Applied Clay Science最新文献_第6页

Compressive stress induced by desiccation shrinkage in clayey soils

IF 5.3 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-02-05 DOI: 10.1016/j.clay.2025.107729

Hao Zeng , Chao-Sheng Tang , Yu-Jun Cui , Abdallah Najdi

The volumetric shrinkage behavior of clayey soils under drying has been well examined, whereas the resulting internal mechanical response remains understudied. This work measured the compressive stress induced by desiccation shrinkage in two types of clayey soils along vertical and lateral directions using a flexible pressure sensor embedded in the slurry samples. The stress evolution was investigated in relation to mineralogical compositions, hydromechanical behavior, microstructures and drying conditions. The results highlighted that the compressive stress developed as a consequence of desiccation shrinkage, particularly in clayey soils with a high montmorillonite content. The development of suction beyond the air entry value (AEV) contributed to a notable increase in the compressive stress. This contribution was enhanced in the vertical direction owing to the face-to-face contact between clay platelets. A decrease in environmental relative humidity caused the compressive stress to initiate at lower water content, yet limited the contribution of suction. Moreover, non-uniform lateral desiccation shrinkage along the soil profile activated contact shear effects among clay platelets, hindering the development of lateral compressive stress. With further drying, the suction contribution to the compressive stress decreased since the increasing formation of air-filled pores disrupted the chains of stress transmission. When the shrinkage limit was reached, the compressive stress stabilized as the clay platelets interlocked under high suction. Furthermore, the directly measurable compressive stress can serve as a mechanical reference for characterizing the volumetric shrinkage behavior of drying clayey soils.

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引用次数: 0

Synergistic effect of processing water treatment sludge rich in kaolinite for the sustainable production of LC3

IF 5.3 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-02-05 DOI: 10.1016/j.clay.2025.107741

Tacila Bertulino , Fernanda W.C. Araújo , Antônio A. Melo Neto

The increasing population and urban development intensify the need for potable water, resulting in higher production of sludge in water treatment plants (WTPs). To mitigate the improper disposal of sludge and reduce carbon dioxide emissions from Portland cement production, the pozzolanic activity of sludge and its ashes, derived from WTPs and referred to as WTPA, is being investigated. These materials are being evaluated as supplementary cementitious materials (SCMs), enabling their application in the development of limestone calcined clay cement (LC³). The WTPA samples calcined at 600, 700, and 800 °C were analyzed using X-ray fluorescence (XRF), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analysis, Blaine fineness, and laser diffraction techniques. Compressive strength, electrical conductivity, and R³ tests were performed to evaluate pozzolanic reactivity of WTPA. The influence of calcination temperature, the proportion of WTPA, and the water/cement ratio were studied using the Box-Behnken design in LC³ mixtures. The results suggest that the calcination temperature of 700 °C is ideal for producing pozzolana, standing out with an SAI of 140 % and 19.09 MPa in the lime test. This temperature also favored a higher combined water content (15.8 g/100 g of paste), indicative of resistant hydrated compounds. Additionally, the multi-objective analysis indicated that the optimal formulation for WTPA use in LC³ involves a calcination temperature around 700 °C, a replacement rate of 17.62 %, and a water/cement ratio of 0.54. This formulation provides a fluid consistency, while compressive strength reaches 35.57 MPa, demonstrating the effectiveness of sludge as pozzolana. This study provides new insights into the use of water treatment plant sludge ash as a sustainable material for the development of LC³, offering a promising alternative to reduce the environmental impact of the cement industry.

