Pub Date : 2025-10-21DOI: 10.1016/j.oceram.2025.100869
E. Tiffo , C.J.N. Sabouang , M. Mouafon , C.C.L. Tchamo , A. Pountouenchi , H.K. Tchakouté , D. Njoya , A. Elimbi
Thermal stability is an essential parameter to consider before using a binder at elevated temperature. This study investigates the effects of boehmite (B) on thermal behaviour and fired characteristics of sodium-based geopolymers respectively obtained from kaolin (K) and metakaolin (MK). To that end, B was used to partially replace the aluminosilicates (0 and 30 % by mass), the resulting mixtures were alkali-activated to produce geopolymers (GK, GKB30, GMK, GMKB30), which were cured, heated (900–1100–1150 °C) and characterised. Thermal behaviour revealed that B improves the thermal stability in the products of GKB30 and GMKB30. Additionally, the compressive strengths were improved respectively of about 66.7 and 82.0 % in GKB30 (1100 °C) and GMKB30 (1150 °C), attributed to densification coupled with the presence of mullite, corundum and quartz. These products endowed with improved fired characteristics and enhanced thermal stability can be used as binders for refractory applications as well as precursors for the production of ceramics.
{"title":"Thermal behaviour of blends kaolin-boehmite and metakaolin-boehmite based-geopolymers: physical and mechanical properties","authors":"E. Tiffo , C.J.N. Sabouang , M. Mouafon , C.C.L. Tchamo , A. Pountouenchi , H.K. Tchakouté , D. Njoya , A. Elimbi","doi":"10.1016/j.oceram.2025.100869","DOIUrl":"10.1016/j.oceram.2025.100869","url":null,"abstract":"<div><div>Thermal stability is an essential parameter to consider before using a binder at elevated temperature. This study investigates the effects of boehmite (B) on thermal behaviour and fired characteristics of sodium-based geopolymers respectively obtained from kaolin (K) and metakaolin (MK). To that end, B was used to partially replace the aluminosilicates (0 and 30 % by mass), the resulting mixtures were alkali-activated to produce geopolymers (GK, GK<sub>B</sub><sup>30</sup>, GMK, GMK<sub>B</sub><sup>30</sup>), which were cured, heated (900–1100–1150 °C) and characterised. Thermal behaviour revealed that B improves the thermal stability in the products of GK<sub>B</sub><sup>30</sup> and GMK<sub>B</sub><sup>30</sup>. Additionally, the compressive strengths were improved respectively of about 66.7 and 82.0 % in GK<sub>B</sub><sup>30</sup> (1100 °C) and GMK<sub>B</sub><sup>30</sup> (1150 °C), attributed to densification coupled with the presence of mullite, corundum and quartz. These products endowed with improved fired characteristics and enhanced thermal stability can be used as binders for refractory applications as well as precursors for the production of ceramics.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"24 ","pages":"Article 100869"},"PeriodicalIF":2.8,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145416608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The phase relations in the Sm2O3–Fe2O3 system at 1300 and 1400 °C were studied in the whole concentration range by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The samples were prepared with a concentration step of 1–5 mol %. The isothermal cross-sections of the Sm2O3–Fe2O3 phase diagram at 1300 and 1400 °C are characterized by the presence of four single-phase (B–Sm2O3, SmFeO3(R), Sm3Fe5O12, Fe2O3), three two-phase (B–Sm2O3+SmFeO3, SmFeO3+ Sm3Fe5O12, Sm3Fe5O12+Fe2O3) regions. The refined lattice parameter of the unit cell and the boundaries of the homogeneity fields for solid solutions were determined. The range of homogeneity of solid solutions based on the R-phase extends from 49 to 52 mol % Sm2O3 at 1300 and 1400 °C. Nanocomposites based on the perovskite phase (SmFeO3) were obtained by the Pechini method and heterogeneous precipitation from nitrate solutions. The influence of the production method on the microstructure, morphology, and magnetic properties of nanopowders (SmFeO3) was studied. According to XRD, infrared spectroscopy, SEM, the synthesized perovskite SmFeO3 is single-phase with a particle size of 50–60 nm. The morphology of powder particles primarily depends on the method of material synthesis. The powders display superparamagnetic-like loops at 300 K, typical of nanoparticle ensembles.
