今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 2 篇,Composites Science and Technology 1 篇
Vibration characteristics of additive manufactured IWP-type TPMS lattice structures
Zhang Cong, Qiao Hui, Yang Lei, Ouyang Wu, He Tao, Liu Bing, Chen Xiyong, Wang Nannan, Yan Chunze
doi:10.1016/j.compstruct.2023.117642
添加剂制造的 IWP 型 TPMS 晶格结构的振动特性
Several research has been done on the conventional strut-based lattice structures, which have the problem of stress concentration in the application. In recent years, a new lattice structure, the triply periodic minimal surface (TPMS) lattice structure is increasingly gaining attention, but its vibrational properties have been less studied. In this study, the IWP-type TPMS lattice structures and ordinary body-centered cubic (BCC) counterparts with similar topology were prepared by selective laser melting (SLM) additive manufacturing (AM) technique. The compression behavior of the structures and the energy absorption capacity were determined by uniaxial compression tests. The frequency response and the damping ratio of the structure were calculated by dynamic vibration transfer rate tests. The results show that the stiffness and inherent frequency of the lattice structure are proportional to the volume fraction and inversely proportional to the cell size. Decreasing the volume fraction and increasing the cell size can be more beneficial to achieve low-frequency vibration isolation. Moreover, the IWP-type triply periodic minimal surface lattice structures have better mechanical properties than BCC structures and have good vibration isolation properties. Insights from this paper provide a reference for improving the load-carrying and vibration isolation performance of lightweight lattice structures.
人们对传统的基于支柱的晶格结构进行了大量研究,但这种结构在应用中存在应力集中的问题。近年来,一种新的晶格结构--三周期最小面(TPMS)晶格结构越来越受到人们的关注,但对其振动特性的研究较少。本研究采用选择性激光熔融(SLM)增材制造(AM)技术制备了 IWP 型 TPMS 晶格结构和具有类似拓扑结构的普通体心立方(BCC)对应结构。通过单轴压缩试验确定了结构的压缩行为和能量吸收能力。通过动态振动传递率试验计算了结构的频率响应和阻尼比。结果表明,晶格结构的刚度和固有频率与体积分数成正比,与单元尺寸成反比。降低体积分数和增大单元尺寸更有利于实现低频隔振。此外,与 BCC 结构相比,IWP 型三周期最小表面晶格结构具有更好的机械性能,并具有良好的隔振性能。本文的见解为提高轻质晶格结构的承载和隔振性能提供了参考。
Super-flexible and highly conductive H-Ti3C2Tx MXene composite films with 3D macro-assemblies for electromagnetic interference shielding
Ye Xiao-Ai, Zhang Si-Ying, Zhao Da-Qiang, Ding Ling, Fang Kan, Zhou Xu, Wang Gui-Gen
doi:10.1016/j.compositesa.2023.107866
用于电磁干扰屏蔽的超柔性高导电性 H-Ti3C2Tx MXene 复合薄膜与 3D 宏组件
2D MXene are showing great prospects for EMI shielding by virtue of abundant surface functional groups and outstanding metallic electrical conductivity. However, it remains a great challenge to simultaneously achieve flexible, lightweight and high stability in MXene shielding materials due to inferior mechanical strength and poor oxidation stability. Gelation paves up an effective and facile strategy to develop highly stable and conductive 3D porous Ti3C2Tx architectures. Herein, super-flexible and highly conductive H-Ti3C2Tx MXene composite films with 3D macro-assemblies for EMI shielding were fabricated through a gelation-densification process initiated by hydrochloric acids, and two-step vacuum-assisted filtration followed by freeze-casting approach. The obtained nanocomposite films manifest satisfactory mechanical properties with a tensile strength of 116.51 MPa, excellent EMI SE of 55.14 dB, superior SSE/t and high EMI SE retention after 5000 cycles of bending deformation. In addition, the as-prepared nanocomposite papers demonstrate outstanding thermal management performances such as rapid response time, high Joule heating temperature (118 °C) at low applied voltage (2.5 V) and eminent working stability (4000 s).