{"title":"Synergistic effect of processing water treatment sludge rich in kaolinite for the sustainable production of LC3","authors":"Tacila Bertulino , Fernanda W.C. Araújo , Antônio A. Melo Neto","doi":"10.1016/j.clay.2025.107741","DOIUrl":"10.1016/j.clay.2025.107741","url":null,"abstract":"<div><div>The increasing population and urban development intensify the need for potable water, resulting in higher production of sludge in water treatment plants (WTPs). To mitigate the improper disposal of sludge and reduce carbon dioxide emissions from Portland cement production, the pozzolanic activity of sludge and its ashes, derived from WTPs and referred to as WTPA, is being investigated. These materials are being evaluated as supplementary cementitious materials (SCMs), enabling their application in the development of limestone calcined clay cement (LC<sup>3</sup>). The WTPA samples calcined at 600, 700, and 800 °C were analyzed using X-ray fluorescence (XRF), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analysis, Blaine fineness, and laser diffraction techniques. Compressive strength, electrical conductivity, and R<sup>3</sup> tests were performed to evaluate pozzolanic reactivity of WTPA. The influence of calcination temperature, the proportion of WTPA, and the water/cement ratio were studied using the Box-Behnken design in LC<sup>3</sup> mixtures. The results suggest that the calcination temperature of 700 °C is ideal for producing pozzolana, standing out with an SAI of 140 % and 19.09 MPa in the lime test. This temperature also favored a higher combined water content (15.8 g/100 g of paste), indicative of resistant hydrated compounds. Additionally, the multi-objective analysis indicated that the optimal formulation for WTPA use in LC<sup>3</sup> involves a calcination temperature around 700 °C, a replacement rate of 17.62 %, and a water/cement ratio of 0.54. This formulation provides a fluid consistency, while compressive strength reaches 35.57 MPa, demonstrating the effectiveness of sludge as pozzolana. This study provides new insights into the use of water treatment plant sludge ash as a sustainable material for the development of LC<sup>3</sup>, offering a promising alternative to reduce the environmental impact of the cement industry.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"267 ","pages":"Article 107741"},"PeriodicalIF":5.3,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164280","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}

引用次数: 0

An integrated micro- and nano-scale investigation of green aluminosilicate materials: New insight into the gel network after natural weathering

IF 5.3 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-02-05 DOI: 10.1016/j.clay.2025.107742

Maria Cristina Caggiani , Roberta Occhipinti , Germana Barone , Giuseppe Cultrone , Paolo Mazzoleni

The microstructures of most of the geopolymers synthesized from different starting materials are composed of a mixture of (semi)-crystalline and amorphous phases. In this work we aim to investigate in dept the nanoscale morphology and composition of the gel phase of two volcanic- (Mt. Etna, Sicily) and metakaolin-based geopolymers. The main technique used is high-resolution transmission electron microscopy (HRTEM), with energy dispersive X-ray compositional analysis (STEM-EDS) and selected area electron diffraction (SAED). The results were compared with those obtained on a larger scale. For the first time, a focus at the micro- and nanoscale of geopolymers synthesized with these binary mixtures was achieved. The effect of weathering on the geopolymer network, the crystalline phases and the chemical composition was also evaluated showing, with the convergence of the results of complementary methods, that environmental exposure affects the products made with one type of precursor (ghiara) more than the other (volcanic ash).

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引用次数: 0

Enhancing illitic-clay geopolymer production: A comparative study of conventional method and mechanosynthesized pre-geopolymer powder

IF 5.3 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-02-04 DOI: 10.1016/j.clay.2025.107727

Maroua Zerzouri , Rabah Hamzaoui , Layella Ziyani , Ammar Yahia , Saliha Alehyen

This study investigates the development of an environmentally sustainable production process for clay-based geopolymers. An illitic clay (IC) sourced from the Fes-Morocco region served as the aluminosilicate precursor after calcination (CIC), which was then activated using an alkaline mix (AM) composed of potassium hydroxide (KOH) and sodium silicate (SS). The pre-geopolymer powders (PGP) were generated by dry-mixing of milled CIC powders with alkaline activators, using various mass ratios of IC/AM and SS/KOH. This mixture underwent milling for brief durations of 3 and 5 min at 400 rpm, employing a planetary ball mill device. The resulting PGP was subsequently hydrated with water to form geopolymer pastes (MGP), which were then cured at 20 °C and 50 % relative humidity. Geopolymer pastes, prepared conventionally using the same mixture design (with a liquid form of sodium silicate) and curing conditions, were also included for comparative analysis of rheological, structural, and mechanical properties with the mechanosynthesized counterparts. The results of the study revealed that the mechanosynthesis process induced significant changes in the properties of the produced geopolymers. X-ray diffraction (XRD) analysis indicated a transformation in mineralogical composition towards amorphization, which is crucial for the formation of the desired Sodium-aluminium-silicate-hydrate(NASH) geopolymer network. Rietveld quantification further confirmed this by highlighting an increase in amorphous content and a decrease in crystalline phase content in the pre-geopolymer samples. Mechanosynthesized geopolymers with higher yield stress and storage modulus showed superior mechanical properties. Moreover, strain sweep analysis revealed greater stiffness and resistance to deformation in mechanosynthesized geopolymers compared to the conventional ones. Finally, compressive strength tests showed that mechanosynthesized geopolymers achieved significantly higher strengths than the conventionally prepared geopolymers, reaching up to 64 MPa after 28 days of curing. This result underscores the efficacy of mechanosynthesis in enhancing geopolymer properties.

