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【新文速递】2023年9月29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 B: Engineering 2 篇,Composites Science and Technology 1 篇

Composite Structures

Bending performance and failure mechanisms of hybrid and regular sandwich composite structures with 3D printed corrugated cores

Shah S.Z.H., Altaf Khurram, Lee Juhyeong, Sharif T., Choudhry R.S., Hussain S.M.

doi:10.1016/j.compstruct.2023.117580

带有 3D 打印波纹芯材的混合和常规夹层复合材料结构的弯曲性能和失效机理

The effect of core geometry and hybridization on the bending performance and failure mechanisms of carbon fibre-reinforced polymer (CFRP) and glass fibre-reinforced polymer (GFRP) corrugated sandwich composite structures (SCS) were experimentally investigated using a three-point bend test. The CFRP and GFRP corrugated cores and facesheets were produced using Fused Filament Fabrication (FFF) and vacuum-assisted infusion processes, respectively. Three types of corrugated SCSs were built: SCSs with different core geometries (circular, square, trapezoidal, sinusoidal, and triangular), hybrid SCSs with different CFRP and GFRP cores and facesheets, and fully 3D-printed CFRP and GFRP SCSs. The corrugated SCS with square core geometry outperformed due to the presence of vertical walls and a large bonding area. The hybrid SCSs with a CFRP core showed a significant load drop due to shear failure in the 3D-printed core caused by weak inter-layer bonding. In contrast, the hybrid SCS with a GFRP core deformed plastically and absorbed more energy without failure due to strong inter-layer bonding. In fully 3D printed SCSs, the GFRP specimen failed catastrophically due to higher bending stress at the bottom facesheet, while the CFRP undergoes plastic deformation without failure. Results elucidate that the hybrid corrugated SCS with a GFRP top facesheet and 3D-printed core is an appropriate configuration for superior bending performance. The proposed 3D-printed SCS enables optimising complex shapes and material distribution in the core, resulting in improved strength-weight ratios. These findings will make an important contribution to the design and development of fibre-reinforced 3D-printed SCS for lightweight and high-performance applications.

通过三点弯曲试验,实验研究了芯材几何形状和杂化对碳纤维增强聚合物(CFRP)和玻璃纤维增强聚合物(GFRP)波纹夹层复合材料结构(SCS)弯曲性能和破坏机制的影响。CFRP 和 GFRP 波纹芯材和面材分别采用熔融长丝制造(FFF)和真空辅助导流工艺制成。共制造了三种波纹 SCS:不同芯材几何形状(圆形、方形、梯形、正弦曲线形和三角形)的 SCS,不同 CFRP 和 GFRP 芯材和面材的混合 SCS,以及完全 3D 打印的 CFRP 和 GFRP SCS。具有方形芯材几何形状的波纹 SCS 由于存在垂直壁和较大的粘合面积而表现出色。带有 CFRP 内核的混合 SCS 由于层间粘结力弱,导致 3D 打印内核剪切失效,从而导致载荷大幅下降。相比之下,带有 GFRP 内核的混合 SCS 由于层间粘结力强,可产生塑性变形并吸收更多能量而不会失效。在完全三维打印的 SCS 中,GFRP 试样由于底部面板的弯曲应力较大而发生灾难性失效,而 CFRP 则发生塑性变形而没有失效。研究结果表明,具有 GFRP 顶部面板和 3D 打印芯材的混合波纹 SCS 是实现优异弯曲性能的合适配置。拟议的三维打印 SCS 能够优化芯材的复杂形状和材料分布,从而提高强度-重量比。这些发现将为设计和开发用于轻质和高性能应用的纤维增强 3D 打印 SCS 做出重要贡献。


A multi resonant wave-absorbing honeycomb sandwich structure with excellent electrical performance damage tolerance

