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1.
采用一种导电材料预制体-单壁碳纳米管(Single-wall carbon nanotube,SWCNT)无纺布与环氧树脂复合制备了电磁屏蔽复合材料,并对所制复合材料的电磁屏蔽性能进行了表征。结果表明:所制复合材料对电磁波的屏蔽效率随SWCNT无纺布厚度的增加而增加。在较低的SWCNT无纺布填加量下所制复合材料可以实现对低频电磁波较高的屏蔽效率。不同于填加粉体导电材料所制电磁屏蔽复合材料,作为导电材料预制体使用的SWCNT无纺布是一个独立的整体导电薄膜,可以直接引入到基体当中,不存在分散问题。并且通过简单的导电预制体多层叠加的方式即可实现复合材料更高的屏蔽效率。 相似文献
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化学镀镍PAN纤维复合材料及导电性研究 总被引:2,自引:0,他引:2
对聚丙烯腈纤维化学镀镍后与HIPS树脂共混制备出导电复合材料的镀层结构、电阻率和导电性进行了研究,并对材料导电性与导电性填普量、混炼时间及偶联剂的加入等进行了探讨。 相似文献
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通过热浸镀及化学镀方法制备了玻璃纤维/Al、玻璃纤维/Ni及玻璃纤维/Ni/Ni-Cu-P三种镀金属纤维,对其制备工艺、机理和性能进行了探讨.用上述三种金属化纤维与ABS树脂共混制备出导电复合材料,对复合材料的导电性及电磁屏蔽性能进行了初步研究. 相似文献
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镀镍PET纤维/环氧树脂复合材料的性能 总被引:4,自引:0,他引:4
以PET纤维经超声波化学镀镍制成的导电PET/Ni纤维作填料,与环氧树脂共混,制得导电环氧树脂复合材料.对纤维表面镀层的形态结构及复合材料的导电性、电磁屏蔽性及力学性能进行了深入的研究.结果表明,填充适量(1%~5%,质量分数,下同)的纤维就可以得到导电性能良好的复合材料,同时也具有较好的电磁屏蔽性能,当纤维含量为3%时材料的力学性能也得到改善. 相似文献
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研究经化学镀镍的聚丙烯腈导电纤维填充的高抗冲聚苯乙烯复合材料的导电性与导电填料浓度的导电性与导电填料浓度的关系及加入有机钛酸酯偶联剂的影响,为了进一步提高复合材料的导电性,在PAN/Ni-P纤维填充的复合材料中又加入不同量的碳黑,由于碳黑粒子的加入改善了纤维间的接触状态,更有利于导电网络的形成,从而大大提高了复合材料的导电能力。 相似文献
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In-house synthesized multiwall carbon nanotubes (MWCNTs) have been dispersed in acrylonitrile butadiene styrene (ABS) using a micro twin-screw extruder with back flow channel. The electrical and mechanical properties of MWCNTs in ABS with different wt% have been studied. Incorporation of only 3 wt. % MWCNTs in ABS leads to significant enhancement in the tensile strength (up to 69.4 MPa) which was equivalent to 29% increase over pure ABS. The effect of MWCNTs on the structural behaviour of ABS under tensile loading showed a ductile to brittle transition with increase concentration of MWCNTs. The results of enhanced mechanical properties were well supported by micro Raman spectroscopic and scanning electron microscopic studies. In addition to the mechanical properties, electrical conductivity of these composites increased from 10−12 to 10−5 Scm−1 showing an improvement of ∼7 orders of magnitude. Due to significant improvement in the electrical conductivity, EMI shielding effectiveness of the composites is achieved up to −39 dB for 10 wt. % loaded MWCNTs/ABS indicating the usefulness of this material for EMI shielding in the Ku-band. The mechanism of improvement in EMI shielding effectiveness is discussed by resolving their contribution in absorption and reflection loss. This material can be used as high-strength EMI shielding material. 相似文献
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In-Soo Han Yun Kyun Lee Heon Sang Lee Ho Gyu Yoon Woo Nyon Kim 《Journal of Materials Science》2014,49(13):4522-4529