{"title":"Phase relations in the Sm2O3-Fe2O3 system: Structure and magnetic properties of perovskite SmFeO3 ceramics","authors":"O.V. Chudinovych , T.V. Tomila , V.G. Kolesnichenko , A.V. Samelyuk , D.V. Vedel , A. Lynnyk","doi":"10.1016/j.oceram.2025.100866","DOIUrl":"10.1016/j.oceram.2025.100866","url":null,"abstract":"<div><div>The phase relations in the Sm<sub>2</sub>O<sub>3</sub>–Fe<sub>2</sub>O<sub>3</sub> system at 1300 and 1400 °C were studied in the whole concentration range by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The samples were prepared with a concentration step of 1–5 mol %. The isothermal cross-sections of the Sm<sub>2</sub>O<sub>3</sub>–Fe<sub>2</sub>O<sub>3</sub> phase diagram at 1300 and 1400 °C are characterized by the presence of four single-phase (B–Sm<sub>2</sub>O<sub>3</sub>, SmFeO<sub>3</sub>(R), Sm<sub>3</sub>Fe<sub>5</sub>O<sub>12</sub>, Fe<sub>2</sub>O<sub>3</sub>), three two-phase (B–Sm<sub>2</sub>O<sub>3</sub>+SmFeO<sub>3</sub>, SmFeO<sub>3</sub>+ Sm<sub>3</sub>Fe<sub>5</sub>O<sub>12</sub>, Sm<sub>3</sub>Fe<sub>5</sub>O<sub>12</sub>+Fe<sub>2</sub>O<sub>3</sub>) regions. The refined lattice parameter of the unit cell and the boundaries of the homogeneity fields for solid solutions were determined. The range of homogeneity of solid solutions based on the R-phase extends from 49 to 52 mol % Sm<sub>2</sub>O<sub>3</sub> at 1300 and 1400 °C. Nanocomposites based on the perovskite phase (SmFeO<sub>3</sub>) were obtained by the Pechini method and heterogeneous precipitation from nitrate solutions. The influence of the production method on the microstructure, morphology, and magnetic properties of nanopowders (SmFeO<sub>3</sub>) was studied. According to XRD, infrared spectroscopy, SEM, the synthesized perovskite SmFeO<sub>3</sub> is single-phase with a particle size of 50–60 nm. The morphology of powder particles primarily depends on the method of material synthesis. The powders display superparamagnetic-like loops at 300 K, typical of nanoparticle ensembles.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"24 ","pages":"Article 100866"},"PeriodicalIF":2.8,"publicationDate":"2025-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145416607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Numerous studies have highlighted the beneficial effects of flash-calcined sediment (SF) substitution on the mechanical performance of materials. However, very few studies have investigated its impacts on durability, especially the leaching. This study aims to assess its potential effects on the mechanical-microstructural development as well as durability against chloride ingress and leaching. The results indicate that the high specific surface area of SF accelerates cement hydration at early ages, while its pozzolanic reactivity contributes to an enhancement of compressive strength and microstructure in SF-based mortar (MSF) in the long term compared to the reference mortar (Mref). In addition, the formation of addition C-S-H gels from the pozzolanic reaction and the reduction in the critical diameter of pores explain the improved resistance of MSF mortar to chloride penetration. The leaching reveals a significant enhancement in the durability of SF-based cement paste, demonstrated by lower quantities of leached elements and reduced degradation depth compared to the reference. These benefits are attributed to lower Ca(OH)₂ content, a reduced Ca/Si ratio in C–S–H, and a refined microstructure in the MSF paste, which strongly hinder ion diffusion. The dissolution of hydrates during leaching also leads to a decrease in the Young’s modulus of hydration products, and degradation of the microstructure. However, the SF incorporation significantly mitigates this effect compared to the reference.