Zhao Yiming, Xing Suli, Tang Nianhua, Wu Nan, Tang Jun, He Yonglyu, Yin Changping, Zhang Jianwei

doi:10.1016/j.compstruct.2023.117581

具有优异电气性能和耐损坏性的多谐振吸波蜂窝夹层结构

Wave-absorbing honeycomb sandwich structure (HSS) is widely used in aviation equipment, playing an important role in the integration of load-bearing and stealth shielding. The high-intensity service of aviation equipment beyond design condition accelerates damage and complicates failure triggers. In this work, a decentralized construction strategy with multiple resonant absorption peaks is proposed to enhance the electrical performance damage tolerance (EDT) of wave-absorbing HSS in 4-18 GHz frequency band. The designed multi resonant absorption peaks for 30 mm thick wave-absorbing honeycomb with 1 mm thick SiO2 fiber reinforced epoxy resin (SiO2f/ER) composites as top and bottom panels occur in the vicinity of 5 GHz, 9 GHz, 13 GHz, and 17 GHz, respectively. When the panel damage area accounts for 72% or the penetrating damage area accounts for 18%, the effective absorption bandwidth (EAB) of proposed HSS covers 4-18 GHz, indicating excellent EDT. By analyzing the normalized impedance, Smith chart, as well as power loss density, the excellent EDT is attributed to the pinning effect at each resonant frequency point, which benefits both impedance matching and electromagnetic wave (EMW) attenuation.

吸波蜂窝夹层结构(HSS)广泛应用于航空设备,在承重和隐身屏蔽一体化中发挥着重要作用。航空设备超出设计状态的高强度服役会加速损坏并使故障触发复杂化。本研究提出了一种具有多个谐振吸收峰的分散结构策略,以提高 4-18 GHz 频段吸波 HSS 的电气性能损伤容限(EDT)。对于 30 毫米厚的吸波蜂窝和 1 毫米厚的二氧化硅纤维增强环氧树脂(SiO2f/ER)复合材料作为顶部和底部面板,设计的多谐振吸收峰分别出现在 5 GHz、9 GHz、13 GHz 和 17 GHz 附近。当面板损伤面积占 72% 或穿透损伤面积占 18% 时,拟议 HSS 的有效吸收带宽(EAB)为 4-18 GHz,表明 EDT 性能优异。通过分析归一化阻抗、史密斯图和功率损耗密度,可将优异的 EDT 归因于每个谐振频率点的针 刺效应,这有利于阻抗匹配和电磁波(EMW)衰减。


Composites Part B: Engineering

Design and manufacture of a Type V composite pressure vessel using automated fibre placement

Air Alexander, Oromiehie Ebrahim, Prusty B. Gangadhara

doi:10.1016/j.compositesb.2023.111027

利用自动纤维放置技术设计和制造 V 型复合材料压力容器

Automated Fibre Placement (AFP) can improve composite pressure vessel design by enabling selective reinforcement and allowing a wider range of fibre orientations than the traditional filament winding process. This paper presents the development of an AFP Type V composite pressure vessel with a design working pressure of 4.22 MPa made using a novel collapsible mandrel. The design process is presented along with a thickness control strategy for the AFP parts using ply drops. The tank was manufactured, and the thickness was validated using 3D scanning. The mass of the AFP parts was also measured to within 2.23% of the predicted values. The finished tank was hydrostatically pressure tested to understand the leakage behaviour. Defects and difficulties encountered in this prototype are discussed and opportunities for future work and improvements have been identified.

与传统的长丝缠绕工艺相比,自动纤维铺放(AFP)工艺可以实现选择性加固并允许更多的纤维取向,从而改进复合材料压力容器的设计。本文介绍了使用新型可折叠心轴开发的 AFP V 型复合材料压力容器,其设计工作压力为 4.22 兆帕。本文介绍了设计过程,以及使用层降技术对 AFP 部件进行厚度控制的策略。水箱已制造完成,并通过 3D 扫描验证了厚度。此外,还测量了 AFP 部件的质量,结果与预测值相差 2.23%。完成后的水箱进行了静水压力测试,以了解其泄漏特性。对原型中遇到的缺陷和困难进行了讨论,并确定了未来工作和改进的机会。


Recent progress and strategic perspectives of high-voltage Na3V2(PO4)2F3 cathode: Fundamentals, modifications, and applications in sodium-ion batteries

