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【新文速递】2024年11月14日复合材料SCI期刊最新文章

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今日更新:Composite Structures 2 篇,Composites Part A: Applied Science and Manufacturing 2 篇,Composites Part B: Engineering 1 篇

Composite Structures

A comparative study of tensile fatigue life in various flexible-oriented three-dimensional woven process structures based on finite element models

Chenchen Tan, Hao Huang, Zheng Sun, Zhongde Shan, Zitong Guo, Kehong Guo, Jinshuai Bian, Weihao Wang

doi:10.1016/j.compstruct.2024.118680

基于有限元模型的不同柔性三维编织工艺结构拉伸疲劳寿命对比研究

To achieve a comparative study of tensile fatigue life in various three-dimensional (3D) structures, 3D orthogonal woven composite (3DOWC), off-axis 3D orthogonal woven composite (OA-3DOWC) and multiaxial 3D woven composite (M3DWC), were designed and manufactured. Tensile and fatigue tests were performed, and microcomputed tomography (Micro-CT) was utilized to observe the mesoscale structural characteristics and the fatigue fracture morphology. Finite element models were established based on the observation. Then a modified power-law fatigue damage model was used for reduction of stiffness and strength during fatigue loading process, and a normalized life model was used to predict the fatigue life at different stress levels. Comparisons were conducted with existing models to analyze their predictive accuracy. Results showed that the tensile strength of M3DWC decreased by 54.6 % compared to 3DOWC, while its fatigue performance of M3DWC was significantly improved. Additionally, OA-3DOWC had the worst tensile strength but slightly improved fatigue performance compared to 3DOWC. And for the maximum error between the prediction and experimental results for the fatigue life is 11.16 %. For the fatigue life at the same stress level, M3DWC > OA-3DOWC > 3DOWC, due to the complex crack propagation paths in the staggered fiber arrangement.

为实现不同三维结构拉伸疲劳寿命的对比研究,设计制造了三维正交编织复合材料(3DOWC)、离轴三维正交编织复合材料(OA-3DOWC)和多轴三维编织复合材料(M3DWC)。进行了拉伸和疲劳试验,并利用微计算机断层扫描(Micro-CT)观察了中尺度结构特征和疲劳断口形貌。在此基础上建立了有限元模型。然后采用修正幂律疲劳损伤模型对疲劳加载过程中的刚度和强度进行降低,并采用归一化寿命模型对不同应力水平下的疲劳寿命进行预测。与现有模型进行比较,分析其预测精度。结果表明,与3DOWC相比,M3DWC的抗拉强度降低了54.6% %,但其疲劳性能得到了显著提高。此外,与3DOWC相比,OA-3DOWC的抗拉强度最差,但疲劳性能略有改善。疲劳寿命预测值与试验值的最大误差为11.16 %。对于相同应力水平下的疲劳寿命,M3DWC > OA-3DOWC > 3DOWC,由于交错纤维排列中裂纹扩展路径复杂。


Additive manufacturing of gradient porous Si/SiC ceramic parts: Quasi-static behaviors and mechanical properties

Ce Sun, Song Zhang, Rong Tu, Lihong Wu, Jiahao Ye, Yusheng Shi, Chunze Yan, Huajun Sun, Yuhan Liao, Peng Chen, Kai Liu

doi:10.1016/j.compstruct.2024.118693

梯度多孔Si/SiC陶瓷零件的增材制造:准静态行为和力学性能

Porous silicon carbide (SiC) ceramic exhibits low density, high toughness, which endow it with an indispensable role in engineering applications. However, the manufacturing, designing, and making full use of the rich pore structure of gradient porous SiC ceramic to improve its mechanical performance still face many challenges. Herein, the manufacture of gradient porous Si/SiC ceramic part is realized for the first time, and the influence of gradient structural on mechanical properties is deeply analyzed. The results indicate that the porous Si/SiC ceramics with constant gradient transition rate is characterized by step-by-step destruction and can carry larger strains than the porous Si/SiC ceramics with non-constant gradient transition rate. Meanwhile, reducing the gradient span can improve the strength, but it is easy to lead to brittle damage. In particular, gradient porous Si/SiC ceramics with constant gradient transition rate and 30 % gradient span can exhibit both good strength and toughness. The compressive strength can reach 11.71 MPa, and the equivalent elastic modulus can reach 2.28 GPa. Finally, a laminar material prediction model for mechanical properties is presented. This paper presents an effective fabrication method for gradient porous ceramic parts and provides a feasible means for the design and prediction of mechanical properties.

