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【新文速递】2024年2月9日复合材料SCI期刊最新文章

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今日更新:Composite Structures 4 篇,Composites Part A: Applied Science and Manufacturing 2 篇,Composites Part B: Engineering 2 篇,Composites Science and Technology 5 篇

Composite Structures

Structural design and experimental study of CFRP bamboo rat tooth bionic drill bit

Fei Su, Ke Chen, Xing Liu, Ke Zhang, Xun Ding

doi:10.1016/j.compstruct.2024.117950

CFRP 竹鼠齿仿生钻头的结构设计与实验研究

The holes are very easy to appear delamination and burr during CFRP drilling. The tool geometry has a great impact on the hole making. In this paper, according to the principle of bionics and structural features, a novel bionic drill bit was designed. The mathematical model of the lower incisor teeth occlusal movement was established. The cutting mechanism of the bamboo rat lower incisor on PW-CFRP material was studied. It was found that the curvature of the contour curves of the front cutter faces were constantly changing, which was conducive to the removal of chips. The curvature change of the contour curve of the rear cutter surface is small and the curve is relatively smooth, which is conducive to reducing friction. The mathematical modeling analysis was carried out on the feeding process of bamboo rats, and the mathematical relationship between the bite radius R and the cutting angle θ was obtained. The optimal cutting angle θ=10° and the corresponding biting radius R=40mm were obtained by finite element simulation. The surface cutting quality of bamboo rat's lower incisors is better than that of ordinary cutting tools. The novel bionic tool can effectively reduce the burr and delamination of the exit layer.

在 CFRP 钻孔过程中,孔很容易出现分层和毛刺。刀具的几何形状对钻孔有很大影响。本文根据仿生学原理和结构特点,设计了一种新型仿生钻头。建立了下门牙咬合运动的数学模型。研究了竹鼠下门齿在 PW-CFRP 材料上的切割机理。研究发现,前刀面轮廓曲线的曲率不断变化,有利于切屑的清除。后刀面轮廓曲线的曲率变化较小,曲线相对平滑,有利于减少摩擦。对竹鼠的进料过程进行了数学建模分析,得到了咬合半径 R 与切削角 θ 之间的数学关系。通过有限元模拟得到了最佳切削角θ=10°和相应的咬合半径R=40mm。竹鼠下门齿的表面切削质量优于普通刀具。新型仿生刀具能有效减少毛刺和出口层的分层。


A theoretical study on the temperature-dependent yield strength of in-situ particle and whisker hybrid-reinforced metal matrix composites

Ruozhen Zhang, Pan Dong, Xuyao Zhang, Ziyuan Zhao, Weiguo Li, Tianbao Cheng, Xianhe Zhang

doi:10.1016/j.compstruct.2024.117962

原位颗粒和晶须混合增强金属基复合材料屈服强度随温度变化的理论研究

The hybrid effect observed in hybrid-reinforced composites presents a promising opportunity to further enhance the mechanical properties of composites. In this study, a theoretical model is established to determine the yield strength of in-situ particle and whisker hybrid-reinforced metal matrix composites by considering the mechanisms of stress transfer strengthening and grain boundary strengthening. And the hybrid effect is well characterized. The model is then extended to incorporate temperature dependence, considering changes in key parameters as temperature varies. With only one readily available experimental reference point, yield strength at different temperatures can be conveniently predicted. Satisfactory agreements are achieved between model predictions and experimental data. Moreover, quantitative analyses are performed to examine the hybrid effect at various temperatures and reinforcement volume fractions. The results show that the hybrid effect increases significantly with the increasing reinforcement volume fraction, but as the temperature increases, the hybrid effect decreases in proportion to the matrix yield strength.

在混合增强复合材料中观察到的混合效应为进一步提高复合材料的机械性能提供了一个大有可为的机会。本研究建立了一个理论模型,通过考虑应力传递强化和晶界强化机制来确定原位颗粒和晶须混合强化金属基复合材料的屈服强度。并很好地描述了混合效应。然后对模型进行了扩展,纳入了温度依赖性,考虑了温度变化时关键参数的变化。只需一个现成的实验参考点,就能方便地预测不同温度下的屈服强度。模型预测与实验数据之间达到了令人满意的一致。此外,还进行了定量分析,以研究不同温度和钢筋体积分数下的混合效应。结果表明,混合效应随着钢筋体积分数的增加而显著增加,但随着温度的升高,混合效应与基体屈服强度成比例地减小。


Fatigue crack growth characterization of composite-to-steel bonded interface using ENF and 4ENF tests

Weikang Feng, Marcio Moreira Arouche, Marko Pavlovic

doi:10.1016/j.compstruct.2024.117963

利用 ENF 和 4ENF 试验鉴定复合材料与钢粘接界面的疲劳裂纹生长特征

In this paper, mode II fatigue crack growth properties of the composite-to-steel interface are characterised through different test configurations, namely ENF and 4ENF tests. Different loading types including force control and displacement control methods are compared. An innovative shear strain based method is proposed for monitoring the mode II crack growth at the bi-material interface through Digital Image Correlation (DIC). A 3D finite element model with Virtual Crack Closure Technique (VCCT) is built and used for obtaining the strain energy release rate (SERR) to investigate the effect of geometrical nonlinearity, friction at the interface and steel yielding, as well as to verify the mode mixity. The results show that the standard 3-point bending ENF specimen can be unstable under force control and sweeps narrow SERR range by a single test under displacement control. The 4-point bending 4ENF test shows stable crack propagation and clear SERR developing trend. More pronounced geometrical nonlinearity and friction effect exist for 4ENF test which can be considered in interpreting the Paris curves by a nonlinear finite element model.

本文通过不同的试验配置,即 ENF 和 4ENF 试验,对复合材料与钢材界面的模式 II 疲劳裂纹生长特性进行了表征。比较了不同的加载类型,包括力控制和位移控制方法。提出了一种基于剪切应变的创新方法,通过数字图像相关性(DIC)监测双材料界面的模式 II 裂纹生长。利用虚拟裂缝闭合技术(VCCT)建立了三维有限元模型,并利用该模型获得应变能释放率(SERR),以研究几何非线性、界面摩擦和钢屈服的影响,并验证模式混合性。结果表明,标准的三点弯曲 ENF 试样在力控制下可能不稳定,在位移控制下通过一次试验就能扫过较窄的 SERR 范围。4 点弯曲 4ENF 试验显示出稳定的裂纹扩展和明显的 SERR 发展趋势。4ENF 试验存在更明显的几何非线性和摩擦效应,可通过非线性有限元模型解释巴黎曲线。


Vibration suppression of a meta-structure with hybridization of Kresling origami and waterbomb-based origami

Haizhou Shi, Kai Zhang, Xiangbing Liu, Hong Liu, Haijun Peng, Zichen Deng

doi:10.1016/j.compstruct.2024.117964

克瑞斯林折纸与水弹折纸杂交的元结构振动抑制技术

In recent years, the unfolding capability and vibration-isolation properties of spacecraft have received increasing attention. Several studies have achieved deployability through origami structures and low-frequency broadband vibration isolation using origami-inspired meta-structures(OIMs). However, traditional origami prototypes do not fully satisfy aerospace engineering requirements. In this study, a new origami-inspired meta-structure with low-frequency broadband vibration-isolation performance was proposed by combining the geometric characteristics of Kresling origami and waterbomb-based origami. The bandgap distribution and transmission rate of the OIMs were investigated through numerical simulations and a transient displacement study to evaluate the vibration-isolation performance of the OIMs. Modulation of the band structures by changing the geometric parameters was also examined. Experimental tests were conducted to demonstrate and validate the vibration-isolation properties of the proposed meta-structure. The transmission rate and bandgap results were in good agreement. Wider bandgaps are achieved through the gradient design, and the truss design makes OIMs more suitable for engineering applications. This study presents a new origami-inspired meta-structure that provides a strategy for application of origami in aerospace engineering.

