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Letteratura scientifica selezionata sul tema "Composite materials Cu"

Autore: Grafiati

Pubblicato: 7 settembre 2024

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Articoli di riviste sul tema "Composite materials Cu"

Ciupiński, Łukas, D. Siemiaszko, Marcin Rosiński, Andrzej Michalski e Krzysztof Jan Kurzydlowski. "Heat Sink Materials Processing by Pulse Plasma Sintering". Advanced Materials Research 59 (dicembre 2008): 120–24. http://dx.doi.org/10.4028/www.scientific.net/amr.59.120.

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A Pulse Plasma Sintering (PPS) process was employed to manufacture Cu-diamond composites with a 50% volume fraction of each constituent. Pure and Cr (0.8wt.%) alloyed copper matrices were used and commercial diamond powders. The composites were sintered at temperature of 900°C for 20 min and under pressure of 60 MPa. In these sintering conditions diamond becomes thermodynamically unstable. Cu0.8Cr-diamond and Cu-diamond composites with relative densities of 99,7% and 96% respectively were obtained. The thermal conductivity of Cu0.8Cr-diamond composite is equal to 640 W(mK)-1 whereas that of Cu-diamond is 200 W(mK)-1. The high thermal conductivity and relative density of Cu0.8Cr-diamond composite is due to the formation of a thin chromium carbide layer at the Cu-diamond interface.

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Kim, Kyungju, Dasom Kim, Kwangjae Park, Myunghoon Cho, Seungchan Cho e Hansang Kwon. "Effect of Intermetallic Compounds on the Thermal and Mechanical Properties of Al–Cu Composite Materials Fabricated by Spark Plasma Sintering". Materials 12, n. 9 (10 maggio 2019): 1546. http://dx.doi.org/10.3390/ma12091546.

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Aluminium–copper composite materials were successfully fabricated using spark plasma sintering with Al and Cu powders as the raw materials. Al–Cu composite powders were fabricated through a ball milling process, and the effect of the Cu content was investigated. Composite materials composed of Al–20Cu, Al–50Cu, and Al–80Cu (vol.%) were sintered by a spark plasma sintering process, which was carried out at 520 °C and 50 MPa for 5 min. The phase analysis of the composite materials by X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) indicated that intermetallic compounds (IC) such as CuAl2 and Cu9Al4 were formed through reactions between Cu and Al during the spark plasma sintering process. The mechanical properties of the composites were analysed using a Vickers hardness tester. The Al–50Cu composite had a hardness of approximately 151 HV, which is higher than that of the other composites. The thermal conductivity of the composite materials was measured by laser flash analysis, and the highest value was obtained for the Al–80Cu composite material. This suggests that the Cu content affects physical properties of the Al–Cu composite material as well as the amount of intermetallic compounds formed in the composite material.

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Xu, Jian, Pei Xian Zhu, Hui Yu Ma e Sheng Gang Zhou. "Characterisation of Ti-Al and Ti-Cu Laminated Composite Electrode Materials". Advanced Materials Research 194-196 (febbraio 2011): 1667–71. http://dx.doi.org/10.4028/www.scientific.net/amr.194-196.1667.

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We proposed using Ti-Al and Ti-Cu laminated composites instead of single Ti electrode metals, as well as studied the difference in performance between laminated composite electrode materials and pure-Ti electrode. The analysis of the conductivity and electrochemical performance of electrode matrix material indicates the result that the improvement of matrix material by using Ti-Al and Ti-Cu laminated composites, better performance for conductivity of electrode, and be beneficial to homogenize the electrode surface potential and current distribution and promote electrocatalytic activity between polar plates. Whereas comparison between Ti-Al and Ti-Cu laminated composites, Ti-Cu laminated composites is better in performance.

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Koltsova, Tatiana, Elizaveta Bobrynina, Aleksei Vozniakovskii, Tatiana Larionova e Olga Klimova-Korsmik. "Thermal Conductivity of Composite Materials Copper-Fullerene Soot". Materials 15, n. 4 (14 febbraio 2022): 1415. http://dx.doi.org/10.3390/ma15041415.

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Copper-based composites strengthened with fullerene soot nanoparticles of 20–30 nm size in concentration up to 23 vol.% were prepared via two methods: mechanical mixing and molecular level mixing. The dependence of thermal conductivity on the carbon concentration was studied. Maxwell’s model describes well the change in the thermal conductivity of the composite obtained by molecular level mixing. However, thermal conductivity of the composite produced by mechanical mixing is significantly lower than the calculated values, due to structural inhomogeneity and residual stresses. Comparison of the thermal conductivity of Cu-fullerene soot composites with that of Cu-based composites described in the literature showed that the prepared materials are not inferior in thermal conductivity to composites containing carbon nanotubes, despite the fact that fullerene soot has a much lower thermal conductivity.

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Sugianto, Sugianto, Ngurah Made Dharma Putra, Endah F. Rahayu, Wahyu B. Widayatno, Cherly Firdharini, Slamet Priyono e Didik Aryanto. "Synthesis, Characterization, and Electrochemical Performance of Reduced Graphene Oxide-Metal (Cu,Zn)-Oxide Materials". Indonesian Journal of Science and Technology 8, n. 2 (10 marzo 2023): 329–44. http://dx.doi.org/10.17509/ijost.v8i2.56065.