多孔碳化硅(SiC)陶瓷具有低密度、高韧性的特点,在工程应用中具有不可缺少的作用。然而,如何制造、设计和充分利用梯度多孔碳化硅陶瓷丰富的孔隙结构来提高其力学性能仍面临诸多挑战。本文首次实现了梯度多孔Si/SiC陶瓷零件的制造,并深入分析了梯度结构对力学性能的影响。结果表明,恒定梯度转变速率的多孔Si/SiC陶瓷比非恒定梯度转变速率的多孔Si/SiC陶瓷具有逐步破坏的特点,并且可以携带更大的应变。同时,减小梯度跨度可以提高强度,但容易导致脆性损伤。梯度过渡率为恒定,梯度跨度为30 %的梯度多孔Si/SiC陶瓷具有良好的强度和韧性。抗压强度可达11.71 MPa,等效弹性模量可达2.28 GPa。最后,提出了层流材料力学性能的预测模型。本文提出了一种有效的梯度多孔陶瓷零件的制备方法,为其力学性能的设计和预测提供了可行的手段。


Composites Part A: Applied Science and Manufacturing

A highly thermally conductive yet electrically insulating boron nitride nanosheets/polyetherimide composite with oriented structure

Tianze Wang, Hui Chi, Danying Zhao, Junguo Dong, Ming Li, Zhenhua Jiang, Yunhe Zhang

doi:10.1016/j.compositesa.2024.108581

一种具有取向结构的高导热且电绝缘的氮化硼纳米片/聚醚酰亚胺复合材料

Due to the continuous development of semiconductor technology and the rapid increase in power density of modern electronic devices, there is an urgent need for a thermal interface material (TIM) with ultra-high heat dissipation capacity and excellent electrical insulation. Here, we report a new embedded series strategy for preparing thermal interface materials. Firstly, ultra-thin boron nitride nanosheets (BNNS) are continuously and neatly embedded into oriented fibers by electrospinning to form an ordered series structure. These composite fibers are then stacked into multiple layers and simply compacted to form a dense structure. Finally, by controlling the hot pressing temperature to confine the movement of oriented fibers, the activated molecular chain segments move in confined space to prepare a composite with oriented structure. The composite provides a reliable conduction path for phonons by embedding neatly arranged BNNS in oriented structure. The composites prepared by this strategy have higher thermal anisotropy (λ=/λ⊥ = 7.16) and in-plane thermal conductivity (3.08 W/(m·K), BNNS Loading: 30 wt%), and also exhibit better electrical insulation (8.16 × 1015 Ω·cm) than those prepared by solution coating and hot pressing.

由于半导体技术的不断发展和现代电子器件功率密度的迅速提高,迫切需要一种具有超高散热能力和优良电绝缘性的热界面材料(TIM)。在这里,我们报告了一种新的嵌入式系列策略来制备热界面材料。首先,通过静电纺丝将超薄氮化硼纳米片(BNNS)连续整齐地嵌入定向纤维中,形成有序的系列结构。然后将这些复合纤维堆叠成多层,简单地压实形成致密的结构。最后,通过控制热压温度来限制取向纤维的运动,使被激活的分子链片段在受限空间内运动,从而制备出具有取向结构的复合材料。该复合材料通过在定向结构中嵌入整齐排列的BNNS,为声子提供了可靠的传导路径。通过该策略制备的复合材料具有更高的热各向异性(λ=/λ⊥= 7.16)和面内导热系数(3.08 W/(m·K), BNNS加载:30 wt%),并且与溶液涂层和热压制备的复合材料相比,还具有更好的电绝缘性(8.16 × 1015 Ω·cm)。


3D printing of graphene frameworks decorated with magnetic components for enhanced electromagnetic interference shielding

