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【新文速递】2024年10月23日复合材料SCI期刊最新文章

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今日更新:Composite Structures 6 篇,Composites Part B: Engineering 2 篇,Composites Science and Technology 1 篇

Composite Structures

Effective flexoelectric properties of inclusion-based composites based on strain gradient theory and homogenization technique

Liangliang Chu, Fuqi Zhou, Guansuo Dui

doi:10.1016/j.compstruct.2024.118665

基于应变梯度理论和均质化技术的包体基复合材料有效挠电性能研究

This study focuses on enhancing flexoelectricity in composites and develops a new micromechanical analytical framework to determine the effective electromechanical properties of inclusion-based flexoelectric composites within the context of SGE. Initially, we specialize in studying isotropic materials and derive the governing Navier equations for the problem. Subsequently, we streamline these differential equations by introducing a Laplacian-type gradient state variable, departing from higher-order gradient-enrichment treatments. The study employs Green’s functions and stress polarization tensors for spherical inhomogeneities, deriving homogenized material properties through volumetric averages of microscopic properties weighted by displacement localization operators. The analytical scheme’s relevance is validated against results from reference models and experimental data. Effective composite properties are evaluated using numerical methods, with an emphasis on assessing the impact of reinforcement on these properties. Our findings lay the foundation for developing a micromechanical method to predict the electromechanical behavior of composites. Specifically, we demonstrate the efficacy of our proposed theory by deriving effective flexoelectric properties of particulate composites.

本研究的重点是增强复合材料的挠曲电性能,并开发了一种新的微力学分析框架,以确定在SGE背景下基于内含物的挠曲电复合材料的有效机电性能。最初,我们专注于研究各向同性材料,并推导出该问题的控制Navier方程。随后,我们通过引入拉普拉斯型梯度状态变量来简化这些微分方程,脱离高阶梯度富集处理。该研究采用格林函数和应力极化张量来描述球面非均质性,通过位移局部化算子加权微观特性的体积平均来推导均质材料特性。通过参考模型和实验数据验证了分析方案的相关性。使用数值方法评估有效复合材料的性能,重点是评估增强对这些性能的影响。我们的发现为开发一种微力学方法来预测复合材料的机电行为奠定了基础。具体来说,我们通过推导颗粒复合材料的有效挠曲电性能来证明我们提出的理论的有效性。


An ultrathin ultralight electromagnetic absorber based on shortcut glass-coated amorphous magnetic Fiber/Salisbury-like screen

Hui Ji, Hong Xiao, Xinyi Ruan, Jianying Chen, Guoliang Dai, Ni Wang

doi:10.1016/j.compstruct.2024.118667

基于快速玻璃涂层非晶磁性纤维/索尔兹伯里屏的超薄超轻电磁吸收器

A structural design methodology is proposed for an ultrathin, ultralight, and absorption-adjustable electromagnetic absorber. The proposed absorber (SFSL) consists of an absorbing layer with shortcut glass-coated amorphous magnetic fiber and a substrate layer with transmitting material. This absorber features a Salisbury-like screen structure and incorporates multiple loss mechanisms. By investigating the influence of fiber distribution, length, content, and substrate layer thickness on absorption performance, it has been determined that the weight per square meter and thickness of a single-layer SFSL can be lowered within 50 g/m2 and 1.5 mm respectively. Furthermore, the absorption intensity and bandwidth can be adjusted by manipulating these parameters. The SFSL exhibits resonant behavior similar to that of a metamaterial absorber; however, SFSL with randomly distributed fibers demonstrates broader and stronger absorption characteristics in the frequency range from 2 to18 GHz. Additionally, the thicknesses of the substrate layer and surface covering affect the electromagnetic response characteristics. This work provides a simple strategy for constructing an ultrathin and ultralight composite to achieve efficient absorption of electromagnetic waves.

提出了一种超薄、超轻、吸光度可调电磁吸收体的结构设计方法。所提出的吸波器(SFSL)由具有近距离玻璃涂层的非晶磁性光纤的吸收层和具有透射材料的基板层组成。这种吸收器具有索尔兹伯里式的屏幕结构,并结合了多种损耗机制。通过研究纤维分布、长度、含量和衬底层厚度对吸光性能的影响,确定单层SFSL的每平方米重量和厚度分别可以降低在50 g/m2和1.5 mm以内。此外,可以通过控制这些参数来调节吸收强度和带宽。SFSL具有类似于超材料吸收体的谐振特性;而光纤随机分布的SFSL在2 ~ 18 GHz频率范围内具有更宽、更强的吸收特性。此外,衬底层和表面覆盖层的厚度也会影响电磁响应特性。这项工作为构建超薄和超轻的复合材料提供了一种简单的策略,以实现电磁波的有效吸收。


Machine learning for nano-level defect detection in aligned random carbon nanotubes-reinforced electrically conductive nanocomposite

