今日更新:Composites Part A: Applied Science and Manufacturing 2 篇,Composites Part B: Engineering 4 篇,Composites Science and Technology 1 篇Composites Part A: Applied Science and ManufacturingEnhanced mechanical property, high-temperature oxidation and ablation resistance of carbon fiber/phenolic composites reinforced by attapulgiteJun-Feng Shi, Nan Li, Feng Zhang, Ze Zong, Zhuo-Yang Li, Yue-Yi Wang, Ding-Xiang Yandoi:10.1016/j.compositesa.2024.108469 凹凸棒土增强碳纤维/酚醛复合材料的力学性能、高温抗氧化性和抗烧蚀性To meet the thermal protection and load-bearing requirements of ultra-high-speed vehicles, it is urgent to improve the ablation resistance, high-temperature oxidation resistance and mechanical properties of carbon fiber/ boron phenolic resin (CF/BPR) composites simultaneously. Herein, polyhedral oligomeric silsesquioxane-modified attapulgite (ASP) with abundant porous structure was successfully introduced into the CF/BPR (CF/ASPBPR). The co-effect of ceramization, high infrared emissivity, and low thermal conductivity endowed the CF/ASPBPR with desirable ablation resistance, where the linear ablation rate and mass ablation rate reduced to 0.038 mm/s and 0.035 g/s, respectively. Meanwhile, due to the high thermal stability and energy dissipation of ASP, the CF/ASPBPR also presented the interlaminar shear strength of 35.40 and 9.79 MPa before and after high-temperature treatment, which were 24 % and 63 % higher than that of CF/BPR, respectively. This study provides a promising pathway for preparing advanced thermal protection materials that can adapt to severe mechanical spalling and thermochemical erosion environments.为满足超高速车辆的热防护和承载要求,迫切需要同时提高碳纤维/硼酚醛树脂(CF/BPR)复合材料的抗烧蚀性、耐高温氧化性和力学性能。将多孔结构丰富的多面体低聚硅氧烷修饰凹凸棒石(ASP)成功引入CF/BPR (CF/ASPBPR)中。陶瓷化、高红外发射率和低导热率的共同作用使CF/ASPBPR具有良好的抗烧蚀性能,其线性烧蚀率和质量烧蚀率分别降至0.038 mm/s和0.035 g/s。同时,由于ASP具有较高的热稳定性和能量耗散性,CF/ASPBPR在高温处理前后的层间剪切强度分别为35.40和9.79 MPa,分别比CF/BPR高24 %和63 %。该研究为制备适应严重机械剥落和热化学侵蚀环境的高级热防护材料提供了一条有希望的途径。3D printing of high-stiffness and high-strength glass fiber reinforced PEEK composites by selective laser sinteringHaibin Tang, Shuxiang Zhang, Lin He, Zeshi Yang, Tingting Liudoi:10.1016/j.compositesa.2024.108470采用选择性激光烧结技术3D打印高刚度、高强度玻璃纤维增强PEEK复合材料Glass fiber reinforced poly-ether-ether-ketone (PEEK) composites are emerging as structural materials of multifunctional devices in space applications, due to their outstanding mechanical properties, electrical insulating properties, and resistance to irradiation. Here, a new approach for preparing glass fiber/PEEK powders tailored for selective laser sintering (SLS) process is proposed. The surface of glass fiber is modified with the sulfonated PEEK following the designed procedure. The flowability of glass fiber/PEEK powders is also improved by adding the nano-scale SiO2 flow agent. The glass fiber reinforced PEEK composites are successfully 3D printed using the glass fiber/PEEK powders. Further, the enhancement of interfacial bonding between PEEK and glass fiber is analyzed through quasi-static tension tests and scanning electron microscopy (SEM) for the SLSed glass fiber reinforced PEEK composites. The average ultimate tensile strength reaches approximately 100 MPa using these optimal process parameters, while the average elastic modulus is around 7 GPa. Finally, the upper limit of fiber weight fraction is evaluated with the X-ray computed tomography (XCT) and the high-fidelity discrete element method (DEM) simulation.