Yue Wang, Jialiang Luo, Gazi Hao, Jun Di, Guigao Liu, Suwei Wang, Wei Jiang

doi:10.1016/j.compositesa.2024.108588

 

用磁性元件装饰的石墨烯框架的3D打印,以增强电磁干扰屏蔽

Three-dimensional (3D) printed graphene frameworks with structural designability and compositional tunability offer new opportunities for electromagnetic interference (EMI) shielding applications. However, advanced EMI shielding materials with customizable structures and magnetic responsiveness remain a challenge. Herein, we construct lightweight and structurally controllable 3D reduced graphene oxide frameworks decorated with magnetic components (MRGO frameworks) via 3D printing technology to tailor EMI shielding properties. By adjusting the preparation conditions of the MRGO frameworks, such as inter-filament spacing, composition, and pyrolysis temperature, the graphitization degree and transmission paths are influenced, enabling electrical conductivity and magnetic property, and ensuring excellent EMI shielding performance. Specifically, the average EMI shielding effectiveness of the MRGO framework in the K-band and Ka-band is 44.95 dB and 53.90 dB, respectively. Furthermore, the 3D MRGO frameworks follow a reflection-dominated EMI shielding mechanism. This work provides insights into the development of EMI shielding materials through structural design and compositional optimization.

三维(3D)打印石墨烯框架具有结构可设计性和成分可调性,为电磁干扰(EMI)屏蔽应用提供了新的机会。然而,具有可定制结构和磁响应性的先进EMI屏蔽材料仍然是一个挑战。在此,我们通过3D打印技术构建了轻质且结构可控的磁性元件装饰的3D还原氧化石墨烯框架(MRGO框架),以定制EMI屏蔽性能。通过调整MRGO骨架的制备条件,如丝间距、组成、热解温度等,可以影响其石墨化程度和传输路径,使其具有良好的导电性和磁性能,并具有良好的电磁干扰屏蔽性能。具体来说,MRGO框架在k波段和ka波段的平均EMI屏蔽效能分别为44.95 dB和53.90 dB。此外,3D MRGO框架遵循反射主导的电磁干扰屏蔽机制。这项工作通过结构设计和成分优化为电磁干扰屏蔽材料的发展提供了见解。


Composites Part B: Engineering

Bird’s nest inspired aerogels towards ultrahigh strength and robust flame retardancy at extreme environment

Hong Zhang, Haiyun Ma, Huiqi Gao, Le Yang, Chang Wang, Yunhong Jiao, Jianzhong Xu

doi:10.1016/j.compositesb.2024.111966

 

受燕窝启发的气凝胶在极端环境下具有超高强度和强大的阻燃性

The mechanical properties of aerogels remain a critical concern for their application. Inspired from the hierarchical architecture of bird's nests, we have designed an effective biomimetic hybrid strategy for creating an aerogel with ultrahigh strength and robust flame retardancy. The super-molecular micro- to nanofibrils formed by boric acid and melamine act as “twigs” while a small part of biobased polysaccharide agar serves as “glue”. Via the water as the solvent and an eco-friendly freeze-drying method, the obtained boric acid-melamine/agar (BMA) aerogel with a low density (0.0760 g/cm3) exhibited exceptional high compressive strength, reaching up to 3.92 MPa at 80% strain. A piece of the BMA aerogel with 10 cm2 can resist a motorcycle (150 kg) easily without any deformation. Additionally, the BMA aerogel demonstrated outstanding inherent flame retardant property (achieving UL-94 V-0 rating with relatively low the heat release, total heat release and CO release rate values) as well as superior thermal insulating properties (with a thermal conductivity as low as 0.0364 W/m⋅K). Given the distinctive mechanical properties and excellent other properties, the BMA aerogels hold great promise for potential promise in energy-saving and thermal protection applications. and the superior stiffness mechanism behind this performance is also analyzed.