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The reduced graphene oxide (rGO) and metal (Cu,Zn)-oxide composites were prepared using a one-step hydrothermal technique. The role of (Cu,Zn)-oxide on the physical and electrochemical properties of the composite was investigated. The composite consists of various shapes of ZnO nanoflowers and micro-spheres, as well as Cu-oxide nanoflakes and octahedron-like shapes. The (Cu,Zn)-oxides were formed in between the rGO layers and observed in the rGO-ZnO, rGO-CuO, and rGO-CuO-ZnO composites. The presence of ZnO, CuO, and rGO within the composite structure is also confirmed by the analyses of crystal structure, microstructure, and surface functional groups. Some excess impurities remaining from the surfactant give considerable differences in the electrochemical performance of the composites. The specific capacitance values of the rGO, rGO-ZnO, rGO-CuO, rGO-(0.5CuO-0.5ZnO), and rGO-(0.25CuO-0.75ZnO) composites are 9.32, 58.53, 54.14, 25.21, and 69.27 F/g, respectively. The formation ofa double metal-oxide structure as well as their insertion into the rGO sheet can significantly improve the electrochemical properties of the supercapacitor.

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Han, Ying, Sida Li, Yundong Cao, Shujun Li, Guangyu Yang, Bo Yu, Zhaowei Song e Jian Wang. "Mechanical Properties of Cu-W Interpenetrating-Phase Composites with Different W-Skeleton". Metals 12, n. 6 (25 maggio 2022): 903. http://dx.doi.org/10.3390/met12060903.

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In this work, copper–tungsten (Cu-W) composites with a cubic and rhombic dodecahedron W-skeleton were fabricated by the infiltration of Cu melt into a three-dimensionally printed W scaffold. The effects of the skeleton structure on the mechanical properties and energy-absorbing characteristics of the Cu-W interpenetrating-phase composite were investigated and compared with those of commercial Cu-W composite fabricated by powder metallurgy. The results indicated that the mechanical properties of the studied Cu-W interpenetrating-phase composites were mainly related to the properties of their ordered skeletons. Compared to the dodecahedron W-skeleton Cu-W composites, cubic-W-skeleton Cu-W composites exhibited higher strengths but lower absorbed energy. The Cu-W composites with ordered W-skeletons displayed much higher energy absorption than the commercial Cu-W ones. By adjusting the ordered W-skeleton structure contained in the composite, the strength and deformation behavior of the Cu-W composite can be effectively improved, which provides a guide to optimizing the mechanical properties and energy absorption of Cu-W composites.

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Kim, Song-Mi, Woo-Rim Park e Oh-Heon Kwon. "The Strength and Delamination of Graphene/Cu Composites with Different Cu Thicknesses". Materials 14, n. 11 (31 maggio 2021): 2983. http://dx.doi.org/10.3390/ma14112983.

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This study analyzed the mechanical and fracture behavior of graphene/copper (Cu) composites with different Cu thicknesses by using molecular dynamics (MD) and representative volume element (RVE) analysis. Three graphene/Cu composite analytical models were classified as 4.8, 9.8, and 14.3 nm according to Cu thicknesses. Using MD analysis, zigzag-, armchair-, and z (thickness)-direction tensile analyses were performed for each model to analyze the effect of Cu thickness variation on graphene/Cu composite strength and delamination fracture. In the RVE analysis, the mechanical characteristics of the interface between graphene and Cu were evaluated by setting the volume fraction to 1.39, 2.04, and 4.16% of the graphene/Cu composite model, classified according to the Cu thickness. From their obtained results, whether the graphene bond is maintained has the greatest effect on the strength of graphene/Cu composites, regardless of the Cu thickness. Additionally, graphene/Cu composites are more vulnerable to armchair direction tensile forces with fracture strengths of 14.7, 8.9, and 8.2 GPa depending on the Cu thickness. The results of this study will contribute to the development of guidelines and performance evaluation standards for graphene/Cu composites.

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Silvain, Jean François, Valérie Denis-Lutard, Pierre Marie Geffroy e Jean Marc Heintz. "Adaptive Composite Materials with Novel Architectures". Materials Science Forum 631-632 (ottobre 2009): 149–54. http://dx.doi.org/10.4028/www.scientific.net/msf.631-632.149.

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Today, there is a strong push to improve the thermal management of electronic components in order to increase the performance and the reliability of electronic devices. Up to now, most of the heat sinks are mainly made of Copper that presents a good thermal conductivity (TC) but a coefficient of thermal expansion (CTE) much higher than the ceramic of the DBC (direct bonding Copper). It induces interfacial thermal stresses and indeed it decreases the reliability of the global electronic system. Therefore, there is a strong need for the development of novel heat dissipation material having low CTE combined with high TC. Carbon fibres reinforced copper matrix offers a good compromise between thermo mechanical properties (i.e. CTE) and medium TC. In order to increase surface TC, pure Copper can be added on the top surface and/or on the bottom one of the composite heat sink playing the role of heat spreader for hot spots linked with the Si components. The fabrication technique of these materials is based on powder metallurgy technique. The thermal properties of adaptive materials, TC and CTE, have been measured for different Copper thicknesses and architectures ([C/Cu], [Cu – C/Cu] and [Cu – C/Cu – Cu]). Simulation of the TC and CTE have been performed and compared to the experimental results.

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Wang, Qing Yun, Wei Ping Shen e Ming Liang Ma. "Mean and Instantaneous Thermal Expansion of Uncoated and Ti Coated Diamond/Copper Composite Materials". Advanced Materials Research 702 (maggio 2013): 202–6. http://dx.doi.org/10.4028/www.scientific.net/amr.702.202.

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Heat sink materials not only should have higher thermal conductivity, but also have smaller difference of thermal expansion with cooled material. diamond/copper composites were made by the powder metallurgy method. Vacuum slowly vapor deposition technique was employed to deposit a titanium film on diamond particles before mixing with Cu powder in order to improve the bonding strength between Cu and diamond particles during sintering. The thermal expansion of diamond/Cu d composite was measured in the temperature range from 50 to 600 °C. The results show that the titanium film on diamond improves the interfacial bonding and reduces the coefficient of thermal expansion (CTE) of Cu/diamond composites. The CTE of diamond/Cu composites decreases with increasing diamond volume fraction as the results of mixture rule and the intense restriction effect of diamond reinforcement on the copper matrix. The residual stresses and pores in the composites affect instantaneous thermal expansion of diamond/Cu composites.

