Pub Date : 2024-05-08DOI: 10.3389/fmats.2024.1412094
Zhen Li, Zhen Lu, Xiajun Liu, Jianxiang Wang
During the preparation of asphalt mixtures, styrene-butadiene rubber (SBR) polymers are susceptible to thermal decomposition, which can significantly impair the binder’s low-temperature performance. This study explores the potential of combining warming agents with waste materials to enhance the low-temperature properties and aging resistance of the binder. Specifically, it examines the synergistic impact of Sasobit/recycled engine oil (Sasobit/REO) composites on the rheological and physical attributes of styrene-butadiene rubber asphalt binder (SBRAB). Utilizing fluorescence microscopy (FM), bending beam rheometer (BBR), and dynamic shear rheometer (DSR), the study assesses the aging resistance and modification mechanisms of Sasobit/REO on SBRAB. The findings indicate that the incorporation of Sasobit/REO composites more effectively reduces the mix preparation temperature than either component alone. The preparation of Sasobit/REO warm mix asphalt mixtures is feasible at temperatures 20°C lower than those required for traditional hot mixtures. These composites also enhance the performance of SBRAB at both high and low temperatures, counteracting the adverse effects associated with the individual use of Sasobit or REO. This reduced short-term aging temperature is beneficial in lessening the negative impact of high temperatures on SBRAB’s performance. Moreover, the addition of Sasobit/REO composites significantly improves the thermal cracking resistance of SBRAB mixtures. The study also demonstrates that Sasobit/REO enhances the short-term and long-term aging resistance of SBRAB, paving the way for the broader application of this novel warm mix additive in the asphalt industry.
{"title":"Investigating the synergistic anti-aging effects of Sasobit and recycled engine oil in styrene-butadiene rubber modified asphalt","authors":"Zhen Li, Zhen Lu, Xiajun Liu, Jianxiang Wang","doi":"10.3389/fmats.2024.1412094","DOIUrl":"https://doi.org/10.3389/fmats.2024.1412094","url":null,"abstract":"During the preparation of asphalt mixtures, styrene-butadiene rubber (SBR) polymers are susceptible to thermal decomposition, which can significantly impair the binder’s low-temperature performance. This study explores the potential of combining warming agents with waste materials to enhance the low-temperature properties and aging resistance of the binder. Specifically, it examines the synergistic impact of Sasobit/recycled engine oil (Sasobit/REO) composites on the rheological and physical attributes of styrene-butadiene rubber asphalt binder (SBRAB). Utilizing fluorescence microscopy (FM), bending beam rheometer (BBR), and dynamic shear rheometer (DSR), the study assesses the aging resistance and modification mechanisms of Sasobit/REO on SBRAB. The findings indicate that the incorporation of Sasobit/REO composites more effectively reduces the mix preparation temperature than either component alone. The preparation of Sasobit/REO warm mix asphalt mixtures is feasible at temperatures 20°C lower than those required for traditional hot mixtures. These composites also enhance the performance of SBRAB at both high and low temperatures, counteracting the adverse effects associated with the individual use of Sasobit or REO. This reduced short-term aging temperature is beneficial in lessening the negative impact of high temperatures on SBRAB’s performance. Moreover, the addition of Sasobit/REO composites significantly improves the thermal cracking resistance of SBRAB mixtures. The study also demonstrates that Sasobit/REO enhances the short-term and long-term aging resistance of SBRAB, paving the way for the broader application of this novel warm mix additive in the asphalt industry.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"37 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141257377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-07DOI: 10.3389/fmats.2024.1407485
Muhammad Ali Bhatti, Elmuez Dawi, Aneela Tahira, Ahmed Ali Hulio, Imran Ali Halepoto, Sajjad Ali Chang, Abdul Ghaffar Solangi, Ayman Nafady, Matteo Tonezzer, Abd Al Karim Haj Ismail, Zafar Hussain Ibupoto
A low temperature aqueous growth followed by mild pyrolysis was used in this study to synthesize high-quality carbonized materials from the deserted plant Citrullus Colocynthis. It was found that the carbon material prepared for this study contained an abundance of functional groups and surface active sites. A few microns were evidently the size of the carbon material. This study investigated a variety of photocatalytic performance evaluation parameters, including initial dye concentration of methylene blue, pH effect on dye solution, scavenger stability, and recycle stability via irradiating UV light. Methylene blue degradation was found to be significantly affected by pH and concentration of the dye solution. It has been found that pH five is the most effective pH for the removal of dyes. As a result of the study, we found that methylene blue decays according to pseudo first order kinetics and is estimated to remove dye at an almost 100% rate.