{"title":"Effects of flash-calcined sediment on the mechanical – microstructural development and the durability of cementitious materials against to chloride attack and leaching","authors":"Mouhamadou Amar , Mahfoud Benzerzour , Duc Chinh Chu , Nor-Edine Abriak , Joelle Kleib","doi":"10.1016/j.oceram.2025.100868","DOIUrl":"10.1016/j.oceram.2025.100868","url":null,"abstract":"<div><div>Numerous studies have highlighted the beneficial effects of flash-calcined sediment (SF) substitution on the mechanical performance of materials. However, very few studies have investigated its impacts on durability, especially the leaching. This study aims to assess its potential effects on the mechanical-microstructural development as well as durability against chloride ingress and leaching. The results indicate that the high specific surface area of SF accelerates cement hydration at early ages, while its pozzolanic reactivity contributes to an enhancement of compressive strength and microstructure in SF-based mortar (MSF) in the long term compared to the reference mortar (Mref). In addition, the formation of addition C-S-H gels from the pozzolanic reaction and the reduction in the critical diameter of pores explain the improved resistance of MSF mortar to chloride penetration. The leaching reveals a significant enhancement in the durability of SF-based cement paste, demonstrated by lower quantities of leached elements and reduced degradation depth compared to the reference. These benefits are attributed to lower Ca(OH)₂ content, a reduced Ca/Si ratio in C–S–H, and a refined microstructure in the MSF paste, which strongly hinder ion diffusion. The dissolution of hydrates during leaching also leads to a decrease in the Young’s modulus of hydration products, and degradation of the microstructure. However, the SF incorporation significantly mitigates this effect compared to the reference.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"24 ","pages":"Article 100868"},"PeriodicalIF":2.8,"publicationDate":"2025-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145362544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-18DOI: 10.1016/j.oceram.2025.100867
Siddhartha Roy
As porous ceramics are attractive materials for different high-temperature applications, such as thermal insulators, high-temperature filters, porous burners, etc., a thorough understanding of their thermal properties is crucial. Among different thermal properties, while the melting points and coefficients of thermal expansion are independent of porosity, thermal conductivity, thermal shock resistance, and thermal fatigue resistance strongly depend upon the selection of the bulk ceramic, amount of porosity, and different pore characteristics such as pore shape and size, pore connectivity and anisotropy, etc. In this review paper, a thorough description of the different structural and physical characteristics controlling the thermal properties of porous ceramics has been provided, along with a critical analysis of the published experimental results. Finally, some potential directions for future research on the thermal properties of porous ceramics have been identified.
{"title":"Thermal properties of porous ceramics","authors":"Siddhartha Roy","doi":"10.1016/j.oceram.2025.100867","DOIUrl":"10.1016/j.oceram.2025.100867","url":null,"abstract":"<div><div>As porous ceramics are attractive materials for different high-temperature applications, such as thermal insulators, high-temperature filters, porous burners, etc., a thorough understanding of their thermal properties is crucial. Among different thermal properties, while the melting points and coefficients of thermal expansion are independent of porosity, thermal conductivity, thermal shock resistance, and thermal fatigue resistance strongly depend upon the selection of the bulk ceramic, amount of porosity, and different pore characteristics such as pore shape and size, pore connectivity and anisotropy, etc. In this review paper, a thorough description of the different structural and physical characteristics controlling the thermal properties of porous ceramics has been provided, along with a critical analysis of the published experimental results. Finally, some potential directions for future research on the thermal properties of porous ceramics have been identified.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"24 ","pages":"Article 100867"},"PeriodicalIF":2.8,"publicationDate":"2025-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Coffee, one of the most popular hot beverages worldwide, generates substantial quantities of waste by-products during its production, including coffee husk (CH). Disposing of large amounts of CH in landfills poses serious ecological and health risks due to the release of toxic gases during organic decomposition. For the clean environmental disposal, the present work aimed to use CH at varied dosages (0, 2.5, 5.0, 7.5 and 10 %) for the production of lightweight laterite-based geopolymer. Results showed that the compressive and flexural strengths decreased from 31.20 to 5.42 MPa and 8.23 to 1.98 MPa with increased CH content up to 10 %. Adding CH into geopolymer generated voids weakened the strength development and increased the water absorption and porosity. The thermal conductivity decreased from 0.65 to 0.41 W/mK with increased CH content, making the geopolymer suitable for insulation applications. Water absorption, bulk density, and porosity were characterised according to ASTM C373–88, and capillary sorption rates using ASTM C1403. The intended product is a lightweight, geopolymer mortar for thermally insulating non-load-bearing elements, conforming to ASTM and/or EN standards for mortars used in construction.
