Co3O4纳米颗粒/中间相沥青基泡沫炭复合材料的结构设计及其电磁屏蔽机理研究

Carbon foam has been considered as one of the good candidates of electromagnetic shielding materials thanks to its small weight density, high mechanical strength, corrosive resistance, good workability, electromagnetic shielding performance and low cost. However, carbon foam suffers from the modest electromagnetic shielding performance and weak mechanical strength. Taking the structural and property advantages of carbon foam and Co3O4 nanoparticles(NPs), herein we propose to use Co3O4 NPs as reinforcement to prepare Co3O4 NPs/mesophase pitch-based carbon foam composite, and systematically study its designed structure, electromagnetic shielding performance, mechanical strength and electromagnetic shielding mechanism. Designing soluble mesophase pitch molecular can help to uniformly disperse Co3O4 NPs forming the Co3O4 NPs/mesophase pitch mixture. Then the mixture will be treated by self-spontaneous method to prepare the Co3O4 NPs/mesophase pitch-based carbon foam composite. The research will study the influence of Co3O4 NPs dispersion state and additive amount on the microstructure of carbon foam and the enhancement mechanism of Co3O4 NPs on electromagnetic shielding performance and mechanical strength. Finally, the electromagnetic shielding mechanism of the composite will be clarified. This study will provide experimental mode and theoretical support for the carbon foam composite practical application in the field of electromagnetic shielding.

泡沫炭因其轻质高强、耐腐蚀、易加工、电磁屏蔽和低成本等独特性能成为电磁屏蔽材料理想的候选材料之一。针对泡沫炭电磁屏蔽性能构成单一和力学性能差等问题，结合泡沫炭和Co3O4纳米颗粒的结构与性能特点，本项目拟采用Co3O4纳米颗粒为增强体，围绕Co3O4纳米颗粒/中间相沥青基泡沫炭复合材料的结构设计、电磁屏蔽性能、力学性能和电磁屏蔽机理展开研究。通过设计可溶性中间相沥青分子，获得均匀分散的Co3O4纳米颗粒/中间相沥青复合体系，然后利用“自发泡”法制备Co3O4纳米颗粒/中间相沥青基泡沫炭复合材料。主要考察Co3O4纳米颗粒分布和添加量对泡沫炭微观结构的影响，研究Co3O4纳米颗粒对泡沫炭电磁屏蔽和力学性能的增强机制，揭示复合材料的电磁屏蔽机理，为促进泡沫炭复合材料在电磁屏蔽领域的应用提供实验模型并奠定理论基础。

中间相沥青基泡沫炭具有轻质高强、导电、耐腐蚀、易加工、低成本等诸多性能优势，是新型电磁屏蔽材料理想的候选材料。如何进一步提高其电磁屏蔽性能是推动其实际应用亟待解决的关键问题。本课题分别以Co3O4纳米颗粒和煤沥青为增强体和前驱体，设计并制备了中间相沥青基泡沫炭电磁屏蔽复合材料，利用增强体和中间相沥青基泡沫炭基体两者性能的协同优化作用，获得了一种高电磁屏蔽性能、高强度的电磁屏蔽复合材料。主要成果包括：(1)增强体的添加显著提高了中间相沥青的粘度，进而影响了复合材料中泡孔的微观结构和形貌；(2)阐明了增强体在发泡过程中的结构演变和相转变，明确了增强体在中间相沥青基泡沫炭基体中的存在形式；(3)增强体在中间相沥青基泡沫炭基体中形成的新界面可以有效提高泡沫炭材料的压缩强度(最高可达23.95MPa)；(4)增强体的添加显著提高了中间相沥青基泡沫炭的磁损耗，增强了其对电磁波的反射。磁损耗和介电损耗的协同作用有效提高了中间相沥青基泡沫炭的电磁屏蔽效能（最高可达34dB）。本研究为新型电磁屏蔽复合材料的开发和设计提供了实验和理论依据，一定程度上促进了电磁屏蔽材料的发展。累计发表论文8篇，授权发明专利2项。