Chen Yu-Hao, Zhao Yi-Han, Tian Shu-Hui, Wang Peng-Fei, Qiu Feilong, Yi Ting-Feng

doi:10.1016/j.compositesb.2023.111030

高压 Na3V2(PO4)2F3 阴极的最新进展和战略前景:钠离子电池的基础、改性和应用

The NASICON structure of Na3V2(PO4)2F3 (NVPF) separates the valence electrons between the polyanion group and V and regulates the redox coupling energy. As a result, NVPF exhibits a high operating voltage in sodium-ion batteries. However, NVPF cathode material has poor specific capacity and low-rate performance. It is necessary to improve the electrochemical performance by increasing the electronic conductivity and accelerating the ion diffusion rate. Through morphology control, more active sites and ion channels can be provided to enhance rate performance and cycle stability. However, there are few reviews on how to control the morphology of NVPF. Therefore, this paper starts with the factors affecting the morphology of NVPF. The effects of pH value, surfactant, and external additives on its morphology were systematically summarized. On this basis, reasonable strategies, including morphology design, preparation method, structure control, surface modification, and defect engineering, are summarized. This paper provides theoretical support for the development of high-voltage NVPF. It provides inspiration for creating NVPF cathode materials with high specific capacity and high cycle performance.

Na3V2(PO4)2F3(NVPF)的 NASICON 结构可分离多阴离子基团和 V 之间的价电子,并调节氧化还原耦合能。因此,NVPF 在钠离子电池中具有很高的工作电压。然而,NVPF 正极材料的比容量较低,速率性能也不高。有必要通过提高电子电导率和加快离子扩散速度来改善电化学性能。通过形态控制,可以提供更多的活性位点和离子通道,从而提高速率性能和循环稳定性。然而,关于如何控制 NVPF 形貌的综述却很少。因此,本文从影响 NVPF 形态的因素入手。系统地总结了 pH 值、表面活性剂和外部添加剂对其形态的影响。在此基础上,总结了包括形态设计、制备方法、结构控制、表面改性和缺陷工程在内的合理策略。本文为高压 NVPF 的开发提供了理论支持。它为创造具有高比容量和高循环性能的 NVPF 阴极材料提供了灵感。


Composites Science and Technology

Superhydrophobic and robust photothermal/electrothermal PVDF-a/CNT-s@PDMS membrane for crude oil removal and dye adsorption

Chen Shengye, Zhou Jiale, Li Kunquan, Chen Zhuohan, Li Xuanjun, Su Xiaojing, Ao Xiaojuan, Xie Huali, Chen Lu, Wu Xuting, Wu Wenjian

doi:10.1016/j.compscitech.2023.110267

用于去除原油和吸附染料的超疏水性和坚固的光热/电热 PVDF-a/CNT-s@PDMS 膜

Recently, the crude oil spill has brought inevitable harm to the global ecological environment. Due to the high-viscosity crude oil, it is wise to take advantage of the photothermal/electrothermal effects of the membrane to separate the crude oil from the water. However, the functional separation membrane always suffers from low photothermal/electrothermal effects and poor stability. Herein, the vinyl polyvinylidene fluoride/mercapto carbon nanotubes@vinyl-terminated polydimethylsiloxane (PVDF-a/CNT-s@PDMS) membrane with fast photothermal/electrothermal effects and organic absorption property was successfully prepared by electrospinning and multi-layer loading method. The prepared PVDF-a/CNT-s@PDMS membrane resisted a variety of liquids and had stable superhydrophobicity (WCA = 156°). Furthermore, the membrane maintained superhydrophobicity even suffer from water and milk under the applied voltage condition. After 100 wear resistance tests, the membrane maintained stable superhydrophobicity and the separation rate remained unchanged. The surface temperature of the membrane rapidly approached to the maximum temperature in 30 s, showing a rapid photothermal/electrothermal effects, and the average separation rate of crude oil was 1185 kg m−2 h−1·bar−1. Meanwhile, the membrane exhibited outstanding efficiency for separate immiscible oil-water mixtures. Importantly, the incorporation of the sulfhydryl group enhanced the special ability of the composite membrane to adsorb organic dyes from oil phase. Therefore, the PVDF-a/CNT-s@PDMS membrane has a wide range of potential application in the domain of oil-water separation.