Iskander S. Akmanov, Stepan V. Lomov, Mikhail Y. Spasennykh, Sergey G. Abaimov

doi:10.1016/j.compstruct.2024.118651

定向随机碳纳米管增强导电纳米复合材料纳米级缺陷检测的机器学习

Machine learning allows fast nano-scale defect detection in polymer-impregnated aligned carbon nanotube (CNT) nanocomposites. Digital twins were populated by TEM-validated geometry; considered defects were flat cracks and close-to-spherical voids. Finite-element analysis of piezoresistive response was conducted by embedment of CNT network into matrix. Identification of a defect by change in CNT network piezoresistivity was challenged by: (1) randomness of CNTs’ shapes and placement, ML training happened on random realisations; (2) high strength of CNTs leading to the preservation of conductive paths along CNTs and changes only in conductivities of tunnelling contacts. “Artificial approximation“ was introduced to economise computer time multi-fold: ML was trained on cases with artificially degraded tunnelling conductivities within the defect. Three ML models: XGBoost, fully connected, and convolution neural networks were employed. All models managed the task for near-spherical voids, but performed poorly for flat cracks, due to the limited number of tunnelling contacts in crack volume. When trained on the mixed set of voids and cracks, both neural networks demonstrated the ability to learn the difference and detected even cracks, while XGBoost was not up to the challenge. By metrics, the convolutional neural network demonstrated the highest accuracy of predictions.

机器学习允许在聚合物浸渍排列碳纳米管(CNT)纳米复合材料中快速检测纳米级缺陷。数字双胞胎由tem验证的几何图形填充;考虑的缺陷是平坦的裂纹和接近球形的空隙。将碳纳米管网络嵌入到矩阵中,进行了压阻响应的有限元分析。通过碳纳米管网络压电阻率的变化来识别缺陷面临以下挑战:(1)碳纳米管形状和位置的随机性,机器学习训练发生在随机实现上;(2)碳纳米管的高强度使得沿碳纳米管的导电路径得以保留,只改变了隧道触点的电导率。引入“人工近似”以节省计算机时间:ML在缺陷内人为降低隧道电导率的情况下进行训练。使用了三种ML模型:XGBoost、全连接和卷积神经网络。所有模型都可以处理近球形空洞的任务,但由于裂纹体积中隧道接触的数量有限,对于扁平裂纹表现不佳。当在空洞和裂缝的混合集上进行训练时,两种神经网络都表现出了学习差异的能力,甚至可以检测到裂缝,而XGBoost无法应对挑战。通过度量,卷积神经网络显示出最高的预测准确性。


Experimental investigation of the behavior of UHPCFST under repeated eccentric compression

Chunlei Yu, Min Yu, Lihua Xu, Liu Sumei, Zewen Sun, Jianqiao Ye

doi:10.1016/j.compstruct.2024.118661

反复偏心压缩下UHPCFST性能的实验研究

This paper investigates the mechanical behavior of ultra-high-performance concrete-filled steel tubes (UHPCFST) under repeated eccentric compression. A total of 30 UHPCFST specimens are designed, fabricated, and tested. The design variables include steel tube thickness, UHPC type, loading eccentricity and load pattern. Failure modes, force-axial shortening curves, section strain distributions, lateral deflection distributions, bearing capacity and stiffness are studied. Three failure modes, i.e., steel tube bulge, compressive crush and tensile crack of the UHPC infill are observed. Specimens with larger loading eccentricity and thinner steel tube are more likely to exhibit all the three modes. Subjected to eccentric loading, the compressive strength and stiffness of the UHPCFST increase significantly with the increase of steel tube thickness and UHPC strength. In the case of repeated loading, stiffness degradation is observed. Existing formulas for the N-M curve and the eccentric compressive capacity are evaluated against the test results. A formula for eccentric compressive stiffness is derived based on the parabolic function assumption. Additionally, an empirical model is introduced to describe the force-axial shortening relationship of the UHPCFST under repeated eccentric compression, which may be applied in practical design and analysis.

本文研究了超高性能钢管混凝土(UHPCFST)在反复偏心受压作用下的力学性能。共设计、制作和测试了30个UHPCFST试件。设计变量包括钢管厚度、UHPC类型、加载偏心和加载方式。研究了破坏模式、力-轴缩短曲线、截面应变分布、侧向挠度分布、承载力和刚度。观察到钢管胀裂、压碎和拉裂三种破坏模式。加载偏心率越大、钢管越薄的试件更容易出现三种模态。在偏心载荷作用下,随着钢管厚度的增加和UHPC强度的增加,UHPCFST的抗压强度和刚度显著增加。在重复加载的情况下,观察到刚度退化。根据试验结果对现有的N-M曲线和偏心抗压能力公式进行了评价。基于抛物线函数假设,导出了偏心抗压刚度的计算公式。此外,还引入了一个经验模型来描述UHPCFST在反复偏心压缩下的力-轴向缩短关系,该模型可用于实际设计和分析。


Mechanical model analysis of column-footing joints with combined socket-corrugated pipe connection

Xiaolong Si, Yanchen Song, Guangda Zhang, Qiang Han, Xiuli Du, Bin Liu

doi:10.1016/j.compstruct.2024.118666

套筒-波纹管组合式柱-基础节点力学模型分析

The socket connection method is widely used in precast column, particularly in seismic regions. However, reducing the socket-depth to lower costs may lead to shear failure in the socketed part of the columns. To address this issue and achieve cost objectives, a new approach combines shallow sockets with corrugated pipes for column-footing joints. Comparative tests were conducted to investigate failure in columns with socket-corrugated pipe connections (SCPC), shallow sockets (SSC), and cast-in-place (CIP). Furthermore, finite element models were employed to validate the experimental and simplified model results. The findings suggest potential shear failure in shallow socket connections, which can be mitigated by using the combined socket-corrugated pipe method that alters force transmission paths. As the axial load ratio increases, both the ultimate lateral load capacity of the specimen and the local stresses at the column base increase. In addition, the ultimate lateral load capacity of the column and the stress of the connection reinforcement are increased by increasing the strength of the longitudinal reinforcement, consequently amplifying the extent of joint area damage. Finally, a simplified strut-and-tie model of the SCPC, validated against numerical and experimental data, accurately represents force paths, ultimate lateral load capacity and failure modes in socket joints.