{"title":"UV photodegradation of methylene blue using microstructural carbon materials derived from citrullus colocynthis","authors":"Muhammad Ali Bhatti, Elmuez Dawi, Aneela Tahira, Ahmed Ali Hulio, Imran Ali Halepoto, Sajjad Ali Chang, Abdul Ghaffar Solangi, Ayman Nafady, Matteo Tonezzer, Abd Al Karim Haj Ismail, Zafar Hussain Ibupoto","doi":"10.3389/fmats.2024.1407485","DOIUrl":"https://doi.org/10.3389/fmats.2024.1407485","url":null,"abstract":"A low temperature aqueous growth followed by mild pyrolysis was used in this study to synthesize high-quality carbonized materials from the deserted plant Citrullus Colocynthis. It was found that the carbon material prepared for this study contained an abundance of functional groups and surface active sites. A few microns were evidently the size of the carbon material. This study investigated a variety of photocatalytic performance evaluation parameters, including initial dye concentration of methylene blue, pH effect on dye solution, scavenger stability, and recycle stability via irradiating UV light. Methylene blue degradation was found to be significantly affected by pH and concentration of the dye solution. It has been found that pH five is the most effective pH for the removal of dyes. As a result of the study, we found that methylene blue decays according to pseudo first order kinetics and is estimated to remove dye at an almost 100% rate.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"19 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141257146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-02DOI: 10.3389/fmats.2024.1388122
Jinguang Huang, Yanlin Huo, Qunshan Su, Dong Lu, Yuanchao Wu, Xinhong Dong, Yang Gao
To mitigate the shrinkage of high-strength alkali-activated slag concrete (AASC), this paper introduces emulsified cooking oil (ECO) and emulsified waste cooking oil (EWCO) into the AASC system. The effects of admixing ECO and EWCO on the compressive strength, drying shrinkage, autogenous shrinkage, carbonation, and sulfuric acid resistance of the AASC are systematically explored. The optimization mechanism is also proposed based on the surface tension and microstructural analysis. The experimental results show that the admixing ECO and EWCO slightly reduce the compressive strength of the AASC by 7.8%. Interestingly, the admixing ECO and EWCO significantly reduce the drying shrinkage and autogenous shrinkage, simultaneously improving the resistance to carbonation and sulfuric acid of the AASC. Specifically, the introduction of 2 wt.% ECO and EWCO can reduce the autogenous shrinkage of the AASC by 66.7% and 41.0%, respectively. Microstructural observations reveal that the addition of ECO and EWCO can reduce the internal surface tension of the AASC, improve the transport and diffusion of the pore solution, and increase the absorbable free water of the slag, which in turn reduces the shrinkage of the composites. It also increases the ionic concentration in the pore solution, resulting in a more complete reaction of the AASC, which can optimize the pore structure and thus improve the durability of the AASC. This study proposes a promising way to develop sustainable alkali-activated slag concrete achieved by recycling waste materials.
