今日更新:Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 1 篇
Multi-stimuli-responsive shape memory flexible composites based on magnetic melamine/polydopamine/phosphorene complex foams and polyethylene glycol
Tao Shi, Huan Liu, Xiaodong Wang
doi:10.1016/j.compositesa.2024.108117
基于磁性三聚氰胺/多巴胺/膦炔复合泡沫和聚乙二醇的多刺 激响应形状记忆柔性复合材料
We have developed a novel type of flexible multi-stimuli-responsive shape memory composite system based on a melamine/polydopamine (PDA)/Fe3O4/phosphorene (PR) complex foam and poly(ethylene glycol) (PEG). The system was constructed through coating PDA on the skeleton of the melamine foam and then decorating the PDA layer with Fe3O4 and PR, followed by vacuum impregnation of PEG. The resultant composites exhibit an intrinsic thermal-driven shape memory behavior with a high shape recovery ratio of around 100% thanks to their high latent heat capacity derived from the loaded PEG. The introduction of magnetic Fe3O4 nanoparticles and PR nanosheets not only enhances the thermal conductance of the composites but also generates good magnetic and photothermal responsiveness. This enables the composites to obtain good light- and magnetic-driven shape memory capabilities in a shorter shape recovery period. This study offers a new strategy for developing smart materials with multiple and effective response to light, heat, and magnetism.
我们以三聚氰胺/多巴胺(PDA)/氧化铁/膦(PR)复合泡沫和聚(乙二醇)(PEG)为基础,开发了一种新型柔性多刺 激响应形状记忆复合材料系统。该系统是通过在三聚氰胺泡沫的骨架上涂覆 PDA,然后用 Fe3O4 和 PR 装饰 PDA 层,接着真空浸渍 PEG 而形成的。由于负载 PEG 带来的高潜热容量,由此产生的复合材料表现出固有的热驱动形状记忆行为,形状恢复率高达 100%。磁性 Fe3O4 纳米颗粒和 PR 纳米片的引入不仅增强了复合材料的导热性,还产生了良好的磁性和光热响应性。这使得复合材料能够在较短的形状恢复期内获得良好的光和磁驱动形状记忆能力。这项研究为开发对光、热和磁具有多种有效响应的智能材料提供了一种新策略。
Regulated orientation and exfoliation of flaky fillers by close packing structures in polymer composites for excellent thermal conduction and EMI shielding
Jiahui Hong, Ning Luo, Zhengmao Zhang, Liang Zhang, Guanghui Zhang, Lijun Ye, Suprakas Sinha Ray, Yongjin Li
doi:10.1016/j.compositesb.2024.111357
通过聚合物复合材料中的紧密堆积结构调节片状填料的取向和剥离,实现优异的热传导和电磁干扰屏蔽性能
Efficient heat dissipation and electromagnetic interference (EMI) shielding are essential demands on packaging intensively integrated circuits in advanced electronics. Multicompetent polymer composites with thermal conduction and EMI shielding capacity have attracted tremendous interest in the material science community. Herein, we report the preparation of thermally conductive polymer composites with superior EMI shielding effectiveness (SE) by building a 3D interconnected conductive network under close-packing circumstances. The build of the 3D network relies on the coordinated stacking of flaky and spherical fillers, where the asymmetric graphite flakes (FG) are confined in the interstitial regions of the close-packing structures of hollow glass microspheres (HGμS). The “rigid” close-packing structure of HGμS inhibits the in-plane orientation of FG along the flow direction during melt processing and facilitates the exfoliation of FG under external forces producing a conductive network with enhanced interconnectedness. The model system comprised of thermoplastic polyurethane (TPU), FG and HGμS has attained in-plane and through-plane thermal conductivity of 20.54 W m−1 K−1 and 6.55 W m−1 K−1 with 30 vol% FG (while maintaining a low mass density of 1.15 g cm−3, identical to neat TPU). Meanwhile, a high EMI SE of 69 dB has been achieved at a thickness of 1 mm.