嵌套连接法在预制柱中得到了广泛的应用,特别是在震区。然而,为了降低成本而减小嵌套深度可能会导致柱嵌套部分的剪切破坏。为了解决这一问题并实现成本目标,一种新的方法将浅插座与波纹管结合起来用于柱基础连接。进行了对比试验,研究了嵌套-波纹管连接(SCPC)、浅嵌套(SSC)和现浇(CIP)柱的破坏情况。采用有限元模型对实验结果和简化模型结果进行了验证。研究结果表明,浅套筒连接的潜在剪切破坏可以通过使用改变力传递路径的套筒-波纹管组合方法来减轻。随着轴向荷载比的增大,试件的极限侧载能力和柱底局部应力均增大。此外,纵筋强度的增加增加了柱的极限侧载能力和连接筋的应力,从而扩大了节点区域的破坏程度。最后,通过数值和实验数据验证了SCPC的简化杆扎模型,该模型准确地反映了承插节点的受力路径、极限侧向载荷能力和破坏模式。


Composites Part B: Engineering

Fibre waviness reduction in thermoplastic pultrusion by using DREF yarns

Maissaloun El-Jakl, Louis Laberge Lebel

doi:10.1016/j.compositesb.2024.111908

用DREF纱降低热塑性拉挤中的纤维波浪度

Non-reactive thermoplastic pultrusion impregnation issues are mitigated by using hybrid input materials. Co-wound (CW) and commingled yarns are an assembly of continuous polymer and reinforcement fibres. Continuous thermoplastic fibres have shown to induce waviness in the reinforcement fibres during pultrusion due to their shrinkage at high temperature. DREF yarns are composed of a core of continuous reinforcement fibres onto which discontinuous polymer fibres are applied using the friction spinning process. This study, based on the application of 3N and 0N tension on CW and DREF yarns, aimed to highlight the contribution of discontinuous polymer fibres on reducing reinforcement waviness in pultruded rods. CW yarns’ reaction to heating showed continuous polyethylene terephthalate (PET) fibres shrinkage resulting in wavy glass fibres (GF). Conversely, the GF in DREF yarns remained straight. Pultrusion experiments with yarn tension of 3N were done to alleviate the GF waviness. However, the porosity was rather high at 4.2% for CW rods and 2.3% for DREF rods. Pultrusion experiments without tension showed lower porosity of level of 2.9% for CW yarns and as low as 1.1% for DREF yarns. However, CT-scan image indicated GF waviness in CW rods. GF in DREF rods remained straight. The in-plane shear strength reached 119 MPa. Thermoplastic pultrusion using DREF yarns resulted in composites without reinforcement fibre waviness, lower porosity level and superior shear strength.

非反应性热塑性拉挤浸渍问题通过使用混合输入材料得到缓解。共卷纱和混纺纱是由连续聚合物和增强纤维组成的纱线。连续热塑性纤维由于在高温下收缩,在拉挤过程中会引起增强纤维的波纹。DREF纱线由连续的增强纤维芯组成,在其上采用摩擦纺丝工艺应用不连续的聚合物纤维。本研究基于3N和0N张力在CW和DREF纱线上的应用,旨在突出不连续聚合物纤维在减少拉挤棒中的增强波浪度方面的贡献。连续化纤对加热的反应表明,聚酯纤维连续收缩,形成波浪状的玻璃纤维。相反,DREF纱线中的GF保持直。为了减轻纤维的波纹,进行了纱线张力为3N的拉挤实验。然而,CW棒的孔隙率相当高,为4.2%,DREF棒为2.3%。无张力拉挤实验表明,连续化纤纱线的孔隙率为2.9%,而DREF纱线的孔隙率为1.1%。然而,ct扫描图像显示在CW棒GF波状。在DREF棒中GF保持直。面内抗剪强度达到119 MPa。采用DREF纱线进行热塑性拉挤制备的复合材料无增强纤维波纹,孔隙率低,抗剪强度高。


A novel model for predicting deformation of thermoplastic composites during heat-pressing process

Jiezheng Qiu, Zhonghai Xu, Chaocan Cai, Dianyu Chen, Shiging Huang, Chunxing Hu, Xiaodong He

doi:10.1016/j.compositesb.2024.111912

一种预测热塑性复合材料热压变形的新模型

Carbon fiber/polyetheretherketone (CF/PEEK) thermoplastic composites are widely used in the aerospace industry due to their excellent mechanical properties and high-temperature resistance. However, the research on heat-pressing deformation and residual stress during high-temperature and high-pressure heat-pressing processes in CF/PEEK was relatively deficient. In this paper, a framework coupled with crystallization kinetics, micromechanics and thermodynamics was developed to predict the heat-pressing deformations of CF/PEEK and it was conducted by UMAT, DISP and UEXPAN subroutines. Moreover, the predictive model was verified by experiments effectively. Finally, we compared the difference in residual stress distributions between symmetric and asymmetric lay-ups and found that the melting temperature, thickness, angle and sequence of layers have a significant impact on the heat-pressing deformation. This work provided an effective tool for predicting heat-pressing deformations, which is great of significance in the manufacturing and application of CF/PEEK.