{"title":"Mechanical, microstructural and thermal insulating properties of iron-rich laterite lightweight based geopolymer composite with appropriate coffee husk waste incorporation: A sustainable solution for valuing coffee husk waste","authors":"Rodrigue Cyriaque Kaze , Abdolhossein Naghizadeh , Jordan Valdès Sontia Metekong , Thiophine Nfongoh , Gisèle Laure Lecomte-Nana","doi":"10.1016/j.oceram.2025.100865","DOIUrl":"10.1016/j.oceram.2025.100865","url":null,"abstract":"<div><div>Coffee, one of the most popular hot beverages worldwide, generates substantial quantities of waste by-products during its production, including coffee husk (CH). Disposing of large amounts of CH in landfills poses serious ecological and health risks due to the release of toxic gases during organic decomposition. For the clean environmental disposal, the present work aimed to use CH at varied dosages (0, 2.5, 5.0, 7.5 and 10 %) for the production of lightweight laterite-based geopolymer. Results showed that the compressive and flexural strengths decreased from 31.20 to 5.42 MPa and 8.23 to 1.98 MPa with increased CH content up to 10 %. Adding CH into geopolymer generated voids weakened the strength development and increased the water absorption and porosity. The thermal conductivity decreased from 0.65 to 0.41 W/mK with increased CH content, making the geopolymer suitable for insulation applications. Water absorption, bulk density, and porosity were characterised according to ASTM <span><span>C373–88</span><svg><path></path></svg></span>, and capillary sorption rates using ASTM <span><span>C1403</span><svg><path></path></svg></span>. The intended product is a lightweight, geopolymer mortar for thermally insulating non-load-bearing elements, conforming to ASTM <span><span>and</span><svg><path></path></svg></span>/or EN standards for mortars used in construction.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"24 ","pages":"Article 100865"},"PeriodicalIF":2.8,"publicationDate":"2025-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145416609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This research aimed to examine the impacts of selenium (Se) doping on the antimicrobial activity and cytotoxicity of CuO-NPs. The NPs were characterized by UV-DRS, XRD, FTIR, and FESEM/EDX analysis. The crystallite size increased from 25 nm to 33 nm in the doped NPs. The FESEM micrographs demonstrated a shift from nearly spherical to spherical shape with Se doping. The antibacterial studies revealed that undoped and doped CuO-NPs effectively inhibited bacteria. The Se-doped CuO NPs (10%) exhibited the highest inhibitory effect on bacterial isolates, including P. aeruginosa (21 mm), A. baumannii (19 mm), and S. aureus (19 mm). The NPs showed considerable antifungal activity against the fungal isolates tested. The enhanced antifungal activity was observed in Se-doped NPs at high concentrations as compared to undoped CuO-NPs. The IC50 values were evaluated by treating HeLa cells with various dosages of NPs. The findings indicate that CuO-NPs-doped Se have improved anticancer efficacy.
{"title":"Plant-mediated synthesis of selenium doped copper oxide nanoparticles and investigation of their cytotoxicity, antifungal, and antibacterial","authors":"Mohammad Javad Javid-Naderi , Zahra Sabouri , Amin Jalili , Hossein Zarrinfar , Majid Darroudi","doi":"10.1016/j.oceram.2025.100864","DOIUrl":"10.1016/j.oceram.2025.100864","url":null,"abstract":"<div><div>This research aimed to examine the impacts of selenium (Se) doping on the antimicrobial activity and cytotoxicity of CuO-NPs. The NPs were characterized by UV-DRS, XRD, FTIR, and FESEM/EDX analysis. The crystallite size increased from 25 nm to 33 nm in the doped NPs. The FESEM micrographs demonstrated a shift from nearly spherical to spherical shape with Se doping. The antibacterial studies revealed that undoped and doped CuO-NPs effectively inhibited bacteria. The Se-doped CuO NPs (10%) exhibited the highest inhibitory effect on bacterial isolates, including <em>P. aeruginosa</em> (21 mm), <em>A. baumannii</em> (19 mm), and <em>S. aureus</em> (19 mm). The NPs showed considerable antifungal activity against the fungal isolates tested. The enhanced antifungal activity was observed in Se-doped NPs at high concentrations as compared to undoped CuO-NPs. The IC<sub>50</sub> values were evaluated by treating HeLa cells with various dosages of NPs. The findings indicate that CuO-NPs-doped Se have improved anticancer efficacy.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"24 ","pages":"Article 100864"},"PeriodicalIF":2.8,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145362543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-09DOI: 10.1016/j.oceram.2025.100863
Abdullah Jabr , Srečo D. Škapin , Sara Tominc , Nina Daneu , Jakob König , Vilma Ducman , Lidija Korat Bensa , Raul Bermejo , Matjaž Spreitzer
Clay-based materials typically require high-temperature processing (>900 °C), resulting in high energy consumption. This study explores cold sintering of metakaolin (MK) powders to achieve high mechanical strength at significantly lower processing temperatures. By applying uniaxial pressure of 400 MPa and heating to only 240 °C in the presence of 15 mol/L NaOH solution, successful densification of structurally sound and dense samples with an average density of 2.16 g/cm³ and a biaxial flexural strength of ∼35 MPa was achieved. This strength surpasses that of conventionally sintered MK (1470 °C) by ∼30 %. Densification was found to be governed by synergistic mechanisms involving MK exfoliation, conformal sintering around aggregates, and the precipitation of an amorphous sodium aluminosilicate hydrate phase. Crack formation was avoided through process optimization and verified using X-ray micro-computed tomography. These findings offer new insights into the chemo-mechanical mechanisms of cold sintering and demonstrate its potential as an efficient route for producing structural materials.