{"title":"Enhancing illitic-clay geopolymer production: A comparative study of conventional method and mechanosynthesized pre-geopolymer powder","authors":"Maroua Zerzouri , Rabah Hamzaoui , Layella Ziyani , Ammar Yahia , Saliha Alehyen","doi":"10.1016/j.clay.2025.107727","DOIUrl":"10.1016/j.clay.2025.107727","url":null,"abstract":"<div><div>This study investigates the development of an environmentally sustainable production process for clay-based geopolymers. An illitic clay (IC) sourced from the Fes-Morocco region served as the aluminosilicate precursor after calcination (CIC), which was then activated using an alkaline mix (AM) composed of potassium hydroxide (KOH) and sodium silicate (SS). The pre-geopolymer powders (PGP) were generated by dry-mixing of milled CIC powders with alkaline activators, using various mass ratios of IC/AM and SS/KOH. This mixture underwent milling for brief durations of 3 and 5 min at 400 rpm, employing a planetary ball mill device. The resulting PGP was subsequently hydrated with water to form geopolymer pastes (MGP), which were then cured at 20 °C and 50 % relative humidity. Geopolymer pastes, prepared conventionally using the same mixture design (with a liquid form of sodium silicate) and curing conditions, were also included for comparative analysis of rheological, structural, and mechanical properties with the mechanosynthesized counterparts. The results of the study revealed that the mechanosynthesis process induced significant changes in the properties of the produced geopolymers. X-ray diffraction (XRD) analysis indicated a transformation in mineralogical composition towards amorphization, which is crucial for the formation of the desired Sodium-aluminium-silicate-hydrate(NASH) geopolymer network. Rietveld quantification further confirmed this by highlighting an increase in amorphous content and a decrease in crystalline phase content in the pre-geopolymer samples. Mechanosynthesized geopolymers with higher yield stress and storage modulus showed superior mechanical properties. Moreover, strain sweep analysis revealed greater stiffness and resistance to deformation in mechanosynthesized geopolymers compared to the conventional ones. Finally, compressive strength tests showed that mechanosynthesized geopolymers achieved significantly higher strengths than the conventionally prepared geopolymers, reaching up to 64 MPa after 28 days of curing. This result underscores the efficacy of mechanosynthesis in enhancing geopolymer properties.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"267 ","pages":"Article 107727"},"PeriodicalIF":5.3,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102078","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}

引用次数: 0

Salinity Controls on Steel Biocorrosion relevant to the Disposal of High-level Radioactive Waste

IF 5.3 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-02-04 DOI: 10.1016/j.clay.2025.107723

M.N. Rose , C. Boothman , S. Shaw , K. Morris , D.L. Engelberg , M.T. Bailey , J.R. Lloyd

In a geological disposal facility (GDF) for spent fuel and high-level radioactive waste, the canister serves as one of the main engineered barriers. The resistance of the canister to degradation processes such as microbially influenced corrosion (MIC) needs be characterised to support GDF environmental safety cases. Here the impacts of salinity on sulfate-reducing bacterial (SRB) activity and associated MIC were explored in 84-day batch incubations at 30 °C. A 5 % standard bentonite slurry (MX80) in a low-salinity (0.1 g l⁻¹ NaCl) artificial groundwater containing lactate added as an electron donor provided suitable conditions for the proliferation of SRB. Corrosion rates of carbon steel (080-A15) coupon surfaces in microcosms amended with lactate were > 2.5 times greater than those absent of lactate, and sterile controls. At an increased salinity of 12.4 g l⁻¹, adding lactate resulted in 2 times the corrosion depth of sterile conditions, but at 50 g l⁻¹ there was no detected microbial activity, and no pronounced increase in corrosion by adding lactate compared to sterile controls. Here, microbial activity and subsequent MIC was suppressed at high salinity (50 g l⁻¹) suggesting that groundwater composition played a controlling role in SRB biocorrosion. The relevance to geodisposal scenarios, where bentonite is used to protect and support the waste canister, is discussed.

