The higher degree of heterogeneity of the target compounds opens yet another dimension in the already broad field of coordination chemistry [...]
目标化合物更高的异质性为本已十分宽广的配位化学领域开辟了另一个维度 [...]
{"title":"Mixed-Metal Coordination Polymers","authors":"Ulli Englert","doi":"10.3390/cryst14090785","DOIUrl":"https://doi.org/10.3390/cryst14090785","url":null,"abstract":"The higher degree of heterogeneity of the target compounds opens yet another dimension in the already broad field of coordination chemistry [...]","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"4 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202512","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}
Guangpan Peng, Chenhao Niu, Yuankun Geng, Weipeng Duan, Shu Cao
To improve the discharge performance of aluminum–air batteries, CeO2/Al6061 composites were prepared as an anode using selective laser melting (SLM). Response surface methodology (RSM) was employed, and the test results were linearly fitted. A prediction model for the forming quality of the composite anode was established, and the reliability of the model and the interaction between process parameters were explored based on variance analysis and significance testing. On this basis, with corrosion potential, self-corrosion rate, and discharge voltage as optimization objectives, the optimal solution set of the SLM forming CeO2/Al6061 anode process parameter was solved through a genetic algorithm, and experimental verification was conducted. The results indicate that the optimal process range for the forming quality and various properties of composite materials is laser power of 265~285 W, scanning speed of 985~1025 mm/s, and scanning spacing of 0.116~0.140 mm. The optimized process parameters were selected for reliability testing, and the errors were all within 3.0%, verifying the accuracy and reliability of the model.
{"title":"Multi-Objective Optimization for the Forming Quality of a CeO2/Al6061 Alloy as an Aluminum–Air Battery Anode Manufactured via Selective Laser Melting","authors":"Guangpan Peng, Chenhao Niu, Yuankun Geng, Weipeng Duan, Shu Cao","doi":"10.3390/cryst14090784","DOIUrl":"https://doi.org/10.3390/cryst14090784","url":null,"abstract":"To improve the discharge performance of aluminum–air batteries, CeO2/Al6061 composites were prepared as an anode using selective laser melting (SLM). Response surface methodology (RSM) was employed, and the test results were linearly fitted. A prediction model for the forming quality of the composite anode was established, and the reliability of the model and the interaction between process parameters were explored based on variance analysis and significance testing. On this basis, with corrosion potential, self-corrosion rate, and discharge voltage as optimization objectives, the optimal solution set of the SLM forming CeO2/Al6061 anode process parameter was solved through a genetic algorithm, and experimental verification was conducted. The results indicate that the optimal process range for the forming quality and various properties of composite materials is laser power of 265~285 W, scanning speed of 985~1025 mm/s, and scanning spacing of 0.116~0.140 mm. The optimized process parameters were selected for reliability testing, and the errors were all within 3.0%, verifying the accuracy and reliability of the model.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"34 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202511","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}
Katarzyna Leszczyńska-Sejda, Joanna Malarz, Mateusz Ciszewski, Dorota Kopyto, Karolina Goc, Alicja Grzybek, Patrycja Kowalik, Szymon Orda, Karolina Pianowska, Aleksandra Turczyńska, Grzegorz Benke
This paper presents a method for obtaining cobalt(II) perrhenate from waste derived from two types of materials, i.e., Li-ion battery scrap, or more precisely, battery mass, and superalloy scrap. Both of the above-mentioned materials are a source of Co. However, a source of rhenium is perrhenic acid produced from ammonium perrhenate (recycled) by the ion exchange method using resins. Co(OH)2 can be precipitated from solutions resulting from the leaching of Li-ion battery mass, sludge from the Zn-Pb industry and superalloy scrap. The compound, after proper purification, can be used in a reaction with perrhenic acid to form Co(ReO4)2. The reaction should be conducted under the following conditions: time 1 h, room temperature, 30% excess of cobalt(II) hydroxide, and rhenium concentration in HReO4 from about 20 g/dm3 to 300 g/dm3. This work shows that with the use of Co(OH)2, obtained from waste, an anhydrous form of cobalt(II) perrhenate can be obtained, containing < 1000 ppm of the cumulative metal impurities.