In this study, the effects of multi-walled carbon nanotube (MWCNT) dispersion and poly(styrene-co-acrylonitrile)-g-maleic anhydride (SAN-g-MAH) as a compatibilizer on the electrical conductivity, electromagnetic interference shielding effectiveness (EMI SE), and rheological properties of polycarbonate (PC)/poly(acrylonitrile–butadiene–styrene) (ABS)/MWCNT composites were investigated. The morphological results from the scanning and transmission electron microscope images showed that the droplet size of the ABS decreased when the SAN-g-MAH (5 phr) was added to the PC/ABS (80/20) blend. This result suggests that the SAN-g-MAH acts as an effective compatibilizer in the PC/ABS blend. Also, the MWCNT appeared to be located more in the ABS phase (dispersed phase) than in the PC phase (continuous phase). The interfacial tension of the ABS/MWCNT composite was lower than that of the PC–MWCNT composite, and the lower value of interfacial tension of the ABS/MWCNT composite affected the preferred location of the MWCNT in the ABS phase more than in the PC phase. The electrical conductivities and EMI SE of the PC/ABS/MWCNT composite with the compatibilizer were higher than those of the composite without compatibilizer. The complex viscosity of the PC/ABS/MWCNT composite containing the SAN-g-MAH increased with the frequency compared to that of the composite without SAN-g-MAH. This result is possibly due to the increased degree of MWCNT dispersion. The result of rheological properties is consistent with the results of the morphology, electrical conductivity, and EMI SE of the PC/ABS/MWCNT composite. 相似文献
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Chien-Lin Huang Yu-Jyun Wang Yang-Chun Fan Chia-Lin Hung Yu-Chia Liu 《Journal of Materials Science》2017,52(5):2560-2580
In this study, the effects of filler geometry on the electrical conductivity and electromagnetic interference (EMI) shielding properties of poly(trimethylene terephthalate) (PTT) composites filled with graphene nanosheets (GNSs), carbon nanotubes (CNTs), and GNS–CNT hybrid nanofillers have been investigated. The GNSs, CNTs, and hybrid GNS–CNT were well dispersed in the PTT matrix using a simple coagulation process. GNSs were prepared from graphene oxide (GO) through hydrazine reduction, and thermal reduction of GO at two different temperatures of 1050 and 1500 °C. PTT filled with different aspect ratios and oxygen functional groups of GNS were also prepared in order to compare the electrical conductivity and EMI shielding properties. The aspect ratios of GNSs and CNTs were estimated by using an ellipsoid model. Percolation scaling laws were applied to the magnitudes of conductivity to reveal the percolation network and filler dispersion. The percolation exponent of the PTT/GNS composites was larger than that of the PTT/CNT composites. The percolated filler–filler network at which the percolation exponent changed was correlated with the filler geometric structure. GNS–CNT hybrid nanofillers formed a complex double brush structure in the PTT/GNS–CNT composites. The geometric structure, aspect ratio, and intrinsic conductivity of carbon nanofillers affected the electrical percolation threshold and EMI shielding efficiency of the composites. 相似文献
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The conductive composites were prepared using two different types of conductive black (Conductex and Printex XE2) filled in
matrices like EVA and NBR and their different blends. The electromagnetic interference shielding effectiveness (EMI SE) of
all composites was measured in the X band frequency range 8–12 GHz. Both conductivity and EMI SE increase with filler loading.