二维 MXene 具有丰富的表面官能团和出色的金属导电性,因此在 EMI 屏蔽方面前景广阔。然而,由于机械强度低、氧化稳定性差,如何同时实现 MXene 屏蔽材料的柔性、轻质和高稳定性仍然是一个巨大的挑战。凝胶化为开发高稳定性和导电性的三维多孔 Ti3C2Tx 结构提供了一种有效而简便的策略。在此,通过盐酸引发的凝胶化-致密化过程,以及两步真空辅助过滤和冷冻铸造方法,制备出了用于电磁干扰屏蔽的超柔性、高导电性 H-Ti3C2Tx MXene 三维宏观组合复合薄膜。所获得的纳米复合薄膜具有令人满意的机械性能:拉伸强度为 116.51 兆帕、优异的 EMI SE(55.14 分贝)、优异的 SSE/t,以及在 5000 次弯曲变形后的高 EMI SE 保持率。此外,制备的纳米复合纸还具有出色的热管理性能,如快速响应时间、在低应用电压(2.5 V)下的高焦耳加热温度(118 °C)和出色的工作稳定性(4000 秒)。
Hierarchical MXene@PBA nanohybrids towards high-efficiency flame retardancy and smoke suppression of robust yet tough polymer nanocomposites at ultra-low additions
Lian Richeng, Gao Qingyao, Zhao Zexuan, Ou Mingyu, Liu Xinliang, Liu Lei, Chen Xilei, Jiao Chuanmei
doi:10.1016/j.compositesb.2023.111074
分层 MXene@PBA 纳米杂化物,以超低添加量实现坚固耐用的聚合物纳米复合材料的高效阻燃和抑烟性能
Developing efficient flame-retardant MXene-based polymeric materials with enhanced mechanical properties has been a huge challenge. Herein, Prussian blue analogues (PBAs) were used to modify the surface of MXene nanosheets via an electrostatic self-assembly method to construct hierarchical MXene-based nanohybrids (MXene@PBA). Then, MXene@PBA was incorporated into the epoxy matrix to fabricate high-performance epoxy nanocomposites (EP-MXene@PBA). The study indicates that hierarchical MXene@PBA exhibits excellent dispersion performance in the epoxy matrix. Notably, MXene@PBA results in high-efficiency flame retardancy and smoke suppression for epoxy nanocomposites at ultra-low additions. What is very surprising is that only 1.0 wt% MXene@PBA can easily enhance the UL-94 rating of EP-1.0%MXene@PBA to V0. Meanwhile, the peak heat release rate (pHRR), total smoke production (TSP), and peak CO production rate (pCO) are remarkably reduced by 36.70%, 34.28%, and 43.48%, compared to those of the pristine epoxy resin, respectively. Furthermore, the 1.0 wt% MXene@PBA nanohybrids can enhance the flexural and impact strengths of EP-1.0%MXene@PBA. This work provides a feasible strategy for the creation of multifunctional MXene derivatives and their polymeric nanocomposites and holds great promise for many industrial applications.
开发具有增强机械性能的高效阻燃 MXene 基聚合物材料一直是一个巨大的挑战。在本文中,普鲁士蓝类似物(PBA)通过静电自组装方法修饰了MXene纳米片的表面,从而构建了分层的MXene基纳米杂化物(MXene@PBA)。然后,将 MXene@PBA 添加到环氧基体中,制备出高性能环氧纳米复合材料(EP-MXene@PBA)。研究表明,分层 MXene@PBA 在环氧基体中表现出优异的分散性能。值得注意的是,MXene@PBA 能以超低添加量实现环氧纳米复合材料的高效阻燃和抑烟效果。令人惊讶的是,仅 1.0 wt% 的 MXene@PBA 就能轻松地将 EP-1.0%MXene@PBA 的 UL-94 等级提高到 V0。同时,与原始环氧树脂相比,峰值热释放率(pHRR)、总烟雾产生率(TSP)和峰值 CO 产生率(pCO)分别显著降低了 36.70%、34.28% 和 43.48%。此外,1.0 wt% MXene@PBA 纳米杂化物还能提高 EP-1.0%MXene@PBA 的抗弯强度和冲击强度。这项工作为创造多功能 MXene 衍生物及其聚合物纳米复合材料提供了一种可行的策略,并为许多工业应用带来了巨大的前景。
Construction of an epoxidized, phosphorus-based poly(styrene butadiene styrene) and its application in high-performance epoxy resin
Wang Cheng, Huo Siqi, Ye Guofeng, Wang Bingtao, Guo Zhenghong, Zhang Qi, Song Pingan, Wang Hao, Liu Zhitian
doi:10.1016/j.compositesb.2023.111075
环氧化磷基聚(苯乙烯-丁二烯-苯乙烯)的构建及其在高性能环氧树脂中的应用
In modern industries, the demand of multifunctional, transparent epoxy resin (EP) combining superior dielectric, mechanical, and fire-safety performances is gradually increasing. However, it was difficult to realize such a performance portfolio in current research. Herein, we fabricated an epoxidized, phosphaphenanthrene-containing poly(styrene butadiene styrene) (ESD) for advanced fire-safe EP. ESD maintains the high transparency of EP and improves the UV-blocking property. 10 wt% ESD makes EP/DDM/10ESD pass a limiting oxygen index (LOI) of 36.0 % and a UL-94 V-0 rating. EP/DDM/10ESD displays improved mechanical properties because of intramolecular cavities and rigid P-based groups in ESD, as reflected by 79.2 %, 68.9 %, and 67.6 % increases in impact strength, tensile strength, and fracture toughness (KIC) relative to EP/DDM. Compared with EP/DDM, EP/DDM/10ESD shows obviously-decreased dielectric constant and loss. EP/DDM/10ESD outperforms many fire-safe epoxy resins due to its superior comprehensive performances. Thus, this work delivers an effective method for developing multifunctional flame-retardant epoxy resin.