{"title":"Hydrometallurgical Technology for Producing Rhenium(VII) and Cobalt(II) from Waste","authors":"Katarzyna Leszczyńska-Sejda, Joanna Malarz, Mateusz Ciszewski, Dorota Kopyto, Karolina Goc, Alicja Grzybek, Patrycja Kowalik, Szymon Orda, Karolina Pianowska, Aleksandra Turczyńska, Grzegorz Benke","doi":"10.3390/cryst14090783","DOIUrl":"https://doi.org/10.3390/cryst14090783","url":null,"abstract":"This paper presents a method for obtaining cobalt(II) perrhenate from waste derived from two types of materials, i.e., Li-ion battery scrap, or more precisely, battery mass, and superalloy scrap. Both of the above-mentioned materials are a source of Co. However, a source of rhenium is perrhenic acid produced from ammonium perrhenate (recycled) by the ion exchange method using resins. Co(OH)2 can be precipitated from solutions resulting from the leaching of Li-ion battery mass, sludge from the Zn-Pb industry and superalloy scrap. The compound, after proper purification, can be used in a reaction with perrhenic acid to form Co(ReO4)2. The reaction should be conducted under the following conditions: time 1 h, room temperature, 30% excess of cobalt(II) hydroxide, and rhenium concentration in HReO4 from about 20 g/dm3 to 300 g/dm3. This work shows that with the use of Co(OH)2, obtained from waste, an anhydrous form of cobalt(II) perrhenate can be obtained, containing < 1000 ppm of the cumulative metal impurities.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"12 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202518","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}
Bogusław Pierożyński, Mateusz Kuczyński, Tomasz Mikołajczyk
The three-dimensional and porous structure of nickel foam makes it an attractive material for employment in cost-effective electrochemical supercapacitors. This communication presents ac. impedance spectroscopy and cyclic voltammetry electrochemical examinations of potential supercapacitor electrode materials, fabricated by means of simple electrochemical procedures, employed to as-received Ni foam material. This involves the electro-oxidation and Co-catalytic modifications of baseline nickel foam samples. Hence, the supercapacitor-type performance (as evidenced over the examined potential range in 0.1 M NaOH solution) of base nickel foam material could extensively be tailored by means of simple surface and catalytic refinements. The latter was evidenced through the employment of combined electrochemical (cyclic voltammetry, ac. impedance) and SEM/EDX (Scanning Electron Microscopy/Energy Dispersive X-Ray) surface spectroscopy evaluations.
泡沫镍的三维多孔结构使其成为具有成本效益的电化学超级电容器的理想材料。这篇通讯介绍了对潜在超级电容器电极材料的交流阻抗光谱和循环伏安电化学检测。这包括对基线泡沫镍样品进行电氧化和协同催化改性。因此，基底泡沫镍材料的超级电容器性能（在 0.1 M NaOH 溶液中的测试电位范围内得到证明）可通过简单的表面和催化改进进行广泛定制。后者通过电化学（循环伏安法、交流阻抗）和扫描电子显微镜/能量色散 X 射线（扫描电子显微镜/能量色散 X 射线）表面光谱联合评估得到了证明。
{"title":"Simple Nickel Foam Modification Procedures for Enhanced Ni Foam Supercapacitor Applications","authors":"Bogusław Pierożyński, Mateusz Kuczyński, Tomasz Mikołajczyk","doi":"10.3390/cryst14090777","DOIUrl":"https://doi.org/10.3390/cryst14090777","url":null,"abstract":"The three-dimensional and porous structure of nickel foam makes it an attractive material for employment in cost-effective electrochemical supercapacitors. This communication presents ac. impedance spectroscopy and cyclic voltammetry electrochemical examinations of potential supercapacitor electrode materials, fabricated by means of simple electrochemical procedures, employed to as-received Ni foam material. This involves the electro-oxidation and Co-catalytic modifications of baseline nickel foam samples. Hence, the supercapacitor-type performance (as evidenced over the examined potential range in 0.1 M NaOH solution) of base nickel foam material could extensively be tailored by means of simple surface and catalytic refinements. The latter was evidenced through the employment of combined electrochemical (cyclic voltammetry, ac. impedance) and SEM/EDX (Scanning Electron Microscopy/Energy Dispersive X-Ray) surface spectroscopy evaluations.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"8 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202513","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}
Ahmed Amine Aidouni, Abdelkader Aissat, Mounir Ould-Mohamed, Mohamed El Amine Benamar, Samuel Dupont, Jean Pierre Vilcot
