摘要
石墨烯和碳纳米管都是新型纳米尺寸碳材料,具有极大的比表面积、良好的导电性以及优秀的机械性能等特性。通过微波膨化法在石墨烯(寡层石墨)表面空隙结构内生长了碳纳米管,制备出石墨烯/碳纳米管复合材料,碳纳米管不仅可以发挥连接石墨烯层片结构的作用,还可以与石墨烯共同发挥协同吸波效应;同时生长碳纳米管所添加的催化剂在微波状态下分解为纳米磁性颗粒,提高整体复合材料的吸波性能。通过采用SEM、EDX、XRD等对材料的形貌、化学成分进行表征,并用矢量网络分析仪测试了材料在2~18GHz频带内的复介电常数和复磁导率,利用计算机模拟出不同厚度的微波衰减性能。结果表明,材料的电磁损耗机制由电介质损耗、磁损耗共同构成,微波吸收峰随着材料厚度的增加向低频移动,当厚度为2.5mm时,在14.4GHz时最大损耗值为-28dB,并且在频带12.4~17.7GHz的范围内达到-10dB的吸收。
Graphene and carbon nanotubes are new carbon nano-materials,which have the characteristics of great specific surface area,good electrical conductivity and excellent mechanical properties.In this paper,graphene/carbon nanotubes composite materials were prepared by using microwave puffing method.Carbon nanotubes not only played a role in connecting the graphene layer structure,but also acted as a synergistic co graphene absorbing effect.Meanwhile the catalyst of carbon nanotubes under microwave condition was decomposed into nano magnetic particles,improvingthe absorbing properties of the composite material.The morphology and chemical compositionof the carbon nanocomposites were examined by SEM,EDX and TEM,respectively.The complex relative permittivity and permeability of the absorber were measured by using a microwave network analyzer in the frequency range of 2-18 GHz.The reflection loss curves of the carbon nanocomposites were calculated using computer simulation technique.The results showed that the electromagnetic loss mechanism consists of dielectric loss and magnetic loss.It was found that in the frequency range of 2-18 GHz,with the increase of the matching thickness,the maximum absorbing peaks of the carbon nanocomposites shifted to lower frequency region.When the matching thickness was 2.5 mm,the maximum absorption peak of the carbon nanocomposites was-28 dB at 14.4 GHz and the maximum reflection loss of-10 dB was achieved within the range of 12.4-17.7 GHz.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2018年第2期2136-2140,共5页
Journal of Functional Materials
基金
国家自然科学基金资助项目(U1710115)
山西省青年科学基金资助项目(2015021083)
四川省军民融合产业发展专项基金资助项目(zyfG2017G70)
关键词
石墨烯
碳纳米管
复合材料
吸波性能
graphene
carbon nanotube
composite materials
microwave absorption properties
