今日更新:Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 2 篇,Composites Science and Technology 1 篇
Making aerogel films like playing LEGO: A universal fabrication strategy for Kevlar based aerogel films with arbitrarily designed functions
Jiaxin Liu, Ziyang Ke, Zhe Wang, Yang Zhou, Guan Yeoh, Carlo Carraro, Guanglan Liao, Roya Maboudian, Tielin Shi, Hu Long
doi:10.1016/j.compositesa.2024.108566
像玩乐高一样制作气凝胶薄膜:具有任意设计功能的凯夫拉尔基气凝胶薄膜的通用制造策略
Highly flexible, ultrathin and mechanically robust aerogel films activated by functional nanofillers exhibit tremendous potentials for wide applications. However, it is difficult to design different functionalities in a single aerogel film, as different nanofillers often possess opposing properties. Herein, a LEGO®-inspired fabrication strategy to construct Kevlar-based aerogel film with arbitrarily designed functions is introduced by stacking functionalized aerogel film units as stacking LEGO® bricks. The aerogel film units are reliably connected by precursor dispersion-derived LEGO® embossed nodes, leading to superior mechanical strength. Moreover, owing to the flexibility of the LEGO®-inspired assembly method, targeted functions of the aerogel films can be achieved by designing and purposefully combining various stacks. As demonstrations, optimized joule heating, greatly enhanced electromagnetic wave shielding and excellent flame-retardant properties are realized with stacking of different aerogel film units. The unique fabrication strategy opens up opportunities for the design and fabrication of aerogel film with tunable and tailored properties for wide applications.
功能化纳米填料活化的高柔韧性、超薄、机械强度高的气凝胶膜具有广阔的应用前景。然而,很难在单个气凝胶膜中设计不同的功能,因为不同的纳米填料通常具有相反的性质。本文介绍了一种受LEGO®启发的制造策略,通过将功能化气凝胶膜单元堆叠为堆叠LEGO®砖块,构建具有任意设计功能的凯夫拉气凝胶膜。气凝胶膜单元通过前驱体分散衍生的LEGO®压花节点可靠地连接在一起,从而具有优越的机械强度。此外,由于乐高®启发组装方法的灵活性,气凝胶膜的目标功能可以通过设计和有目的地组合各种堆栈来实现。结果表明,通过不同气凝胶单元的叠加,可实现焦耳加热优化、电磁波屏蔽能力大大增强和阻燃性能优异。独特的制造策略为设计和制造具有可调和定制性能的气凝胶膜提供了机会,可广泛应用。
Enhancing Microwave Absorption of Bio-inspired Structure through 3D Printed Concentric Infill Pattern
Huaiyu Dong, Shuailong Gao, Chen Yu, Zhichen Wang, Yixing Huang, Tian Zhao, Ying Li
doi:10.1016/j.compositesb.2024.111924
通过3D打印同心填充图案增强仿生结构的微波吸收
Despite numerous reports on microwave absorbing materials and structures with excellent performance, research on the impact of the carrier of microwave absorbers and their preparation processes on microwave absorption performance still faces challenges. To address this issue, this study combines theoretical analysis, simulation, and experimental validation to compare the differences in microwave absorption performance between 3D printed ABS/CF/MWCNTs materials and traditionally cast paraffin/CF/MWCNTs materials. Furthermore, the study explores the impact of linear and concentric filling patterns in 3D printing processes on the performance of tree-shaped microwave absorbing meta-structures. From a material level perspective, the 3D printed ABS/CF/MWCNTs composite plate with a thickness of 3mm has an effective absorption bandwidth of 5.16 GHz. Additionally, the bio-inspired tree-shaped structure optimized by the ant colony algorithm achieves an effective absorption bandwidth of up to 11.5 GHz at a thickness of 10.8 mm, with a minimum reflection loss of less than -9 dB across the entire frequency range (2 to 18 GHz). Moreover, the microwave absorbing meta-structure reinforced with carbon fiber-reinforced plastic laminates exhibits outstanding tensile and bending strength, with an average tensile strength and bending strength reaching 197.7 MPa and 188.6 MPa, respectively. In summary, this study provides valuable insights into the optimization of preparation processes for microwave absorbing materials or structures and offers a scientific basis for the design and application of high-performance microwave absorbing materials.