This study analyzes the lattice dynamics of HgS under various pressures using ab initio self-consistent calculations based on the plane-wave method (PW) and generalized gradient approximation (GGA). The static study, performed by enthalpy calculations, predicts that the transition from the cinnabar phase (α-HgS) to the zinc-blende B3 (β-HgS) or wurtzite (2H) structures occurs at very low pressures, at 0.65 or 0.70 GPa, respectively. Furthermore, the transition from β-HgS to the rocksalt (B1) phase occurs at 7 GPa, and at high pressure, specifically at 110 GPa, HgS can adopt the CsCl (B2) phase. The mechanical study confirms the stability of the β and 2H phases at 0 GPa. Phonon calculations corroborate the results of the static and mechanical studies regarding stability (, and the results indicate that the instabilities of the transverse acoustic (TA) modes, induced by the application of pressures of 10.5 GPa, 21 GPa, and 190 GPa, are responsible for the observed phase transitions in part of the Brillouin.
{"title":"Ab Initio Study of the Crystalline Structure of HgS under Low and High Pressure","authors":"Ahmed Amine Aidouni, Abdelkader Aissat, Mounir Ould-Mohamed, Mohamed El Amine Benamar, Samuel Dupont, Jean Pierre Vilcot","doi":"10.3390/cryst14090780","DOIUrl":"https://doi.org/10.3390/cryst14090780","url":null,"abstract":"This study analyzes the lattice dynamics of HgS under various pressures using ab initio self-consistent calculations based on the plane-wave method (PW) and generalized gradient approximation (GGA). The static study, performed by enthalpy calculations, predicts that the transition from the cinnabar phase (α-HgS) to the zinc-blende B3 (β-HgS) or wurtzite (2H) structures occurs at very low pressures, at 0.65 or 0.70 GPa, respectively. Furthermore, the transition from β-HgS to the rocksalt (B1) phase occurs at 7 GPa, and at high pressure, specifically at 110 GPa, HgS can adopt the CsCl (B2) phase. The mechanical study confirms the stability of the β and 2H phases at 0 GPa. Phonon calculations corroborate the results of the static and mechanical studies regarding stability (, and the results indicate that the instabilities of the transverse acoustic (TA) modes, induced by the application of pressures of 10.5 GPa, 21 GPa, and 190 GPa, are responsible for the observed phase transitions in part of the Brillouin.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"28 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202517","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}
N. V. Krishna Prasad, K. Chandra Babu Naidu, D. Baba Basha
Chemically stable two-dimensional nanostructured graphene with huge surface area, high electrical conductivity and mechanical excellence has gained significant research attention in the past two decades. Its excellent characteristics make graphene one of the important materials in various applications such as environmental and energy storage devices. Graphene no doubt has been a top priority among the carbon nanomaterials owing to its structure and properties. However, the functionalization of graphene leads to various nanocomposites where its properties are tailored to be suited for various applications with more performance, environmental friendliness, efficiency, durability and cost effectiveness. Graphene nanocomposites are said to exhibit more surface area, conductivity, power conversion efficiency and other characteristics in energy devices like supercapacitors. This review was aimed to present some of the applications of graphene-based nanocomposites in energy conversion devices like supercapacitors and Li-ion batteries and some of the environmental applications. It was observed that the performance of supercapacitors was obstructed due to restacking and agglomeration of graphene layers. This was addressed by combining MO (metal oxide) or CP (conducting polymer) with graphene as material for electrodes. Electrodes with CP or MO/graphene composites are summarized. Heterogeneous catalysts were of environmental concern in recent years. In this context, graphene-based nanocomposites gained significance due to expansion in structural diversity. A minimum overview is presented in this paper in terms of structural aspects and properties of GO/rGO-based materials used in supercapacitors and environmental applications like dye removal. Continuous efforts towards synthesis of productive graphene-based nanocomposites might lead to significant output in applications related to environment and energy sectors.