{"title":"Salinity Controls on Steel Biocorrosion relevant to the Disposal of High-level Radioactive Waste","authors":"M.N. Rose , C. Boothman , S. Shaw , K. Morris , D.L. Engelberg , M.T. Bailey , J.R. Lloyd","doi":"10.1016/j.clay.2025.107723","DOIUrl":"10.1016/j.clay.2025.107723","url":null,"abstract":"<div><div>In a geological disposal facility (GDF) for spent fuel and high-level radioactive waste, the canister serves as one of the main engineered barriers. The resistance of the canister to degradation processes such as microbially influenced corrosion (MIC) needs be characterised to support GDF environmental safety cases. Here the impacts of salinity on sulfate-reducing bacterial (SRB) activity and associated MIC were explored in 84-day batch incubations at 30 °C. A 5 % standard bentonite slurry (MX80) in a low-salinity (0.1 g l<sup>−1</sup> NaCl) artificial groundwater containing lactate added as an electron donor provided suitable conditions for the proliferation of SRB. Corrosion rates of carbon steel (080-A15) coupon surfaces in microcosms amended with lactate were > 2.5 times greater than those absent of lactate, and sterile controls. At an increased salinity of 12.4 g l<sup>−1</sup>, adding lactate resulted in 2 times the corrosion depth of sterile conditions, but at 50 g l<sup>−1</sup> there was no detected microbial activity, and no pronounced increase in corrosion by adding lactate compared to sterile controls. Here, microbial activity and subsequent MIC was suppressed at high salinity (50 g l<sup>−1</sup>) suggesting that groundwater composition played a controlling role in SRB biocorrosion. The relevance to geodisposal scenarios, where bentonite is used to protect and support the waste canister, is discussed.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"267 ","pages":"Article 107723"},"PeriodicalIF":5.3,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102077","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}

引用次数: 0

Study on CO₂ adsorption of illite and its microstructural characterization post adsorption: High-pressure and supercritical tests

IF 5.3 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-02-03 DOI: 10.1016/j.clay.2025.107738

Xianfeng Ma , Guohang Tang , Fawu Wang , Jianglin Cao , Bolong Ma , Haihua Zhang

Illite, a prevalent clay mineral, is extensively found in sedimentary rocks, weathering crusts, and soils. Its adsorption capacity has attracted considerable interest for carbon dioxide (CO₂) geological sequestration research. This study aimed to investigate the fundamental CO₂ adsorption behavior of illite, as well as the effects of moisture content and temperature on this process, utilizing high-pressure adsorption and supercritical adsorption tests. Nitrogen adsorption tests were conducted to assess the variations in specific surface area, pore volume, and average pore size of illite before and after CO₂ adsorption. Additionally, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) techniques were employed to characterize the mineral composition and elemental characteristics of raw illite, CO₂-adsorbed illite under dry conditions, and CO₂-adsorbed illite under wet conditions. The results indicated that an increase in moisture content diminishes CO₂ adsorption capacity of illite and leads to a transition of the isosteric heat of adsorption from positive to negative. Furthermore, with rising temperature and moisture content, the specific surface area, pore volume, and average pore size of illite increased following CO₂ adsorption. Additionally, CO₂ adsorption modified the mineral and elemental composition of illite. These results were essential for enhancing the fundamental understanding of CO₂ geological sequestration efficiency and hold promise as a technical foundation for engineering applications.

{"title":"Study on CO₂ adsorption of illite and its microstructural characterization post adsorption: High-pressure and supercritical tests","authors":"Xianfeng Ma , Guohang Tang , Fawu Wang , Jianglin Cao , Bolong Ma , Haihua Zhang","doi":"10.1016/j.clay.2025.107738","DOIUrl":"10.1016/j.clay.2025.107738","url":null,"abstract":"<div><div>Illite, a prevalent clay mineral, is extensively found in sedimentary rocks, weathering crusts, and soils. Its adsorption capacity has attracted considerable interest for carbon dioxide (CO₂) geological sequestration research. This study aimed to investigate the fundamental CO₂ adsorption behavior of illite, as well as the effects of moisture content and temperature on this process, utilizing high-pressure adsorption and supercritical adsorption tests. Nitrogen adsorption tests were conducted to assess the variations in specific surface area, pore volume, and average pore size of illite before and after CO₂ adsorption. Additionally, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) techniques were employed to characterize the mineral composition and elemental characteristics of raw illite, CO₂-adsorbed illite under dry conditions, and CO₂-adsorbed illite under wet conditions. The results indicated that an increase in moisture content diminishes CO₂ adsorption capacity of illite and leads to a transition of the isosteric heat of adsorption from positive to negative. Furthermore, with rising temperature and moisture content, the specific surface area, pore volume, and average pore size of illite increased following CO₂ adsorption. Additionally, CO₂ adsorption modified the mineral and elemental composition of illite. These results were essential for enhancing the fundamental understanding of CO₂ geological sequestration efficiency and hold promise as a technical foundation for engineering applications.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"267 ","pages":"Article 107738"},"PeriodicalIF":5.3,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102075","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}

