不同纯化处理方法对多壁碳纳米管电磁性能的影响

Effect of different purification method on electromagnetic propetries of multiwalled carbon nanotubes

采用硝酸回流、混酸回流、硝酸回流与混酸超声、混酸超声与双氧水回流、盐酸超声与双氧水回流5种不同工艺方法对多壁碳纳米管进行了纯化处理,使用TEM、XRD和FT-IR比较各种方法对碳管表面结构的影响程度,运用同轴法测定碳纳米管在2～18GHz频段内的复介电常数和复磁导率,研究了不同纯化处理方法对多壁碳纳米管复介电常数与复磁导率的影响。结果表明,经过纯化处理后,碳纳米管表面的无定形碳及催化剂颗粒均能被有效去除,并在其表面嫁接有羟基、羧基官能团;经过纯化处理,碳纳米管的复介电常数的实部与虚部均有所降低,而复磁导率的没有明显变化。综合考察测试结果,优选硝酸回流处理工艺纯化多壁碳纳米管。

Multi-walled carbon nanotubes （MWCNTs） were purified using such five different methods as nitric acid reflux, vitriol reflux, nitration mixture reflux etc. Then these MWCNTs were analyzed by TEM, XRD and FT-IR to study the change of external structure. The complex permittivity and permeability were measured from 2-18GHz by the coaxial method. The effect of different purified methods on complex permittivity and per- meability were investigated. The results show that amorphous carbon and catalyst particles on the surface of MWCNTs are wiped off effectively, and such functional groups as carboxyl and hydroxylare introduced. Real and imaginary part of complex permittivity both drop, and complex permeability has no substantial changes. To comprehensively survey of the test results, preferably choosing nitric acid reflux treatment process to purify MWCNTs.