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Niu, Bing, Dongdong Xie, Yanxin Zhang, Yuxiao Bi, Yigui Li, Guifu Ding e Liyan Lai. "Morphology Control and Mechanism of Different Bath Systems in Cu/SiCw Composite Electroplating". Nanomaterials 14, n. 12 (18 giugno 2024): 1043. http://dx.doi.org/10.3390/nano14121043.

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With the rapid development of electronic technology and large-scale integrated circuit devices, it is very important to develop thermal management materials with high thermal conductivity. Silicon carbide whisker-reinforced copper matrix (Cu/SiCw) composites are considered to be one of the best candidates for future electronic device radiators. However, at present, most of these materials are produced by high-temperature and high-pressure processes, which are expensive and prone to interfacial reactions. To explore the plating solution system suitable for SiCw and Cu composite electroplating, we tried two different Cu-based plating solutions, namely a Systek UVF 100 plating solution of the copper sulfate (CuSO4) system and a Through Silicon Via (TSV) plating solution of the copper methanesulfonate (Cu(CH3SO3)2) system. In this paper, Cu/SiCw composites were prepared by composite electrodeposition. The morphology of the coating under two different plating liquid systems was compared, and the mechanism of formation of the different morphologies was analyzed. The results show that when the concentration of SiCw in the bath is 1.2 g/L, the surface of the Cu/SiCw composite coating prepared by the CuSO4 bath has more whiskers with irregular distribution and the coating is very smooth, but there are pores at the junction of the whiskers and Cu. There are a large number of irregularly distributed whiskers on the surface of the Cu/SiCw composite coating prepared with the copper methanesulfonate (Cu(CH3SO3)2) system. The surface of the composite is flat, and Cu grows along the whisker structure. The whisker and Cu form a good combination, and there is no pore in the cross-section of the coating. The observation at the cross-section also reveals some characteristics of the toughening mechanism of SiCw, including crack deflection, bridging and whisker pull-out. The existence of these mechanisms indicates that SiCw plays a toughening role in the composites. A suitable plating solution system was selected for the preparation of high-performance Cu/SiCw thermal management materials with the composite electrodeposition process.

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Più fonti

Tesi sul tema "Composite materials Cu"

Guazzone, Federico. "Engineering of substrate surface for the synthesis of ultra-thin composite Pd and Pd-Cu membranes for H₂ separation". Link to electronic thesis, 2005. http://www.wpi.edu/Pubs/ETD/Available/etd-011006-123013/.

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Kaforey, Monica L. "Solid state thermal gradient processing of Y₁Ba₂Cu₃O₇âx/Ag superconducting composite ribbons". Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/28038.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1994.
Vita. Title as it appears in the Feb. 1994 MIT Graduate List: Solid state temperature gradient processing of Y₁Ba₂Cu₃O₇âx/Ag superconducting composite ribbons.
Includes bibliographical references (leaves 197-202).
by Monical L. Kaforey.
Ph.D.

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Kraiem, Nada. "Impression 3D de matériaux composites à base de diamant pour des applications de gestion thermique". Electronic Thesis or Diss., Bordeaux, 2024. http://www.theses.fr/2024BORD0129.

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Avec la tendance à la miniaturisation croissante des équipements électriques et à l'augmentation constante de la densité de puissance dans les dispositifs à base de semiconducteurs, la gestion efficace de la chaleur est devenue un enjeu majeur pour les chercheurs. En effet, cette évolution technologique impose des contraintes de plus en plus strictes en termes de dissipation thermique, nécessitant des solutions innovantes pour garantir une meilleure durabilité et fiabilité des composants. Dans ce contexte, l'utilisation de matériaux composites offrant une conductivité thermique élevée et un coefficient de dilatation thermique faible par rapport aux métaux purs est devenue essentielle pour résoudre les problèmes de surchauffe des composants électroniques. L'intégration de matériaux avancés tels que le diamant (D), avec ses propriétés exceptionnelles de conductivité thermique et de dureté, constitue une option privilégiée pour renforcer les matrices métalliques. Toutefois, son incorporation dans les matériaux composites nécessite la création d'une interface D-métal bien définie, à la fois pour éviter la formation de porosité et assurer un transfert efficace des propriétés thermiques. La fabrication additive de matériaux 3D par fusion laser émerge comme une solution prometteuse, non seulement pour la facilité de mise en œuvre de ces composites, mais aussi pour la création de structures complexes dédiées à la dissipation de chaleur. Ces structures jouent un rôle crucial dans l'optimisation de la surface d'échange thermique par convection avec l'air environnant, permettant ainsi une dissipation efficace de la chaleur générée par les dispositifs électroniques modernes.Dans cette étude, l`impression 3D du cuivre (Cu) a été réalisée grâce à l`ajout d`une quantité optimale d’aluminium. Cette approche a permis d'améliorer considérablement la densification de matériaux à base de cuivre, malgré les défis posés par sa forte réflectivité. Par la suite, l'investigation approfondie et l'optimisation de l`impression 3D laser de l'alliage AlSi10Mg, avant et après l'incorporation de D, ont été réalisées. Enfin, une étape cruciale de post-traitement a été optimisée consistant à polir des matériaux composites Al/D par ablation laser.Ce travail a été réalisé dans le cadre d'une collaboration internationale entre l'Université du Nebraska, Lincoln aux États-Unis d'Amérique, et l'Université de Bordeaux en France
With the trend towards miniaturization of electrical equipment and the constant increase in power density in semiconductor devices, efficient heat management has become a major concern for researchers. Indeed, this technological evolution imposes increasingly strict constraints in terms of thermal dissipation, necessitating innovative solutions to ensure better durability and reliability of components. In this context, the use of composite materials offering high thermal conductivity and low coefficient of thermal expansion compared to pure metals has become essential to address overheating issues in electronic components. The utilization of advanced materials such as diamond (D), with exceptional thermal conductivity and hardness properties, stands out as a preferred choice for reinforcing metal matrices. However, its incorporation into composite materials requires the creation of a well-defined D-metal interface, both to avoid porosity formation and to ensure efficient transfer of thermal properties. Additive manufacturing of 3D materials by laser fusion is emerging as a promising solution, not only for the ease of implementation of these composites, but also for the creation of complex structures dedicated to heat dissipation. These structures play a crucial role in optimizing the heat exchange surface by convection with the surrounding air, thus allowing efficient dissipation of heat generated by modern electronic devices.In this study, 3D printing of copper (Cu) was achieved through the addition of an optimal amount of aluminum. This approach significantly improved the densification of copper-based materials, despite the challenges posed by its high reflectivity. Subsequently, in-depth investigation and optimization of laser 3D printing of the AlSi10Mg alloy, before and after the incorporation of D, were carried out. Finally, a crucial post-processing step was optimized, consisting of polishing Al/D composite materials using laser ablation.This work was carried out as part of an international collaboration between the University of Nebraska, Lincoln in the United States of America, and the University of Bordeaux in France