近年来,航天器的展开能力和隔振特性日益受到关注。一些研究通过折纸结构实现了可展开性,并利用折纸启发元结构(OIM)实现了低频宽带隔振。然而,传统的折纸原型并不能完全满足航空航天工程的要求。本研究结合克瑞斯林折纸和水弹折纸的几何特性,提出了一种具有低频宽带隔振性能的新型折纸启发元结构。通过数值模拟和瞬态位移研究,研究了 OIM 的带隙分布和传输速率,从而评估了 OIM 的隔振性能。此外,还研究了通过改变几何参数对带状结构进行调制的问题。为证明和验证拟议元结构的隔振性能,还进行了实验测试。传输率和带隙结果非常吻合。通过梯度设计实现了更宽的带隙,而桁架设计则使 OIM 更适合工程应用。本研究提出了一种新的受折纸启发的元结构,为折纸在航空航天工程中的应用提供了一种策略。


Composites Part A: Applied Science and Manufacturing

Enhancing Oxidation Resistance of Carbon Fibre Reinforced Phenolic Composites by ZrO2 Nanoparticles through Out-of-autoclave Vacuum Infusion

Zhao Sha, Wenmu Yang, Cheng Wang, Mohammad S. Islam, Guan Heng Yeoh, David L. Officer, Warren Canning, Jin Zhang, Chun H. Wang

doi:10.1016/j.compositesa.2024.108071

通过釜外真空灌注 ZrO2 纳米粒子增强碳纤维增强酚醛复合材料的抗氧化性

This study reports a vacuum-assisted resin infusion method for achieving low-porosity carbon fibre/phenolic resin composites utilizing a low-viscosity (∼281 cp) phenolic resin enhanced by ZrO2 nanoparticles. The experimental results reveal that this method can yield composites with a low porosity of 8.6±2.5 % and average pore size of 3.8±1.73 μm, while demonstrating mechanical properties that fulfill the requirements for high-temperature structural applications, such as the nozzle of rocket motor. Moreover, the resultant composites exhibit distinct advantages over composites produced using other out-of-autoclave and autoclave methods investigated in this study in terms of flexural strength and modulus after oxidation treatment. The vacuum infusion approach retains higher resin content in composites than the autoclave method, leading to increased residual modulus post-oxidation. Furthermore, incorporating ZrO2 nanoparticles in the phenolic matrix has shown a significant potential in achieving increased residual mass, flexural strength, and flexural modulus of composites, notably after exposure to short-duration oxidation.

本研究报告了一种真空辅助树脂灌注方法,该方法利用纳米 ZrO2 增强的低粘度(∼281 cp)酚醛树脂实现低孔隙率碳纤维/酚醛树脂复合材料。实验结果表明,该方法可获得孔隙率为 8.6±2.5 %、平均孔径为 3.8±1.73 μm 的低孔隙率复合材料,同时其力学性能也能满足火箭发动机喷嘴等高温结构应用的要求。此外,就氧化处理后的弯曲强度和模量而言,与本研究中采用其他釜外法和釜内法生产的复合材料相比,所生产的复合材料具有明显优势。与高压釜法相比,真空灌注法在复合材料中保留了更高的树脂含量,从而提高了氧化后的残余模量。此外,在酚醛基质中加入 ZrO2 纳米粒子在增加复合材料的残余质量、抗弯强度和抗弯模量方面具有显著的潜力,尤其是在暴露于短时间氧化后。


Bending behaviors and toughening mechanism of carbon fiber-aluminum honeycomb sandwich structures with stitched fiber belts

Haipeng Yu, Hongjie Chen, Bingyi Liang, Zhi Sun, Xu Guo

doi:10.1016/j.compositesa.2024.108072

带缝合纤维带的碳纤维-铝蜂窝夹层结构的弯曲行为和增韧机理

Bending behaviors of carbon fiber-aluminum honeycomb sandwich structures, that are toughened by stitched fiber belts, are experimentally and numerically studied. It is found that the stitched fiber belts show potential to enhance the peak load of sandwich specimens by up to 44.3%, and to arrest interfacial crack growth. Firstly, FE models are proposed for the sandwich structures with stitched carbon fiber belts, and the FE models are verified by three-point bending tests. Secondly, the effects of stitched carbon fiber belts on bending behaviors of sandwich beam are studied. Combining the experimental and numerical results, the main toughening mechanism of stitched fiber belts is observed. The stitched fiber belts increase bonding area between face-sheets and honeycomb core, on one hand, and therefore enhance the interfacial strength. On the other hand, the angled fiber belts inside the core are found to enhance load bearing capacity and transverse shear stiffness.

实验和数值研究了通过缝合纤维带增韧的碳纤维-铝蜂窝夹层结构的弯曲行为。研究发现,缝合纤维带有可能将夹层试样的峰值载荷提高 44.3%,并阻止界面裂纹生长。首先,针对带有缝合碳纤维带的夹层结构提出了有限元模型,并通过三点弯曲试验验证了有限元模型。其次,研究了缝合碳纤维带对夹层梁弯曲行为的影响。结合实验和数值结果,观察了缝合纤维带的主要增韧机理。一方面,缝合纤维带增加了面层与蜂窝芯之间的粘合面积,从而提高了界面强度。另一方面,芯材内部的斜纤维带可提高承载能力和横向剪切刚度。


Composites Part B: Engineering

Reformable and sustainable thermosetting carbon fiber composites from epoxy vitrimer

Philip R. Barnett, Justin A. Brackenridge, Abigail A. Advincula, Laine A. Taussig, Dhriti Nepal

doi:10.1016/j.compositesb.2024.111270

环氧玻璃聚合物的可改造和可持续热固性碳纤维复合材料

Vitrimers are an emerging class of thermosetting materials that undergo reversible dynamic covalent bonding to enable thermoplastic-like repair, joining, and recycling that is currently inaccessible to traditional thermosets. This work demonstrates the production of sustainable recycled carbon fiber/epoxy based vitrimer composites. A method of preparing B-staged vitrimer films enabled infusion of the vitrimer into a fibrous preform using scalable compression molding techniques to form fully cured, room temperature stored organosheets that were then consolidated into laminates. The influence of consolidation time on the thermo-mechanical properties of the resulting composites was evaluated using several techniques. Short beam strength testing was used to evaluate the interlaminar properties of the composites and assess the repairability of tested specimens. Additional processing time was shown to stiffen the materials at room temperature, due to thermo-oxidative crosslinking as opposed to further thermal cure. This led to an initial improvement in the short beam strength, but a reduction in energy absorption and ductility. The results of this work show that vitrimer composites may be effective in extending the life of in-service composite structures by mitigating or repairing damage.