{"title":"Environmental and Energy Applications of Graphene-Based Nanocomposites: A Brief Review","authors":"N. V. Krishna Prasad, K. Chandra Babu Naidu, D. Baba Basha","doi":"10.3390/cryst14090781","DOIUrl":"https://doi.org/10.3390/cryst14090781","url":null,"abstract":"Chemically stable two-dimensional nanostructured graphene with huge surface area, high electrical conductivity and mechanical excellence has gained significant research attention in the past two decades. Its excellent characteristics make graphene one of the important materials in various applications such as environmental and energy storage devices. Graphene no doubt has been a top priority among the carbon nanomaterials owing to its structure and properties. However, the functionalization of graphene leads to various nanocomposites where its properties are tailored to be suited for various applications with more performance, environmental friendliness, efficiency, durability and cost effectiveness. Graphene nanocomposites are said to exhibit more surface area, conductivity, power conversion efficiency and other characteristics in energy devices like supercapacitors. This review was aimed to present some of the applications of graphene-based nanocomposites in energy conversion devices like supercapacitors and Li-ion batteries and some of the environmental applications. It was observed that the performance of supercapacitors was obstructed due to restacking and agglomeration of graphene layers. This was addressed by combining MO (metal oxide) or CP (conducting polymer) with graphene as material for electrodes. Electrodes with CP or MO/graphene composites are summarized. Heterogeneous catalysts were of environmental concern in recent years. In this context, graphene-based nanocomposites gained significance due to expansion in structural diversity. A minimum overview is presented in this paper in terms of structural aspects and properties of GO/rGO-based materials used in supercapacitors and environmental applications like dye removal. Continuous efforts towards synthesis of productive graphene-based nanocomposites might lead to significant output in applications related to environment and energy sectors.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"45 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202519","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 characterization of objects of historical and cultural interest represents a crucial topic, specifically when it regards gemstones. Actually, the advanced investigation of precious minerals of gemological interest requires exclusively non-destructive analyses which are also suitable for determining their provenance when it is unknown. In this study, a non-destructive analytical protocol, previously tested on diamonds for petrogenetic studies, has been applied to a natural diamond of very high historical and gemological value, donated in 1852 by Monsignor Lavinio de ‘Medici Spada to the Museum of Earth Sciences of Sapienza University (Rome). The analytical protocol used includes X-ray diffraction topography, micro-computed X-ray tomography, single-crystal micro-X-ray diffraction and Fourier-transform infrared spectroscopy. The results show the presence of dislocations originating from inclusions and a very low degree of plastic deformation. The aggregation states of its N impurities show that this diamond is type IaAB, while the inclusions consist of olivine (Fo92-93), suggesting a lithospheric origin. The historical references found in the catalogs of the Museum indicate only a Brazilian origin, without any reference to the mining district. The information acquired in this study, enhanced by document research on mining in Brazil since 1700, suggests that the diamond likely comes from the district of Diamantina, Mina Gerais, Brazil.