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Tilliander, Ulrika. "Synthesis of nano sized Cu and Cu-W alloy by hydrogen reduction". Licentiate thesis, KTH, Materials Science and Engineering, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-353.

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The major part of the present work, deals with the reduction kinetics of Cu₂O powder and a Cu₂O-WO₃ powder mixture by hydrogen gas, studied by ThermoGravimetric Analysis (TGA). The reduction experiments were carried out both isothermally and non-isothermally on thin powder beds over different temperature intervals. During the experiments, the reductant gas flow rate was kept just above the starvation rate for the reaction to ensure that chemical reaction was the rate-controlling step. The activation energy for the reactions was evaluated from isothermal as well as non-isothermal reduction experiments.

In the case of the reduction of Cu₂O, the impact of the stability of the copper oxide on the activation energy for hydrogen reduction under identical experimental conditions is discussed. A closer investigation of additions of Ni or NiO to Cu₂O did not have a perceptible effect on the kinetics of reduction.

In the case of the reduction of the Cu₂O-WO₃mixture, the reaction mechanism was found to be affected in the temperature range 923-973 K, which is attributed to the reaction/transformation in the starting oxide mixture. At lower temperatures, Cu₂O was found to be preferentially reduced in the early stages, followed by the reduction of the tungsten oxide. At higher temperatures, the reduction kinetics was strongly affected by the formation of a complex oxide from the starting materials. It was found that the Cu₂O-WO₃mixture underwent a reaction/transformation which could explain the observed kinetic behavior.

The composition and microstructures of both the starting material and the reaction products were analyzed by X-ray diffraction (XRD) as well as by microprobe analysis. vi Kinetic studies of reduction indicated that, the mechanism changes significantly at 923 K and the product formed had unusual properties. The structural studies performed by XRD indicated that, at 923 K, Cu dissolved in W forming a metastable solid solution, in amorphous/nanocrystalline state. The samples produced at higher as well as lower temperatures, on the other hand, showed the presence two phases, pure W and pure Cu. The SEM results were in conformity with the XRD analysis and confirmed the formation of W/Cu alloy. TEM analysis results confirmed the above observations and showed that the particle sizes was about 20 nm.

The structure of the W/Cu alloy produced in the present work was compared with those for pure copper produced from Cu2O produced by hydrogen reduction under similar conditions. It indicated that the presence of W hinders the coalescence of Cu particles and the alloy retains its nano-grain structure. The present results open up an interesting process route towards the production of intermetallic phases and composite materials under optimized conditions.

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Guazzone, Federico. "Engineering of Substrate Surface for the synthesis of Ultra-Thin Composite Pd and Pd-Cu Membranes for H2 Separation". Digital WPI, 2006. https://digitalcommons.wpi.edu/etd-dissertations/442.

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This work describes a novel technique to prepare ultra-thin composite Pd-porous metal membranes for H2 separation. This novel technique consists of the gradual smoothing of the Porous Metal (PM) support's surface with several layers of pre-activated alumina particles of different sizes. The deposition of coarse, fine and ultra-fine alumina particles resulted in the narrowing of the PM' surface pore size distribution. The excellent surface smoothness achieved after the grading of the PM 's surface support allowed for the preparation of gas tight Pd layers as thin as 5.6?m. The Pd layers were extremely uniform due to the presence of the grade layer and strongly attached to the support. Composite Pd membranes prepared on graded supports showed H2 permeance as high as 50 m3/(m2 h bar0.5) at 500ºC and ideal selectivities (H2/He) as high as 27000. Moreover, the H2 permeance and ideal selectivity were stable over 1100 hours at 500ºC in H2 atmosphere. Composite Pd-Cu membranes showed H2 permeance as high as 30 m3/(m2 h bar0.5) at 450ºC and ideal selectivities (H2/He) as high as 900. The H2 permeance and ideal selectivity of Pd-Cu membranes were stable over 500 hours at 450ºC in H2 atmosphere. The outstanding long-term H2 permeance and ideal selectivity stability of all composite Pd and Pd-Cu membranes represented a breakthrough in composite Pd membrane synthesis. The thermal stresses arising from the mismatch in the coefficient of thermal expansion between the Pd film and the support were determined by means of x-ray diffraction. The results indicated that the release of stresses began to occur at temperatures close to 400ºC. Also, the release of stresses took place with a visible sintering of Pd clusters within the thin Pd film. The stresses due to the absorption of H2 were also studied and modeled. It was estimated that the maximum compressive stress under which these composite Pd membranes were characterized was equal to 260 MPa.