尽管已有大量研究报道了性能优异的吸波材料和结构,但研究微波吸收剂的载体及其制备工艺对微波吸收性能的影响仍然面临挑战。为了解决这一问题,本研究将理论分析、仿真和实验验证相结合,比较3D打印ABS/CF/MWCNTs材料与传统铸造石蜡/CF/MWCNTs材料在微波吸收性能上的差异。此外,该研究还探讨了3D打印过程中线性和同心填充模式对树形微波吸收元结构性能的影响。从材料层面来看,3D打印的ABS/CF/MWCNTs复合板的有效吸收带宽为5.16 GHz,厚度为3mm。此外,蚁群算法优化的仿生树形结构在厚度为10.8 mm时的有效吸收带宽高达11.5 GHz,在整个频率范围(2至18 GHz)内的最小反射损耗小于-9 dB。碳纤维增强复合材料增强的微波吸收元结构具有优异的抗拉强度和抗弯强度,平均抗拉强度和抗弯强度分别达到197.7 MPa和188.6 MPa。综上所述,本研究为微波吸波材料或结构的制备工艺优化提供了有价值的见解,为高性能吸波材料的设计和应用提供了科学依据。
Damage-free Non-mechanical Transfer Strategy for Highly Transparent, Stretchable Embedded Metallic Micromesh Electrodes
Zeqi Nie, Wenkai Yan, Xin Han, Huihuang Yu, Yapeng Zhang, Mengqi Tian, Xinyu Zhang, Yige Xiong, Peng Cao, Guanhua Zhang
doi:10.1016/j.compositesb.2024.111934
高透明、可拉伸嵌入式金属微孔电极的无损伤非机械转移策略
Stretchable, flexible, transparent electrodes garner significant research interest as indispensable components of flexible optoelectronic devices. However, frequent mechanical transfers during processing pose a considerable challenge in preparing electrodes of scalable size with superior performance and intact structure. Herein, we present a stretchable embedded metallic micromesh (SEMM) electrode with high optoelectronic and robust mechanical properties. The SEMM electrode is fabricated via a damage-free non-mechanical transfer strategy with the assistance of a bifunctional metal transition layer that serves as both a seed layer during electrodeposition and a sacrificial layer during stripping of the electrode. Consequently, the SEMM electrode features a scalable size and an intact structure. By optimizing the electrodeposition parameters, the SEMM achieves high optical transmittance (∼83%) and low sheet resistance (0.22 Ω sq-1), with a figure of merit reaching 8600 – 53 times greater than that of commercial polyethylene terephthalate-indium tin oxide (PET-ITO). Furthermore, the SEMM exhibits excellent mechanical stability, enduring up to 60% of tensile strain and maintaining almost constant normalized resistance after 20,000 bending cycles. Based on the SEMM, a transparent film heater yields rapid response time, low operating voltage, and fast defogging capability. This non-mechanical transfer strategy offers a compelling approach for enhancing the structural integrity and scalability of stretchable embedded transparent electrodes.