玻璃聚合物是一类新兴的热固性材料,可进行可逆的动态共价键合,从而实现类似热塑性塑料的修复、连接和回收,这是传统热固性材料目前无法实现的。这项研究展示了可持续再生碳纤维/环氧树脂基玻璃纤维复合材料的生产过程。采用一种制备 B 级玻璃聚合物薄膜的方法,利用可扩展的压缩成型技术将玻璃聚合物注入纤维预型件中,形成完全固化、室温储存的有机片材,然后将其加固成层压板。我们使用多种技术评估了固化时间对所得复合材料热机械性能的影响。短梁强度测试用于评估复合材料的层间性能,并评估测试试样的可修复性。结果表明,由于热氧化交联而非进一步的热固化,额外的加工时间可使材料在室温下更加坚硬。这使得短梁强度得到初步改善,但能量吸收和延展性有所降低。这项工作的结果表明,通过减轻或修复损坏,玻璃纤维复合材料可以有效延长在用复合材料结构的寿命。


Metal-electronegativity-induced sulfur-vacancies and heterostructures of MnS1-x/ZnS-NC@C with dual-carbon decoration for high-performance sodium-ion storage

Hongyu Zhang, Zhenjiang Lu, Baolin Liu, Chun Yuan, Yali Cao

doi:10.1016/j.compositesb.2024.111267

 

金属负电荷诱导的硫空位和具有双碳装饰的 MnS1-x/ZnS-NC@C 异质结构用于高性能钠离子存储

Engineering unique architectural anode electrode materials with high storage capacity and stable structures to balance kinetics and capacity between anode and cathode possesses a huge challenge for sodium-ion hybrid capacitors (SIHCs). Herein, beginning with well-organized MnS nanoparticles, an elaborate design of introducing metal-organic frameworks and decorating with dual-carbon is presented to fabricate a desirable composite of bimetallic sulfide and carbon with carbon matrix/coating layers via electronegativity induction. The simultaneously formed rich sulfur-vacancies and heterostructures can significantly boost fast electron/ion diffusion kinetics and induce high reversible sodium-ion storage capacities. Moreover, dual-carbon decoration tactics allow the electrodes for superior electronic conductivity, guarantee a splendid structural stability and offer an avenue for electron transport, which enable MnS1-x/ZnS-NC@C (MSZNC) composites a steady capacity of 354 mAh g−1 for 1600 cycles at a high rate of 10 A g−1 in sodium-ion batteries (SIBs). Integrated with theoretical calculations, the systemic electrochemical kinetic analytical results reveal that the synergistic effect of heterostructures and sulfur-vacancies can furnish more reversible active sites and boost charge transfer, thereby accelerating reaction kinetics for an enhanced sodium-ion storage capability. As expected, the assembled SIHCs full cell based on MSZNC anode and AC cathode exhibits a high energy density of 116 W h kg−1 and a high power output of 95 W kg−1, a capacity retention of 87% at 2 A g−1 for 2000 cycles, certifying its practical applications potential on a wide scale for sodium-based energy storage devices.

对于钠离子混合电容器(SIHC)来说,如何设计具有高存储容量和稳定结构的独特建筑阳极电极材料,以平衡阳极和阴极之间的动力学和容量,是一个巨大的挑战。本文从组织良好的 MnS 纳米颗粒入手,精心设计了引入金属有机框架和双碳装饰的方法,通过电负性诱导制造出理想的双金属硫化物和碳复合材料,并带有碳基质/涂层层。同时形成的丰富硫空位和异质结构可显著提高电子/离子的快速扩散动力学,并诱导出较高的可逆钠离子存储容量。此外,双碳装饰策略使电极具有卓越的电子传导性,保证了出色的结构稳定性,并为电子传输提供了途径,从而使 MnS1-x/ZnS-NC@C (MSZNC) 复合材料在钠离子电池(SIB)中以 10 A g-1 的高倍率循环 1600 次后,仍能保持 354 mAh g-1 的稳定容量。结合理论计算,系统电化学动力学分析结果表明,异质结构和硫空位的协同效应可以提供更多可逆活性位点并促进电荷转移,从而加速反应动力学以增强钠离子存储能力。正如预期的那样,基于 MSZNC 阳极和交流阴极组装的 SIHCs 全电池表现出 116 W h kg-1 的高能量密度和 95 W kg-1 的高功率输出,在 2 A g-1 循环 2000 次的情况下容量保持率为 87%,这证明了其在钠基储能设备方面的广泛实际应用潜力。


Composites Science and Technology

Fabrication of knitted Polyethylene/SiO2 composite membrane modules for one-step microfiltration and particle removal in wastewater treatment

Dan Guo, Jianguo Xu, Xiaodong Zhang, Ngie Hing Wong, Jaka Sunarso, Shaomin Liu, Nana Li

doi:10.1016/j.compscitech.2024.110479

 

编织聚乙烯/二氧化硅复合膜组件,用于废水处理中的一步式微滤和颗粒去除

Sewage treatment efficiency is affected by the membrane module design. In this study, SiO2 was employed as additives in the formation of polyethylene/SiO2 hollow fibre composite membranes using the thermally induced phase separation (TIPS) method. This approach effectively addressed the limitations of pure polyethylene hollow fibres, such as poor network pore structure and low flux. The investigation revealed that the addition of SiO2 enhanced gas flux by 30%, increased porosity by 20%, and provided a commendable tensile strength of 2.1 MPa, suitable for weaving knitted composite membrane module. The voids of the membrane module facilitated particle filtration and microfiltration through micropores of the composite membrane, successfully integrated into a one-step wastewater treatment process. The knitted composite membrane module's particle filtration process effectively intercepted all particles A (30 μm), and the microfiltration process rejected particles B (1.3 < size <15 μm). During these processes, the rejection rate of talc powder in the membrane module was as high as 90%, and the gas flux was remained at 1200 L m−2∙min−1. The strategy of knitted composite membrane modules demonstrates versatility in applications and has the potential for expanding the design to various microporous hollow fibre materials for diverse separation purposes.

