【摘要】 作者研究了未经处理的多壁碳纳米管/聚偏氟乙烯(MWNT/PVDF)复合材料体系的介电性能发现,在低频下,复合材料的介电常数随MWNT的含量增加而迅速增加,当体积分数为2.0%时,介电常数高达300左右,并且复合材料的渗流阈值仅为1.61%.MWNT较大的长径比和较高的电导率导致复合体系渗流阈值较低.发生渗流效应时,复合材料的介电损耗低于0.4,与频率无关.因此,可以认为未经过化学处理的碳纳米管可以大幅度地改善PVDF基复合材料的介电性能.更多还原

【Abstract】 Dielectric properties of the untreated multi-wall carbon-nanotubes/poly(vinylidene fluoride) (MWNT/PVDF) composites are studied. Towardslow frequencies, the dielectric constant of a composite with about 2.0% of MWNT increases rapidly and the value of the dielectric constant is as high as 300. However, by a calculation, the percolation threshold of the MWNT/PVDF composites is only 1.61% (0.0161 volume fraction) of MWNT. Both the large aspect ratio and the high conductivity of the MWNT may lead to the low percolation threshold of the MWNT/PVDF composites. For the percolation composite, the dielectric loss value is always less than 0.4, irrespective of the frequency. Therefore, the experimental results suggest that the dielectric properties of MWNT/PVDF composites may be improved significantly without the chemical functionalization to carbon nanotubes.更多还原