{"title":"Enhancing densification of metakaolin-based geopolymers via the cold sintering process","authors":"Abdullah Jabr , Srečo D. Škapin , Sara Tominc , Nina Daneu , Jakob König , Vilma Ducman , Lidija Korat Bensa , Raul Bermejo , Matjaž Spreitzer","doi":"10.1016/j.oceram.2025.100863","DOIUrl":"10.1016/j.oceram.2025.100863","url":null,"abstract":"<div><div>Clay-based materials typically require high-temperature processing (>900 °C), resulting in high energy consumption. This study explores cold sintering of metakaolin (MK) powders to achieve high mechanical strength at significantly lower processing temperatures. By applying uniaxial pressure of 400 MPa and heating to only 240 °C in the presence of 15 mol/L NaOH solution, successful densification of structurally sound and dense samples with an average density of 2.16 g/cm³ and a biaxial flexural strength of ∼35 MPa was achieved. This strength surpasses that of conventionally sintered MK (1470 °C) by ∼30 %. Densification was found to be governed by synergistic mechanisms involving MK exfoliation, conformal sintering around aggregates, and the precipitation of an amorphous sodium aluminosilicate hydrate phase. Crack formation was avoided through process optimization and verified using X-ray micro-computed tomography. These findings offer new insights into the chemo-mechanical mechanisms of cold sintering and demonstrate its potential as an efficient route for producing structural materials.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"24 ","pages":"Article 100863"},"PeriodicalIF":2.8,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
While the individual effects of particle size on ceramic properties are well-documented, the synergistic interactions between multiple components’ granulometry remain poorly understood. This study employs a full 23 factorial design to decouple and quantify these complex interactions between chamotte (CHM), clay binder (KG), and RH particle size (0 – 100 µm vs. 100 – 250 µm) particle sizes on porosity, flexural strength, and firing shrinkage. The results demonstrate that property optimization is governed by significant binary interactions where the effect of one component is contingent upon the granulometry of others. Maximum porosity (68 %) was achieved with fine particles of all components, while minimum shrinkage (0.43 %) required medium CHM with fine KG and RH. Highest strength (3.4 MPa) was obtained with the fine CHM and medium KG. Our models demonstrate, for instance, that the influence of chamotte particle size on strength reverses depending on clay binder size, challenging conventional single-component optimization approaches.