However, Printex black shows higher conductivity and better EMI SE at the same loading compared to Conductex black, and this
can be used as a material having high EMI shielding effectiveness value. The conductivity of different blends with same filler
loading generally found to increase slightly with the increase in NBR concentration. However, EMI SE has some dependency on
blend composition. EMI SE increases linearly with thickness of the sample. EMI SE versus conductivity yields two master curves
for two different fillers. EMI SE depends on formation of closed packed conductive network in insulating matrix, and Printex
black is better than Conductex black in this respect. Some of the composites show appreciably high EMI SE (>45 dB). 相似文献
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CFRP复合材料具有优异的力学性能,在航空航天装备中有广泛应用,但是因其单层铺层内部的结构各向异性,单向纤维铺层对于垂直极化波的电磁屏蔽效能较弱。为应对日益复杂的电磁环境,保护电子元器件不受干扰,增强复合材料的电磁屏蔽效能显得尤为重要,本工作利用非连续Al颗粒在层间面内紧密排列,构建了一种层间面内含连续Al屏蔽层的CFRP复合材料,并研究了不同Al颗粒含量对复合材料电磁屏蔽效能和力学性能的影响规律。结果表明,随着Al颗粒含量的增加,CFRP复合材料的导电性和电磁屏蔽效能也随之增加,当聚合物中Al颗粒质量分数达到33.3%时,复合材料的面内电导率提高了3个数量级,在垂直于纤维方向上对频率为3~17 GHz的电磁波的电磁屏蔽效能提高了10 dB以上。随着Al颗粒含量的增加,复合材料层间剪切强度与弯曲强度出现先上升后下降的变化规律,当树脂中Al质量分数为33.3%时,复合材料的层间剪切性能提高了5.2%达到80.5 MPa,当树脂中Al质量分数为50%时,复合材料的弯曲强度提高了20%至1441.0 MPa,弯曲模量提高了10.2%达到101.83 GPa。由此可见,Al颗粒夹层CFRP复合材料可以实现力学性能和电磁屏蔽效能的同步提升,是一种具有广泛应用前景的结构-电磁屏蔽一体化复合材料。 相似文献
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Novel carbon nanotube-polystyrene foam composites for electromagnetic interference shielding 总被引:2,自引:0,他引:2
A novel carbon nanotube-polystyrene foam composite has been fabricated successfully. The electromagnetic interference (EMI) shielding effectiveness measurements indicated that such foam composites can be used as very effective, lightweight shielding materials. The correlation between the shielding effectiveness and electrical conductivity and the EMI shielding mechanism of such foam composites are also discussed. 相似文献
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针对低频频段(<1.5GHz)的电磁屏蔽涂层,采用快速混合法制备出导电聚苯胺纳米线,使用透射电镜(TEM)对其形貌和尺度进行表征,研究了搅拌方式对聚苯胺/聚氨酯涂层的导电性能和电磁屏蔽性能的影响。研究表明,由于磁场的作用,采用电磁搅拌法可以缩短聚苯胺聚合反应时间,合成均一的导电聚苯胺纳米线,其渗滤阈值为33.3%,含量为33.3%的聚苯胺纳米线的聚苯胺/聚氨酯涂层的电磁屏蔽性能为32.2dB,优于含量为45%的机械搅拌法制备的聚苯胺粉体,这可能是由于线性结构的导电聚苯胺在基体中能够较容易形成三维导电网络结构所致。 相似文献
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Poly(trimethylene terephthalate) (PTT)/multiwalled carbon nanotube (MWCNT) composites have been fabricated to evaluate the
potential of PTT composites as electromagnetic interference (EMI) shielding material. The room temperature electrical conductivity,
complex permittivity, and shielding effectiveness (SE) of PTT/MWCNT composites were studied in the frequency range of 8.2–12.4 GHz
(X-band). The dc conductivity (σ) of composites increased with increasing MWCNT loading and a typical percolation behavior
was observed at 0.48 vol% MWCNT loading. The highest EMI SE of PTT/MWCNT composites was ~23 decibel (dB) at 4.76 vol% MWCNT
loading which suggest that these composites can be used as light weight EMI shielding materials. The correlation among the
SE, complex permittivity, and electrical conductivity was also studied. The EMI shielding mechanism of PTT/MWCNT composites
was studied by resolving the total EMI SE into absorption and reflection loss. 相似文献
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《Science and Technology of Advanced Materials》2005,6(5):513-518
With the increasing of electromagnetic pollution and the widely use of commercial and military products, there is an increasing interest in electromagnetic interference (EMI) shielding. This paper mainly aims at electrical conductivity and EMI shielding effectiveness (SE) of the conducting composites made from silicone rubber (SR) with different loading levels of HCl-doped polyaniline (PAN-HCl) in the low frequency range from 3 to 1500 MHz. The result indicates that SE of the composites increase and the volume resistivity decrease with increasing mass ratio loading of PAN-HCl in the SR. The measured SE of the composites are from 16 to 19.3 dB at 100 mass ratio loading of the PAN-HCl and the volume resistivity decrease nine orders of magnitude compared with that of the emeraldine base form of PAN (PAN-EB) composites. 相似文献