碳纳米管/聚苯胺纳米复合管的制备及其微波介电特性研究

用原位乳液聚合法在碳纳米管表面包覆聚苯胺，制备出了碳纳米管/聚苯胺一维纳米复合管.复合管的直径为50—80 nm，聚苯胺包覆层的厚度为20—30 nm，聚苯胺在碳纳米管表面以层状和枝晶状两种形态生长.研究了碳纳米管/聚苯胺复合管在2—18 GHz的微波介电特性.与纯碳纳米管相比，碳纳米管/聚苯胺复合管的介电常数的实部ε′和虚部ε″在2—18 GHz随频率变化较小，在低频波段介电常数值较小，作为微波吸收剂容易实现与自由空间的阻抗匹配，而且它的介电损耗角正切(tanδ=ε″/ε′)较高，是一种很好的微波吸收剂.关键词：碳纳米管聚苯胺微波介电特性微波吸收剂

Synthesis of carbon nanotube/polyaniline composite nanotube and its microwave permittivity

A carbon nanotube/polyaniline composite nanotube with a diameter of 50—80 nm has been prepared. The carbon nanotubes encapsulated by polyaniline (PANI) with a thickness of 20—30 nm have been synthesized by in-situ emulsion polymerization. The microwave permittivity of the carbon nanotube/polyaniline composite nanotubes has been investigated in the frequency range of 2—18 GHz. The real part (ε′) and imaginary part (ε″) of the complex permittivity of carbon nanotube/polyaniline composite nanotube change little, as compared with those of carbon nanotubes at frequencies 2—18 GHz. The ε′ and ε″ of the carbon nanotube/polyaniline composite nanotube are small at low frequencies, which make it easy to match the impedance of free-space in the design of microwave absorbing materials. The dissipation factor tanδ(ε″/ε′) of carbon nanotube/polyaniline composite nanotube is high. So the carbon nanotube/polyaniline composite nanotube is a good microwave absorbent.