{"title":"Sustainable high-strength alkali-activated slag concrete is achieved by recycling emulsified waste cooking oil","authors":"Jinguang Huang, Yanlin Huo, Qunshan Su, Dong Lu, Yuanchao Wu, Xinhong Dong, Yang Gao","doi":"10.3389/fmats.2024.1388122","DOIUrl":"https://doi.org/10.3389/fmats.2024.1388122","url":null,"abstract":"To mitigate the shrinkage of high-strength alkali-activated slag concrete (AASC), this paper introduces emulsified cooking oil (ECO) and emulsified waste cooking oil (EWCO) into the AASC system. The effects of admixing ECO and EWCO on the compressive strength, drying shrinkage, autogenous shrinkage, carbonation, and sulfuric acid resistance of the AASC are systematically explored. The optimization mechanism is also proposed based on the surface tension and microstructural analysis. The experimental results show that the admixing ECO and EWCO slightly reduce the compressive strength of the AASC by 7.8%. Interestingly, the admixing ECO and EWCO significantly reduce the drying shrinkage and autogenous shrinkage, simultaneously improving the resistance to carbonation and sulfuric acid of the AASC. Specifically, the introduction of 2 wt.% ECO and EWCO can reduce the autogenous shrinkage of the AASC by 66.7% and 41.0%, respectively. Microstructural observations reveal that the addition of ECO and EWCO can reduce the internal surface tension of the AASC, improve the transport and diffusion of the pore solution, and increase the absorbable free water of the slag, which in turn reduces the shrinkage of the composites. It also increases the ionic concentration in the pore solution, resulting in a more complete reaction of the AASC, which can optimize the pore structure and thus improve the durability of the AASC. This study proposes a promising way to develop sustainable alkali-activated slag concrete achieved by recycling waste materials.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"135 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140833905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-01DOI: 10.3389/fmats.2024.1406583
Yu Lu, Jing Gu, Jinhe Yuan, Lina Wu, Xinxin Wang, Xiaofang Xu, Fuqiang Ye, Libin He
In light of escalating global climate change concerns and the pressing need to address industries with high carbon emissions and pollution, enhancing the preparation of phenol-formaldehyde epoxy resins has emerged as a critical research focus. This study seeks to fabricate waterborne phenol-formaldehyde epoxy resins with superior performance by investigating pivotal factors influencing their properties and refining preparation methods. Utilizing tetrabutylammonium bromide as a phase transfer catalyst, the phenol-formaldehyde epoxy resins are synthesized via a two-step alkalization process. Subsequent etherification reactions involve modifying the phenol-formaldehyde epoxy resins using cationic modifier diethanolamine (DEA) and anionic modifier sodium p-amino benzenesulfonate, resulting in waterborne phenol-formaldehyde epoxy resins. Subsequently, in situ synthesis is employed to produce nanoscale silica (SiO2) modified waterborne phenol-formaldehyde epoxy resins. The findings reveal that when the ratio of n1 to n2 falls within the range of 1/3.25 to 1/3, the emulsion displays a moderate particle size and maintains stable storage. Furthermore, an increase in DEA dosage leads to a particle size of less than 324 nm when the ratio of n1 to n2 exceeds 1/3, indicating stability. Moreover, optimal stability and prolonged storage lifespan are achieved when the nano SiO2 content is approximately 1.5%. This study contributes by synthesizing high-quality waterborne phenol-formaldehyde epoxy resin emulsions through optimized methods. The research findings offer a theoretical foundation for this domain and support the practical application of low-carbon and environmentally friendly concepts in the coatings industry.