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Quelennec, Xavier. "Nanostructuration d'un composite Cu-Fe par déformation intense : vers un mélange forcé à l'échelle atomique". Phd thesis, Université de Rouen, 2008. http://tel.archives-ouvertes.fr/tel-00648688.

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Les techniques d'élaboration par déformation plastique intense permettent d'obtenir des matériaux nanostructurés à l'état massif. La grande quantité de défauts (dislocations, lacunes,...) peut donner lieur à des transformations de phases hors équilibre. L'objectif de ce travail à été de produire par HPT (high pressure torsion) une solution solide hors équilibre à partir du système modèle Cu-Fe et de comprendre les mécanismes physiques à l'origine de sa formation. Le matériau initial est un nanocomposite filamentaire Cu-cfc/Fe-α. Des tranches de ce composite ont été déformées par HPT pour une large gamme de taux de déformation. Le matériau obtenu a été caractérisé par DRX, spectroscopie Mössbauer, MET et sonde atomique tomographique. Les filaments de ferrite sont dans une premier temps amincis jusqu'à environ 5nm. Le mélange forcé commence alors par diffusion de Fe dans Cu-cfc pour enfin aboutir à une solution solide homogène de Fe dans Cu-cfc. A la vue des données, les dislocations et le cisaillement répété des interfaces ne peuvent pas expliquer la formation du mélange forcé. Celle-ci est attribuée à la diffusion accélérée par les lacunes en excès.

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Shi, Hailong. "Recrystallization of 2D dimensioned Copper (Cu) foils and graphene nanosheets (GNSs) reinforced Cu matrix laminated composites". Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0096.

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La recristallisation est le processus des métaux déformés à froid qui se produit lors du traitement thermique. La texture de recristallisation contribue à l'anisotropie des propriétés mécaniques et physiques. Motivés par la minimisation des produits, les matériaux 2D et les composites stratifiés sont de plus en plus demandés pour des applications. Ainsi, à des fins scientifiques et techniques, des recherches sur la recristallisation de tels matériaux sont nécessaires pour comprendre les mécanismes sous-jacents. Dans ce travail, des feuilles de Cu et des composites stratifiés à matrice de Cu renforcé de nanofeuilles de graphène (GNS) avec des épaisseurs de Cu de 10 μm et 30 μm ont été fabriqués. La recristallisation a été étudiée de l'échelle microscopique à l'échelle macroscopique par SEM-EBSD pour l'observation de microstructure, rayonnement neutronique et synchrotron pour l'analyse de texture et rayonnement synchrotron in situ pour l'évaluation de la déformation du réseau. Les données obtenues ont été analysées dans le cadre de la cristallographie combinée à l'élasticité et à l'énergie de surface. Les résultats ont montré que le comportement de recristallisation de Cu était grandement affecté par l'épaisseur de la feuille de Cu et l'ajout des GNSs. Pour les feuilles de Cu de 10 μm sans GNSs, elles ont subi une transition de la texture de laminage à froid à une texture de recristallisation dominée par des composants Cube tourné RD et Copper tourné φ2. La transition a été contrôlée par des facteurs intrinsèques microstructuraux et extrinsèques géométriques d'échantillons. Les orientations des germes sont héritées des orientations de déformation. Ceux avec des facteurs de Taylor faibles (Cube, Goss et Brass) ont montré une préférence de taille. La croissance post-nucléation a été affectée par la contrainte d'élasticité thermique biaxiale et l'énergie de surface. En raison de leurs effets opposés, les orientations ayant des modules biaxiaux et une densité d'énergie de surface modérés (S, Copper, Brass et composants de recristallisation) ont survécu, résultant en une texture mixte à la fin de la recristallisation. Les joints Σ3 cohérents entre les nouvelles composantes ont stabilisé leur croissance en consommant les autres séparés par des joints aléatoires à grand angle. Une fois le Cu fritté en masse, sa texture était dominée par les orientations des grains à croissance anormale. Les effets des GNSs sur la recristallisation des feuilles de Cu dépendaient également de l'épaisseur de la feuille de Cu. Pour les feuilles de 10 μm d'épaisseur, l'effet des GNSs se manifeste après le frittage des échantillons à des températures élevées (> 700 ℃). Au lieu de créer beaucoup de contraintes à l'expansion des feuilles de Cu adjacentes, les GNSs ont fonctionné comme une barrière empêchant la pénétration des grains de Cu développés, entraînant la stabilisation de la texture de recristallisation représentée par les deux composantes tournées. Pour le composite Cu/GNS avec une épaisseur de Cu de 30 μm, les résultats ont montré qu'une forte orientation Cube était produite dans le composite Cu/GNS au lieu des orientations individuelles non Cube dans l'empilement de Cu pur sans GNSs. Une analyse détaillée de l'état de déformation de Cu dans le composite Cu/GNS a révélé que le comportement d'expansion anisotrope du GNS qui est incompatible avec celui de Cu imposait de multiples contraintes élastiques aux feuilles, entraînant un état isocontrainte biaxiale dans la couche en surface et un état de déformation en compression uniaxiale dans la couche centrale. L'anisotropie élastique du Cu favorise la croissance des grains orientés Cube pour minimiser l'énergie totale de déformation. Les résultats du présent travail fournissent des informations quantitatives détaillées sur la recristallisation de feuilles de Cu et de composites stratifiés, ce qui contribue à approfondir la compréhension du comportement de recristallisation des matériaux 2D
Recrystallization is the intrinsic process of cold-deformed metallic materials that occurs inevitably during the thermal treatment. The produced recrystallization texture contributes to the anisotropy of the mechanical and physical properties. Motivated by the minimization of modern products, 2D materials and laminated composites are increasingly demanded by many applications. Thus, for both scientific and engineering purposes, investigations on the recrystallization of such materials are needed to understand the underlying mechanisms. In this work, Cu foils and graphene nanosheets (GNSs) reinforced Cu matrix laminated composites with Cu foil thicknesses of 10 μm and 30 μm were fabricated, and the recrystallization features were thoroughly investigated from microscale to macroscale by means of SEM-EBSD for microstructure observation, neutron and synchrotron radiation for texture analysis and in-situ synchrotron radiation for lattice strain evaluation. The obtained data were analyzed in the frame of crystallography combined with crystal elasticity and surface energy. The results showed that the recrystallization behavior of the Cu foils were greatly affected by the Cu foil thickness and the addition of the GNSs. For the 10 μm thick Cu foils without GNS, they underwent a transition from the cold-rolling texture to a recrystallization texture dominated by RD-rotated Cube and φ_2-rotated Copper components. The transition was screened by both intrinsic microstructural and extrinsic sample geometrical factors. The orientations of the nuclei were mainly inherited from the deformation orientations. Those with low Taylor factors (Cube, Goss and Brass) demonstrated size preference. The post-nucleation growth was affected by the biaxial thermal elastic constraint and surface energy. Due to their opposite effects, the orientations having moderate biaxial moduli and surface energy density (S, Copper, Brass and recrystallization components) survived, resulting in a mixed texture at the completion of recrystallization. The coherent Σ3 boundaries between the new components stabilized their growth through consuming the other oriented crystals separated by random high-angle boundaries. When sintered into bulk, the texture of the Cu was dominated by the orientations of the abnormally grown grains. The effects of GNSs on the recrystallization of Cu foils were also Cu foil thickness dependent. For the 10 μm thick foils, the effect of the GNSs manifested after the samples were sintered to high temperatures (> 700 ℃). Instead of creating much constraint to the expansion of the adjacent Cu foils, the GNSs worked as a barrier preventing the penetration of the grown Cu grains, resulting in the stabilization of the recrystallization texture represented by the two rotated components. For the Cu/GNS composite with Cu foil thickness of 30 μm, the results evidenced that a strong Cube orientation was produced in the Cu/GNS composite instead of the individual non-Cube orientations in the pure Cu stack without GNSs. Detailed strain-state analysis of the Cu foils in the Cu/GNS composite revealed that the anisotropic expansion behavior of the GNS that is incompatible with that of the Cu foils imposed multiple elastic constraints to the foils, resulting in a biaxial isostrain state in the surface layers and a uniaxial compressive strain state in the central layer. The elastic anisotropy of Cu favors the growth of the Cube oriented grains to minimize the total strain energy. The results of the present work provide quantitative and detailed information on recrystallization of thin Cu foils and laminated composite, which contributes to deepening the understanding of recrystallization behaviour of 2D materials. The mechanisms revealed are useful for analysing abnormal grain growth in elastically strained materials and can also be applied to fabrication process for texturization or even monocrystallization