碳纤维/聚醚醚酮(CF/PEEK)热塑性复合材料因其优异的机械性能和耐高温性能而广泛应用于航空航天工业。然而,对CF/PEEK高温高压热压过程中的热压变形和残余应力的研究相对缺乏。本文建立了一个结合结晶动力学、微观力学和热力学的框架,通过UMAT、DISP和UEXPAN子程序对CF/PEEK的热压变形进行了预测。通过实验验证了该预测模型的有效性。最后,对比了对称层和非对称层的残余应力分布差异,发现熔化温度、层厚、层角和层序对热压变形有显著影响。该工作为预测CF/PEEK的热压变形提供了有效的工具,对CF/PEEK的制造和应用具有重要意义。


Composites Science and Technology

Vascular Bundle-Structured Polymeric Composites with Fire-safe, Self-detecting and Heat Warning Capabilities for Power Batteries Thermal Management

Xinyan An, Nvfan Tang, Yilin Liu, Shiqiang Song, Chaoyue Chen, Guohao Han, Weizhen Li, Yong Zhang

doi:10.1016/j.compscitech.2024.110921

 

用于动力电池热管理的具有火灾安全、自探测和热预警能力的维管束结构聚合物复合材料

The trend of miniaturization and integration poses challenges to the thermal management of electronic devices, requiring high thermal conductivity and potential fire safety, etc. In this study, inspired by plant vascular structure, we developed a polymer composite with a vertical vascular bundle structure via a sacrificial template method and subsequent assembly of transition metal carbides/nitrides (MXene) nanosheets and phytic acid (PA) coordinated cobalt ions (Co2+) complex. The embedded MXene and PA@Co exhibit multilayer multiscale structural features, forming heat transfer channels and protective cells within the composite. The resultant composites possess high out-of-plane thermal conductivity (∼1.54 W‧m-1‧k-1) and excellent flame retardancy, including self-extinguishing, and significantly reduced heat and smoke release. Interestingly, the MXene vascular bundle structure imparts heat early warning capabilities and intelligent damage self-detection, suggesting an effective means of preventing early-stage fires and real-time monitoring of composite structural and functional integrity. Such biomimetic strategies enable new insights into the designing of multifunctional, intelligent polymer composites.

小型化和集成化的趋势对电子器件的热管理提出了挑战,要求高导热性和潜在的火灾安全等。在本研究中,受植物维管束结构的启发,我们通过牺牲模板法和随后的过渡金属碳化物/氮化物(MXene)纳米片和植酸(PA)配位钴离子(Co2+)配合物的组装,开发了具有垂直维管束结构的聚合物复合材料。嵌入的MXene和PA@Co表现出多层多尺度的结构特征,在复合材料内部形成传热通道和保护细胞。合成的复合材料具有高的面外导热系数(约1.54 W·m·1·k-1)和优异的阻燃性,包括自熄性,并显着减少热量和烟雾释放。有趣的是,MXene维管束结构具有热预警能力和智能损伤自检测能力,是预防早期火灾和实时监测复合材料结构和功能完整性的有效手段。这种仿生策略为多功能智能聚合物复合材料的设计提供了新的见解。



来源:复合材料力学仿真Composites FEM
ACTMechanicalHPCInspireMAGNETDeform复合材料电路航空航天电子裂纹理论材料多尺度仿生控制试验
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【新文速递】2024年10月28日复合材料SCI期刊最新文章