最近,原油泄漏给全球生态环境带来了不可避免的危害。由于原油粘度高,利用膜的光热/电热效应将原油从水中分离出来是明智之举。然而,功能分离膜总是存在光热/电热效应低、稳定性差的问题。本文采用电纺丝和多层负载法成功制备了具有快速光热/电热效应和有机吸收特性的乙烯基聚偏氟乙烯/巯基碳纳米管@乙烯基封端聚二甲基硅氧烷(PVDF-a/CNT-s@PDMS)膜。所制备的 PVDF-a/CNT-s@PDMS 膜可抵抗多种液体,并具有稳定的超疏水性能(WCA = 156°)。此外,在施加电压的条件下,该膜即使受到水和牛奶的侵蚀也能保持超疏水性能。经过 100 次耐磨测试后,膜仍能保持稳定的超疏水性,分离率也保持不变。膜的表面温度在 30 秒内迅速接近最高温度,显示出快速的光热/电热效应,原油的平均分离率为 1185 kg m-2 h-1-bar-1 。同时,该膜在分离互不相溶的油水混合物方面表现出卓越的效率。重要的是,巯基的加入增强了复合膜从油相吸附有机染料的特殊能力。因此,PVDF-a/CNT-s@PDMS 膜在油水分离领域具有广泛的应用前景。



来源:复合材料力学仿真Composites FEM
ACTAdditiveSystemMAGNETDeform复合材料化学隐身航空电子理论材料控制试验电气
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【新文速递】2023年9月24日复合材料SCI期刊最新文章