玻璃纤维增强聚醚醚酮(PEEK)复合材料由于其优异的机械性能、电绝缘性能和耐辐照性能,正在成为空间应用中多功能器件的结构材料。本文提出了一种适合于选择性激光烧结(SLS)工艺的玻璃纤维/PEEK粉末制备新方法。用磺化PEEK按照设计的工艺对玻璃纤维表面进行改性。通过添加纳米级SiO2流动剂,提高了玻璃纤维/PEEK粉末的流动性。利用玻璃纤维/PEEK粉末成功3D打印了玻璃纤维增强PEEK复合材料。此外,通过准静态拉伸试验和扫描电镜(SEM)分析了SLSed玻璃纤维增强PEEK复合材料对PEEK与玻璃纤维界面结合的增强作用。使用这些优化工艺参数,平均抗拉强度达到约100 MPa,而平均弹性模量约为7 GPa。最后,利用x射线计算机断层扫描(XCT)和高保真离散元法(DEM)模拟计算了纤维重量分数的上限。Composites Part B: EngineeringAchieving significant grain refinement efficiency in Mg-Al alloys via a GNP@MgO composite refinerHailong Shi, Shuaihu Wei, Xiaojun Wang, Xuejian Li, Dongrong Liu, Chao Xu, Zhenpeng Pu, Xiaoshi Hudoi:10.1016/j.compositesb.2024.111822通过GNP@MgO复合细化剂实现显著的Mg-Al合金晶粒细化效率Master alloys containing Zirconium (Zr) serve as effective grain refiners in most commercial cast magnesium (Mg) alloys. However, their efficacy is diminished in Mg-Al series alloys due to the formation of Al-Zr compounds. In this work, a novel Mg-GNP@MgO master alloy was prepared utilizing the in-situ reaction between CO2 and Mg. The grain refinement efficiency of this composite inoculation on Mg-9Al alloys was systematically investigated using SEM-EBSD, HRTEM observations, Density Functional Theory (DFT), and Sharp Interface Model (SIM) calculations. The findings suggest that the composite grain refiner (GNP@MgO) exerted a notable refining influence on Mg-9Al alloy. Through the conventional casting process, the average grain size was refined to approximately 13 μm upon the addition of 3 vol.% GNP@MgO, achieving a grain refinement efficiency of 90%. The enhanced refining efficiency arises from the synergistic control over the nucleation and growth processes of α-Mg grains, facilitated by GNP@MgO particles. This process includes improved heterogeneous nucleation, triggered by the newly formed Al4C3 phases through the interaction between GNPs and Al element, followed by the limited expansion of α-Mg grains induced by the nano-sized MgO particles. The MgO particles predominantly gather around grain boundaries to establish stable nano-coating layers, thereby exerting a substantial Zener pinning effect. The pinning role played by the MgO nanoparticles was also verified by a sharp interface model. The findings in this work not only carve out a new avenue for the grain refinement of cast Mg-Al alloys but also inspire fresh perspectives for the development of novel grain refiners.含有锆(Zr)的中间合金在大多数商业铸造镁(Mg)合金中作为有效的晶粒细化剂。然而,在Mg-Al系列合金中,由于Al-Zr化合物的形成,它们的效果降低了。本文利用CO2与Mg的原位反应制备了一种新型Mg-GNP@MgO中间合金。采用SEM-EBSD、HRTEM观察、密度泛函理论(DFT)和锐界面模型(SIM)计算等方法对Mg-9Al合金复合孕育的晶粒细化效率进行了系统研究。结果表明,复合晶粒细化剂(GNP@MgO)对Mg-9Al合金的细化效果显著。通过传统的铸造工艺,当添加3 vol.% GNP@MgO时,平均晶粒尺寸细化到约13 μm,晶粒细化效率达到90%。细化效率的提高是由于GNP@MgO颗粒对α-Mg晶粒形核和长大过程的协同控制。