今日更新:Composites Part A: Applied Science and Manufacturing 3 篇,Composites Part B: Engineering 4 篇,Composites Science and Technology 1 篇Composites Part A: Applied Science and ManufacturingImproving strength-ductility synergy of titanium matrix composites containing nitrogen via the introduction of intragranular nano-TiBKe Feng, Hongmei Zhang, Xingwang Cheng, Qunbo Fan, Xiaonan Mu, Yanan Sun, Ni Xiong, Hao wang, Hongqiang Duan, Yu Wangdoi:10.1016/j.compositesa.2024.108551通过引入晶内纳米tib提高含氮钛基复合材料的强度-塑性协同作用We prepared a titanium matrix composite (TMC) with added boron nitride nanosheets (BNNSs) for strength-ductility trade-off issues. The composite, characterized by in-situ nano-TiB intragranular distribution and trace nitrogen solid solution, was prepared using rapid hot press sintering (FHP) and short-duration hot rolling. During pre-rolling heat preservation, the diffusion of boron and nitrogen resulted in the intragranular distribution of nano-TiB and nitrogen solid solution. The nano-TiB demonstrated excellent load transfer, fracture suppression, and dislocation storage capabilities at both room and high temperatures. Coupled with the nitrogen solid solution, the composite exhibited a significant enhancement in strain hardening effect compared to the titanium matrix. The composite outperformed the titanium matrix in strength and ductility at both room and high temperatures, demonstrating a notable strength-ductility synergy. This work provides a reference for designing TMCs with excellent performance at both room and high temperatures.为了解决强度与延性的权衡问题,我们制备了一种添加氮化硼纳米片的钛基复合材料(TMC)。采用快速热压烧结(FHP)和短时间热轧法制备了原位纳米tib晶内分布和微量氮固溶体的复合材料。在预轧保温过程中,硼和氮的扩散导致纳米tib和氮固溶体在晶内分布。纳米tib在室温和高温下均表现出优异的载荷传递、断裂抑制和位错存储能力。与钛基相比,氮固溶体对复合材料的应变硬化效果有显著增强。该复合材料在室温和高温下的强度和延展性都优于钛基,表现出显著的强度-延性协同效应。为设计室温和高温下性能优异的tmc材料提供了参考。Intelligent predicting and monitoring of ultra-high-performance fiber reinforced concrete composites − A reviewDingqiang Fan, Ziao Chen, Yuan Cao, Kangning Liu, Tianyi Yin, Xue-Sen Lv, Jian-Xin Lu, Ao Zhou, Chi Sun Poon, Rui Yudoi:10.1016/j.compositesa.2024.108555高性能纤维增强混凝土复合材料智能预测与监测研究综述Ultra-high-performance fiber reinforced concrete (UHPFRC) is an advanced composite known for its exceptional mechanical properties and durability, playing a vital role in modern civil engineering. The convergence of cutting-edge information technology has propelled UHPFRC into a new era characterized by intelligent advancements. This review explores state-of-the-art advancements in UHPFRC, focusing on two key areas: intelligent prediction methods and monitoring techniques. Current methods for predicting UHPFRC properties are mainly divided into statistical and machine learning (ML) approaches. While statistical methods rely on regression models derived from experimental data, ML techniques leverage artificial intelligence to deliver higher accuracy in predicting UHPFRC properties. The intelligent monitoring methods for UHPFRC structures predominantly include sensor monitoring, visual identity monitoring and self-sensing monitoring. AI aid method can further improve the efficiency of the sensor monitoring. Among these, self-sensing monitoring has good prospects since it can be motivated by the piezoelectric effect of the UHPFRC matrix acting as a sensor for in-situ monitoring. The integration of these intelligent prediction and monitoring systems indicates a significant advancement for UHPFRC, enhancing its capability as an intelligent construction material that supports performance evaluation and structural monitoring during its life cycle.超高性能纤维增强混凝土(UHPFRC)是一种先进的复合材料,以其优异的力学性能和耐久性而闻名,在现代土木工程中发挥着至关重要的作用。前沿信息技术的融合,推动UHPFRC进入了智能化发展的新时代。本综述探讨了UHPFRC的最新进展,重点关注两个关键领域:智能预测方法和监测技术。目前预测UHPFRC性能的方法主要分为统计方法和机器学习方法。统计方法依赖于来自实验数据的回归模型,而机器学习技术利用人工智能在预测UHPFRC性能方面提供更高的准确性。UHPFRC结构的智能监测方法主要包括传感器监测、视觉识别监测和自感知监测。人工智能辅助方法可以进一步提高传感器监测的效率。其中,利用UHPFRC基体的压电效应作为传感器进行原位监测,具有良好的应用前景。这些智能预测和监测系统的集成标志着UHPFRC的重大进步,增强了其作为智能建筑材料的能力,支持其生命周期内的性能评估和结构监测。