在现代工业中,对兼具优异介电性能、机械性能和防火安全性能的多功能透明环氧树脂(EP)的需求逐渐增加。然而,目前的研究很难实现这种性能组合。在此,我们制备了一种环氧化、含磷菲的聚苯乙烯-丁二烯-苯乙烯(ESD),用于先进的防火安全环氧树脂。ESD 保持了 EP 的高透明度,并改善了其紫外线阻隔性能。10 wt% 的 ESD 使 EP/DDM/10ESD 的极限氧指数 (LOI) 达到 36.0 %,并通过了 UL-94 V-0 评级。由于 ESD 中的分子内空腔和刚性 P 基团,EP/DDM/10ESD 的机械性能得到了改善,与 EP/DDM 相比,其冲击强度、拉伸强度和断裂韧性(KIC)分别提高了 79.2%、68.9% 和 67.6%。与 EP/DDM 相比,EP/DDM/10ESD 的介电常数和损耗明显降低。EP/DDM/10ESD 的综合性能优于许多防火环氧树脂。因此,这项工作为开发多功能阻燃环氧树脂提供了一种有效的方法。
Ultrathin solid polymer electrolyte enabling mechanically-strong energy storing fiber reinforced composites
Chen Yifan, Xie Tianming, Dai Tengfei, Qiao Xinfeng, Fu Yu, Li Yan
doi:10.1016/j.compscitech.2023.110319
超薄固体聚合物电解质可实现机械强度高的储能纤维增强复合材料
Structural batteries attract enormous research interest due to their advantages of integrated energy storage function in structure. Superior to the co-cured composite structural batteries based on glass fiber supported/reinforced liquid/low-strength polymer electrolyte, enhanced mechanical strength of solid polymer electrolyte would enable the facile fabrication of composite structural batteries through layer-by-layer stack up of composites and solid-state batteries. This work encloses a mechanically strong and self-supportive solid polymer electrolyte with a tensile strength of 9.28 MPa, significantly superior to the traditional PEO (Lithium salt) electrolyte. Systematic analysis of phase-microstructure-mechanical/electrochemical properties relationship of SPE with different fluoroethylene carbonate (FEC) amounts helps to find out a solid polymer electrolyte (SPE) with satisfactory ionic conductivity (0.35 × 10−4 S/cm) and high electrochemical stability window (4.6 V vs Li/Li+), based on which dimension-adaptable and mechanically-strong energy storing laminates which have high tensile strength of 343 MPa, tensile modulus of 30.6 GPa, flexural strength of 308 MPa, and high impact resistance have been successfully fabricated. The most surprising result is a capacity retention of as high as 67% of the original capacity in the 1st cycle and stable cycling of composite structural batteries over 50 cycles for the failed tensile sample, which points out its potential application in emergency rescue. We believe this work not only presents a facile method to fabricate solid polymer electrolytes but demonstrates the potential of this solid polymer electrolyte in facile fabrication of mechanically-strong composite structural batteries.
结构电池因其在结构上集成储能功能的优势而备受研究关注。与基于玻璃纤维支撑/增强液态/低强度聚合物电解质的共固化复合结构电池相比,固体聚合物电解质的机械强度更高,可以通过逐层堆叠复合材料和固态电池来方便地制造复合结构电池。这项研究获得了一种机械强度高、自支撑性强的固体聚合物电解质,其拉伸强度达到 9.28 兆帕,明显优于传统的 PEO(锂盐)电解质。对不同氟碳酸乙烯酯(FEC)用量的固态聚合物电解质的相-微观结构-机械/电化学性能关系进行系统分析,有助于找到一种具有令人满意的离子电导率(0.35 × 10-4 S/cm)和高电化学稳定性窗口(4.6 V vs Li/Li+),并在此基础上成功制造出了尺寸适应性强、机械强度高的储能层压板,其抗拉强度高达 343 MPa,拉伸模量为 30.6 GPa,抗弯强度为 308 MPa,并且具有很强的抗冲击性。最令人惊讶的结果是,拉伸失败的样品在第一个循环中的容量保持率高达原始容量的 67%,并且复合结构电池在 50 个循环中保持稳定循环,这指出了其在紧急救援中的潜在应用。我们相信,这项工作不仅提出了一种制造固体聚合物电解质的简便方法,而且证明了这种固体聚合物电解质在简便制造机械强度复合结构电池方面的潜力。