污水处理效率受膜组件设计的影响。本研究采用热诱导相分离(TIPS)法,将二氧化硅作为添加剂用于聚乙烯/二氧化硅中空纤维复合膜的形成。这种方法有效地解决了纯聚乙烯中空纤维的局限性,如网络孔隙结构差和通量低。研究表明,加入二氧化硅后,气体通量提高了 30%,孔隙率增加了 20%,抗拉强度达到 2.1 兆帕,适合编织针织复合膜组件。膜组件的空隙有利于通过复合膜的微孔进行颗粒过滤和微过滤,成功地集成到一步式污水处理工艺中。针织复合膜组件的颗粒过滤过程有效地拦截了所有颗粒 A(30 μm),而微滤过程则剔除了颗粒 B(1.3 < 粒径 <15 μm)。在这些过程中,膜组件对滑石粉的截留率高达 90%,气体通量保持在 1200 L m-2∙min-1。编织复合膜组件的策略展示了应用的多样性,并有可能将设计扩展到各种微孔中空纤维材料,以实现不同的分离目的。


Flexible phase change composites with multiple colors and reversible thermochromic for temperature indication and battery thermal management

Yujiao Li, Zhuoni Jiang, Yongsheng Li, Fangfang He, Zhengguo Chen, Xiaoan Li, Peng Wang, Guansong He, Wenbin Yang

doi:10.1016/j.compscitech.2024.110481

 

具有多种颜色和可逆热致变色功能的柔性相变复合材料,用于温度指示和电池热管理

In this paper, a series of silicone rubber (SR)/thermochromic microcapsules (TC@MF)/cuprous oxide (Cu2O) flexible phase change composites (STC) with multi-colors and reversible thermochromic were prepared. In this composite, SR was used as polymer matrix and TC@MF with phase change enthalpy of 193 J/g was used as functional filler. Moreover, different contents of Cu2O were introduced to change color of composites and improve thermal conductivity and photothermal conversion. The STC composites could undergo reversible color changes from blue-violet to red with a color change temperature of approximately 52 °C. And it exhibited excellent leakage resistance with the leakage rate of STC-2 as low as 0.41%. The thermal conductivity of the STC-3 composite reached 0.33 W m−1 K−1 at Cu2O content of 9 phr. The STC composites were applied to dissipate heat from the battery and the maximum surface temperature was only 49.0 °C at 9.8 A discharge rate which represented 24.03 % reduction in surface temperature compared to the bare battery. This work offers an effective route for preparation of battery thermal regulation materials based on thermochromic microcapsules, which has significant potential for application in the field of battery thermal management.

本文制备了一系列具有多色和可逆热致变色功能的硅橡胶(SR)/热致变色微胶囊(TC@MF)/氧化亚铜(Cu2O)柔性相变复合材料(STC)。在该复合材料中,SR 用作聚合物基体,相变焓为 193 J/g 的 TC@MF 用作功能填料。此外,还引入了不同含量的 Cu2O,以改变复合材料的颜色,并提高热导率和光热转换率。STC 复合材料可以实现从蓝紫色到红色的可逆变色,变色温度约为 52 ℃。此外,STC-2 还具有出色的抗泄漏性能,泄漏率低至 0.41%。当 Cu2O 含量为 9 phr 时,STC-3 复合材料的热导率达到 0.33 W m-1 K-1。STC 复合材料用于电池散热,在放电率为 9.8 A 时,最大表面温度仅为 49.0 °C,与裸电池相比,表面温度降低了 24.03%。这项工作为制备基于热致变色微胶囊的电池热调节材料提供了一条有效途径,在电池热管理领域具有巨大的应用潜力。


Advanced composite armor protection systems for military vehicles: Design methodology, ballistic testing, and comparison

Evangelos Tsirogiannis, Evangelos Daskalakis, Christos Vogiatzis, Foivos Psarommatis, Paulo Bartolo

doi:10.1016/j.compscitech.2024.110486

 

军用车辆的先进复合装甲防护系统:设计方法、弹道测试和比较

This study presents a new methodology for designing, manufacturing, and testing advanced armor protection systems and applied to the development of three different protection solutions suitable for real armored vehicles. The backplate laminates of the presented composite armor protection solutions were composed of three different materials: steel, aluminum AA6082, and aluminum alloy AA2024 reinforced by multi-walled carbon nanotubes (MWCNTs). The frontal laminates remained the same for the three cases. Keeping almost the same mass while changing the material of each backplate and adapting the thickness, the three different protection systems were ballistically tested and compared according to Level 4 (Level IV) of the standard AEP-STANAG 4569 (projectile 14.5 mm × 114 mm API B32) with real military tests. Furthermore, the performance of the total laminated structure and the performance of each backplate in the total laminated structure were compared in terms of deformation and ballistic fractures. High-quality images acquired by the high-speed camera were helpful in evaluating and comparing the backplates and the entire protection system. The results show that all three protection configurations present high performance mechanical properties and ballistic characteristics compared to commonly used armor systems. Even the under-developed AA2024-CNTs composite is a promising near-term backplate solution.

本研究介绍了一种设计、制造和测试先进装甲防护系统的新方法,并将其应用于开发适合真实装甲车辆的三种不同防护解决方案。所介绍的复合装甲防护解决方案的背板层压板由三种不同的材料组成:钢、铝 AA6082 和由多壁碳纳米管(MWCNTs)增强的铝合金 AA2024。三种方案的正面层压板保持不变。在改变背板材料和厚度的同时,保持几乎相同的质量,对三种不同的防护系统进行了弹道测试,并根据 AEP-STANAG 4569 标准第 4 级(第 IV 级)(射弹 14.5 毫米 × 114 毫米 API B32)与实际军事测试进行了比较。此外,还从变形和弹道断裂的角度对整体层压结构的性能和整体层压结构中每块背板的性能进行了比较。高速摄像机获得的高质量图像有助于评估和比较背板和整个保护系统。结果表明,与常用的装甲系统相比,所有三种防护配置都具有高性能的机械性能和弹道特性。即使是尚未充分开发的 AA2024-CNTs 复合材料也是一种很有前景的近期背板解决方案。


Experimental method for in-situ real-time measurement of mixed mode fibre/matrix interface debonding and comparison of fibre sizings in single short fibre composites

Mehdi Nikforooz, Olivier Verschatse, Lode Daelemans, Karen De Clerck, Wim Van Paepegem

doi:10.1016/j.compscitech.2024.110488

 

原位实时测量混合模式纤维/基体界面脱胶的实验方法以及单根短纤维复合材料中纤维尺寸的比较

In short fibre composites, off-axis fibres are potentially subject to mixed-mode loading, which results in interactive debonding growth in opening and sliding modes. This synergy might differ for strong and weak fibre/matrix bondings inducing discrete debonding patterns. This study employed an optical visualization technique to investigate, for the first time, the mixed-mode debonding growth for short fibres with different sizings and off-axis angles, through in-situ real-time measurements. For this purpose, embedded single short-fibre specimens were fabricated using E-glass fibres and an epoxy matrix, with a novel and more efficient manufacturing method than done so far in literature. E-glass fibres with two different sizings were utilized, including a polypropylene-compatible (weak) sizing and an epoxy-compatible (strong) sizing. While there was a relatively rapid debonding growth for the transverse fibres with the weak sizing, the strong sizing experienced a gradual debonding growth independent of the fibre angle. For the weak sizing, partial debonding cracks were initiated at different locations along the length of the fibres, where they coalesced into dominant debonding cracks. For the strong sizing, debonding was always initiated and localized at the fibre tip, and there was a clear synchronous propagation of debonding in the arc and length of the fibre.