这一过程包括GNPs与Al元素相互作用形成的新Al4C3相引发的非均相形核的改善,以及纳米MgO颗粒诱导α-Mg晶粒的有限膨胀。MgO颗粒主要聚集在晶界周围,建立稳定的纳米涂层,从而产生实质性的齐纳钉扎效应。通过锐界面模型验证了MgO纳米颗粒的钉钉作用。本工作的发现不仅为铸造Mg-Al合金晶粒细化开辟了一条新的途径,而且为新型晶粒细化剂的开发提供了新的视角。Partially bio-derived phosphazene-tannic acid microspheres as fire retardant additives for an epoxy tannic acid resin system.Rusheni Bhagya Senanayake, Houlei Gan, Dan Liu, Juan Zhang, Asanka P. Basnayake, Michael T. Heitzmann, Russell J. Varleydoi:10.1016/j.compositesb.2024.111831 部分生物衍生的磷腈-单宁酸微球作为环氧单宁酸树脂体系的阻燃添加剂。In this work, partially bio-derived colloidal microspheres are synthesised from tannic acid (TA) and hexachloro-cyclophosphazene (HCCP), then investigated for their effectiveness as a fire-retardant additive to a partially bioderived epoxy resin system. The epoxy resin system is based upon diglycidyl ether of bisphenol A (DGEBA) and tannic acid (TA), a bio-derived highly aromatic phenolic curative noted for its inherent fire retardancy. This study presents the impact of increasing the concentration of the phosphazene-TA microspheres (TAPZ) and varying the DGEBA-TA stoichiometry to determine the optimum formulation required to achieve the greatest improvement in fire retardancy. At 15 wt.% TAPZ addition, the DGEBA-TA resin system easily achieves a V-0 rating according to the UL-94 vertical burn test, measures 29% for the limiting oxygen value (LOI) and displays a 62% reduction in peak heat release rate (PHRR) compared with the unmodified DGEBA-TA network. TAPZ addition however reduces the glass transition temperature (Tg) from 187°C to 155°C, flexural strength by up to 30% and increases viscosity significantly. Varying the stoichiometry between DGEBA and TA shows that additional surface hydroxyl groups from the TAPZ microspheres accelerate the DGEBA-TA reaction through enhancing interfacial reaction between residual epoxide groups of the cured epoxy network. Overall, these results present a promising approach to the development of a highly fire retardant, high performance, and highly bio-derived epoxy network and composite.在这项工作中,由单宁酸(TA)和六氯环磷腈(HCCP)合成了部分生物衍生的胶体微球,然后研究了它们作为部分生物衍生环氧树脂体系阻燃添加剂的有效性。环氧树脂体系是基于双酚A二缩水甘油酯醚(DGEBA)和单宁酸(TA),单宁酸是一种生物衍生的高芳香酚醛粘合剂,以其固有的阻燃性而闻名。本研究提出了增加磷腈- ta微球(TAPZ)的浓度和改变DGEBA-TA化学计量的影响,以确定实现阻燃性最大改善所需的最佳配方。在添加15 wt.%的TAPZ时,根据UL-94垂直燃烧测试,DGEBA-TA树脂系统很容易达到V-0等级,极限氧值(LOI)为29%,与未改性的DGEBA-TA网络相比,峰值热释放率(PHRR)降低了62%。然而,加入TAPZ可以将玻璃化转变温度(Tg)从187°C降低到155°C,弯曲强度可达30%,粘度显著增加。改变DGEBA和TA之间的化学计量表明,来自TAPZ微球的额外表面羟基通过增强固化环氧网络中残余环氧基团之间的界面反应来加速DGEBA-TA反应。总的来说,这些结果为开发高阻燃、高性能和高度生物衍生的环氧网络和复合材料提供了一条有希望的途径。Design-Driven Approach for Engineered Geopolymer Composite with Recorded Low Fiber ContentFei Wang, Jiabao Zhai, Yao Ding, Tomoya Nishiwaki, Jiangtao Yu, Victor C. Li, Kequan Yudoi:10.1016/j.compositesb.2024.111834低纤维含量工程地聚合物复合材料的设计驱动方法How to design an engineered cementitious composite (ECC) achieving both economic viability and ultra-sustainability has been the longstanding goal of ECC community. This study presents a design-driven approach to tackle this challenge through yielding a low matrix fracture