Composites Part A: Applied Science and ManufacturingTailoring the Interfacial Interaction of Collagen Fiber/Waterborne Polyurethane Composite via Plant Polyphenol for Mechanically Robust and Breathable Wearable SubstrateLi Shuangyang, Shuai Pengyu, Wang Aoqi, Zhou Jianfei, Shi Bidoi:10.1016/j.compositesa.2023.107810通过植物多酚定制胶原纤维/水性聚氨酯复合材料的界面相互作用,以获得机械坚固且透气的可穿戴基底材料Collagen fiber-waterborne polyurethane composites possess great potential applications in flexible wearable devices owing to their excellent biocompatibility, flexibility, and biodegradability. However, the weak interfacial interactions which result in poor mechanical strength and breathability, have significantly hindered their practical application. Herein, high-performance collagen fiber-based wearable substrates prepares by constructing a hydrogen-bonded cross-linked network structure using bayberry tannin, a natural plant polyphenol, as a coupling bridge to bind collagen fibers and waterborne polyurethane (WPU). The dynamic rupture and reformation of sacrificial hydrogen bonds on the molecular scale effectively dissipate energy under mechanical stress, endowing these composites with remarkable toughness and ultrahigh water vapor permeability (WVP). The resultant composite’s tensile strength and WVP are 100% and 60 times higher than WPU, respectively. Additionally, this cost-effective strategy enables easy large-scale composite production. This method guides the development of high-performance, multifunctional collagen fiber-based wearable composites while advancing the tannery solid waste circular economy.胶原纤维-水性聚氨酯复合材料具有良好的生物相容性、柔韧性和生物降解性,因此在柔性可穿戴设备中具有巨大的应用潜力。然而,由于界面相互作用较弱,导致机械强度和透气性较差,大大阻碍了其实际应用。在此,我们利用天然植物多酚月桂鞣酸作为耦合桥,将胶原纤维和水性聚氨酯(WPU)结合在一起,构建了氢键交联网络结构,从而制备出基于胶原纤维的高性能可穿戴基材。分子尺度上牺牲氢键的动态断裂和重构可有效消散机械应力下的能量,从而使这些复合材料具有出色的韧性和超高的水蒸气渗透性(WVP)。这种复合材料的拉伸强度和 WVP 分别是 WPU 的 100% 和 60 倍。此外,这种具有成本效益的策略还能轻松实现大规模复合材料生产。该方法为开发基于胶原纤维的高性能、多功能耐磨复合材料提供了指导,同时推动了制革固体废物循环经济的发展。Composites Part B: EngineeringA functional coating with mechanoluminescent properties for sensing cavitation erosion and early warning of protection failureWu Yuli, Hou Guoliang, Cui Haixia, Zhang Yue, Chen Lei, An Yulong, Zhou Huidi, Chen Jianmindoi:10.1016/j.compositesb.2023.111021具有机械发光特性的功能涂层,用于感知空化侵蚀和预警保护失效Protective materials coated on the surface of fluid machinery are often used to slow down the damage caused by cavitation. Once the protective material fails, there is no real-time monitoring to predict, which will directly threaten the safe operation of the equipment. In this work, we designed a functional SrAl2O4: Eu2+, Dy3+ coating by atmospheric plasma spraying (APS), which can sense the impact of bubble implosion and realize the early warning of the failure of anti-cavitation erosion polyurethane (PU) coating. It is found that the luminescent properties of the functional coatings are easily affected by lattice defects, amorphous phase and valence state of europium ions. The functional coating is more sensitive to the perception of micro-jets and shock waves after vacuum thermal reduction treatment, and can distinguish the difference in stress by the brightness of the light. More importantly, when the surface polyurethane coating is removed by cavitation erosion (CE) down to 0.1 mm, this functional coating emits light to warn the polyurethane coating of impending failure. Therefore, this work provided a solution for sensing CE and predicting when the protection would fail.涂覆在流体机械表面的保护材料通常用于减缓气蚀造成的损坏。一旦保护材料失效,无法实时监测预测,将直接威胁设备的安全运行。在这项工作中,我们利用大气等离子喷涂(APS)技术设计了一种功能性 SrAl2O4: Eu2+, Dy3+ 涂层,它能感知气泡内爆的冲击力,实现对防气蚀侵蚀聚氨酯(PU)涂层失效的预警。研究发现,功能涂层的发光特性容易受到晶格缺陷、非晶相和铕离子价态的影响。真空热还原处理后的功能涂层对微喷射和冲击波的感知更加敏感,并能通过光的亮度区分应力的不同。更重要的是,当表面聚氨酯涂层被空化侵蚀(CE)去除至 0.1 毫米时,这种功能涂层会发光,警告聚氨酯涂层即将失效。