{"title":"Optimization of preparation techniques for high-temperature resistant waterborne phenolic-epoxy resin emulsion under low carbon background","authors":"Yu Lu, Jing Gu, Jinhe Yuan, Lina Wu, Xinxin Wang, Xiaofang Xu, Fuqiang Ye, Libin He","doi":"10.3389/fmats.2024.1406583","DOIUrl":"https://doi.org/10.3389/fmats.2024.1406583","url":null,"abstract":"In light of escalating global climate change concerns and the pressing need to address industries with high carbon emissions and pollution, enhancing the preparation of phenol-formaldehyde epoxy resins has emerged as a critical research focus. This study seeks to fabricate waterborne phenol-formaldehyde epoxy resins with superior performance by investigating pivotal factors influencing their properties and refining preparation methods. Utilizing tetrabutylammonium bromide as a phase transfer catalyst, the phenol-formaldehyde epoxy resins are synthesized via a two-step alkalization process. Subsequent etherification reactions involve modifying the phenol-formaldehyde epoxy resins using cationic modifier diethanolamine (DEA) and anionic modifier sodium p-amino benzenesulfonate, resulting in waterborne phenol-formaldehyde epoxy resins. Subsequently, <jats:italic>in situ</jats:italic> synthesis is employed to produce nanoscale silica (SiO<jats:sub>2</jats:sub>) modified waterborne phenol-formaldehyde epoxy resins. The findings reveal that when the ratio of n1 to n2 falls within the range of 1/3.25 to 1/3, the emulsion displays a moderate particle size and maintains stable storage. Furthermore, an increase in DEA dosage leads to a particle size of less than 324 nm when the ratio of n1 to n2 exceeds 1/3, indicating stability. Moreover, optimal stability and prolonged storage lifespan are achieved when the nano SiO<jats:sub>2</jats:sub> content is approximately 1.5%. This study contributes by synthesizing high-quality waterborne phenol-formaldehyde epoxy resin emulsions through optimized methods. The research findings offer a theoretical foundation for this domain and support the practical application of low-carbon and environmentally friendly concepts in the coatings industry.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"39 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140842097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-01DOI: 10.3389/fmats.2024.1401094
Anwei Wang, Yang Wang, Hongwu Zhu, Hanxiao Sun, Yansen Li
In this study, the effect of cyclic compression on the micromechanical properties of a Zr-based metallic glass (MG) was investigated via nanoindentation. Cyclic compression significantly softened the surface of the sample, with a maximum hardness loss of 19.93%. The number of cyclic compression passes had a greater effect on the hardness of the sample than the cyclic compression load. The elastic modulus exhibited a nonlinear variation upon increasing the cyclic loading or number of passes at a lower loading rate due to the coupling effect of loading rate and cyclic compression treatment. Then, the serration behavior and strain rate sensitivity analysis were applied. The calculated m-values obtained for MGs were all negative and gradually tended to zero upon further cyclic compression treatment. This demonstrated the weakening effect of cyclic compression on the strain rate sensitivity of MG, and the underlying mechanism was discussed. This study provides a process reference for studying the fatigue failure behaviors of MGs from the perspective of mechanical properties, which is useful for understanding their fatigue generation.
本研究通过纳米压痕法研究了循环压缩对锆基金属玻璃（MG）微机械性能的影响。循环压缩明显软化了样品表面，最大硬度损失为 19.93%。与循环压缩载荷相比，循环压缩次数对样品硬度的影响更大。由于加载速率和循环压缩处理的耦合效应，在较低加载速率下增加循环加载或循环次数时，弹性模量呈现非线性变化。然后，应用了锯齿行为和应变速率敏感性分析。计算得出的 MG m 值均为负值，并在进一步循环压缩处理后逐渐趋于零。这证明了循环压缩对 MG 应变率敏感性的削弱作用，并对其内在机理进行了探讨。该研究为从力学性能角度研究 MG 的疲劳破坏行为提供了工艺参考，有助于理解其疲劳产生的原因。