Polyaniline nanoparticles intercalated Ti3C2 MXene reinforced waterborne epoxy nanocomposites for electromagnetic wave absorption and anticorrosion coating applicationsQingsong Zhu, Xinyu Lei, Xiaoqin Zha, Eman Ramadan Elsharkawy, Chenye Ren, Huiyuan Chang, Salah M. El-Bahy, Juanna Ren, Renjie Wang, Zeinhom M. El-Bahy, Zhanhu Guodoi:10.1016/j.compositesa.2024.108557聚苯胺纳米粒子插层Ti3C2 MXene增强水性环氧纳米复合材料的电磁波吸收和防腐涂层应用Ti3C2 MXene (TM) has great application potential in the field of wave absorption and corrosion resistance due to its unique performance, such as high specific surface area, high electrical conductivity, excellent mechanical and good chemical stability. However, it is difficult to obtain uniformly dispersed TM in the resin matrix due to rapid agglomeration behavior. It is difficult to obtain uniformly dispersed Ti3C2 MXene (TM) in the resin matrix due to rapid agglomeration behavior. Heren, a novel method is presented to improve the corrosion protection and dispersion of TM by polymerizing polyaniline (PANI) nanoparticles between layers. The waterborne epoxy (WEP) coating with PANI-TM had high mechanical properties including impact resistance, adhesion, and flexibility and wear resistance. The PANI-TM-WEP composites can effectively absorb more than 90 % of the electromagnetic waves and demonstrate a decreased glass transition temperature of WEP from 128.0 to 107.6 ℃. Moreover, the |Z|0.01Hz value of the PANI-TM0.5 % was 1.2369 × 106 Ω·cm2, which was one order of magnitude larger than WEP coating. The high-performance anticorrosion of PANI intercalated TM coating is attributed to the synergistic effect of impermeable TM nanosheets and passivation effect of PANI. Therefore, PANI-TM is a potential choice for applications in the fields of anticorrosion and microwave absorption.Ti3C2 MXene (TM)具有高比表面积、高导电性、优异的机械稳定性和良好的化学稳定性等独特性能,在吸波和耐腐蚀领域具有很大的应用潜力。然而,由于其快速的团聚行为,很难在树脂基体中获得均匀分散的TM。由于Ti3C2 MXene (TM)在树脂基体中的快速团聚行为,很难得到均匀分散的Ti3C2 MXene (TM)。本文提出了一种通过层间聚合聚苯胺(PANI)纳米粒子来提高TM防腐蚀性能和分散性的新方法。聚苯胺- tm水性环氧树脂(WEP)涂层具有良好的抗冲击、附着力、柔韧性和耐磨性等力学性能。PANI-TM-WEP复合材料能有效吸收90% %以上的电磁波,并将WEP的玻璃化转变温度从128.0℃降低到107.6℃。pani - tm0.5%涂层的|Z|0.01Hz值为1.2369 × 106 Ω·cm2,比WEP涂层大一个数量级。不透水TM纳米片与聚苯胺的钝化作用协同作用,使聚苯胺嵌层TM涂层具有高性能的防腐性能。因此,聚苯胺- tm在防腐和微波吸收领域具有潜在的应用前景。Composites Part B: EngineeringMultifunctional Highly Conductive Cellulose Nanopaper with Ordered PEDOT:PSS Alignment Enabled by External Surface Area-Promoted Phase SeparationNingxin Chen, Sida Xie, Jie Deng, Biao Wang, Shanchen Yang, Zhaohui Wangdoi:10.1016/j.compositesb.2024.111919 具有有序PEDOT的多功能高导电纤维素纳米纸:由外表面积促进相分离使PSS对齐Integrating cellulose, the most abundant biopolymer on Earth, with PEDOT:PSS, the most commercially available conducting polymer, can create multifunctional conductive nanopapers for sustainable electronics. However, conventional PEDOT:PSS/cellulose composites often exhibit limited conductivity, primarily due to the random distribution of PEDOT and the aggregation of PSS within the cellulose matrix. Herein, we introduce a confined phase separation approach that leverages the inherent physical characteristics of the cellulose substrate to enhance the performance of these composites. By systematically investigating the influence of the external surface area of nanocellulose on PEDOT:PSS coverage and composition evolution, we demonstrate that a higher external surface area ensures uniform PEDOT:PSS coating on nanocellulose networks and facilitates effective PSS removal during secondary doping. This process enhances phase separation and promotes ordered alignment of PEDOT chains along nanocellulose, resulting in an electrical conductivity of up to 252 S cm-1. Such highly conductive nanopapers exhibit exceptional performances in supercapacitors and electromagnetic shielding, achieving an ultrahigh specific electromagnetic shielding effectiveness of 33,122 dB cm2 g⁻1 at only 6 μm thickness. Our study highlights the critical role of cellulose substrate selection at the nanoscale and elucidates the interactions within conducting polymers, offering a promising pathway for developing high-performance, sustainable electronics.将纤维素(地球上最丰富的生物聚合物)与PEDOT:PSS(最具商业价值的导电聚合物)结合起来,可以为可持续电子产品创造多功能导电纳米纸。然而,传统的PEDOT:PSS/纤维素复合材料通常表现出有限的导电性,主要是由于PEDOT的随机分布和PSS在纤维素基体中的聚集。在这里,我们介绍了一种限制相分离方法,利用纤维素基质的固有物理特性来增强这些复合材料的性能。通过系统地研究纳米纤维素的外表面积对PEDOT:PSS覆盖和组成演变的影响,我们证明了更高的外表面积可以确保纳米纤维素网络上均匀的PEDOT:PSS涂层,并有助于在二次掺杂过程中有效地去除PSS。这一过程增强了相分离,促进了PEDOT链沿纳米纤维素的有序排列,导致电导率高达252 S cm-1。这种高导电性的纳米纸在超级电容器和电磁屏蔽方面表现出优异的性能,在仅6 μm的厚度下实现了33122 dB cm2 g - 1的超高比电磁屏蔽效率。我们的研究强调了纤维素底物选择在纳米尺度上的关键作用,并阐明了导电聚合物内部的相互作用,为开发高性能、可持续的电子产品提供了一条有希望的途径。