因此,这项工作为感知 CE 和预测保护何时失效提供了一种解决方案。Composites Science and TechnologyZnO-poly(acrylonitrile) composite films with improved piezoelectric properties for energy harvesting and sensing applicationsKaur Gurneet, Sharma Akhilesh Kumar, Jassal Manjeet, Agrawal Ashwini K.doi:10.1016/j.compscitech.2023.110260具有更好压电特性的氧化锌-聚丙烯腈复合薄膜,可用于能量收集和传感应用Piezoelectric nanogenerators are one of the possible solutions for generating power in milliwatts for various mobility applications. They can also be utilized as tactile sensors. Since poly(acrylonitrile) (PAN) has a greater dipole moment (3.5 D) than poly (vinylidene fluoride) (PVDF), it has a strong potential for use as piezoelectric nanogenerators and pressure sensors. However, due to strong dipole-dipole repulsion, the nitrile groups are difficult to align in a zig-zag configuration resulting in reduced ability of the system to convert mechanical energy into electrical energy. To address this issue, we have incorporated ZnO nanoparticles (ZnP) and ZnO nanowires (ZnW) in PAN films. Due to the strong interaction of ZnO nanostructures with PAN, the dipole-dipole repulsion reduces resulting in increased zigzag conformation of PAN. Compared to ZnP, ZnW was found to show better alignment of PAN nitrile groups and faster relaxation of dipoles after removal of stress. Without any external poling, PAN, ZnP-PAN, and ZnW-PAN films based piezoelectric nanogenerators could generate 27.6, 79.3 and 86.3 mW/m2 of power, respectively. The incorporation of 5 wt% ZnP and ZnW also significantly improved the pressure sensitivities of the devices to 0.9 fFPa−1 and 1.1 fFPa−1, respectively, as compared to 0.1 fFPa−1 for pristine PAN film.压电纳米发电机是为各种移动应用提供毫瓦级功率的可行解决方案之一。它们还可用作触觉传感器。由于聚丙烯腈(PAN)比聚偏二氟乙烯(PVDF)具有更大的偶极矩(3.5 D),因此极有可能用作压电纳米发电机和压力传感器。然而,由于腈基具有很强的偶极-偶极斥力,因此很难以之字形构型排列,从而降低了系统将机械能转化为电能的能力。为了解决这个问题,我们在 PAN 薄膜中加入了氧化锌纳米颗粒(ZnP)和氧化锌纳米线(ZnW)。由于 ZnO 纳米结构与 PAN 的相互作用很强,偶极子-偶极子斥力减小,导致 PAN 的 "之 "字形构象增加。与 ZnP 相比,ZnW 在消除应力后能更好地排列 PAN 腈基,并加快偶极子的松弛。在没有任何外部极化的情况下,基于 PAN、ZnP-PAN 和 ZnW-PAN 薄膜的压电纳米发电机可分别产生 27.6、79.3 和 86.3 mW/m2 的功率。与原始 PAN 薄膜的 0.1 fFPa-1 相比,加入 5 wt% 的 ZnP 和 ZnW 还显著提高了器件的压力灵敏度,分别达到 0.9 fFPa-1 和 1.1 fFPa-1。Design-manufacturing-evaluation integration of microwave absorbing metastructures based on additive manufacturingLei Han, Shan Mengtong, Zhang Yuhui, Zhao Pengzhen, Yu Chen, Huang Yixingdoi:10.1016/j.compscitech.2023.110270基于增材制造的微波吸收转移结构的设计-制造-评估一体化The study of microwave-absorbing materials and microwave-absorbing structures holds significant importance in fields such as human health and military defense. With the advancement of information technology, the severity of electromagnetic pollution has increased, resulting in a greater need for microwave protection. Simultaneously, additive manufacturing has garnered significant attention from scholars due to its ability to utilize diverse materials and construct complex models with flexibility. In this paper, we have successfully achieved the integration of design, manufacturing and evaluation. Specifically, we have combined material extrusion technology with microwave-absorbing materials and structures to conduct research on absorbing functional composites using material extrusion. By employing large variation genetic algorithm, we designed an electric-loss honeycomb metastructure (ELHM). The ELHM demonstrates effective broadband absorption performance within the frequency ranges of 2–6.8 GHz and 10.4–40 GHz. It maintains excellent absorption properties even during oblique incidence reflection tests under different polarization modes. Additionally, it exhibits outstanding load-bearing capacity.微波吸收材料和微波吸收结构的研究在人类健康和军事防御等领域具有重要意义。随着信息技术的发展,电磁污染日益严重,对微波防护的需求也随之增加。与此同时,快速成型制造技术因其能够利用多种材料并灵活构建复杂模型而备受学者关注。