在短纤维复合材料中,偏离轴线的纤维可能会受到混合模式加载的影响,从而导致开放模式和滑动模式下的交互脱粘增长。这种协同作用可能会因纤维/基体粘合力的强弱而不同,从而诱发离散的脱粘模式。本研究采用光学可视化技术,通过原位实时测量,首次研究了不同尺寸和离轴角的短纤维的混合模式脱胶增长。为此,我们使用 E 玻璃纤维和环氧树脂基体制作了嵌入式单根短纤维试样,与迄今为止的文献相比,这种制作方法更新颖、更高效。使用了两种不同规格的 E 玻璃纤维,包括聚丙烯相容(弱)规格和环氧树脂相容(强)规格。采用弱施胶的横向纤维脱胶相对较快,而采用强施胶的横向纤维则逐渐脱胶,与纤维角度无关。对于弱施胶,部分脱胶裂纹开始出现在纤维长度的不同位置,并在这些位置凝聚成主要的脱胶裂纹。对于强施胶,脱胶总是在纤维顶端开始并局部出现,脱胶在纤维的弧度和长度上明显同步扩展。


Honeycomb-like Polyimide/Fe3O4@PPy foam for electromagnetic wave shielding with excellent absorption characteristics

Wei Chu, Jianwei Li, Jun Lin, Wen Li, Jiazhi Xin, Fei Liu, Xinhai He, Zhonglei Ma, Qiangli Zhao

doi:10.1016/j.compscitech.2024.110489

 

用于电磁波屏蔽的蜂窝状聚酰亚胺/Fe3O4@PPy 泡沫,具有优异的吸收特性

Electromagnetic interference (EMI) shielding materials with low reflection and excellent microwave absorption characteristics are highly desirable for high-speed electronics devices to attenuate radiated emissions. Herein, we developed a highly absorption dominated composite EMI shielding foams with “honeycomb” structure through chemical foaming and subsequent in situ vapor deposition of polypyrrole (PPy) within polyimide (PI) foams. After the deposition of PPy, the obtained porous PI foams exhibit electrical conductivity of 2.7 × 103 S/m. In addition, the composite foams demonstrate the highest absorption coefficient of 0.8 and EMI shielding efficiency of 41.1 dB with a thickness of 8 mm. Moreover, the optimal reflection loss (RL) of the composite PI/Fe3O4-20@PPy foam (PF/Fe3O4-20@PPy) reach up to −31 dB at 6.0 mm and ≤ −10 dB in the whole X band with a thickness of ≥4 mm. Moreover, the 3D porous structure of PI foam and favorable electrical conductivity of in-situ formed PPy film can contribute to the high sensing performance of PI@PPy foam (PF@PPy). This study provides a novel strategy for the development of lightweight, EMI shielding and microwave absorption materials for advanced applications in flexible anti-radiation and stealth devices.

具有低反射和优异微波吸收特性的电磁干扰(EMI)屏蔽材料是高速电子设备衰减辐射发射的理想材料。在此,我们通过化学发泡,并随后在聚酰亚胺(PI)泡沫中原位气相沉积聚吡咯(PPy),开发出一种具有 "蜂窝 "结构的高吸收主导型复合 EMI 屏蔽泡沫。沉积 PPy 后,得到的多孔 PI 泡沫的导电率达到 2.7 × 103 S/m。此外,复合泡沫的吸收系数最高,为 0.8,EMI 屏蔽效率为 41.1 dB(厚度为 8 毫米)。此外,PI/Fe3O4-20@PPy 复合泡沫(PF/Fe3O4-20@PPy)的最佳反射损耗(RL)在 6.0 mm 时高达 -31 dB,厚度≥4 mm 时整个 X 波段的最佳反射损耗(RL)≤ -10 dB。此外,PI 泡沫的三维多孔结构和原位形成的 PPy 薄膜良好的导电性也有助于 PI@PPy 泡沫(PF@PPy)实现高传感性能。这项研究为开发轻质、电磁干扰屏蔽和微波吸收材料提供了一种新的策略,可用于柔性抗辐射和隐形设备的高级应用。



来源:复合材料力学仿真Composites FEM
ACTMechanicalAdditiveOpticalSystem振动疲劳断裂复合材料非线性化学航空航天建筑电子裂纹BIM理论化机材料
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【新文速递】2024年2月10日复合材料SCI期刊最新文章