{"title":"Effect of cyclic compression on the micromechanical properties of a Zr-based metallic glass","authors":"Anwei Wang, Yang Wang, Hongwu Zhu, Hanxiao Sun, Yansen Li","doi":"10.3389/fmats.2024.1401094","DOIUrl":"https://doi.org/10.3389/fmats.2024.1401094","url":null,"abstract":"In this study, the effect of cyclic compression on the micromechanical properties of a Zr-based metallic glass (MG) was investigated via nanoindentation. Cyclic compression significantly softened the surface of the sample, with a maximum hardness loss of 19.93%. The number of cyclic compression passes had a greater effect on the hardness of the sample than the cyclic compression load. The elastic modulus exhibited a nonlinear variation upon increasing the cyclic loading or number of passes at a lower loading rate due to the coupling effect of loading rate and cyclic compression treatment. Then, the serration behavior and strain rate sensitivity analysis were applied. The calculated m-values obtained for MGs were all negative and gradually tended to zero upon further cyclic compression treatment. This demonstrated the weakening effect of cyclic compression on the strain rate sensitivity of MG, and the underlying mechanism was discussed. This study provides a process reference for studying the fatigue failure behaviors of MGs from the perspective of mechanical properties, which is useful for understanding their fatigue generation.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"70 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141257155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-26DOI: 10.3389/fmats.2024.1367251
Bei Pu, Lusha Deng, Jun Lu, Liang Wei, Xiaoxing Xiong
This research study focuses on the investigation of a three-dimensional reconstructed carbon coating based on stainless steel. The investigation encompasses the assessment of surface structure, elemental composition, cytotoxicity, and impact on wound healing. The findings indicate that the carbon coating possesses an approximate thickness of 700 nm, exhibiting a distinctive porous structure. Moreover, the surface water contact angle measures 97.7°, representing a 48.4° increase compared to uncoated stainless steel. Energy-dispersive spectroscopy (EDS) analysis confirms the uniform distribution of diverse elements on the coating’s surface. Additionally, X-ray photoelectron spectroscopy (XPS) verifies a substantial carbon accumulation. The electrical resistance of the stainless steel remains largely intact after the application of the coating, as demonstrated by the four-probe method. Notably, ex vivo porcine liver tissue cutting experiments using carbon-coated electrosurgical pencil electrodes showed a significant anti-adhesion effect, with a reduction in tissue adhesions of 81.3%. Furthermore, the MTT test indicates no significant cytotoxicity associated with the carbon coating. Rat skin-cutting experiments further validate that the coating does not impede the process of wound healing. Overall, this study successfully validated the desirable properties of stainless steel-based 3D reconstructed carbon coatings, such as enhanced surface properties, improved anti-adhesion efficacy, negligible cytotoxicity, and compatibility with wound healing. These findings are important for advancing medical device technology and improving patient outcomes.
{"title":"Anti-adhesion study of three-dimensional reconstructed carbon coatings","authors":"Bei Pu, Lusha Deng, Jun Lu, Liang Wei, Xiaoxing Xiong","doi":"10.3389/fmats.2024.1367251","DOIUrl":"https://doi.org/10.3389/fmats.2024.1367251","url":null,"abstract":"This research study focuses on the investigation of a three-dimensional reconstructed carbon coating based on stainless steel. The investigation encompasses the assessment of surface structure, elemental composition, cytotoxicity, and impact on wound healing. The findings indicate that the carbon coating possesses an approximate thickness of 700 nm, exhibiting a distinctive porous structure. Moreover, the surface water contact angle measures 97.7°, representing a 48.4° increase compared to uncoated stainless steel. Energy-dispersive spectroscopy (EDS) analysis confirms the uniform distribution of diverse elements on the coating’s surface. Additionally, X-ray photoelectron spectroscopy (XPS) verifies a substantial carbon accumulation. The electrical resistance of the stainless steel remains largely intact after the application of the coating, as demonstrated by the four-probe method. Notably, <jats:italic>ex vivo</jats:italic> porcine liver tissue cutting experiments using carbon-coated electrosurgical pencil electrodes showed a significant anti-adhesion effect, with a reduction in tissue adhesions of 81.3%. Furthermore, the MTT test indicates no significant cytotoxicity associated with the carbon coating. Rat skin-cutting experiments further validate that the coating does not impede the process of wound healing. Overall, this study successfully validated the desirable properties of stainless steel-based 3D reconstructed carbon coatings, such as enhanced surface properties, improved anti-adhesion efficacy, negligible cytotoxicity, and compatibility with wound healing. These findings are important for advancing medical device technology and improving patient outcomes.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"100 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140798904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-26DOI: 10.3389/fmats.2024.1368618