气凝胶的力学性能仍然是其应用的关键问题。受燕窝分层结构的启发,我们设计了一种有效的仿生混合策略,用于制造具有超高强度和强大阻燃性的气凝胶。由硼酸和三聚氰胺形成的超分子微至纳米原纤维充当“细枝”,而一小部分生物基多糖琼脂充当“胶水”。以水为溶剂,采用生态友好的冷冻干燥方法,得到了低密度(0.0760 g/cm3)的硼酸-三聚氰胺/琼脂(BMA)气凝胶,在80%应变下,其抗压强度高达3.92 MPa。一块10平方厘米的BMA气凝胶可以很容易地抵抗摩托车(150公斤)而不会变形。此外,BMA气凝胶具有优异的固有阻燃性能(达到UL-94 V-0等级,放热量、总放热量和CO释放率值相对较低)和优越的隔热性能(导热系数低至0.0364 W/m·K)。由于其独特的机械性能和优异的其他性能,BMA气凝胶在节能和热保护应用方面具有很大的潜力。并对其优越的刚度机理进行了分析。



来源:复合材料力学仿真Composites FEM
ACTMechanicalAdditiveInspireMAGNET疲劳复合材料半导体电子增材裂纹材料仿生控制试验
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首次发布时间:2024-11-21
最近编辑:3天前
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【新文速递】2024年8月14日复合材料SCI期刊最新文章