在本文中,我们成功实现了设计、制造和评估的一体化。具体而言,我们将材料挤压技术与微波吸收材料和结构相结合,利用材料挤压技术开展了吸收功能复合材料的研究。通过采用大变异遗传算法,我们设计了一种电损耗蜂窝结构(ELHM)。ELHM 在 2-6.8 GHz 和 10.4-40 GHz 频率范围内表现出有效的宽带吸收性能。即使在不同极化模式下进行斜入射反射测试,它也能保持出色的吸收性能。此外,它还具有出色的承载能力。Polymer nanocomposite adhesives with internal nano-heaters to facilitate multilayer laminate separationSeyler H., Quiles-Díaz S., Ellis G.J., Shuttleworth P.S., Flores A., Gómez-Fatou M.A., Salavagione H.J.doi:10.1016/j.compscitech.2023.110271带有内部纳米加热器的聚合物纳米复合粘合剂可促进多层层压板分离Laminating adhesives used in multilayer films present strong, irreversible adhesion that limits the produced packaging systems to single-use applications. From a sustainability point of view, the recovery of individual polymers after use is imperative and a pivotal step is to make this adhesion reversible via breakdown of the adhesive structure. This work describes a promising strategy based on the incorporation of graphene into thermoreversible adhesive resin formulations to trigger the rupture of the adhesive network by exposure to IR radiation. Graphene is a thermal absorber that abruptly heats up under irradiation and efficiently dissipates this heat to the surrounding environment causing the adhesive network to collapse, resulting in remarkable changes in its mechanical properties. In this study, graphene was incorporated at low concentrations (0.25–1 wt. %) into solvent-free polyurethane adhesives containing thermoreversible moieties. The photothermal effect at different loadings was evaluated and the formulation displaying the best balance between photothermal effect and optical properties was selected. Furthermore, the effect of irradiation on cyclability, fluidity and mechanical properties of the graphene-containing adhesives is evaluated. Good cyclability was observed and samples with a graphene loading of 0.25 wt. % and 11.5 wt. % of thermoreversible bonds (TRB) showed the largest difference in elongation under IR irradiation with respect to the neat adhesive. Creep testing demonstrated that the strain of this sample increases by almost 200% after irradiation due to the breakdown of the three-dimensional adhesive network triggered by the photothermal effect of graphene.多层薄膜中使用的复合粘合剂具有很强的不可逆粘合力,这就限制了所生产的包装系统的一次性使用。从可持续发展的角度来看,必须在使用后回收单个聚合物,而关键的一步就是通过分解粘合剂结构使这种粘合力可逆。这项工作介绍了一种很有前景的策略,即在热可逆粘合剂树脂配方中加入石墨烯,通过暴露在红外辐射下触发粘合剂网络破裂。石墨烯是一种热吸收体,在辐照下会突然升温,并有效地将热量散发到周围环境中,导致粘合剂网络坍塌,从而使其机械性能发生显著变化。在这项研究中,石墨烯以低浓度(0.25-1 wt.%)加入到含有热可逆分子的无溶剂聚氨酯粘合剂中。评估了不同添加量下的光热效应,并选出了光热效应和光学特性之间平衡最佳的配方。此外,还评估了辐照对含石墨烯粘合剂的循环性、流动性和机械性能的影响。观察到样品具有良好的循环性,石墨烯含量为 0.25 重量百分比和热可逆键(TRB)含量为 11.5 重量百分比的样品在红外辐照下的伸长率与纯粘合剂相比差异最大。蠕变测试表明,由于石墨烯的光热效应导致三维粘合剂网络破裂,该样品的应变在辐照后增加了近 200%。Enhanced extreme temperature bending and delamination resistance of GFRP composites through z-directional aligned nano-reinforcement: Emphasizing the effects of CNT functionalizationFulmali Abhinav Omprakash, Patnaik Satyaroop, Rathore Dinesh Kumar, Bhattacharjee Debashish, Gwalani Bharat, Ray Bankim Chandra, Prusty Rajesh Kumardoi:10.1016/j.compscitech.2023.110272通过 Z 向排列的纳米加固增强 GFRP 复合材料在极端温度下的抗弯曲和抗分层性能:强调 CNT 功能化的影响Laminated FRP composites' weak out-of-plane mechanical performance prevents their usage in structural applications where homogeneous load bearing qualities are required. In this regard, a z-directional nano-reinforcement approach was implemented to mitigate the poor in-plane shear and out-of-plane response of laminated glass fiber epoxy (GE) composites under extreme in-service temperature conditions. CNT and functionalized CNT (FCNT) were dispersed separately in the GE composites' epoxy matrix and subjected to a z-direction electric field alignment treatment. Flexural and short beam shear tests of GE composites with random and aligned CNT/FCNT