016/j.clay.2025.108107","url":null,"abstract":"<div><div>Developing bio-based and high-performance lubricants for sustainable metal forming processes is an increasing necessity in the industry. This study systematically investigated the cold rolling performance of palm nanolubricant doped with oleic acid-modified kaolin nanoparticles. The nanolubricants were prepared at different particle sizes (350 nm and 650 nm) and concentrations (0.125, 0.25, and 0.5 wt%). Cold-rolling experiments were then performed on AISI 304 stainless steel strips using reduction ratios of 1.5 % and 7.5 %. The results indicate that, at a 1.5 % reduction ratio, the doping of 0.5 wt% kaolin nanoparticles with a size of 350 nm to the lubricant reduced the rolling force by 28 % compared to pure palm oil and by 40 % under dry conditions. Furthermore, surface roughness values showed significant improvement, with enhancements of 35 % and 51 %, respectively. Small particles (350 nm) were found to effectively fill surface micro-voids to form a protective tribo-film layer, reducing friction and wear and significantly improving surface quality. Two-dimensional (2D) roughness measurements, three-dimensional (3D) area scanning analyses, and material ratio curves (MRC) support each other, confirming this mechanism. The study demonstrates that doping surface-modified kaolin nanoparticles suitable for vegetable-based lubricants is a promising approach for developing new-generation nanolubricants. Under the tested laboratory-scale conditions, these nanolubricants showed potential to reduce friction and wear in cold rolling applications, which may contribute to lower energy consumption and longer roll life, while supporting sustainable manufacturing objectives.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"282 ","pages":"Article 108107"},"PeriodicalIF":5.8,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838209","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号