Natural loofah sponge inspired 3D printed bionic scaffolds promote personalized bone defect regenerationXingyu Gui, Ping Song, Boqing Zhang, Haoyuan Lei, Lina Wu, Jiayi Sun, Rong Tang, Hui Zhang, Yuxiang Qin, Zixuan Su, Jianxun Sun, Zhihe Zhao, Min Han, Wei Wei, Yujiang Fan, Changchun Zhoudoi:10.1016/j.compositesb.2024.111920受天然丝瓜海绵启发的3D打印仿生支架促进个性化骨缺损再生Critical-sized bone defects pose serious health concerns for patients. Clinically, the use of functionalized bone implants has emerged as an effective solution. However, the rapid advancement in drug and biomaterials has led to an increasing design cost, triggering discussions in the field about how to efficiently create customized functional bone implants. Inspired by the unique structure of natural loofah sponges that effectively deliver nutrients to seeds, we designed a functionalized bone implant emulating this structure. Drug-release gradients were achieved through the application of different concentrations of hydrogels within the composite scaffold. This approach allowed active substances to be released outwardly during the early stage of bone repair, sustaining a local drug micro-environment within the implant scaffold that promotes angiogenesis and osteogenic differentiation in damaged areas. In vivo experiments showed that our loofah sponge bionic scaffold outperformed traditional hydroxyapatite scaffolds by promoting both bone and vascular regeneration. We expect the design of loofah sponge bionic scaffold could potentially deliver an effective strategy in the development of functionalized bone implants.严重的骨缺损会给患者带来严重的健康问题。临床上,使用功能化骨植入物已成为一种有效的解决方案。然而,药物和生物材料的快速发展导致了设计成本的增加,引发了该领域关于如何有效地创建定制功能骨植入物的讨论。受天然丝瓜海绵独特结构的启发,我们设计了一种模拟这种结构的功能化骨植入物。通过在复合支架内应用不同浓度的水凝胶来实现药物释放梯度。这种方法允许活性物质在骨修复的早期阶段向外释放,在植入支架内维持局部药物微环境,促进受损区域的血管生成和成骨分化。体内实验表明,丝瓜海绵仿生支架在促进骨和血管再生方面优于传统的羟基磷灰石支架。我们期望丝瓜海绵仿生支架的设计能够为功能化骨植入物的开发提供一种有效的策略。Exceptional strength-toughness-hardness integrated B4C ceramics with synergistic reinforcement of nano-BN and in-situ ceramic phasesHeng Wang, Yi Zeng, Tianbin Zhu, Yibiao Xu, Yawei Li, Zhengyi Fudoi:10.1016/j.compositesb.2024.111921 优异的强度-韧性-硬度集成B4C陶瓷与纳米bn和原位陶瓷相的协同增强Boron carbide (B4C) ceramics with enhanced mechanical properties were fabricated by incorporating nano boron nitride (nano-BN), obtained through high-energy ball milling (HEBM) using ZrO2 balls as the medium, and utilizing the spark plasma sintering (SPS) technique. During the densification process of B4C/nano-BN composite powders, an in-situ reaction between the B4C matrix and ZrO2 resulted in the formation of ZrB2 ceramic phases at 1200-1300 °C. Additionally, the rapid sintering densification temperature of composites is reduced to 1500-1700 °C, approximately 80 °C lower than that required for pure B4C ceramics. Notably, while maintaining a high relative density (99.5%), the Vickers hardness, flexural strength, and fracture toughness of B4C ceramics reinforced with synergistic effects of nano-BN and ZrB2 fabricated at 1750 °C are significantly improved to reach values of 36.8±0.15 GPa, 701±12 MPa, and 5.01±0.13 MPa·m1/2 respectively; representing an increase of 3.5 GPa (10.5%), 225 MPa (47.3%), and 1.72 MPa·m1/2 (52.3%) compared to pure B4C ceramics alone. The multiple reinforcement mechanisms including pinning effects provided by nano-BN and in-situ formed ZrB2 ceramic phases, B4C/ZrB2 grain boundary pressure and intracrystalline pressure within B4C, interlayer dislocations of nano-BN and turbulent layer of B4C/BN boundaries contribute to energy dissipation during fracture processes, such as crack deflection, bridging, propagation hindrance and branching effect; ultimately resulting in exceptional strength-toughness-hardness integrated B4C-based ceramics.以ZrO2球为介质,采用高能球磨(HEBM)法制备纳米氮化硼(nano- bn),并采用火花等离子烧结(SPS)技术制备了具有增强力学性能的碳化硼(B4C)陶瓷。在B4C/纳米bn复合粉体的致密化过程中,B4C基体与ZrO2在1200 ~ 1300℃发生原位反应,形成ZrB2陶瓷相。此外,复合材料的快速烧结致密化温度降低到1500-1700℃,比纯B4C陶瓷低约80℃。值得注意的是,在保持较高相对密度(99.5%)的同时,在1750℃下制备的纳米bn和ZrB2协同增强的B4C陶瓷的维氏硬度、抗弯强度和断裂韧性显著提高,分别达到36.8±0.15 GPa、701±12 MPa和5.01±0.13 MPa·m1/2;分别比纯B4C陶瓷高3.5 GPa(10.5%)、225 MPa(47.3%)和1.72 MPa·m1/2(52.3%)。纳米BN和原位形成的ZrB2陶瓷相的钉钉效应、B4C/ZrB2晶界压力和B4C内的晶内压力、纳米BN的层间位错和B4C/BN晶界的湍流层等多种强化机制有助于断裂过程中的能量耗散,如裂纹偏转、桥接、扩展阻碍和分支效应;最终产生了卓越的强度-韧性-硬度集成的b4c基陶瓷。