具有历史和文化价值的物品的特征描述是一个至关重要的课题，特别是在宝石方面。事实上，要对具有宝石学价值的珍贵矿物进行深入研究，就必须进行专门的非破坏性分析，这种分析也适用于在来源不明的情况下确定其出处。在这项研究中，先前在钻石上测试过的用于岩石学研究的非破坏性分析方案，已被应用于一颗具有极高历史和宝石学价值的天然钻石，这颗钻石是由 Monsignor Lavinio de 'Medici Spada 于 1852 年捐赠给罗马萨皮恩扎大学地球科学博物馆的。所使用的分析方案包括 X 射线衍射拓扑图、微观 X 射线层析成像、单晶微 X 射线衍射和傅立叶变换红外光谱。结果表明，存在源自夹杂物的位错，塑性变形程度很低。其 N 杂质的聚集状态表明这块钻石属于 IaAB 型，而包裹体由橄榄石（Fo92-93）组成，表明其来源于岩石圈。博物馆目录中的历史参考资料仅表明其产地为巴西，但未提及矿区。通过对 1700 年以来巴西采矿情况的文献研究，本研究获得的信息表明，这颗钻石很可能来自巴西米纳吉拉斯的 Diamantina 地区。
{"title":"Going Inside a Historical Brazilian Diamond from the Spada Collection (19th Century)","authors":"Giovanna Agrosì, Daniela Mele, Gioacchino Tempesta","doi":"10.3390/cryst14090779","DOIUrl":"https://doi.org/10.3390/cryst14090779","url":null,"abstract":"The characterization of objects of historical and cultural interest represents a crucial topic, specifically when it regards gemstones. Actually, the advanced investigation of precious minerals of gemological interest requires exclusively non-destructive analyses which are also suitable for determining their provenance when it is unknown. In this study, a non-destructive analytical protocol, previously tested on diamonds for petrogenetic studies, has been applied to a natural diamond of very high historical and gemological value, donated in 1852 by Monsignor Lavinio de ‘Medici Spada to the Museum of Earth Sciences of Sapienza University (Rome). The analytical protocol used includes X-ray diffraction topography, micro-computed X-ray tomography, single-crystal micro-X-ray diffraction and Fourier-transform infrared spectroscopy. The results show the presence of dislocations originating from inclusions and a very low degree of plastic deformation. The aggregation states of its N impurities show that this diamond is type IaAB, while the inclusions consist of olivine (Fo92-93), suggesting a lithospheric origin. The historical references found in the catalogs of the Museum indicate only a Brazilian origin, without any reference to the mining district. The information acquired in this study, enhanced by document research on mining in Brazil since 1700, suggests that the diamond likely comes from the district of Diamantina, Mina Gerais, Brazil.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"07 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202514","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}
We used the chemical vapor deposition process to deposit carbon film at a high temperature (900 °C). The carbon films were deposited on AISI 1006 foils using an acetylene gas. We analyzed the carbon film deposited on the surface using Raman spectroscopy, scanning electron microscopy, and high-resolution transmission electron microscopy to define changes in the bonding structure of the carbon film. The results of Raman spectroscopy and high-resolution transmission electron microscopy revealed that as the acetylene flow rate increased, the shape of the deposited carbon film changed from graphene to graphite. In addition, in order to compare the quality of the carbon film in terms of mechanical and electrical properties, carbon films treated under various conditions were closely analyzed using nano-indenter and a sheet resistance meter. Therefore, the optimal condition (1 Torr-50 sccm) was selected in which graphene was uniformly deposited and had the lowest electrical resistance (500 Ω/sq) and highest hardness (12 GPa).