toughness and a sufficiently strong interfacial bonding between fiber and matrix concurrently. As a result, only 0.2% fiber content was sufficient for achieving robust strain-hardening in Engineered Geopolymer Composite (EGC), which, to the authors’ knowledge, is the lowest recorded thus far. The tensile strain-to-fiber content ratio reached 25, a remarkable 233% higher than the existing strain-hardening composites. Besides, the compressive strength was around 40 MPa, marking the highest specific strength among the ECCs with a density below 1450 kg/m3. Leveraging the high porosity of 38% and the presence of shrinkage micro-cracks in the matrix, a low fracture toughness, combined with a robust friction between fiber and matrix, facilitated the noticeable strain-hardening. The reaction product was identified as a dense alkaline aluminosilicate hydrate (N-A-S-H) gel, benefiting the interfacial bonding and compressive strength. The embodied energy and carbon of the EGC diminished by 27% and 63% compared to ordinary concrete, respectively, and the corresponding cost was 79% lower than the classic M45-ECC, contributing significantly to ultra-sustainability.如何设计一种既具有经济可行性又具有超可持续性的工程胶凝复合材料(ECC)一直是ECC社区长期以来的目标。该研究提出了一种设计驱动的方法,通过降低基体断裂韧性和纤维与基体之间足够强的界面结合来解决这一挑战。因此,仅0.2%的纤维含量就足以在工程地聚合物复合材料(EGC)中实现稳健的应变硬化,据作者所知,这是迄今为止最低的记录。拉伸应变/纤维含量比达到25,比现有的应变硬化复合材料提高了233%。抗压强度在40 MPa左右,比强度在1450 kg/m3以下的混凝土中最高。利用38%的高孔隙率和基体中存在的收缩微裂纹,低断裂韧性加上纤维与基体之间的强劲摩擦,促进了明显的应变硬化。反应产物为致密碱性水合硅酸铝凝胶(N-A-S-H),有利于界面结合和抗压强度。与普通混凝土相比,EGC的隐含能量和碳分别减少了27%和63%,相应的成本比经典的M45-ECC低79%,对超可持续性做出了重大贡献。Regulation of charge transfer direction and key steps via Y modification of redox-active sites on borocarbonitride for photocatalytic CO2 reductionXianghui Zeng, Xuelin Bu, Hui Chen, Zhaohui Huang, Wei Fang, Daheng Wang, Xuan He, Xing Du, Weixin Li, Haijun Zhang, Lei Zhaodoi:10.1016/j.compositesb.2024.111838氮化硼氧化还原活性位点Y修饰光催化CO2还原中电荷转移方向及关键步骤的调控Hexagonal borocarbonitride(h-BCN) have garnered significant attention for their unique optoelectronic properties in solar-to-fuel conversions. However, the efficiency of h-BCN in the field of photocatalytic CO2 reduction is limited by high reaction energy barriers and serious charge recombination. Here, a Y-modified h-BCN were synthesized through an organic-inorganic hybrid precursor pyrolysis method. Both theoretical simulation and experimental analysis demonstrated that the Y-modified sample exhibits an inhomogeneous charge distribution that favours rapid charge transfer and can decrease the reaction barrier of the rate-control step. Further investigations indicated that adding Y changes the electronic structure of BCN, which leads to rapid charge transfer/separation and an increased lifespan for photoinduced electrons. As a result, 2.5%Y/BCN exhibited improved CO2 photoreduction activity with a fuel yield of 50.35 μmol·g-1. Notably, this outstanding performance was achirateeved without the use of any cocatalyst or sacrificial agent. In the meanwhile, cycle test shows the photocatalyst's great stability. The findings provide a useful suggestions for BCN-based photocatalysts.