今日更新:Composites Part A: Applied Science and Manufacturing 2 篇,Composites Science and Technology 4 篇Composites Part A: Applied Science and ManufacturingNear pixel-level characterisation of microfibres in 3D-printed cementitious composites and migration mechanisms using a novel iterative methodRijiao Yang, Chengji Xu, Yan Lan, Yue Qiu, Zhendi Wang, Yu Peng, Qiang Zengdoi:10.1016/j.compositesa.2024.108404近像素级表征微纤维在3d打印胶凝复合材料和迁移机制使用一种新的迭代方法Microfibre reinforcement is widely used for additively manufactured composites, however, it remains a challenging task to resolve the 3D distribution of microfibres in the matrix with low contrast and resolution for imaging analysis. To address this challenge, we propose a novel iterative destruction–filtering–repairing (DFR) image processing method, and take glass microfibre-embedded extrusion-moulded cementitious filaments (EMCFs) as an example for 3D structural analysis with X-ray computed tomography. Results show that the DFR method enables near pixel-level microfibre diagnosis with high accuracy beyond the ordinary image processing method. The glass microfibres are unevenly distributed in the EMCFs and their orientations are different between the filament body and the interfacial zone, uncovering the mechanisms of extrusion-affected material migration, collision, and redistribution. Our findings make a breakthrough in imaging analysis with limited resolution and contrast, providing a broad path towards better understanding microstructure of 3D printed fibre-reinforcement composites.微纤维增强材料广泛应用于增材制造复合材料,然而,在低对比度和分辨率的情况下,解决微纤维在基体中的三维分布问题仍然是一项具有挑战性的任务。为了解决这一挑战,我们提出了一种新的迭代破坏-滤波-修复(DFR)图像处理方法,并以玻璃微纤维嵌入挤压成型胶凝细丝(EMCFs)为例,使用x射线计算机断层扫描进行三维结构分析。结果表明,DFR方法能够实现近像素级的微纤维诊断,比普通图像处理方法具有更高的诊断精度。玻璃微纤维在EMCFs中的分布不均匀,其取向在丝体和界面区之间存在差异,揭示了挤压影响材料迁移、碰撞和再分布的机制。我们的发现在有限分辨率和对比度的成像分析方面取得了突破,为更好地理解3D打印纤维增强复合材料的微观结构提供了广阔的途径。A novel strategy to break through the strength-ductility trade-off of titanium matrix compositesQiang Wang, Zhao-Hui Zhang, Luo-Jin Liu, Xiao-Tong Jia, Yang-Yu He, Jin-Zhao Zhou, Yuan-Hao Sun, Xing-Wang Chengdoi:10.1016/j.compositesa.2024.108407突破钛基复合材料强度-延性权衡的新策略This study used a solution blending method to coat Ti64 alloy particles with an organopolysilazane (OPSZ) precursor, creating (TiC + Ti3Si)/Ti64 composites via spark plasma sintering (SPS). During SPS, OPSZ decomposes, releasing silicon, carbon, and nitrogen. Nitrogen exits as NH3 and N2, while carbon and silicon partially dissolve in the matrix and partially react with titanium to form TiC and Ti3Si particles. The composite with 0.5 wt% OPSZ exhibited a tensile strength of 1135 MPa and an elongation of 19.0 %, 18.2 % and 28.5 % higher than commercial Ti64 alloy, respectively. The strength increase is attributed to grain refinement, solid solution strengthening, Orowan strengthening, and L phase strengthening. The improved ductility results from fine precipitates promoting dislocation multiplication, the dislocation storage effect of the interface L-phase, and matrix purification by H2 and NH3 from OPSZ decomposition.本研究采用溶液共混的方法,用有机聚硅氮烷(OPSZ)前驱体包覆Ti64合金颗粒,通过火花等离子烧结(SPS)制备(TiC + Ti3Si)/Ti64复合材料。在SPS过程中,OPSZ分解,释放出硅、碳和氮。氮以NH3和N2的形式存在,碳和硅部分溶解于基体中,与钛部分反应形成TiC和Ti3Si颗粒。添加0.5 wt% OPSZ的复合材料的抗拉强度为1135 MPa,伸长率分别比工业Ti64合金高19.0 %、18.2 %和28.5 %。强度的提高主要是由于晶粒细化、固溶强化、Orowan强化和L相强化。微相促进位错增殖、界面l相的位错储存作用以及OPSZ分解产生的H2和NH3对基体的净化作用是提高塑性的主要原因。