虽然颗粒大小对陶瓷性能的个别影响是有目共睹的，但多种组分粒度之间的协同相互作用仍然知之甚少。本研究采用全23因子设计来解耦和量化浆料（CHM）、粘土粘结剂（KG）和RH粒度（0 - 100 μ m vs. 100 - 250 μ m）对孔隙率、抗弯强度和烧成收缩率的复杂相互作用。结果表明，性能优化是由显著的二元相互作用，其中一个组成部分的影响是取决于其他的粒度。所有组分的细颗粒均可实现最大孔隙率（68%），而最小收缩率（0.43%）需要具有细KG和RH的中等CHM。细CHM和中等KG的强度最高，为3.4 MPa。例如，我们的模型表明，黏结剂粒径对强度的影响与黏结剂粒径相反，这对传统的单组分优化方法提出了挑战。
{"title":"Full factorial design unravels critical particle size interactions governing porosity-strength balance in clay-chamotte-rice husk refractories","authors":"Saliou Njuhou, Ladouce Achiwoue Mefire Alima, Ramadan Njindam Oumarou, Cherif Mountapbeme Ibrahim, Yacouba Mfomboum Kouotou, Amadou Pountouenchi, Dayirou Njoya","doi":"10.1016/j.oceram.2025.100862","DOIUrl":"10.1016/j.oceram.2025.100862","url":null,"abstract":"<div><div>While the individual effects of particle size on ceramic properties are well-documented, the synergistic interactions between multiple components’ granulometry remain poorly understood. This study employs a full 2<sup>3</sup> factorial design to decouple and quantify these complex interactions between chamotte (CHM), clay binder (KG), and RH particle size (0 – 100 µm vs. 100 – 250 µm) particle sizes on porosity, flexural strength, and firing shrinkage. The results demonstrate that property optimization is governed by significant binary interactions where the effect of one component is contingent upon the granulometry of others. Maximum porosity (68 %) was achieved with fine particles of all components, while minimum shrinkage (0.43 %) required medium CHM with fine KG and RH. Highest strength (3.4 MPa) was obtained with the fine CHM and medium KG. Our models demonstrate, for instance, that the influence of chamotte particle size on strength reverses depending on clay binder size, challenging conventional single-component optimization approaches.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"24 ","pages":"Article 100862"},"PeriodicalIF":2.8,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145362545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-04DOI: 10.1016/j.oceram.2025.100860
Franklin Kenne Tazune , A․Oumarou Amadou , Jean Mermoz Siéwé , Jean Jacques Kouadjo Tchekwagep , Hervé Kouamo Tchakouté , Claus Henning Rüscher , Pengku Hou
The goal of this research work is to use ferrisilicates containing low weight concentration in ferric ion (0.02 g/L) as an additive to enhance the characteristics of metakaolin-based geopolymers. The ferrisilicates were produced by adding 6.6, 13.2, 19.8, 26.4 and 33 mL of ferric ions to 10, 20, 30, 40 and 50 mL of sodium waterglass, respectively. Geopolymers were obtained by separately adding 10 wt. % of each ferrisilicate to the metakaolin. The micrographies demonstrate that the addition of 13.2 mL of Fe³⁺ ions to 20 mL of sodium waterglass results in the formation of ferrisilicate with smaller particle sizes. A maximum compressive strength of 71.59 MPa is achieved using ferrisilicate from 13.2 mL of Fe³⁺ and 20 mL of sodium waterglass. One potential methodology for the production of geopolymers involves the utilisation of ferrisilicate, which exhibits a low weight concentration of ferric ions (0.02 g/L).
{"title":"Behavior of amorphous ferrisilicates with low weight concentration in ferric ions on the properties of metakaolin-based geopolymers","authors":"Franklin Kenne Tazune , A․Oumarou Amadou , Jean Mermoz Siéwé , Jean Jacques Kouadjo Tchekwagep , Hervé Kouamo Tchakouté , Claus Henning Rüscher , Pengku Hou","doi":"10.1016/j.oceram.2025.100860","DOIUrl":"10.1016/j.oceram.2025.100860","url":null,"abstract":"<div><div>The goal of this research work is to use ferrisilicates containing low weight concentration in ferric ion (0.02 g/L) as an additive to enhance the characteristics of metakaolin-based geopolymers. The ferrisilicates were produced by adding 6.6, 13.2, 19.8, 26.4 and 33 mL of ferric ions to 10, 20, 30, 40 and 50 mL of sodium waterglass, respectively. Geopolymers were obtained by separately adding 10 wt. % of each ferrisilicate to the metakaolin. The micrographies demonstrate that the addition of 13.2 mL of Fe³⁺ ions to 20 mL of sodium waterglass results in the formation of ferrisilicate with smaller particle sizes. A maximum compressive strength of 71.59 MPa is achieved using ferrisilicate from 13.2 mL of Fe³⁺ and 20 mL of sodium waterglass. One potential methodology for the production of geopolymers involves the utilisation of ferrisilicate, which exhibits a low weight concentration of ferric ions (0.02 g/L).