were performed at room temperature, in-situ cryogenic and elevated temperature conditions (RT, CT and ET, respectively). GE composite with aligned FCNT (A-FCNT-GE) consistently outperformed other composites at all considered temperatures with remarkable improvements, specifically ∼39%, ∼41% and ∼47% in flexural strength, and ∼30%, ∼30%, and ∼24% in interlaminar shear strength (ILSS) over the control GE composite at RT, CT and ET, respectively. Dynamic mechanical thermal analysis suggested that the synergetic impact of functionalization and alignment of FCNT improved the viscoelastic properties of the A-FCNT-GE composite across a range of temperature conditions. Fractography analysis provided insight into the interfacial and interlayer mechanisms that improved the extreme temperature condition mechanical performance. The reliability of electric field aligned FCNT as a z-directional nano-reinforcement in laminated composites at extreme temperature conditions was established in this study.层压玻璃纤维复合材料的平面外机械性能较弱,因此无法在需要均匀承载质量的结构应用中使用。为此,我们采用了一种 Z 向纳米加固方法,以缓解层压玻璃纤维环氧树脂(GE)复合材料在极端使用温度条件下平面内剪切和平面外响应较差的问题。将碳纳米管和功能化碳纳米管(FCNT)分别分散在 GE 复合材料的环氧基体中,并进行 Z 向电场排列处理。在室温、原位低温和高温条件下(分别为 RT、CT 和 ET),对含有随机和对齐 CNT/FCNT 的 GE 复合材料进行了挠曲和短梁剪切试验。在所有温度条件下,含有对齐 FCNT 的 GE 复合材料(A-FCNT-GE)的性能始终优于其他复合材料,尤其是在 RT、CT 和 ET 温度条件下,与对照 GE 复合材料相比,弯曲强度分别提高了 ∼39%、∼41% 和 ∼47%,层间剪切强度分别提高了 ∼30%、∼30% 和 ∼24%。动态机械热分析表明,FCNT 功能化和排列的协同作用改善了 A-FCNT-GE 复合材料在各种温度条件下的粘弹性能。碎裂分析深入揭示了改善极端温度条件下机械性能的界面和层间机制。本研究证实了在极端温度条件下,电场排列的 FCNT 作为层状复合材料中的 Z 向纳米增强材料的可靠性。Construction of three-dimensional interconnected boron nitride/sliver networks within epoxy composites for enhanced thermal conductivityWu Xudong, Yu Haojie, Wang Li, Gong Xiaodan, Chen Dingning, Hong Yichuan, Zhang Yanhuidoi:10.1016/j.compscitech.2023.110268在环氧树脂复合材料中构建三维互联氮化硼/银网络以增强导热性能With the advent of the 5G era, the conspicuous increases in operating power and thermogenic capacity of integrated electronic components necessitated the development of enhanced thermal conductive polymeric composites with excellent heat dissipation properties. Herein, the polydopamine (PDA) and silver (Ag) modified BN (BN-PDA-Ag) was synthesized and a three-dimensional (3D) interconnected BN-PDA-Ag porous network was successfully fabricated by the salt template-assisted method to improve the thermal conductivity property of epoxy based composites. The high thermal conductive epoxy resin composites (3D BN-PDA-Ag/EP) were obtained by infiltrating epoxy into the 3D BN-PDA-Ag porous network. On one hand, the 3D BN-PDA-Ag porous skeleton provided continuous transfer paths for phonons, which was conducive to reducing phonon scattering. On the other hand, the Ag nanoparticles loaded on the BN surface bridged the adjacent BN sheets, significantly decreasing the thermal contact resistance between adjacent fillers. The isotropic thermal conductivity (TC) of 3D BN-PDA-Ag/EP composite with a BN-PDA-Ag content of 20.3 wt% reached 1.37 W/(m·K), which exhibited a evident enhancement of 661% compared with pure epoxy. The thermal management simulation and application results showed the composite had enormous application potential for electronic devices and components in heat dissipation.随着 5G 时代的到来,集成电子元件的工作功率和发热能力显著提高,因此有必要开发具有优异散热性能的增强导热聚合物复合材料。本文合成了聚多巴胺(PDA)和银(Ag)改性 BN(BN-PDA-Ag),并采用盐模板辅助法成功制备了三维(3D)互连 BN-PDA-Ag 多孔网络,以改善环氧基复合材料的导热性能。通过将环氧树脂渗入三维 BN-PDA-Ag 多孔网络,获得了高导热环氧树脂复合材料(三维 BN-PDA-Ag/EP)。一方面,三维 BN-PDA-Ag 多孔骨架为声子提供了连续的传输路径,有利于减少声子散射。另一方面,负载在 BN 表面的 Ag 纳米粒子桥接了相邻的 BN 片,显著降低了相邻填料之间的热接触电阻。三维 BN-PDA-Ag/EP 复合材料(BN-PDA-Ag 含量为 20.3 wt%)的各向同性导热系数(TC)达到了 1.37 W/(m-K),与纯环氧树脂相比明显提高了 661%。热管理模拟和应用结果表明,该复合材料在电子设备和元件的散热方面具有巨大的应用潜力。 来源:复合材料力学仿真Composites FEM

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