引用次数: 0

Determination of effective diffusion properties based on 3D FIB/SEM images of clays

IF 5.3 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-02-03 DOI: 10.1016/j.clay.2025.107717

Fares Bennai , Mohamed Khaled Bourbatache , Tien Dung Le , Mahdia Hattab , Olivier Millet

This article presents a numerical approach aiming to estimate the effective diffusion properties of clay using real 3D images obtained through Focused Ion Beam and Scanning Electron Microscopy (FIB/SEM). A description of the original FIB/SEM procedure, specifically developed for observing remoulded clays at the particle scale, is presented. Image processing allowed the reconstruction of a micro-volume extracted from a clay sample subjected to an oedometric loading with an effective vertical stress of 1000 kPa. Numerical calculations of effective diffusivity were performed on the real 3D images using periodic homogenization technique. The results revealed anisotropy in the diffusion phenomena of the studied clay: the effective diffusion coefficient is lower along the direction of the mechanical loading and higher in the plane normal to the stress axis. These findings are consistent with quantitative pore orientation results obtained through image processing, where it was shown that, after mechanical loading, the pores tend to orient towards the plane normal to the axis of the effective vertical stress. These results demonstrate that incorporating the real geometry of clay microstructure into diffusion property calculations allows for a better consideration of the complexity of the clay fabric in relation to mechanical loading.

{"title":"Determination of effective diffusion properties based on 3D FIB/SEM images of clays","authors":"Fares Bennai , Mohamed Khaled Bourbatache , Tien Dung Le , Mahdia Hattab , Olivier Millet","doi":"10.1016/j.clay.2025.107717","DOIUrl":"10.1016/j.clay.2025.107717","url":null,"abstract":"<div><div>This article presents a numerical approach aiming to estimate the effective diffusion properties of clay using real 3D images obtained through Focused Ion Beam and Scanning Electron Microscopy (FIB/SEM). A description of the original FIB/SEM procedure, specifically developed for observing remoulded clays at the particle scale, is presented. Image processing allowed the reconstruction of a micro-volume extracted from a clay sample subjected to an oedometric loading with an effective vertical stress of 1000 kPa. Numerical calculations of effective diffusivity were performed on the real 3D images using periodic homogenization technique. The results revealed anisotropy in the diffusion phenomena of the studied clay: the effective diffusion coefficient is lower along the direction of the mechanical loading and higher in the plane normal to the stress axis. These findings are consistent with quantitative pore orientation results obtained through image processing, where it was shown that, after mechanical loading, the pores tend to orient towards the plane normal to the axis of the effective vertical stress. These results demonstrate that incorporating the real geometry of clay microstructure into diffusion property calculations allows for a better consideration of the complexity of the clay fabric in relation to mechanical loading.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"267 ","pages":"Article 107717"},"PeriodicalIF":5.3,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102076","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}

引用次数: 0

Flame-retardant effect of scalable all clay composite films

IF 5.3 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-02-03 DOI: 10.1016/j.clay.2025.107724

Yixuan Fu , Zhaoyi Wang , Huiquan Liu , Ke Zhang , Lunxiang Zhang , Yongchen Song , Peng Wu , Yanghui Li , Zheng Ling