C/C-(Hf0.5Zr0.3Ti0.2)C-W-Cu composites: Long-term ablation resistance based on active-passive protection at 2600 °CJunjie Xu, Wei Sun, Xiang Xiong, Hongbo Zhangdoi:10.1016/j.compositesb.2024.111889C/C-(Hf0.5Zr0.3Ti0.2)C- w - cu复合材料:基于2600℃主动式被动防护的长期抗烧蚀性能Compared with the traditional C/C composites modified by ultra-high-temperature ceramics (C/C-UHTCs), those modified by metal/medium-entropy ceramics have excellent mechanical properties, thermophysical properties, and long-term ablation resistance. These composites have great potential towards improving the high-temperature resistance and service life of thermal protection systems for spacecraft. In this study, a new type of (Hf0.5Zr0.3Ti0.2)C-W-Cu cermet-modified C/C composites (C/C-(Hf0.5Zr0.3Ti0.2)C-W-Cu) was prepared at 1500 °C. Compared with C/C-UHTCs, the bending strength and fracture toughness of C/C-(Hf0.5Zr0.3Ti0.2)C-W-Cu increased by 70% and 110% to 364.25 MPa and 14.64 MPa·m1/2, respectively. Due to the high thermal conductivity of Cu and W, the thermal conductivity of this new composite was 106% higher than that of C/C-(Hf0.5Zr0.3Ti0.2)C (44.26 versus 21.53 W/m·K). Under a high heat flow of 4.18 MW/m2, this material exhibited very low mass and linear ablation rates (−0.163 mg/s and −0.193 μm/s, respectively). Active and passive protection occur during ablation due to the evaporative cooling of Cu, CuO, and WO3 as well as a dense outer oxide layer that inhibits oxygen diffusion. The internal oxide layer forms a Hf-Zr-Ti-C-O framework mingled with Ti-rich Ti-Hf-Zr-C-O and an unoxidised W-Cu structure, effectively reducing the osmotic oxygen content. This work provides a new direction for developing thermal protection materials capable of long-term service in ultra-high-temperature environments.与传统的超高温陶瓷(C/C- uhtcs)改性的C/C复合材料相比,金属/中熵陶瓷改性的C/C复合材料具有优异的力学性能、热物理性能和长期抗烧蚀性能。这些复合材料在提高航天器热防护系统的耐高温性能和使用寿命方面具有很大的潜力。本研究在1500℃下制备了一种新型(Hf0.5Zr0.3Ti0.2)C- w - cu陶瓷改性C/C复合材料(C/C-(Hf0.5Zr0.3Ti0.2)C- w - cu)。与C/C- uhtcs相比,C/C-(Hf0.5Zr0.3Ti0.2)C- w - cu的抗弯强度和断裂韧性分别提高了70%和110%,分别达到364.25 MPa和14.64 MPa·m1/2。由于Cu和W的高导热系数,该复合材料的导热系数比C/C-(Hf0.5Zr0.3Ti0.2)C (44.26 vs 21.53 W/m·K)高106%。在4.18 MW/m2的高热流下,该材料的质量烧蚀率和线性烧蚀率分别为- 0.163 mg/s和- 0.193 μm/s。由于Cu、CuO和WO3的蒸发冷却以及致密的外层氧化层抑制氧气扩散,在烧蚀过程中发生主动和被动保护。内部氧化层与富钛的Ti-Hf-Zr-C-O混合形成Hf-Zr-Ti-C-O骨架和未氧化的W-Cu结构,有效降低了渗透氧含量。本工作为开发能够在超高温环境下长期使用的热防护材料提供了新的方向。Composites Science and TechnologyLayer-by-layer assembling boron nitride/polyethyleneimine/MXene hierarchical sandwich structure onto basalt fibers for high-performance epoxy compositesYing Yu, Shaolong Han, Haoyu Wang, Gang Wei, Zheng Gu, Ping Handoi:10.1016/j.compscitech.2024.110931 在玄武岩纤维上逐层组装氮化硼/聚乙烯亚胺/MXene分层夹层结构制备高性能环氧复合材料Interfacial adhesion directly affects the mechanical properties of basalt fiber (BF)-reinforced polymer composites. To construct a more superior interphase between BFs and epoxy resin (EP) than a weak interphase of the unmodified BF/EP, we propose a hierarchical sandwich structure consisting of sodium hydroxide–activated boron nitride (BNOH), polyethyleneimine (PEI), and MXene (MX, Ti3C2Tx) through facile layer-by-layer self-assembly. The fabricated BNOH/P/MX sandwich structure (P denoting “PEI”) can synergistically improve the interface adhesion by enhancing the mechanical interlocking and chemical bonding of the composites. When the composites reinforced by BF–BNOH/P/MX subject to the external loading, flexible PEI molecules allow two-dimensional (2D) rigid BNOH and MX nanosheets to slip at the interface by uncurling the molecular chains, dissipating a great amount of energy during the fracture progress. Meanwhile, the hierarchical BNOH/P/MX sandwich structure acts as an excellent interface and possesses multistage gradient modulus and wider thickness, uniformly and efficiently transferring the stress from the EP matrix to BFs. The interfacial shear strength, impact strength, and fracture toughness of BF–BNOH/P/MX-reinforced EP composite are substantially improved by 45.9%, 60.6%, and 148.9%, respectively, compared with bare BF–based composites. This study can provide valuable references and inspirations for designing and constructing high-quality interfaces for high-strength and high-toughness BF structural materials, taking advantage of 2D materials.界面粘附性直接影响玄武岩纤维增强聚合物复合材料的力学性能。为了在BF和环氧树脂(EP)之间构建比未改性BF/EP的弱界面更优越的界面相,我们提出了一种由氢氧化钠活化的氮化硼(BNOH)、聚乙烯亚胺(PEI)和MXene (MX, Ti3C2Tx)组成的分层夹层结构,通过易于层层自组装。制备的BNOH/P/MX夹层结构(P表示“PEI”)可以通过增强复合材料的机械联锁和化学键合来协同提高界面附着力。当BF-BNOH /P/MX增强的复合材料受到外部载荷时,柔性PEI分子通过解开分子链使二维刚性BNOH和MX纳米片在界面处滑动,从而在断裂过程中耗散大量能量。同时,层叠式BNOH/P/MX夹层结构作为一种优良的界面,具有多级梯度模量和更宽的厚度,可以均匀有效地将应力从EP基体传递到bf。与纯bf基复合材料相比,BF-BNOH /P/ mx增强EP复合材料的界面抗剪强度、冲击强度和断裂韧性分别显著提高45.9%、60.6%和148.9%。本研究可为利用二维材料的优势设计和构建高强度、高韧性BF结构材料的高质量界面提供有价值的参考和启示。来源:复合材料力学仿真Composites FEM

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