今日更新:Composite Structures 3 篇,Composites Part A: Applied Science and Manufacturing 4 篇,Composites Part B: Engineering 2 篇,Composites Science and Technology 1 篇Composite StructuresInterface microstructures and mechanical properties of foamable precursor sandwiches and aluminum foam sandwichesShijie Yang, Hongjie Luo, Li Wang, Jie Wu, Yongliang Mu, Linli Wudoi:10.1016/j.compstruct.2024.117961可发泡前驱体夹层和泡沫铝夹层的界面微结构和机械性能In this paper, the aluminum foam sandwich (AFS) was obtained from foamable precursor sandwich (FPS) through a foaming process, in which the preparation of FPS was achieved by compound casting with hot rolling. The effects of rolling and foaming on the interface microstructures and mechanical properties were investigated. Furthermore, the interface bonding mechanisms and strengthening mechanisms were revealed. For FPSs, increasing the rolling pass increased the interface thermodynamic energy, which was beneficial to the achievement of a more effectively bonded interface. Meanwhile, the grains were refined, the fractions of low angle grain boundaries (fLGABs) and average geometrically necessary dislocation density (ρ¯GND) at the interface increased, which collectively contributed to the enhancement of interface bonding strength and ductility. In the foaming process, although the interface thermodynamic energy led to a reduction in the original interface defects and an enhancement in elements diffusion at the pre-existing well-bonded interface, AFSs displayed lower interface bonding strength and ductility compared to their corresponding FPSs due to coarse grains, decreased fLGABs and ρ¯GND. Moreover, an analysis of interface strengthening mechanisms revealed that the increase of rolling pass for FPS resulted in an improvement in the interface bonding strength and ductility of the corresponding AFS.本文通过发泡工艺从可发泡前驱体夹层(FPS)中获得了泡沫铝夹层(AFS),其中 FPS 的制备是通过热轧复合铸造实现的。研究了轧制和发泡对界面微结构和机械性能的影响。此外,还揭示了界面结合机制和强化机制。对 FPS 而言,增加轧制道次可提高界面热力学能量,有利于实现更有效的界面结合。同时,晶粒细化,界面上的低角度晶界分数(fLGABs)和平均几何必要位错密度(ρ¯GND)增加,共同促进了界面结合强度和延展性的提高。在发泡过程中,虽然界面热力学能导致原始界面缺陷减少,元素在原有良好结合界面的扩散增强,但与相应的 FPS 相比,AFSs 由于晶粒粗大、fLGABs 和 ρ¯GND 减少而显示出较低的界面结合强度和延展性。此外,对界面强化机制的分析表明,增加 FPS 的轧制次数可提高相应 AFS 的界面结合强度和延展性。Multi-stimulus responsive shape memory polyurea incorporating stress-mismatching structure for soft actuators and reversible deployable structuresWen Liu, Deyan Kong, Wei Zhao, Jinsong Lengdoi:10.1016/j.compstruct.2024.117966采用应力失配结构的多刺 激响应型形状记忆聚脲,用于软促动器和可逆展开结构Shape memory polymer (SMP) has demonstrated practical applications, including aerospace structures, medical devices, and flexible electronics. The programmability and controllability provide essential convenience for many device applications. Imperfectly, once a programmed temporary shape is deployed into a permanent shape, it cannot recover to the programmed shape without being reprogrammed. Here, through differential thermal expansion material synergistic design constructing stress-mismatching structure. The bilayer actuator is constructed, featuring excellent mechanical strength and toughness, responsive to light, humidity and electric field. the multi-dimensional cross layers of carbon material and intrinsic humidity response of shape memory polyurea (SMPU) is an active layer and PET is a passive layer. The bilayer actuator bends 140 ° within 5 s under 30 V voltage and recovers quickly within 20 s. Controlling the angle of light, the wheeled robot could crawl back and forth 20 cm, also achieving the bionic actuators, and deployable structures with an automatic roll-unfold.形状记忆聚合物(SMP)已在航空航天结构、医疗设备和柔性电子产品等领域得到实际应用。可编程性和可控性为许多设备应用提供了必要的便利。不完美的是,一旦编程的临时形状变成永久形状,如果不重新编程,就无法恢复到编程形状。在此,我们通过热膨胀材料差协同设计来构建应力错配结构。碳材料的多维交叉层和形状记忆聚脲(SMPU)的固有湿度响应是主动层,PET 是被动层。双层致动器在 30 V 电压下 5 秒内弯曲 140 °,20 秒内迅速恢复。控制光的角度,轮式机器人可前后爬行 20 厘米,还实现了仿生致动器,以及可自动翻滚展开的可部署结构。Anisotropic hygrothermal fracture mechanics in orthotropic materials: A novel efficient interpolating modified MLS-based EFGM employing radial basis functionS.K. Lohit, Amar K. Gaonkar, Tejas P. Gotkhindidoi:10.1016/j.compstruct.2024.117968正交各向异性材料中的各向异性湿热断裂力学:采用径向基函数的基于 MLS 的新型高效插值修正 EFGMA novel Wendland’s radial basis function (RBF) based Interpolating Modified MLS-based (IMMLS) technique in EFGM is proposed and demonstrated in this work. Anisotropic Hygrothermoelastic Fracture Mechanics (AHFM) problems with orthotropic material model are employed to illustrate Wendland’s RBF-based IMMLS technique and, in addition, to address the research gap in EFGM fomulations for these problems. The Wendland’s RBF-based IMMLS EFGM, like IMMLS EFGM incorporating regularised weight functions (RWF), results in interpolating shape functions which address the limitations of classical MLSA-based EFGM. To assess efficacy, an illustrative case is benchmarked with FEM. For all the EFG techniques — formulated using Wendland’s RBF, RWFs, and classical MLSA-based EFGM, L2 norm results show a good correspondence with FEM. Subsequently, a comparative study among various EFG techniques is undertaken for Mode 1 and Mixed-mode cases incorporating regular and irregular nodal configurations. In comparison to the classical MLSA-based EFGM, IMMLS results employing Wendland’s RBF and RWFs corroborate closely with FEM results and show better computational efficiency. On the other hand, Wendland’s RBF-based IMMLS yields results similar to RWF-based IMMLS with nearly similar computational efficiency and advantages. Thus, Wendland’s RBF-based IMMLS extends the class of IMMLS techniques and offers a potential tool to solve fracture mechanics problems.本研究提出并演示了一种新颖的基于 Wendland 径向基函数(RBF)的 EFGM 互推修正 MLS(IMMLS)技术。本文采用了具有正交材料模型的各向异性热弹性断裂力学(AHFM)问题来说明基于 Wendland RBF 的 IMMLS 技术,并解决了针对这些问题的 EFGM 仿真方面的研究空白。Wendland 基于 RBF 的 IMMLS EFGM 与包含正则化权重函数 (RWF) 的 IMMLS EFGM 一样,都能产生内插形状函数,从而解决基于 MLSA 的经典 EFGM 的局限性。为了评估效果,我们用有限元模型对一个示例进行了基准测试。对于所有 EFG 技术(使用 Wendland 的 RBF、RWF 和基于 MLSA 的经典 EFGM),L2 准则结果显示与 FEM 有很好的对应关系。随后,针对包含规则和不规则节点配置的模式 1 和混合模式情况,对各种 EFG 技术进行了比较研究。与经典的基于 MLSA 的 EFGM 相比,采用 Wendland 的 RBF 和 RWF 的 IMMLS 结果与有限元结果非常吻合,并显示出更高的计算效率。另一方面,基于 Wendland RBF 的 IMMLS 与基于 RWF 的 IMMLS 得出的结果相似,计算效率和优势几乎相近。因此,Wendland 基于 RBF 的 IMMLS 扩展了 IMMLS 技术的类别,为解决断裂力学问题提供了一种潜在的工具。