Flame retardants reduce fire risks from everyday materials that sustain a high standard of living. There is growing interest in applying surface treatments to localize flame-retardant chemistry at the surface of combustible material. This popular treatment method aims to maintain the desired bulk properties of materials and reduce the quantity of additives required. Owing to the excellent thermal stability, low cost and lightweight, clay nanomaterials are potential as environmentally friendly, lightweight, and practical flame-retardant materials. However, such potential may be restricted by the slow, tedious, energy-intensive, and unscalable fabrication process. Herein, large-area and flexible clay nanocomposite lamellar films with excellent thermal stability were fabricated by a simple and rapid doctor-blade coating method. The clay lamellar films can be applied to the surface of combustible materials to insulate them from heat and oxygen to provide a flame-retardant effect. By regulating the thickness of films and folding the films multiple times, the flame spread area decreased by 97.3 % and the total smoke production decreased by 74.7 % compared to the pure basswood board, showing excellent fire-retardancy. The large-area clay lamellar films made with simple processes and low-cost materials prove new strategies for efficient and environmentally friendly flame-retardant.

{"title":"Flame-retardant effect of scalable all clay composite films","authors":"Yixuan Fu , Zhaoyi Wang , Huiquan Liu , Ke Zhang , Lunxiang Zhang , Yongchen Song , Peng Wu , Yanghui Li , Zheng Ling","doi":"10.1016/j.clay.2025.107724","DOIUrl":"10.1016/j.clay.2025.107724","url":null,"abstract":"<div><div>Flame retardants reduce fire risks from everyday materials that sustain a high standard of living. There is growing interest in applying surface treatments to localize flame-retardant chemistry at the surface of combustible material. This popular treatment method aims to maintain the desired bulk properties of materials and reduce the quantity of additives required. Owing to the excellent thermal stability, low cost and lightweight, clay nanomaterials are potential as environmentally friendly, lightweight, and practical flame-retardant materials. However, such potential may be restricted by the slow, tedious, energy-intensive, and unscalable fabrication process. Herein, large-area and flexible clay nanocomposite lamellar films with excellent thermal stability were fabricated by a simple and rapid doctor-blade coating method. The clay lamellar films can be applied to the surface of combustible materials to insulate them from heat and oxygen to provide a flame-retardant effect. By regulating the thickness of films and folding the films multiple times, the flame spread area decreased by 97.3 % and the total smoke production decreased by 74.7 % compared to the pure basswood board, showing excellent fire-retardancy. The large-area clay lamellar films made with simple processes and low-cost materials prove new strategies for efficient and environmentally friendly flame-retardant.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"267 ","pages":"Article 107724"},"PeriodicalIF":5.3,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097682","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}

引用次数: 0

Eco-friendly design of active montmorillonite nanofillers for reinforcing the anti-corrosion property of epoxy coating

IF 5.3 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-02-02 DOI: 10.1016/j.clay.2025.107739

Xianliang Li, Yawei Shao, Yanqiu Wang, Junyi Wang

In this work, a montmorillonite (MMT)-based composite coating with long-term corrosion protection for mild steel was prepared. This composite coating incorporated the montmorillonite@polydopamine@cerium phytate (MMT@PDA@PACe) nanofiller, prepared by the easily layer-by-layer surface assembly method. Electrochemical impedance spectroscopy (EIS) and surface morphology studies showed that the prepared composite coating exhibited long-term protective performance, self-healing performance, and good integrity. In this instance, on the one hand, two-dimensional (2D) MMT could block the path of corrosive media penetrating the coating. Also, organic modification of PDA and PACe could enhance the dispersibility and compatibility of inorganic MMT fillers, thus enhancing the coating barrier effect. On the other hand, composite materials could perceive corrosion reactions and actively release corrosion inhibitors to improve corrosion resistance performance further. The coating's self-healing performance and release characteristics of corrosion inhibitors were investigated by the EIS and inductively coupled plasma optical emission spectrometer (ICP-OES) tests. Moreover, after 60 d immersion, the |Z|_{0.01 Hz} value of the 0.5 wt% MMT@PDA@PACe composite coating was over 10⁹ Ω·cm², which is 3 orders of magnitude higher than that of the bare coating. Simultaneously, the adhesive force studies were applied to the composite coatings, and the results illustrated that the coating had the highest dry conditions adhesion force with 5.43 MPa and the lowest adhesion force loss rate at 14.1 % after 30 d of immersion.