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H, Lavrenyuk O. Mykhalichko V. Olijnyk B. Mykhalichko. "Stereochemical aspect of influence of [Cu(diethylenetriamine)(H2O)] SO4 H2O chelate compound onto combustibility decrease of epoxy-amine composite materials". Thesis, Book of abstr. Third EuCheMS Inorganic Chemistry Conference “Chemistry over the horizon” , Wroclaw, 2015. http://hdl.handle.net/123456789/1645.

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COSTA, FRANCINE A. da. "Sintese e sinterizacao de pos compositos do sistema W-Cu". reponame:Repositório Institucional do IPEN, 2004. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11176.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
FAPESP:00/00255-9

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Tang, Fei. "The Microstructure-Processing-Property Relationships in an Al Matrix Composite System Reinforced by Al-Cu-Fe Alloy Particles". Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2004. http://www.osti.gov/servlets/purl/835313-syGDu9/webviewable/.

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Più fonti

Libri sul tema "Composite materials Cu"

Moore, Thomas J. Tensile strength of simulated and welded butt joints in W-Cu-composite sheet. Cleveland, Ohio: Lewis Research Center, 1994.

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Capitoli di libri sul tema "Composite materials Cu"

Shohji, Ikuo, Susumu Arai, Naoki Kano, Noboru Otomo e Masahisa Uenishi. "Development of Cu Brazing Sheet with Cu-P Composite Plating". In Key Engineering Materials, 2025–28. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-456-1.2025.

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Jiang, Guosheng, Liyong Diao e Ken Kuang. "Improved Manufacturing Process of Cu/Mo70-Cu/Cu Composite Heat Sinks for Electronic Packaging Applications". In Advanced Thermal Management Materials, 99–107. New York, NY: Springer New York, 2012. http://dx.doi.org/10.1007/978-1-4614-1963-1_7.

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Lin, Hong Ming, Giin Shan Chen e Pee Yew Lee. "Microstructure and Properties of Vacuum Hot-Pressing SiC/ Ti-Cu-Ni-Sn Bulk Metallic Glass Composites". In Composite Materials V, 26–30. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-451-0.26.

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Fan, Zhi Kang, e Peng Xiao. "Morphology of Chromium in Cu- 2.0%~4.2%Cr Alloys". In Advances in Composite Materials and Structures, 277–80. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-427-8.277.

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Wang, Xin Hong, Zeng Da Zou, Min Zhang, Si Li Song e Shi Yao Qu. "Bonding Strength and Microstructure of Cermet/Cu-Based Alloy Composite Brazed Coatings". In Key Engineering Materials, 154–59. Stafa: Trans Tech Publications Ltd., 2005. http://dx.doi.org/10.4028/0-87849-978-4.154.

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Xiao, Peng, e Zhi Kang Fan. "Effects of Chromium Particle on Elevated Temperature Tensile Strength of Cu-Cr Alloy". In Advances in Composite Materials and Structures, 273–76. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-427-8.273.