Composites Part A: Applied Science and ManufacturingPolydopamine interface-modulated MXene-based conductive antibacterial hydrogels for on-skin health monitoring and diabetic wound healingDandan Liu, Siwei Bi, Haibo Wang, Jun Gu, Shuang Wangdoi:10.1016/j.compositesa.2024.108065用于皮肤健康监测和糖尿病伤口愈合的聚多巴胺界面调制 MXene 导电抗菌水凝胶Flexible health management systems integrating health monitoring and wound healing capabilities are highly desirable. Electronic skins (E-skins) based on conductive antibacterial hydrogels are an ideal platform for building flexible health management systems. Here, a multifunctional E-skin is designed based on a conductive, antibacterial, biocompatible, self-adhesive, and stretchable hydrogel (PPMAg). The PPMAg hydrogel is developed by combining a surface-modified MXene nanocomposite (PMAg) with a P(AM-co-SBMA) matrix. The PMAg nanocomposite is designed in a heterostructured configuration by depositing Ag nanoparticles on the polydopamine interface-modulated MXene nanosheets. The PPMAg-based E-skin, with a wide operating range, high sensitivity, good reproducibility, rapid responsiveness and resilience, can detect various human motions, facial expressions, and in vivo heartbeat signals. Moreover, the E-skin can also promote diabetic wound healing under electrical stimulation. Thus, this study indicates that the designed E-skin system has great potential to serve as a promising platform for the next generation flexible health management systems.集健康监测和伤口愈合功能于一体的灵活健康管理系统非常受欢迎。基于导电抗菌水凝胶的电子皮肤(E-skin)是构建灵活健康管理系统的理想平台。本文设计了一种基于导电、抗菌、生物相容性、自粘性和可拉伸水凝胶(PPMAg)的多功能电子皮肤。PPMAg 水凝胶是通过将表面改性的 MXene 纳米复合材料(PMAg)与 P(AM-co-SBMA)基质相结合而制成的。通过在聚多巴胺界面修饰的 MXene 纳米片上沉积银纳米粒子,PMAg 纳米复合材料被设计成异质结构。基于 PPMAg 的电子皮肤具有工作范围广、灵敏度高、重现性好、响应速度快和复原能力强等特点,可以检测人体的各种动作、面部表情和活体心跳信号。此外,电子皮肤还能在电刺 激下促进糖尿病伤口愈合。因此,这项研究表明,所设计的电子皮肤系统具有巨大潜力,有望成为下一代灵活健康管理系统的平台。Fabrication of polydopamine-coated ZIF-67 derived Co@CN/rGO composite with excellent electromagnetic wave absorption propertiesCankun Ma, Shuojue Wang, Siyi Xie, Mengfei Yuan, Yicheng Wang, Jing Peng, Jie Kong, Maolin Zhai, Huiling Ma, Xiuqin Zhangdoi:10.1016/j.compositesa.2024.108066 制备具有优异电磁波吸收特性的聚多巴胺涂层 ZIF-67 衍生 Co@CN/rGO 复合材料Constructing a reasonable microstructure and component modulation is considered as an effective way to improve the absorption performance of the absorbents. Herein, a series of Co@CN/rGOs composites were obtained via simple pyrolysis of dopamine-coated ZIF-67 loaded graphene oxide (ZIF-67@PDA/GO) at a high temperature. The existence of rGO after thermal treatment effectively improved dielectric loss. The multiple heterogeneous interfaces between rGO and the carbon layers formed by the polydopamine pyrolysis facilitated the interfacial polarization and relaxation. As a result, with only 20 wt% filler content, the RLmin value of Co@CN/10%rGO reached -49.98 dB at 5.50 GHz (low frequency) with a thickness of 4.5 mm. The effective absorption bandwidth increased to 5.70 GHz (10.26-15.96 GHz) by adjusting the thickness to 2.3 mm. This work provides a facile method for the construction of multicomponent nonhomogeneous interfaces and offers a novel strategy for the design of efficient absorbents.构建合理的微观结构和组分调制被认为是提高吸收剂吸收性能的有效方法。在此,我们通过在高温下简单热解多巴胺包覆的 ZIF-67 氧化石墨烯(ZIF-67@PDA/GO),得到了一系列 Co@CN/rGOs 复合材料。热处理后 rGO 的存在有效改善了介电损耗。rGO 与多巴胺热解形成的碳层之间的多重异质界面促进了界面极化和弛豫。因此,在填料含量仅为 20 wt% 的情况下,RLmin值达到了 -49.98 dB,频率为 5.50 GHz(低频),厚度为 4.5 mm。将厚度调整到 2.3 mm 时,有效吸收带宽增加到 5.70 GHz(10.26-15.96 GHz)。这项研究为构建多组分非均质界面提供了一种简便的方法,并为设计高效吸波材料提供了一种新的策略。Vascular Carbon/Carbon composites for concentrated solar powerJose C. Cordeiro, Matt Zuzelski, Mark H. Olima, Daniel W. Crunkleton, Todd Otanicar, Hema Ramsurn, Michael W. Kellerdoi:10.1016/j.compositesa.2024.108069用于聚光太阳能发电的维管束碳/碳复合材料Due to their exceptional mechanical and thermal properties under high temperature conditions, for the first time, a novel vascular (embedded channels) Carbon/Carbon (C/C) composite was developed for use as a modular concentrated solar power (CSP) gas receiver. The fabrication process involves the combination of the vaporization of sacrificial component (VaSC) technique with conventional methods to produce C/C composites with well preserved channels. Different heat treatments were evaluated together with X-ray diffraction (XRD) analysis to determine optimal fabrication conditions that maintains the material and channel’s integrity. Mechanical testing confirms that structural integrity is maintained, with statistical analyses indicating no compromise in flexural strength or modulus. This research introduces an innovative pathway for efficient CSP gas receivers, which can bridge the gap towards improved energy generation efficiency in next-gen CSP plants through higher operating temperatures with the use of C/C composites.由于碳/碳(C/C)复合材料在高温条件下具有优异的机械性能和热性能,我们首次开发出一种新型血管(嵌入式通道)碳/碳(C/C)复合材料,可用作模块化聚光太阳能(CSP)气体接收器。制造工艺包括将牺牲部件气化(VaSC)技术与传统方法相结合,生产出具有完好保存通道的碳/碳复合材料。对不同的热处理和 X 射线衍射 (XRD) 分析进行了评估,以确定保持材料和通道完整性的最佳制造条件。机械测试证实,结构的完整性得以保持,统计分析表明,抗弯强度或模量没有受到影响。这项研究为高效的 CSP 气体接收器引入了一条创新途径,通过使用 C/C 复合材料提高工作温度,为提高下一代 CSP 发电厂的发电效率架起了一座桥梁。A mesoscopic model for inter-yarn frictionA.N. Vu, W.J.B. Grouve, M.B. de Rooij, R. Akkermandoi:10.1016/j.compositesa.2024.108070纱线间摩擦的中观模型Friction between yarns is a crucial phenomenon in fabric manufacturing processes, and it becomes more complex when using lubrication agents to improve processing. This work presents an experimental investigation of the frictional behaviour of different combinations of yarns under dry and wet conditions, as occurring in overbraiding processes. The experiments were designed to maintain a constant yarn tension, and subsequently also a constant normal force and contact area during the test. Both the inter-yarn angle and the normal force significantly influence the friction coefficient. The additional contribution of the capillary force results in consistently higher friction coefficients for the water-lubricated yarns compared to the dry yarns. An anisotropic friction model is proposed to capture the influence of the inter-yarn angle, normal force, and capillary effects observed during the experiments. The model shows that the friction follows Amontons’ friction at high external normal forces and Howell’s friction at moderate normal forces.纱线之间的摩擦是织物生产过程中的一个重要现象,当使用润滑剂来改善加工过程时,这一现象变得更加复杂。这项工作介绍了对不同纱线组合在干湿条件下的摩擦行为进行的实验研究,就像在包边工艺中出现的情况一样。实验旨在保持恒定的纱线张力,并在测试过程中保持恒定的法向力和接触面积。纱线间角度和法向力对摩擦系数都有很大影响。毛细力的额外作用使得水润滑纱线的摩擦系数始终高于干纱。我们提出了一个各向异性的摩擦模型,以捕捉实验中观察到的纱线间角度、法向力和毛细管效应的影响。该模型显示,在高外部法向力时,摩擦力遵循阿蒙顿摩擦力,而在中等法向力时,摩擦力遵循豪厄尔摩擦力。