Fathi Shaqour
Mixtures of variable proportions of kaolin, quartz sand, zeolitic tuff, and cement kiln dust were blended while adding an 8 M sodium hydroxide (NaOH) solution to allow alkali-activation of kaolin and achieve the optimum strength. This study investigated the mineralogy, microstructure, and geotechnical properties of the prepared mixtures. The aim was to produce a sustainable, environmentally friendly landfill liner. The samples were compacted in stainless steel molds to a maximum dry density and optimum moisture content, extruded from the molds, and left to cure in an oven at varying temperatures from 40°C to 80°C for 24 h. The investigations included XRD, SEM, unconfined compressive strength, and hydraulic conductivity tests. Test results showed the development of a hydroxysodalite binder due to the alkali reaction of kaolin, which caused an increase in strength ranging from 20 to 25 MPa depending on the curing temperature. Alkaline activation was effective even at temperatures as low as 40°C. A mixture of 100 units of kaolin, 45 units of sand, 45 units of zeolitic tuff, and 10% by weight cement kiln dust (CKD) with an 8 M sodium hydroxide activator was found to best achieve the required strength and hydraulic conductivity of 10−9 m/s for the landfill liner. The zeolitic tuff with high cation exchange capacity, available in the mixture, absorbs contaminants in the leachate and prevents pollution of the groundwater. The use of cement kiln dust contributes to enhancing strength and solving an acute environmental problem.
将不同比例的高岭土、石英砂、沸石凝灰岩和水泥窑粉尘混合，同时加入 8 M 氢氧化钠（NaOH）溶液，使高岭土碱活化并达到最佳强度。本研究调查了所制备混合物的矿物学、微观结构和岩土力学性能。目的是生产一种可持续的环保型垃圾填埋场衬垫。样品在不锈钢模具中压实至最大干密度和最佳含水量，从模具中挤出，在 40°C 至 80°C 的不同温度下在烘箱中固化 24 小时。测试结果表明，由于高岭土的碱反应，羟基钠盐粘合剂得以形成，根据固化温度的不同，强度增加了 20 至 25 兆帕。即使温度低至 40°C，碱性活化也很有效。研究发现，由 100 个单位的高岭土、45 个单位的沙子、45 个单位的沸石凝灰岩和 10% 重量的水泥窑粉尘（CKD）与 8 M 氢氧化钠活化剂组成的混合物最能达到垃圾填埋场衬垫所需的强度和 10-9 m/s 的水力传导率。混合物中具有高阳离子交换能力的沸石凝灰岩可吸收渗滤液中的污染物，防止地下水受到污染。水泥窑粉尘的使用有助于提高强度和解决严重的环境问题。
{"title":"Mineralogy and geotechnical properties of alkaline-activated kaolin with zeolitic tuff and cement kiln dust as landfill liners","authors":"Fathi Shaqour","doi":"10.3389/fmats.2024.1368618","DOIUrl":"https://doi.org/10.3389/fmats.2024.1368618","url":null,"abstract":"Mixtures of variable proportions of kaolin, quartz sand, zeolitic tuff, and cement kiln dust were blended while adding an 8 M sodium hydroxide (NaOH) solution to allow alkali-activation of kaolin and achieve the optimum strength. This study investigated the mineralogy, microstructure, and geotechnical properties of the prepared mixtures. The aim was to produce a sustainable, environmentally friendly landfill liner. The samples were compacted in stainless steel molds to a maximum dry density and optimum moisture content, extruded from the molds, and left to cure in an oven at varying temperatures from 40°C to 80°C for 24 h. The investigations included XRD, SEM, unconfined compressive strength, and hydraulic conductivity tests. Test results showed the development of a hydroxysodalite binder due to the alkali reaction of kaolin, which caused an increase in strength ranging from 20 to 25 MPa depending on the curing temperature. Alkaline activation was effective even at temperatures as low as 40°C. A mixture of 100 units of kaolin, 45 units of sand, 45 units of zeolitic tuff, and 10% by weight cement kiln dust (CKD) with an 8 M sodium hydroxide activator was found to best achieve the required strength and hydraulic conductivity of 10<jats:sup>−9</jats:sup> m/s for the landfill liner. The zeolitic tuff with high cation exchange capacity, available in the mixture, absorbs contaminants in the leachate and prevents pollution of the groundwater. The use of cement kiln dust contributes to enhancing strength and solving an acute environmental problem.