可拉伸、柔性、透明电极作为柔性光电器件不可或缺的组成部分,引起了人们极大的研究兴趣。然而,在加工过程中频繁的机械转移对制备具有优越性能和完整结构的可扩展尺寸的电极构成了相当大的挑战。在此,我们提出了一种具有高光电性能和强大机械性能的可拉伸嵌入金属微孔(SEMM)电极。在双功能金属过渡层的帮助下,通过无损伤的非机械转移策略制造SEMM电极,该过渡层在电沉积期间充当种子层,在电极剥离期间充当牺牲层。因此,SEMM电极具有可扩展的尺寸和完整的结构。通过优化电沉积参数,SEMM实现了高透光率(~ 83%)和低薄片电阻(0.22 Ω sq-1),其优点值比商用聚对苯二甲酸乙二醇酯-氧化铟锡(PET-ITO)高8600 - 53倍。此外,SEMM具有优异的机械稳定性,可承受高达60%的拉伸应变,并在20,000次弯曲循环后保持几乎恒定的归一化电阻。基于SEMM,透明薄膜加热器具有快速响应时间,低工作电压和快速除雾能力。这种非机械转移策略为增强可拉伸嵌入式透明电极的结构完整性和可扩展性提供了一种引人注目的方法。
Recyclable and highly thermally conductive nanocomposite with binary thermally conductive networks constructed from boron nitride nanoribbons and nanosheets
Liyuan Guo, Lei Feng, Caiyue Huang, Qiang Song, Peng Wei, Dongfang Xu, Mengdan Hou, Haojie Song
doi:10.1016/j.compscitech.2024.110954
由氮化硼纳米带和纳米片构成二元导热网络的可回收高导热纳米复合材料
Technological advances have accelerated the development of high-performance insulation-based Thermal Interface Materials (TIMs), leading to increased generation of electronic waste. A significant challenge is the development of recyclable TIMs with superior thermal conductivity. Hemiaminal dynamic covalent network (HDCN) polymers are considered as an ideal matrix material for recyclable TIMs due to their high degradability at low pH (pH < 2). In this work, binary thermally conductive paths of hexagonal boron nitride nanoribbons (BNNRs) and boron nitride nanosheets (BNNSs) are introduced into the HDCN to improve the thermal conductivity of HDCN without sacrificing its electrically insulating properties. The functional BNNSs (f-BNNSs) are attached onto the surfaces of BNNRs to achieve the homogeneous distribution of nanosheets within the HDCN. Benefiting from the binary thermally conductive paths, an excellent in-plane thermal conductivity of 3.12 W·m-1K-1 for BNNS-BNNR/HDCN nanocomposite is achieved at a BN loading of 14 wt% (containing 2 wt% BNNRs and 12 wt% f-BNNS), increased by 1299% comparing to the pure HDCN polymer, as well as superior to those reported for polymer composites with similar loading of BNNRs or BNNSs. Additionally, the nanocomposite demonstrated efficient recyclability of BNNSs and BNNRs hybrid fillers in an acidic environment (pH < 2) at 25 °C with a recycling efficiency of 82%. Notably, the nanocomposite exhibited noteworthy electrical insulation properties. This study demonstrates the potential of BNNS-BNNR/HDCN as a recyclable TIMs and provides a new idea for the future research and development of recyclable high performance TIMs.
技术进步加速了高性能绝缘热界面材料(TIMs)的发展,导致电子垃圾的产生增加。一个重大的挑战是开发具有优异导热性的可回收TIMs。半氨基动态共价网络(HDCN)聚合物由于其在低pH (pH < 2)下的高降解性被认为是可回收TIMs的理想基体材料。在本研究中,将六方氮化硼纳米带(BNNRs)和氮化硼纳米片(BNNSs)的二元导热路径引入HDCN中,以提高HDCN的导热性,同时又不牺牲HDCN的绝缘性能。功能化的BNNSs (f-BNNSs)附着在BNNRs的表面,实现了纳米片在HDCN内的均匀分布。得益于二元导热路径,BNNS-BNNR/HDCN纳米复合材料在BN负载为14 wt%(含2 wt% bnnr和12 wt% f-BNNS)时的面内导热系数为3.12 W·m-1K-1,比纯HDCN聚合物提高了1299%,也优于类似负载bnnr或bnns的聚合物复合材料。此外,该纳米复合材料在25°C的酸性环境(pH < 2)下具有BNNSs和BNNRs杂化填料的高效可回收性,回收率为82%。值得注意的是,纳米复合材料表现出显著的电绝缘性能。本研究证明了BNNS-BNNR/HDCN作为一种可回收的TIMs的潜力,为未来可回收的高性能TIMs的研究和开发提供了新的思路。