Composites Science and TechnologyEffects of welding displacement and energy director thickness on the ultrasonic welding of epoxy-to-polyetherimide based hybrid composite jointsJiaming Liu, Dongsheng Yue, Xuemin Wang, Jiaying Pan, Dongmin Yang, Dong Quan, Guoqun Zhaodoi:10.1016/j.compscitech.2024.110810 焊接位移和导能器厚度对环氧-聚醚酰亚胺基复合材料接头超声焊接的影响This study aimed to develop robust thermoplastic-to-thermoset composite joints upon an ultrasonic welding process. The carbon fiber/epoxy composite was topped with a layer of polyetherimide (PEI) film by a co-curing process, making it “weldable” with the carbon fiber/PEI composite. The effects of welding displacement and thickness of the energy director (ED) on the welding process of the epoxy-to-PEI hybrid composite joints were investigated. The experimental results demonstrated that an optimal welding displacement existed for the best welding quality, whose value depended on the ED thickness. Given a certain ED thickness, the lap-shear strength (LSS) of the hybrid joints increased to a maximum value and then decreased as the welding displacement increased. By optimizing the displacement and ED thickness, a maximum LSS of 39.4 MPa was obtained for the hybrid joints. In which case, the level of the defects within the welding line was minimized, and the joints failed cohesively within the composite substrates.本研究旨在利用超声波焊接工艺开发坚固的热塑性-热固性复合材料接头。通过共固化工艺,在碳纤维/环氧复合材料表面覆盖一层聚醚酰亚胺(PEI)薄膜,使其与碳纤维/PEI复合材料“可焊接”。研究了焊接位移和导能器厚度对环氧- pei复合材料接头焊接过程的影响。实验结果表明,为了获得最佳焊接质量,存在一个最优焊接位移,其大小与ED厚度有关。在一定ED厚度下,随着焊接位移的增大,混合接头的搭接抗剪强度先增大后减小。通过对位移和ED厚度的优化,得到了混合接头最大LSS为39.4 MPa。在这种情况下,焊接线内的缺陷水平被最小化,接头在复合基板内粘结失效。Strongly reinforced mechanical and thermal properties of polyamide 66 by high loading titanium dioxide whiskersYankun Gong, Juan Chen, Jiacheng Zhang, Yanfen Ding, Peng Liu, Haijun Fan, Mingshu Yangdoi:10.1016/j.compscitech.2024.110811 高负荷二氧化钛晶须增强聚酰胺66的机械和热性能Of large length-to-diameter ratio and specific area, inorganic whiskers were widely applied for polymer reinforcement. As a well-known nanofiller, titanium dioxide (TiO2) has been welcome by polymer engineering, mostly for whitening with spherical shapes favored. To date, there have been no TiO2 whiskers reported for polymer reinforcement. In this work, a rutile type TiO2 whisker was compounded with polyamide 66 (PA66) to prepare nanocomposites with surficial modification being conducted to further improve the compatibility between them. It was found that the rutile-type TiO2 whisker significantly improves the mechanical properties of PA66 at high loadings and the performance went better when surficial modification for it was applied. Under 50 wt% addition of TiO2 whisker either modified or not, the tensile strength, tensile modulus, flexural strength, flexural modulus, impact strength and heat deformation temperature of prepared PA66 composites were respectively increased by 52%, 279%, 44%, 313%, 20%, 199% and 84%, 279%, 88%, 303%, 114%, 207%, comparing with the pristine PA66. The mechanism regarding the overall reinforcement was analyzed, which was attributed to the shape-relevant multiple interactions between TiO2 and PA66. Besides, the improved adhesion due to strong stable chemical bonding by surficial modification of fillers, is also accountable.无机晶须具有较大的长径比和比表面积,在聚合物增强中得到了广泛的应用。二氧化钛(TiO2)作为一种众所周知的纳米填料,一直受到聚合物工程的欢迎,主要用于增白,其球形结构受到青睐。到目前为止,还没有TiO2晶须用于聚合物增强的报道。本文将金红石型TiO2晶须与聚酰胺66 (PA66)复合制备纳米复合材料,并对其进行表面改性,进一步提高两者之间的相容性。结果表明,金红石型TiO2晶须在高负载下显著提高了PA66的力学性能,并对其进行表面改性后性能得到改善。当TiO2晶须添加量为50wt %时,制备的PA66复合材料的拉伸强度、拉伸模量、弯曲强度、弯曲模量、冲击强度和热变形温度分别比原始PA66提高了52%、279%、44%、313%、20%、199%和84%、279%、88%、303%、114%、207%。分析了整体增强的机理,认为这是TiO2与PA66之间形状相关的多重相互作用所致。此外,由于填料的表面改性产生了强而稳定的化学键,从而提高了附着力。Green Crosslinking Strategy for Ethylene-Vinyl Acetate Rubber Composites with NH2-POSS as a Crosslinking Agent and Reinforcing NanofillerJunjie Peng, Guojie Zhang, Yourong Duan, Hanbing Wang, Yong Zhangdoi:10.1016/j.compscitech.2024.110808 以NH2-POSS为交联剂和增强纳米填料的乙烯-醋酸乙烯橡胶复合材料绿色交联策略Ethylene-vinyl acetate rubber is extensively utilized in various fields including electrical wires and cables, automotive, and electronic components. Traditional peroxide vulcanization methods, however, release volatile organic compounds, posing environmental pollution concerns. To address this, 3-amino-polyhedral oligomeric silsesquioxane (NH2-POSS) was synthesized through hydrolytic