{"title":"Influence of the Acetylene Flow Rate and Process Pressure on the Carbon Deposition Behavior by Thermal Chemical Vapor Deposition Process","authors":"Gi-Hoon Kwon, Byoungho Choi, Young-Kook Lee, Kyoungil Moon","doi":"10.3390/cryst14090782","DOIUrl":"https://doi.org/10.3390/cryst14090782","url":null,"abstract":"We used the chemical vapor deposition process to deposit carbon film at a high temperature (900 °C). The carbon films were deposited on AISI 1006 foils using an acetylene gas. We analyzed the carbon film deposited on the surface using Raman spectroscopy, scanning electron microscopy, and high-resolution transmission electron microscopy to define changes in the bonding structure of the carbon film. The results of Raman spectroscopy and high-resolution transmission electron microscopy revealed that as the acetylene flow rate increased, the shape of the deposited carbon film changed from graphene to graphite. In addition, in order to compare the quality of the carbon film in terms of mechanical and electrical properties, carbon films treated under various conditions were closely analyzed using nano-indenter and a sheet resistance meter. Therefore, the optimal condition (1 Torr-50 sccm) was selected in which graphene was uniformly deposited and had the lowest electrical resistance (500 Ω/sq) and highest hardness (12 GPa).","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"28 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202520","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}
Synthetic fibers can effectively inhibit the formation and propagation of micro-cracks in concrete, significantly reducing the number and scale of cracks within the concrete matrix, thereby enhancing the concrete’s crack resistance and seepage prevention capabilities. In this study, two types of synthetic fibers, polyvinyl alcohol (PVA) and polypropylene (PP), were incorporated into cement mortar to investigate their microstructural evolution at elevated temperatures and their influence on the mechanical properties of the mortar. Both fibers were added at a volume content of 0.5%. The mortar samples were subjected to the following temperature conditions: 20 °C (ambient), 200 °C, 400 °C, and 500 °C. The results indicate that the synthetic fibers employed in this study improved the tensile properties of the mortar at room temperature (20 °C). This enhancement persisted up to 400 °C, beyond which, at 500 °C, the mechanical properties of the fiber-reinforced mortar deteriorated significantly. At 400 °C, the tensile strength of the PVA group increased by approximately 16% compared to the unblended fiber group (JZ) and by about 45% compared to the PP group. After treatment at 500 °C, the tensile strength of mortar specimens in the PVA group and the PP group decreased by 36.47% and 24.14%, respectively, compared with that at 20 °C. The porous structure formed due to the high-temperature ablation of the synthetic fibers contributed to relieving the internal pressure within the mortar.
合成纤维可有效抑制混凝土中微裂缝的形成和扩展，显著减少混凝土基体中裂缝的数量和规模，从而提高混凝土的抗裂性和防渗能力。本研究在水泥砂浆中加入了聚乙烯醇（PVA）和聚丙烯（PP）两种合成纤维，以研究它们在高温下的微观结构演变及其对砂浆机械性能的影响。两种纤维的添加量均为 0.5%。砂浆样品经受了以下温度条件的考验：20°C（环境温度）、200°C、400°C 和 500°C。结果表明，本研究中使用的合成纤维改善了砂浆在室温（20 °C）下的拉伸性能。这种改善一直持续到 400 °C，当温度超过 500 °C时，纤维增强砂浆的机械性能显著下降。400 °C 时，PVA 组的拉伸强度比未掺入纤维组（JZ）提高了约 16%，比 PP 组提高了约 45%。经过 500 °C 处理后，PVA 组和 PP 组砂浆试样的抗拉强度分别比 20 °C 时降低了 36.47% 和 24.14%。合成纤维高温烧蚀形成的多孔结构有助于缓解砂浆内部的压力。
{"title":"Effect of High Temperature on Micro-Structure and Mechanical Properties of Fiber-Reinforced Cement-Based Composites","authors":"Chen Ge, Xiaoliang Chen, Yongfan Gong, Xijun Kong, Fei Chen","doi":"10.3390/cryst14090778","DOIUrl":"https://doi.org/10.3390/cryst14090778","url":null,"abstract":"Synthetic fibers can effectively inhibit the formation and propagation of micro-cracks in concrete, significantly reducing the number and scale of cracks within the concrete matrix, thereby enhancing the concrete’s crack resistance and seepage prevention capabilities. In this study, two types of synthetic fibers, polyvinyl alcohol (PVA) and polypropylene (PP), were incorporated into cement mortar to