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"15 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140798923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to study the bending properties of tropical tree species rich in organic extracts, the effects of temperature and time on the bending performance of hydrothermal treatment were investigated. The effects of power and time on bending performance under microwave heating conditions were investigated. It is found that the chemical composition does not undergo obvious degradation at 80°C–100°C, and the bending performance gradually becomes better with the increase in heating time; when the hydrothermal time exceeds 4 h, the bending performance varies with heating time. The growth is better than the difference, reaching the maximum at 4 h. When the water temperature is 140°C, the bending performance is negatively correlated with the heating time. When the hydrothermal treatment time is the same, the bending property becomes better as the temperature increases. The most reasonable process for microwave softening heating is with a power of 480 W and a heating time of 4 min. A softening treatment method combining water heat and microwave can achieve a better softening effect. When the final moisture content is controlled to 8%, the bending setting effect is the best. The optimum drying time is 6 h, and the optimum drying temperature is 50°C.
{"title":"Effects of hydrothermal–microwave treatment on bending properties of teak in plantation","authors":"Donghai Huang, Huajie Shen, Jilin Zhang, Xinzhen Zhuo, Liangzhou Dong","doi":"10.3389/fmats.2024.1278707","DOIUrl":"https://doi.org/10.3389/fmats.2024.1278707","url":null,"abstract":"In order to study the bending properties of tropical tree species rich in organic extracts, the effects of temperature and time on the bending performance of hydrothermal treatment were investigated. The effects of power and time on bending performance under microwave heating conditions were investigated. It is found that the chemical composition does not undergo obvious degradation at 80°C–100°C, and the bending performance gradually becomes better with the increase in heating time; when the hydrothermal time exceeds 4 h, the bending performance varies with heating time. The growth is better than the difference, reaching the maximum at 4 h. When the water temperature is 140°C, the bending performance is negatively correlated with the heating time. When the hydrothermal treatment time is the same, the bending property becomes better as the temperature increases. The most reasonable process for microwave softening heating is with a power of 480 W and a heating time of 4 min. A softening treatment method combining water heat and microwave can achieve a better softening effect. When the final moisture content is controlled to 8%, the bending setting effect is the best. The optimum drying time is 6 h, and the optimum drying temperature is 50°C.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"9 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141523935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To address the challenges posed by the significant quantity of ammonia-alkali white mud, this study explores the preparation of fluid solidified soil using ammonia-alkali white mud, mineral powder, and fly ash. The findings reveal that ammonia-alkali white mud primarily comprises sulfate, carbonate, and soluble chloride salt, with an alkaline solution and a well-developed pore structure. Optimal fluid solidified soil formulation, comprising 30% white mud, 30% salt mud, 25% mineral powder, 10% fly ash, and 5% calcium oxide, yields a slurry fluidity of 176 mm and a compressive strength of 3.98 MPa at 28 days. Microscopic analysis highlights AFt and C-S-H gel as the principal hydration products of fluid solidified soil. The fine particles of calcium carbonate in ammonia-alkali white mud fill the structural pores and intertwine with the hydration products, facilitating the formation of a dense structure, which constitutes the primary source of strength in fluid solidified soil. Furthermore, the heavy metal content of the solidified soil aligns with the first type of land use requirements outlined in the GB 36600-2018 standard, and the toxicity of the leaching solution adheres to the emission concentration limit stipulated by GB 8978-1996.