六方硼碳氮化物(h-BCN)因其独特的光电特性在太阳能-燃料转换中引起了人们的广泛关注。然而,h-BCN在光催化CO2还原领域的效率受到高反应能垒和严重电荷复合的限制。本文采用有机-无机杂化前驱体热解法合成了y修饰的h-BCN。理论模拟和实验分析均表明,y修饰后的样品具有非均匀电荷分布,有利于快速电荷转移,降低了速率控制步骤的反应势垒。进一步的研究表明,Y的加入改变了BCN的电子结构,导致了快速的电荷转移/分离和光致电子的寿命增加。结果表明,2.5%Y/BCN的CO2光还原活性提高,燃料产率达到50.35 μmol·g-1。值得注意的是,这种出色的性能是在没有使用任何助催化剂或牺牲剂的情况下实现的。同时,循环试验表明该光催化剂具有良好的稳定性。研究结果为bcn基光催化剂的开发提供了有益的建议。Composites Science and TechnologyComprehensive evaluation of interfacial interactions optimization for CF reinforced high-performance thermoplastic composites by electrochemical deposition of conjugated polymersYue Qiao, Hang Jia, Yu Zhang, Wenqi Zhao, Enmao Zhang, Shouhai Zhang, Xigao Jian, Cheng Liudoi:10.1016/j.compscitech.2024.110863 电化学沉积共轭聚合物增强高性能热塑性复合材料界面相互作用优化的综合评价The mechanical properties of carbon fiber (CF) reinforced high-performance thermoplastic composites are significantly compromised due to inadequate interface bonding between CF and matrix. In this study, electrochemical polymerization techniques were employed to modify CFs with polypyrrole (PPy), poly-aniline (PANI), and poly-o-phenylenediamine (PoPd), to systematically investigate the impact of conjugated polymers on the interfacial properties of CF/copoly (phthalazinone ether sulfone ketone)s (PPESK) composites through a combination of experimental and molecular dynamics (MD) approaches. The findings revealed distinct differences among these conjugated polymers in terms of their effects on both IFSS and ILSS for CF/PPESK composites. Among all tested laminates, PoPd@CF-60s/PPESK exhibited the highest IFSS, ILSS and flexural strength values of 39.8 MPa, 75.6 MPa, and 1494 MPa, respectively, 94.1%, 20.6%, and 47.6% higher than those of CF-desized/PPESK, without compromising CFs strength and thermal resistance of CF/PPESK composites. MD simulations combined with fracture morphology analysis confirmed that compatibility between conjugated polymers and matrix played a pivotal role in enhancing interface properties for CF/PPESK composites. Furthermore, the AFM outcomes demonstrated that the PoPd layer could serve as the modulus transition layer between the CF phase and the PPESK phase, which effectively enhancing the load transfer efficiency between the two phases under external forces. To summarize, this work presents a straightforward yet non-destructive approach that effectively enhances the interface strength within advanced CF reinforced high performance thermoplastic polymer composites (CFRHPTPs).碳纤维增强高性能热塑性复合材料的力学性能受到碳纤维与基体界面结合不足的影响。本研究采用电化学聚合技术,采用聚吡咯(PPy)、聚苯胺(PANI)和聚邻苯二胺(PoPd)对CF进行改性,通过实验和分子动力学(MD)相结合的方法,系统研究了共轭聚合物对CF/共聚(酞嗪酮醚砜酮)5 (PPESK)复合材料界面性能的影响。研究结果表明,这些共轭聚合物对CF/PPESK复合材料的IFSS和ILSS的影响存在明显差异。在不影响CF强度和抗热性能的情况下,PoPd@CF-60s/PPESK复合材料的IFSS、ILSS和抗弯强度分别为39.8 MPa、75.6 MPa和1494 MPa,比CF/PPESK复合材料的IFSS、ILSS和抗弯强度分别高94.1%、20.6%和47.6%。MD模拟结合断裂形貌分析证实,共轭聚合物与基体之间的相容性对增强CF/PPESK复合材料的界面性能起着关键作用。此外,AFM结果表明,PoPd层可以作为CF相和PPESK相之间的模量过渡层,有效地提高了外力作用下两相之间的载荷传递效率。总之,这项工作提出了一种简单而非破坏性的方法,可以有效地提高高级CF增强高性能热塑性聚合物复合材料(cfrhptp)的界面强度。来源:复合材料力学仿真Composites FEM