活化碳纳米管的孔结构及微波吸收性能的研究

以KOH为活化剂对碳纳米管进行活化处理，将碳纳米管的比表面积从24．5m^2/g提高到360．1m^2／g，孔容从0．051cc／g提高到0．572cc/g。对碳纳米管的微波吸收性能进行测试，研究结果发现，未活化碳纳米管在9．91～14．16GHz范围内对电磁波的反射率低于-5dB，最大衰减峰值为8．57dB；活化碳纳米管在5．37～18GHz范围内对电磁波的反射率低于一5dB，在6．48～10．88GHz范围内对电磁波的反射率低于一10dB，最大的衰减峰值达到22．58dB。通过比较得出，活化能够有效地提高碳纳米管的微波吸收性能。产生的原因是由于活化碳纳米管具有大的比表面积和丰富的孔结构，电磁波在这些孔结构中不断的被反射、漫射而逐渐衰减。

STUDY ON THE PORE STRUCTURES AND THE MICROWAVE ABSORBING PROPERTY OF THE ACTIVATED CARBON NANOTUBES

The carbon nanotubes(CNTs)were activated by KOH. The specific surface area increases from 24. 5 m2/g to 360. 1 m2/g,and the total pore volume increases to 0. 572 cc/g from 0. 051 cc/g. The microwave absorbing properties of the non-activated CNTs and the activated CNTs were measured. The band width(R<-5 dB) of the non-activated CNTs is 4. 25 dB at the frequency range of 9. 91 GHz to 14. 15 GHz,and the maximum absorbing peak is 8. 57 dB at 11. 67 GHz. The reflectivity lower than -5dB of the activated CNTs is in the range of 5. 37 GHz to 18GHz, while that lower than -10dB is in the range of 6. 48GHz to 10. 88 GHz. The maximum absorbing peak of the activated CNTs reaches 22. 58 dB at 8. 08 GHz. Those results show that activation is a very effective method to enhance the microwave absorbing property of CNTs. The reason is that the activated CNTs have large surface area and abundant pore structures, so electromagnetic wave is reflected and diffused repeatedly in the pore structures of the activated CNTs and attenuates gradually. .