investigate their microstructural evolution at elevated temperatures and their influence on the mechanical properties of the mortar. Both fibers were added at a volume content of 0.5%. The mortar samples were subjected to the following temperature conditions: 20 °C (ambient), 200 °C, 400 °C, and 500 °C. The results indicate that the synthetic fibers employed in this study improved the tensile properties of the mortar at room temperature (20 °C). This enhancement persisted up to 400 °C, beyond which, at 500 °C, the mechanical properties of the fiber-reinforced mortar deteriorated significantly. At 400 °C, the tensile strength of the PVA group increased by approximately 16% compared to the unblended fiber group (JZ) and by about 45% compared to the PP group. After treatment at 500 °C, the tensile strength of mortar specimens in the PVA group and the PP group decreased by 36.47% and 24.14%, respectively, compared with that at 20 °C. The porous structure formed due to the high-temperature ablation of the synthetic fibers contributed to relieving the internal pressure within the mortar.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"8 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202516","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}
Claudia Diletto, Fiorita Nunziata, Salvatore Aprano, Ludovico Migliaccio, Maria Grazia Maglione, Alfredo Rubino, Paolo Tassini
Indium tin oxide (ITO) is a transparent conductive oxide (TCO) commonly used in the realization of optoelectronic devices needing at least a transparent electrode. In this work, ITO thin films were deposited on glass substrates by non-reactive RF magnetron sputtering, investigating the effects of power density, sputtering pressure, and substrate temperature on the electrical, optical, and structural properties of the as-grown films. High-quality films, in terms of crystallinity, transparency, and conductivity were obtained. The 120 nm thick ITO films grown at 225 °C under an argon pressure of 6.9 mbar and a sputtering power density of 2.19 W/cm2 without post-annealing treatments in an oxidizing environment showed an optical transmittance near 90% at 550 nm and a resistivity of 2.10×10−4 Ω cm. This material was applied as the electrode of simple-structure organic light-emitting diodes (OLEDs).
氧化铟锡（ITO）是一种透明导电氧化物（TCO），常用于实现至少需要一个透明电极的光电设备。在这项工作中，通过非反应射频磁控溅射法在玻璃基底上沉积了 ITO 薄膜，研究了功率密度、溅射压力和基底温度对所生长薄膜的电气、光学和结构特性的影响。在结晶度、透明度和导电性等方面都获得了高质量的薄膜。在氩气压力为 6.9 毫巴、溅射功率密度为 2.19 瓦/平方厘米、未进行退火后处理的氧化环境下，于 225 °C 生长的 120 nm 厚 ITO 薄膜在 550 nm 波长处的光学透过率接近 90%，电阻率为 2.10×10-4 Ω cm。这种材料被用作结构简单的有机发光二极管（OLED）的电极。
{"title":"Influence of Process Parameters on Properties of Non-Reactive RF Magnetron-Sputtered Indium Tin Oxide Thin Films Used as Electrodes for Organic Light-Emitting Diodes","authors":"Claudia Diletto, Fiorita Nunziata, Salvatore Aprano, Ludovico Migliaccio, Maria Grazia Maglione, Alfredo Rubino, Paolo Tassini","doi":"10.3390/cryst14090776","DOIUrl":"https://doi.org/10.3390/cryst14090776","url":null,"abstract":"Indium tin oxide (ITO) is a transparent conductive oxide (TCO) commonly used in the realization of optoelectronic devices needing at least a transparent electrode. In this work, ITO thin films were deposited on glass substrates by non-reactive RF magnetron sputtering, investigating the effects of power density, sputtering pressure, and substrate temperature on the electrical, optical, and structural properties of the as-grown films. High-quality films, in terms of crystallinity, transparency, and conductivity were obtained. The 120 nm thick ITO films grown at 225 °C under an argon pressure of 6.9 mbar and a sputtering power density of 2.19 W/cm2 without post-annealing treatments in an oxidizing environment showed an optical transmittance near 90% at 550 nm and a resistivity of 2.10×10−4 Ω cm. This material was applied as the electrode of simple-structure organic light-emitting diodes (OLEDs).","PeriodicalId":10855,"journal":{"name":"Crystals","volume":"51 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202526","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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