碳纳米电磁屏蔽复合材料的选择性激光烧结机理研究

With the advantages of light weight, good stability and processability, carbon nanofiller/polymer composites have great application prospects in the electromagnetic interference shielding field. To fabricate and process the carbon nanofiller composites efficiently, and solve the issues such as carbon nanofillers agglomeration; the excessive nanofiller loading affecting the mechanical properties; and the complicated process of constructing three-dimensional network of nanofillers, this project introduces a novel processing method based on Selective Laser Sintering (SLS). Firstly, the modification-dispersion-coating mechanism of the carbon nanofillers (Carbon Nanotube/Graphene) will be studied, and the Nylon 12 powders will be coated with the carbon nanofillers densely to prepare the nanocomposite powders. Then through experiments and simulations, the thermodynamics relationship between the properties of the nanocomposite and the laser sintering process will be analysed; the influence of carbon nanofillers on the heat absorption – heat conduction – sintering process of the nanocomposite will be revealed; the processing parameters of the laser sintering process will be optimized; the effect of carbon nanofiller loading and three-dimensional network structure on the electromagnetic shielding performance and mechanical properties of the nanocomposite components will be studied. Finally the method of efficiently preparing and processing the carbon nanofiller composites by SLS to achieve improved electromagnetic shielding and mechanical properties will be established. This project will provide the technical reference for preparation and processing of high performance electromagnetic shielding composite materials, which has important scientific significance and engineering application value.

碳纳米高分子复合材料有着质量轻、稳定性好、易加工等优点，在电磁屏蔽领域有着广泛的应用前景。针对碳纳米复合材料制备加工过程中纳米填料难以均匀分散、添加量过多影响力学性能、构建填料三维网络工艺复杂等难题，本项目提出了一种基于选择性激光烧结工艺的高效制备加工方法。首先研究碳纳米填料(碳纳米管、石墨烯)的改性-分散-包覆机理，设计并制备碳纳米填料均匀高密包覆的尼龙12复合材料粉末。然后实验和模拟相结合，研究复合材料相关属性与激光烧结过程的热力学关系，揭示纳米填料对复合材料吸热-传热-烧结过程的影响规律，优化激光烧结过程的加工参数。研究碳纳米填料含量及三维网络结构对复合材料制件电磁屏蔽性能、机械性能的影响及增强机理，建立利用选择性激光烧结高效制备具有优良电磁屏蔽和力学性能的复合材料的方法。本项目的研究成果将为高性能电磁屏蔽复合材料的制备及加工提供技术参考，具有重要的科学意义和工程应用价值。

本项目以碳纳米高分子复合材料在电气设备电磁屏蔽等领域的应用为导向，从复合材料制备、增材制造工艺优化以及性能评测三个方面开展相关的应用基础研究。在碳纳米高分子复合材料制备方面，重点研究了石墨烯和碳纳米管的改性分散、相分离制备以及材料特性评测。掌握了碳纳米填料的改性-分散-包覆的机理，成功制备出均匀稳定分散的碳纳米高分子复合材料。在增材制造工艺研究方面，分析了碳纳米高分子复合材料的热学行为，优化了激光功率、扫描速度和分层厚度等工艺参数组合，揭示了不同工艺参数组合对碳纳米高分子复合材料成型质量和成型后电学性能的影响规律。在成型件性能研究方面，探究了石墨烯和碳纳米管的添加量对成型件电磁屏蔽性能、热稳定性能、机械性能等的影响规律，阐明了石墨烯和碳纳米管的三维导电网络通路的形成机制。本项目的研究探索开发了利用增材制造技术成形碳纳米高分子复合材料的新技术，对拓展碳纳米高分子复合材料在电子信息、先进制造等领域的应用具有重要意义。