高效散热和电磁干扰(EMI)屏蔽是先进电子产品中密集集成电路封装的基本要求。具有热传导和电磁干扰屏蔽能力的多功能聚合物复合材料引起了材料科学界的极大兴趣。在此,我们报告了在紧密堆积的情况下,通过构建三维互连导电网络,制备出具有卓越电磁干扰屏蔽效果(SE)的导热聚合物复合材料。三维网络的构建依赖于片状和球形填料的协调堆叠,其中不对称石墨片(FG)被限制在中空玻璃微球(HGμS)紧密堆积结构的间隙区域。在熔融加工过程中,HGμS 的 "刚性 "紧密堆积结构抑制了石墨烯沿流动方向的平面内取向,并有利于石墨烯在外力作用下剥离,形成互连性更强的导电网络。由热塑性聚氨酯 (TPU)、FG 和 HGμS 组成的模型系统在含有 30 Vol% FG 的情况下,平面内和通面热导率分别达到 20.54 W m-1 K-1 和 6.55 W m-1 K-1(同时保持 1.15 g cm-3 的低密度,与纯 TPU 相同)。同时,在厚度为 1 毫米时,EMI SE 高达 69 分贝。
Photo-curable bio-based comb/bottle brush epoxy resin/beeswax/copper foam phase change materials with high enthalpy value, high conductivity, and multifunctional properties
Yanyun Li, Yu Fan, Ziyu Liu, Junying Zhang, Jue Cheng, Qingsong Lian
doi:10.1016/j.compscitech.2024.110506
具有高焓值、高导电性和多功能特性的光固化生物基梳子/瓶刷环氧树脂/蜂蜡/泡沫铜相变材料
At present, the demand for green energy has reached a new height in history, and thermal energy storage technology has been widely used to reduce energy consumption. It is still a challenge to develop bio-based polymeric form-stable phase change materials (FSPCMs) with high enthalpy value and thermal conductivity (TC), short curing time, and multifunctional properties. This work not only exploited a series of adjustable and photo-curable comb/bottle brush bio-based epoxy resin/beeswax (bw) FSPCMs with the above superiorities, but also revealed the effects of cross-linking density on the energy storage capacity and encapsulation rate of the FSPCMs. As a result, the optimal system can encapsulate the maximum amount of bw (60 wt%) and obtain the highest enthalpy value (142.1 J/g) with only 0.5% enthalpy loss. Through further introducing the optimal curing system into the copper (Cu) foam, the electromagnetic interference shielding property, TC, tensile strength, and photo-thermal conversion efficiency of the final composite (modified by Cu of 95% porosity) can reach 110 dB, 2.387 W m−1K−1, 2.81 MPa, and 80%, respectively, and the enthalpy value (84.2 J/g) is still satisfactory. This study can provide theoretical guidance for the structural design of reliable fast photo-curable bio-based polymeric FSPCMs with excellent phase change performances and multifunctional properties.
目前,人们对绿色能源的需求已达到历史新高度,热能储存技术已被广泛用于降低能源消耗。开发具有高热焓值和热导率(TC)、固化时间短、多功能特性的生物基高分子形稳相变材料(FSPCMs)仍是一项挑战。这项研究不仅开发了一系列具有上述优点的可调光固化梳状/瓶刷状生物基环氧树脂/蜂蜡(bw)FSPCM,还揭示了交联密度对 FSPCM 储能能力和封装率的影响。结果表明,最佳体系可以封装最大量的 bw(60 wt%),并获得最高的焓值(142.1 J/g),而焓损失仅为 0.5%。通过在泡沫铜(Cu)中进一步引入最佳固化体系,最终复合材料(孔隙率为 95% 的 Cu 改性)的电磁干扰屏蔽性能、TC、拉伸强度和光热转换效率分别达到 110 dB、2.387 W m-1K-1、2.81 MPa 和 80%,焓值(84.2 J/g)仍然令人满意。该研究可为具有优异相变性能和多功能特性的可靠快速光固化生物基聚合物 FSPCM 的结构设计提供理论指导。