condensation and used both as a crosslinking agent and a filler in the preparation of ethylene-vinyl acetate-glycidyl methacrylate terpolymer (EVM-GMA) composites. Notably, NH2-POSS not only effectively crosslinks EVM-GMA, but also thus promotes the dispersion of the silica in the composites. EVM-GMA/silica composites crosslinked by NH2-POSS display superior mechanical properties and thermal stability compared to EVM-GMA/silica composites crosslinked by organic peroxide. EVM-GMA composite with 4.5 phr NH2-POSS and 30 phr SiO2 has a tensile strength of 10.7 MPa and an elongation at the break of 240%. This study introduces a novel and environmentally friendly crosslinking strategy for producing high-performance EVM-GMA composites without additional additives.乙烯-醋酸乙烯橡胶广泛应用于电线电缆、汽车、电子元器件等领域。然而,传统的过氧化物硫化方法 会释放出挥发性有机化合物,造成环境污染问题。为了解决这一问题,采用水解缩合的方法合成了3-氨基多面体低聚硅氧烷(NH2-POSS),并将其作为交联剂和填料用于制备乙烯-醋酸乙烯-甲基丙烯酸缩水甘油酯三元共聚物(EVM-GMA)复合材料。值得注意的是,NH2-POSS不仅有效地交联了EVM-GMA,而且促进了二氧化硅在复合材料中的分散。与有机过氧化物交联的EVM-GMA/silica复合材料相比,NH2-POSS交联的EVM-GMA/silica复合材料具有更好的力学性能和热稳定性。含有4.5 phr NH2-POSS和30 phr SiO2的EVM-GMA复合材料的抗拉强度为10.7 MPa,断裂伸长率为240%。本研究介绍了一种新的环保交联策略,用于生产高性能EVM-GMA复合材料,无需额外的添加剂。Enhancing Electromagnetic Shielding Property and Absorption Coefficients via Constructing Electromagnetic Rings in Janus CompositesXin Hou, Xue-Rong Feng, Ke Jiang, Yu-Chen Zheng, Jiang-Tao Liu, Ming Wangdoi:10.1016/j.compscitech.2024.110809 通过构造电磁环提高Janus复合材料的电磁屏蔽性能和吸收系数Polymer based electromagnetic wave (EMW) shielding materials with high conductivity have excellent electromagnetic shielding properties, but also exhibit high reflection of EMWs, resulting in inevitable secondary electromagnetic pollution. EMW shielding materials with low reflection have extensive potential applications in the next generation of anti-EMW equipment. Herein, a production strategy combining three dimensional (3D) printing technology and solution casting method was proposed to prepare polylactic acid (PLA)@multi-walled carbon nanotubes (MWCNT)/polydimethylsiloxane (PDMS)@carbonyl iron powder (CIP) absorptive electromagnetic shielding Janus composites with a ring-shaped electromagnetic synergistic structure (spiral rings or concentric circular rings). By utilizing PLA and MWCNTs as primary components, a 3D integrated framework that combines a highly conductive reflector and a ring inductance structure can achieve significant EMW shielding performance with low reflection. With PDMS as a matrix and magnetic CIP as functional fillers, a strong magnetic permeability network is provided around the ring inductance frame. The magnetic loss resulting from electromagnetic cooperative ring structure further enhances microwave absorption capacity. The composite materials, benefiting from the synergistic interaction between the electromagnetic rings and the reflector, demonstrate excellent impedance matching and efficient EMW shielding capabilities. Specifically, the PLA@MWCNT/PDMS@CIP Janus composites with ring structure exhibit a notable EMW shielding effectiveness (SE) of 31 dB and a reflection coefficient as minimal as 0.3. Therefore, this study presents a powerful approach to the development of low-reflective materials with high EMW SE, promising potential applications in the next-generation intelligent electronic devices.聚合物基高导电性电磁波屏蔽材料具有优异的电磁屏蔽性能,但对电磁波的反射也较高,不可避免地造成二次电磁污染。低反射的电磁屏蔽材料在新一代抗电磁设备中具有广泛的应用前景。本文提出了三维打印技术与溶液铸造技术相结合的生产策略,制备了具有环形电磁协同结构(螺旋环或同心圆环)的聚乳酸(PLA)@多壁碳纳米管(MWCNT)/聚二甲基硅氧烷(PDMS)@羰基铁粉(CIP)吸收电磁屏蔽Janus复合材料。利用PLA和MWCNTs作为主要元件,结合高导电性反射器和环形电感结构的三维集成框架可以实现低反射、显著的EMW屏蔽性能。以PDMS为基体,磁性CIP为功能填料,在环形电感框架周围形成强磁导率网络。电磁协同环结构产生的磁损失进一步提高了微波吸收能力。该复合材料得益于电磁环与反射器之间的协同作用,具有良好的阻抗匹配和高效的EMW屏蔽能力。其中,环状结构的PLA@MWCNT/PDMS@CIP Janus复合材料的EMW屏蔽效果(SE)为31 dB,反射系数低至0.3。因此,该研究为开发具有高EMW SE的低反射材料提供了一种强有力的方法,在下一代智能电子设备中具有潜在的应用前景。来源:复合材料力学仿真Composites FEM

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