{"title":"Study on characteristics of ammonia alkali white mud and mechanical properties of preparation of fluid solidified soil","authors":"Shifeng Fu, Zhiquan Li, Guangtian Zhang, Biao Zhang, Yanjia Zhang","doi":"10.3389/fmats.2024.1390421","DOIUrl":"https://doi.org/10.3389/fmats.2024.1390421","url":null,"abstract":"To address the challenges posed by the significant quantity of ammonia-alkali white mud, this study explores the preparation of fluid solidified soil using ammonia-alkali white mud, mineral powder, and fly ash. The findings reveal that ammonia-alkali white mud primarily comprises sulfate, carbonate, and soluble chloride salt, with an alkaline solution and a well-developed pore structure. Optimal fluid solidified soil formulation, comprising 30% white mud, 30% salt mud, 25% mineral powder, 10% fly ash, and 5% calcium oxide, yields a slurry fluidity of 176 mm and a compressive strength of 3.98 MPa at 28 days. Microscopic analysis highlights AFt and C-S-H gel as the principal hydration products of fluid solidified soil. The fine particles of calcium carbonate in ammonia-alkali white mud fill the structural pores and intertwine with the hydration products, facilitating the formation of a dense structure, which constitutes the primary source of strength in fluid solidified soil. Furthermore, the heavy metal content of the solidified soil aligns with the first type of land use requirements outlined in the GB 36600-2018 standard, and the toxicity of the leaching solution adheres to the emission concentration limit stipulated by GB 8978-1996.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"87 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140628090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The elastic modulus of rocks is a measure of the ability of rocks to resist elastic deformation. It is related to the size of rocks and can effectively measure the internal physical and mechanical strength of rocks. The development of joint fractures is the main reason for the size effect of rocks. Therefore, exploring the influence of joint roughness on the elastic modulus of rocks of different sizes is of great significance in mining rock mechanics. The article investigates the size effect of joint roughness on elastic modulus of rocks by establishing simulation schemes for 30 working conditions. By analyzing the stress-strain curves of rocks with different roughness and sizes, the deformation and failure patterns of rocks with different sizes were obtained. Research has found that the elastic modulus of rocks is in a power function relationship with joint roughness, while the elastic modulus of rocks is negatively exponentially related to rock size; The characteristic elastic modulus of rocks is in a power function relationship with joint roughness. The above relationships not only reveal the variation of rock elastic modulus with size, but also reveal the influence of joint roughness on elastic modulus, providing important basis for understanding the stability of mining rock engineering.
{"title":"Study on the size effect of rock elastic modulus considering the influence of joint roughness","authors":"Gaojian Hu, Bin Wang, Wenbing Guo, Yuan Xing, Junxia Zhou, Lanchang Zha, Shiyu Meng","doi":"10.3389/fmats.2024.1367006","DOIUrl":"https://doi.org/10.3389/fmats.2024.1367006","url":null,"abstract":"The elastic modulus of rocks is a measure of the ability of rocks to resist elastic deformation. It is related to the size of rocks and can effectively measure the internal physical and mechanical strength of rocks. The development of joint fractures is the main reason for the size effect of rocks. Therefore, exploring the influence of joint roughness on the elastic modulus of rocks of different sizes is of great significance in mining rock mechanics. The article investigates the size effect of joint roughness on elastic modulus of rocks by establishing simulation schemes for 30 working conditions. By analyzing the stress-strain curves of rocks with different roughness and sizes, the deformation and failure patterns of rocks with different sizes were obtained. Research has found that the elastic modulus of rocks is in a power function relationship with joint roughness, while the elastic modulus of rocks is negatively exponentially related to rock size; The characteristic elastic modulus of rocks is in a power function relationship with joint roughness. The above relationships not only reveal the variation of rock elastic modulus with size, but also reveal the influence of joint roughness on elastic modulus, providing important basis for understanding the stability of mining rock engineering.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"27 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140627973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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