</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"24 ","pages":"Article 100860"},"PeriodicalIF":2.8,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145324747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-03DOI: 10.1016/j.oceram.2025.100861
Amine el Mahdi Safhi , Mostafa Aliyari , Shima Pilehvar , Moncef L. Nehdi , Mahdi Kioumarsi
Geometry-dependent strength reporting has hindered reliable design of Class F fly-ash geopolymer concrete (FA-GPC). In this study, compressive-strength (CS) results from about 800 mixtures were normalized to the reference 150Ø300 mm cylinder, permitting direct cross-comparison of specimen geometries extracted from 67 peer-reviewed papers. The harmonized dataset bundles oxide chemistry, mix proportions, activator composition, curing schedules, fresh-state metrics, multi-age strengths, and cradle-to-gate CO₂ inventories. Normalized CS across 1–365 days spans 5.8–85.0 MPa, and CO₂ intensities range 66–895 kg CO₂/m³ (mean 160 ± 91). Data mining isolates practical activation windows—NaOH 10–12 M, silica modulus 1.5–2.3, curing ≤ 75 °C—that consistently deliver 28-d CS ≥ 50 MPa at ∼160 kg CO₂/m³. Compared to strength-matched OPC concretes, these mixes reduce embodied carbon by ∼45–55 % (median ≈ 50 %). Strength–carbon design maps and the open dataset enable practitioners to target structural classes under explicit CO₂ budgets and provide a reproducible springboard for machine learning-based prediction, life-cycle assessment, and optimization of alkali-activated concretes and geopolymers.
几何相关强度报告阻碍了F级粉煤灰地聚合物混凝土（FA-GPC）的可靠设计。在这项研究中，大约800种混合物的压缩强度（CS）结果归一化到参考150Ø300 mm圆柱体，允许直接交叉比较从67篇同行评审论文中提取的试样几何形状。统一的数据集包括氧化物化学、混合比例、活化剂组成、固化时间表、新鲜状态指标、多龄期强度和从摇篮到闸门的二氧化碳清单。1-365天的标准化CS范围为5.8-85.0 MPa， CO₂强度范围为66-895 kg CO₂/m³（平均160±91）。数据挖掘分离出实际的激活窗口——naoh 10-12 M，二氧化硅模量1.5-2.3，固化≤75°c——在~ 160 kg CO₂/ M³下，持续提供28天CS≥50 MPa。与强度匹配的OPC混凝土相比，这些混合物减少了约45 - 55%（中位数≈50%）的隐含碳。强度-碳设计地图和开放数据集使从业者能够在明确的二氧化碳预算下针对结构类别，并为基于机器学习的预测、生命周期评估和碱活性混凝土和地聚合物的优化提供可重复的起点。
{"title":"Systematic data-driven meta-analysis of class F fly-ash geopolymer concrete","authors":"Amine el Mahdi Safhi , Mostafa Aliyari , Shima Pilehvar , Moncef L. Nehdi , Mahdi Kioumarsi","doi":"10.1016/j.oceram.2025.100861","DOIUrl":"10.1016/j.oceram.2025.100861","url":null,"abstract":"<div><div>Geometry-dependent strength reporting has hindered reliable design of Class F fly-ash geopolymer concrete (FA-GPC). In this study, compressive-strength (CS) results from about 800 mixtures were normalized to the reference 150Ø300 mm cylinder, permitting direct cross-comparison of specimen geometries extracted from 67 peer-reviewed papers. The harmonized dataset bundles oxide chemistry, mix proportions, activator composition, curing schedules, fresh-state metrics, multi-age strengths, and cradle-to-gate CO₂ inventories. Normalized CS across 1–365 days spans 5.8–85.0 MPa, and CO₂ intensities range 66–895 kg CO₂/m³ (mean 160 ± 91). Data mining isolates practical activation windows—NaOH 10–12 M, silica modulus 1.5–2.3, curing ≤ 75 °C—that consistently deliver 28-d CS ≥ 50 MPa at ∼160 kg CO₂/m³. Compared to strength-matched OPC concretes, these mixes reduce embodied carbon by ∼45–55 % (median ≈ 50 %). Strength–carbon design maps and the open dataset enable practitioners to target structural classes under explicit CO₂ budgets and provide a reproducible springboard for machine learning-based prediction, life-cycle assessment, and optimization of alkali-activated concretes and geopolymers.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"24 ","pages":"Article 100861"},"PeriodicalIF":2.8,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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