Composites Part B: EngineeringEnhancing the electromagnetic interference shielding of epoxy resin composites with hierarchically structured graphite/MXene aerogelZhongjie He, Weirui Zhang, Jing Zhang, Jinliang Xie, Fangfang Su, Yuchen Li, Dongdong Yao, Yudeng Wang, Yaping Zhengdoi:10.1016/j.compositesb.2024.111230用分层结构石墨/MXene 气凝胶增强环氧树脂复合材料的电磁干扰屏蔽性能Graphene aerogels (GAs) exhibits immense potential in the field of electromagnetic interference (EMI) shielding due to their ultralow density, inherent conductive network, and porous structure. However, the optimization of structure and conductivity of GAs remains a significant challenge. To address this issue, a double template method was utilized to regulate the structure of graphene aerogel, resulting in a well-ordered hierarchical architecture. Subsequently, MXene was deposited on the surface of GA-1 through an immersion method to enhance the conductivity. The as-prepared MXene/graphene composite aerogel (MGA-10) showed excellent compression properties with ultra-high specific stress of 9.6 kPa cm3 mg−1 at 80% strain. Besides, due to the unique structure, the GA-x/epoxy composite (GA-x/EP) demonstrated excellent EMI shielding performances of more than 45 dB in both the C-band and X-band. The increase in conductivity and the introduction of new interfaces caused by MXene deposition further improved the EMI properties of MGAs/EP. After 10 times of deposition, MGA-10/EP displayed an impressive EMI performance above 68 dB in both the C-band and X-band. Moreover, MGA-10/EP exhibited excellent photothermal conversion performance, making it highly suitable for applications such as anti-icing and deicing. This work provides a valuable idea for designing efficient EMI materials.石墨烯气凝胶(GAs)因其超低密度、固有导电网络和多孔结构,在电磁干扰(EMI)屏蔽领域展现出巨大潜力。然而,如何优化 GAs 的结构和导电性仍然是一个重大挑战。为了解决这个问题,我们采用了双模板法来调节石墨烯气凝胶的结构,从而形成了一种有序的分层结构。随后,通过浸渍法在 GA-1 表面沉积了 MXene,以增强导电性。制备出的MXene/石墨烯复合气凝胶(MGA-10)显示出优异的压缩性能,在80%应变下具有9.6 kPa cm3 mg-1的超高比应力。此外,由于其独特的结构,GA-x/环氧复合材料(GA-x/EP)在 C 波段和 X 波段均表现出超过 45 dB 的优异电磁干扰屏蔽性能。MXene 沉积带来的电导率增加和新界面的引入进一步改善了 MGAs/EP 的 EMI 性能。经过 10 次沉积后,MGA-10/EP 在 C 波段和 X 波段的 EMI 性能均超过 68 dB,令人印象深刻。此外,MGA-10/EP 还具有优异的光热转换性能,因此非常适合防冰和除冰等应用。这项研究为设计高效的 EMI 材料提供了宝贵的思路。Bio-based pH-responsive microcapsules derived from Schiff base structures for acid rain protectionQin Chen, Aonan Zhang, Cheng Hao, Limin Guo, Long Bai, Jiyou Gu, Ning Yandoi:10.1016/j.compositesb.2024.111289 源自希夫碱结构的生物基 pH 响应微胶囊用于酸雨防护Self-healing technology based on microcapsules (MCs) holds great promise for preventing material performance deterioration, extending material lifespan, and reducing maintenance costs. In this study, a novel pH-responsive MC with a vanillin-based Schiff base polyurea shell and an isocyanate core was successfully prepared using interfacial polymerization. Vanillin-based Schiff base-containing triamines were synthesized, and their existence was confirmed through ATR-FTIR and 1H NMR analyses. The core-shell structures of the MCs were identified using FTIR and TGA. Additionally, the excellent response of the MCs to acid rain was demonstrated by determining the core content and recording optical images of the healing agent release process, with the fastest release rate observed at a pH of 2.98. According to the FTIR and TGA results, the release of the healing agent was continuous rather than occurring once. The MCs were incorporated into outdoor building materials (OBMs) (carbon steel, concrete, and wood) as a coating in conjunction with paint or polyvinyl alcohol (PVA). The pressure response, hydrogen bonding response, and hydrophobicity of the composite coating were assessed using SEM and water contact angle measurements. After subjecting the materials to 50 cycles of acid rain wet-dry tests (pH = 5.03), the carbon steel remained largely rust-free, whereas untreated carbon steel could only withstand a single cycle. Consequently, this study highlights a novel green structure and scalable manufacturing process for functional self-healing MCs, with significant implications for the advancement of stimulus-responsive composite materials and the realization of a sustainable and environmentally friendly economy.基于微胶囊(MC)的自修复技术在防止材料性能退化、延长材料寿命和降低维护成本方面大有可为。本研究采用界面聚合法成功制备了一种新型 pH 响应 MC,它具有香兰素基席夫基聚脲外壳和异氰酸酯内核。合成了含香兰素基席夫碱三胺,并通过 ATR-FTIR 和 1H NMR 分析证实了它们的存在。利用傅立叶变换红外光谱和热重分析确定了 MCs 的核壳结构。此外,通过测定核心含量和记录愈合剂释放过程的光学图像,证明了 MCs 对酸雨的卓越响应,在 pH 值为 2.98 时释放速度最快。根据傅立叶变换红外光谱和热重分析结果,愈合剂的释放是连续的,而不是一次性的。MCs 作为涂层与涂料或聚乙烯醇(PVA)一起加入室外建筑材料(OBM)(碳钢、混凝土和木材)中。利用扫描电镜和水接触角测量法评估了复合涂层的压力响应、氢键响应和疏水性。在对材料进行 50 次酸雨湿-干试验(pH = 5.03)后,碳钢基本上没有生锈,而未经处理的碳钢只能承受一次酸雨湿-干试验。因此,本研究强调了功能性自修复 MC 的新型绿色结构和可扩展制造工艺,对刺 激响应型复合材料的发展和实现可持续环保经济具有重要意义。Composites Science and TechnologyMultifunctional syndiotacticity-rich poly (vinyl alcohol)/MXene sediment for multilayered composite films with effective electromagnetic interference shielding and thermal conductivityFan Kang, Jiayu Wang, Ge Huang, Qunyang Li, Yongjun Chen, Zhixin Jia, Hui He, Demin Jiadoi:10.1016/j.compscitech.2024.110490 多功能富含辛迪加活性的聚(乙烯醇)/MXene 沉积物,用于制造具有有效电磁干扰屏蔽和导热性能的多层复合薄膜Utilizing remarkable polymer matrix and efficient filler to propose an ingenious strategy for designing composite films synergistically with high electromagnetic interference shielding effectiveness (EMI SE) and thermal conductivity. Herein, a novel type of flexible composite film based on syndiotacticity-rich poly (vinyl alcohol) (sPVA)/modified MXene sediment (mMS) is fabricated through an alternating casting approach. The sPVA/mMS multilayered film containing effective noncovalent combining between sPVA layer and mMS layer not only presents a high strength of ∼66.3 MPa but also possesses a superior electrical conductivity of 683 S/m. Notably, the mMS layer with dense conductive and thermal networks endows the 95-μm-thick composite film with the synergy of favorable EMI SE (∼15.8 dB) in the X band and impressive in-plane thermal conductivity (3.31 W/mK, enhanced by ∼2365%). Moreover, this multilayered architecture realizes multiple internal reflection-absorption of microwaves and efficient heat dissipation, while confers the film with advantageable flame retardancy and significant water resistance. Therefore, sPVA-based composite films from MS provide a promising solution for the development of multifunctional polymeric materials tailored for upcoming electronic devices in challenging environments.利用非凡的聚合物基体和高效填料,提出了一种设计具有高电磁干扰屏蔽效能(EMI SE)和热导率的协同复合薄膜的巧妙策略。本文通过交替浇铸的方法,制备了一种基于富含辛迪加活性的聚乙烯醇(sPVA)/改性MXene沉积物(mMS)的新型柔性复合薄膜。sPVA/mMS多层膜含有sPVA层和mMS层之间有效的非共价结合,不仅具有66.3 MPa的高强度,还具有683 S/m的优异导电性。值得注意的是,mMS 层具有致密的导电和导热网络,使 95μm 厚的复合薄膜在 X 波段具有良好的 EMI SE(∼15.8 dB),同时还具有惊人的面内导热性(3.31 W/mK,增强了 ∼2365%)。此外,这种多层结构实现了微波的多重内部反射-吸收和高效散热,同时还赋予了薄膜良好的阻燃性和显著的防水性。因此,来自 MS 的基于 sPVA 的复合薄膜为开发多功能聚合物材料提供了一种前景广阔的解决方案,这种材料专为即将到来的挑战性环境中的电子设备量身定制。来源:复合材料力学仿真Composites FEM

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