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Han, Guihong, Pengfei Tang, Hongyang Wu, Jun Ma, Xiaomeng Yang e Yongsheng Zhang. "Adsorption Behavior of Cu(II) to Silica-Humics Composite Aerogels". In The Minerals, Metals & Materials Series, 91–96. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-05749-7_10.

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Joo, K. H., K. I. Chang, Hyoung Seop Kim e Sun Ig Hong. "Processing of Ultrafine-Grained Cu-Fe-Cr Composite by Equal Channel Angular Pressing". In Materials Science Forum, 71–76. Stafa: Trans Tech Publications Ltd., 2006. http://dx.doi.org/10.4028/0-87849-985-7.71.

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Qi, Yu Hong, Z. P. Zhang, D. L. Liu e Z. K. Hei. "Microstructure and Mechanical Properties of Al-Cu-Cr Quasicrystals/Al Matrix Composites Synthesized by Hot-Pressing Technique". In Advances in Composite Materials and Structures, 1061–64. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-427-8.1061.

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Xu, Qiang, Xing Hong Zhang, Jie Cai Han e Xiao Dong He. "Preparation of TiB₂ Nanoparticles Reinforced Cu-Matrix Composite by Direct Combustion Synthesis". In Key Engineering Materials, 1339–41. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-410-3.1339.

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Atti di convegni sul tema "Composite materials Cu"

Sundaram, Rajyashree, Guohai Chen, Takeo Yamada, Don Futaba, Kenji Hata, Ken Kokubo e Atsuko Sekiguchi. "Lightweight Cu/Carbon Nanotube Composite Electric Conductors". In 2020 International Conference on Solid State Devices and Materials. The Japan Society of Applied Physics, 2020. http://dx.doi.org/10.7567/ssdm.2020.k-9-03.

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Yungang Li, Limin Liu e Jie Li. "The progress of W-Cu composite materials preparation technique". In Environment (ICMREE). IEEE, 2011. http://dx.doi.org/10.1109/icmree.2011.5930584.

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Hu, Wang, Zhang Zhaohui, Hu Zhengyang, Li Shenglin, Yin Shipan e Song Qi. "CNTs/Cu composites fabricated by ball mixing and spark plasma sintering". In 2ND INTERNATIONAL CONFERENCE ON COMPOSITE MATERIALS AND MATERIAL ENGINEERING (ICCMME 2017). Author(s), 2017. http://dx.doi.org/10.1063/1.4983592.

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Zhang, Yinghui, Linghui He, Haixia Tian e Kai Peng. "Influences of Carbon Nanotubes on Performance of W-Cu Composite Materials". In 2015 International Conference on Advanced Material Engineering. WORLD SCIENTIFIC, 2015. http://dx.doi.org/10.1142/9789814696029_0051.

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Moskvichev, E. N. "Fabrication of NiAl strengthened Cu-Al based composite". In PROCEEDINGS OF THE II INTERNATIONAL CONFERENCE ON ADVANCES IN MATERIALS, SYSTEMS AND TECHNOLOGIES: (CAMSTech-II 2021). AIP Publishing, 2022. http://dx.doi.org/10.1063/5.0092748.

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Masuda, Chitoshi, e Yoshihisa Tanaka. "Fatigue Properties of Cu-Cr In-Situ Composite". In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-2458.

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Abstract The new electrical conductive material, Cu-15wt%Cr in-situ composite, was developed for the application of lead frame, high field magnet and trolley wire. The Cu-Cr composite was fabricated by casting method in vacuum and forged, solution-treated, and cold drawn (η = 4.66 and 6.94). In this paper the cold drawn Cu-Cr composite was tested under cyclic loading at room temperature in comparison to the data for pure copper. The fatigue stresses decreased with increasing the number of cycles to failure and the double -knees were not seen on the S-N curves for both alloys as in other face centered cubic materials such as aluminum alloys and high strength steels, such as spring steels and carburized steels. The fatigue strength of Cu-Cr composite is double that for pure copper. The fatigue strength of Cu-Cr composite with cold drawing at η = 6.94 is higher than that at η = 4.66 tested under an axial loading (R = 0.1). On the fatigue fracture surface, the fatigue crack initiated from the un-dissolved chromium particle situated beneath the specimen surface and the crack direction was changed along the chromium fiber. In order to improve the fatigue strength of Cu-Cr composite it is very important that the size and amount of un-dissolved chromium particles would be reduced.

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Ramli, M. I. I., M. A. A. Mohd Salleh, M. M. Al Bakri Abdullah, R. M. Said, A. V. Sandu e N. Saud. "Microstructural and phase analysis of Sn-Cu-Ni-XSiC composite solder". In ADVANCED MATERIALS ENGINEERING AND TECHNOLOGY V: International Conference on Advanced Material Engineering and Technology 2016. Author(s), 2017. http://dx.doi.org/10.1063/1.4981848.

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Ramli, M. I. I., M. A. A. Mohd Salleh, R. M. Said e N. Saud. "Thermal and mechanical properties of Sn-Cu-Ni-XSiC composite solder". In ADVANCED MATERIALS ENGINEERING AND TECHNOLOGY V: International Conference on Advanced Material Engineering and Technology 2016. Author(s), 2017. http://dx.doi.org/10.1063/1.4981849.

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Shu, Kuen Ming, Hung Rung Shih, Wen Feng Lin e G. C. Tu. "Hybrid EDM and Grinding Hard Materials Using a Metal Matrix Composite Electrode". In ASME 7th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2004. http://dx.doi.org/10.1115/esda2004-58098.