{"title":"Eco-friendly design of active montmorillonite nanofillers for reinforcing the anti-corrosion property of epoxy coating","authors":"Xianliang Li, Yawei Shao, Yanqiu Wang, Junyi Wang","doi":"10.1016/j.clay.2025.107739","DOIUrl":"10.1016/j.clay.2025.107739","url":null,"abstract":"<div><div>In this work, a montmorillonite (MMT)-based composite coating with long-term corrosion protection for mild steel was prepared. This composite coating incorporated the montmorillonite@polydopamine@cerium phytate (MMT@PDA@PACe) nanofiller, prepared by the easily layer-by-layer surface assembly method. Electrochemical impedance spectroscopy (EIS) and surface morphology studies showed that the prepared composite coating exhibited long-term protective performance, self-healing performance, and good integrity. In this instance, on the one hand, two-dimensional (2D) MMT could block the path of corrosive media penetrating the coating. Also, organic modification of PDA and PACe could enhance the dispersibility and compatibility of inorganic MMT fillers, thus enhancing the coating barrier effect. On the other hand, composite materials could perceive corrosion reactions and actively release corrosion inhibitors to improve corrosion resistance performance further. The coating's self-healing performance and release characteristics of corrosion inhibitors were investigated by the EIS and inductively coupled plasma optical emission spectrometer (ICP-OES) tests. Moreover, after 60 d immersion, the <em>|Z|</em><sub>0.01 Hz</sub> value of the 0.5 wt% MMT@PDA@PACe composite coating was over 10<sup>9</sup> Ω·cm<sup>2</sup>, which is 3 orders of magnitude higher than that of the bare coating. Simultaneously, the adhesive force studies were applied to the composite coatings, and the results illustrated that the coating had the highest dry conditions adhesion force with 5.43 MPa and the lowest adhesion force loss rate at 14.1 % after 30 d of immersion.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"267 ","pages":"Article 107739"},"PeriodicalIF":5.3,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097681","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}

引用次数: 0

Clay minerals formation in MgO-SiO2-H2O low temperature system by hydrothermal synthesis: A study in function of Mg/Si molar ratio and pH

IF 5.3 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-02-01 DOI: 10.1016/j.clay.2024.107647

Alexandra Jourdain , Patrick Dutournié , Laure Michelin , Jean-Marc Le Meins , Jocelyne Brendlé , Nicolas Michau , Christelle Martin , Liva Dzene

Magnesium only-phyllosilicates such as serpentines (1:1) and stevensite (2:1) do exist in nature but are not abundant in pure form, whereas synthesized materials can ensure higher purity. Clay mineral hydrothermal synthesis is quite easy to perform, however, the condensation reactions leading to the formation of these phyllosilicates and their precursors are not well understood. Such knowledge would allow to predict the synthesis outcome in case of variation of experimental parameters. This study reports a chemical reaction mechanism explaining the parameters that are determining the type of the formed clay mineral. After a detailed characterization of each obtained phase, it is shown that pH has a lower effect compared to Mg to Si molar ratio. Our results show that above pH 10 the mechanisms of lizardite and stevensite formation are similar with the same elementary units, but that the type of material obtained depends on the availability in excess of magnesium (formation of lizardite) or silicon (formation of stevensite).

{"title":"Clay minerals formation in MgO-SiO2-H2O low temperature system by hydrothermal synthesis: A study in function of Mg/Si molar ratio and pH","authors":"Alexandra Jourdain , Patrick Dutournié , Laure Michelin , Jean-Marc Le Meins , Jocelyne Brendlé , Nicolas Michau , Christelle Martin , Liva Dzene","doi":"10.1016/j.clay.2024.107647","DOIUrl":"10.1016/j.clay.2024.107647","url":null,"abstract":"<div><div>Magnesium only-phyllosilicates such as serpentines (1:1) and stevensite (2:1) do exist in nature but are not abundant in pure form, whereas synthesized materials can ensure higher purity. Clay mineral hydrothermal synthesis is quite easy to perform, however, the condensation reactions leading to the formation of these phyllosilicates and their precursors are not well understood. Such knowledge would allow to predict the synthesis outcome in case of variation of experimental parameters. This study reports a chemical reaction mechanism explaining the parameters that are determining the type of the formed clay mineral. After a detailed characterization of each obtained phase, it is shown that pH has a lower effect compared to Mg to Si molar ratio. Our results show that above pH 10 the mechanisms of lizardite and stevensite formation are similar with the same elementary units, but that the type of material obtained depends on the availability in excess of magnesium (formation of lizardite) or silicon (formation of stevensite).</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"264 ","pages":"Article 107647"},"PeriodicalIF":5.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181991","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}

引用次数: 0