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Electrical discharge machining (EDM) has been shown to be a versatile method for machining difficult-to-work materials including heated-treated steels, tungsten carbides and various conductive ceramics. However, low machining efficiency is one of the main EDM disadvantages. The topic of how to reduce machining time and maintains reasonable accuracy has always been of research interest. The main object of the present work was to develop an electrical discharge machining and grinding (EDMG) methodology to remove the re-solidified layer through the grinding induced by a metal matrix composite electrode prior to the re-solidified layer solidification. A metal matrix composite (Cu/SiCp) electrode, with an electroless pretreatment of Cu coating on SiCp to enhance bonding status between Cu and SiCp, with a rotating device was made and employed to study the EDMG technology. Machinabilities of mold material, HPM50 mold steel and P20 WC/Co, were investigated by the combined technologies of EDMG. The machined surfaces of these materials were examined by scanning electron microscopy (SEM) and their surface roughness measured by a profile meter. From the experimental results, it was found that higher material removal rate and lower surface roughness can be achieved when suitable electrode rotating speed, SiCp size and working current are chosen. In addition, the surface roughness of both materials could be improved as compared with that following the EDM process.

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Bharathi, K. Divya, M. R. Rahman, Sunita Choudhary e S. B. Arya. "Development and characterization of Cu/MWCNT composite prepared by electrodeposition technique". In ADVANCES IN MECHANICAL DESIGN, MATERIALS AND MANUFACTURE: Proceeding of the Second International Conference on Design, Materials and Manufacture (ICDEM 2019). AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0010560.

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Rapporti di organizzazioni sul tema "Composite materials Cu"

Chefetz, Benny, Baoshan Xing, Leor Eshed-Williams, Tamara Polubesova e Jason Unrine. DOM affected behavior of manufactured nanoparticles in soil-plant system. United States Department of Agriculture, gennaio 2016. http://dx.doi.org/10.32747/2016.7604286.bard.

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The overall goal of this project was to elucidate the role of dissolved organic matter (DOM) in soil retention, bioavailability and plant uptake of silver and cerium oxide NPs. The environmental risks of manufactured nanoparticles (NPs) are attracting increasing attention from both industrial and scientific communities. These NPs have shown to be taken-up, translocated and bio- accumulated in plant edible parts. However, very little is known about the behavior of NPs in soil-plant system as affected by dissolved organic matter (DOM). Thus DOM effect on NPs behavior is critical to assessing the environmental fate and risks related to NP exposure. Carbon-based nanomaterials embedded with metal NPs demonstrate a great potential to serve as catalyst and disinfectors. Hence, synthesis of novel carbon-based nanocomposites and testing them in the environmentally relevant conditions (particularly in the DOM presence) is important for their implementation in water purification. Sorption of DOM on Ag-Ag₂S NPs, CeO₂ NPs and synthesized Ag-Fe₃O₄-carbon nanotubebifunctional composite has been studied. High DOM concentration (50mg/L) decreased the adsorptive and catalytic efficiencies of all synthesized NPs. Recyclable Ag-Fe₃O₄-carbon nanotube composite exhibited excellent catalytic and anti-bacterial action, providing complete reduction of common pollutants and inactivating gram-negative and gram-positive bacteria at environmentally relevant DOM concentrations (5-10 mg/L). Our composite material may be suitable for water purification ranging from natural to the industrial waste effluents. We also examined the role of maize (Zeamays L.)-derived root exudates (a form of DOM) and their components on the aggregation and dissolution of CuONPs in the rhizosphere. Root exudates (RE) significantly inhibited the aggregation of CuONPs regardless of ionic strength and electrolyte type. With RE, the critical coagulation concentration of CuONPs in NaCl shifted from 30 to 125 mM and the value in CaCl₂ shifted from 4 to 20 mM. This inhibition was correlated with molecular weight (MW) of RE fractions. Higher MW fraction (> 10 kDa) reduced the aggregation most. RE also significantly promoted the dissolution of CuONPs and lower MW fraction (< 3 kDa) RE mainly contributed to this process. Also, Cu accumulation in plant root tissues was significantly enhanced by RE. This study provides useful insights into the interactions between RE and CuONPs, which is of significance for the safe use of CuONPs-based antimicrobial products in agricultural production. Wheat root exudates (RE) had high reducing ability to convert Ag+ to nAg under light exposure. Photo-induced reduction of Ag+ to nAg in pristine RE was mainly attributed to the 0-3 kDa fraction. Quantification of the silver species change over time suggested that Cl⁻ played an important role in photoconversion of Ag+ to nAg through the formation and redox cycling of photoreactiveAgCl. Potential electron donors for the photoreduction of Ag+ were identified to be reducing sugars and organic acids of low MW. Meanwhile, the stabilization of the formed particles was controlled by both low (0-3 kDa) and high (>3 kDa) MW molecules. This work provides new information for the formation mechanism of metal nanoparticles mediated by RE, which may further our understanding of the biogeochemical cycling and toxicity of heavy metal ions in agricultural and environmental systems. Copper sulfide nanoparticles (CuSNPs) at 1:1 and 1:4 ratios of Cu and S were synthesized, and their respective antifungal efficacy was evaluated against the pathogenic activity of Gibberellafujikuroi(Bakanae disease) in rice (Oryza sativa). In a 2-d in vitro study, CuS decreased G. fujikuroiColony- Forming Units (CFU) compared to controls. In a greenhouse study, treating with CuSNPs at 50 mg/L at the seed stage significantly decreased disease incidence on rice while the commercial Cu-based pesticide Kocide 3000 had no impact on disease. Foliar-applied CuONPs and CuS (1:1) NPs decreased disease incidence by 30.0 and 32.5%, respectively, which outperformed CuS (1:4) NPs (15%) and Kocide 3000 (12.5%). CuS (1:4) NPs also modulated the shoot salicylic acid (SA) and Jasmonic acid (JA) production to enhance the plant defense mechanisms against G. fujikuroiinfection. These results are useful for improving the delivery efficiency of agrichemicals via nano-enabled strategies while minimizing their environmental impact, and advance our understanding of the defense mechanisms triggered by the NPs presence in plants.

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