化学镀镍碳纤维/环氧树脂复合材料电磁屏蔽性能

采用化学镀方法对碳纤维进行表面镀镍,采用SEM、EDX、XRD分析了镀镍碳纤维的微观形貌、镀层成分和镀层结构,通过电阻测试研究了镀镍碳纤维的导电性.将体积分数为2.5％、5％、7.5％、10％的镀镍碳纤维作为导电填料制备镀镍碳纤维/环氧树脂复合材料,并用屏蔽室法测试了不同频段复合材料的屏蔽效能.结果表明:碳纤维化学镀镍后,表面形成了一层均匀的复合镀层,镀层中镍的质量分数高达94％,镀镍碳纤维的电阻值仅为碳纤维原丝的1/54.镀镍碳纤维/环氧树脂复合材料的电磁屏蔽能力较碳纤维原丝有所提高.复合材料的屏蔽效能随镀镍碳纤维添加量的增加而升高.在低频频段(kHz频段),复合材料的屏蔽能力主要决定于材料的本征参数,不同镀镍碳纤维含量的镀镍碳纤维/环氧树脂复合材料的屏蔽能力相差不大;在中高频频段(MHz、GHz频段),镀镍碳纤维/环氧树脂复合材料屏蔽效能主要决定于材料的电阻率.     

3D编织碳纤维复合材料的制备及其屏蔽性能的研究

用三维五向3D编织技术和模压成型工艺制备了碳纤维增强环氧树脂基电磁屏蔽复合材料,测试结果表明,三维五向编织结构可形成良好的导电网络,基于该结构制成的碳纤维复合材料屏蔽效能最高可达85dB,编织体整体化学镀镍可使材料的屏蔽效能提高约15dB,镀镍后的复合材料在14kHz～18GHz频段内具有较高的屏蔽效能,最高可达95dB。同时发现,该材料的屏蔽性能显示各向异性,这与编织体的纤维取向和电磁波的极化方向有关。     

碳纤维连续镀镍生产工艺及其屏蔽复合材料

为了提高碳纤维镀镍工艺的生产效率以及对填充复合型电磁屏蔽材料的开发,使用自行研发的碳纤维(CF)连续电镀镍生产设备生产镀镍碳纤维(Ni-CF),并制备了镀镍碳纤维增强丙烯腈-丁二烯-苯乙烯共聚物(ABS)复合材料(Ni-CF/ABS),研究了偶联剂对复合材料力学性能的影响,以及纤维金属化及纤维含量对复合材料电磁屏蔽性能的影响。结果表明,偶联剂使复合材料具有更好的力学性能,拉伸和弯曲强度分别达到41 MPa和61.4 MPa。纤维质量分数为12%时,复合材料达到最佳的电磁屏蔽效能。     

镀镍PET纤维/环氧树脂复合材料的性能

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.     

化学镀法制备电磁屏蔽木材-Ni-P复合材料研究

用化学镀镍方法在落叶松木材单板表面沉积Ni-P合金制备了木材-Ni-P复合材料.用能谱(EDS)分析了镀层成分,采用扫描电镜(SEM)表征了复合材料的表面形貌,用X射线衍射研究了镀层的微结构,用低电阻测定仪和频谱仪分别测定了复合材料的表面电阻及电磁屏蔽效能,利用直拉法测定了镀层与木材的结合强度.结果表明:所得复合材料依然保持着木材的多孔性结构,表面镀层均匀;镀层为晶态结构的Ni-P合金,其中P的含量为1.53%;复合材料的表面电阻率在10-1～100Ω/cm2,电磁屏蔽效能在9 kHz～1.5 GHz的频段可达60 dB,且镀层与木材表面结合牢固.     

电刷镀电磁屏蔽涂层制备工艺与性能研究

采用电刷镀方法在环氧树脂表面制备镍铜层状电磁屏蔽复合镀层。分析了工作电压对复合镀层表面形貌、沉积速率、复合镀层与基体的结合力的影响,最后对不同工艺参数下层状复合电磁屏蔽镀层的电磁屏蔽效能进行了测试。结果表明,电刷镀铜的最佳刷镀电压是5V,电刷镀镍的最佳电压是4V,镀笔运动最佳速度为6m/min。在此工艺条件下制备的复合镀层与基体的结合力可达20.44N,电磁屏蔽效能达到74dB以上。     

NaBH_4前处理桦木化学镀镍制备木质电磁屏蔽复合材料

以桦木单板为基材,利用NaBH4处理后直接进行化学镀镍制备电磁屏蔽复合材料。研究NaBH4浓度和浸渍时间、施镀时间和NaOH浓度对表面电阻率的影响。分别采用扫描电镜(SEM)和X射线衍射(XRD)分析对比NaBH4前处理和胶体钯活化所得复合材料的表面形貌和组织结构,利用频谱仪和直拉法分别测定电磁屏蔽效能和镀层附着强度。结果表明:利用4g/L的NaOH配制3g/L的NaBH4溶液,前处理5~10min,化学镀镍20min,此条件下制备的复合材料的表面电阻率低于150mΩ/cm2,在9kHz~1.5GHz频段,电磁屏蔽效能高于60dB。NaBH4前处理所得复合材料的电磁屏蔽效能高于胶体钯活化;从表面形貌上观察,两种方法均可得到均匀、连续和致密的镀层,镀层完全覆盖了木材表面,具有金属光泽;XRD分析表明,NaBH4前处理所得镀层厚些,且结晶状态更佳,木材和镀层之间为物理结合;强度测试显示两种方法所得镀层均与木材表面结合牢固。     

碳系导电填料性质对PVB基功能薄膜结构及电磁屏蔽效能的影响

分别以形状和电导率不同的石墨、镀镍石墨和镀银碳纤维为功能填料,采用溶液流延法制备了聚乙烯醇缩丁醛基导电薄膜,并对薄膜的微观结构和电学性能进行了研究。结果表明:填料性质(包括形状、密度和电导率)对复合材料的分布结构和电学性能有重要影响,纤维状的填料更容易搭接成导电网络。石墨和镀银碳纤维填充体系中,填料在聚合物基体内部分布基本均匀;而镀镍石墨填充体系中,填料在聚合物基体内部形成了梯度分布。不同的分布状态导致材料的导电性能在薄膜的上下表面产生差异并对复合材料的电磁屏蔽效能产生影响。在同等体积含量下,复合材料的电磁屏蔽效能主要受材料电导率的影响,三种复合材料中,镀银碳纤维填充体系的屏蔽效能最高,镀镍石墨填充体系次之,石墨填充体系最低。     

多壁碳纳米管/聚乙烯醇复合材料电磁屏蔽性能研究

通过熔融共混、流延成膜法制备了多壁碳纳米管/聚乙烯醇(MWCNTs/PVA)复合材料,并研究了碳纤维作为增强体的作用。扫描电子显微镜、傅里叶变换红外光谱、热重分析表明:MWCNTs在PVA基体中均匀分散且形成了良好的空间导电网络;MWCNTs的加入会使吸收峰转移并与PVA发生键合反应;MWCNTs/PVA复合材料具有优异的热稳定性,热分解温度低于105℃时只有少量水分蒸发。导电性和电磁屏蔽测试表明,MWCNTs/PVA复合材料电磁屏蔽性能随其导电性的增强而提高,MWCNTs质量分数为1.2%的复合材料样品,在干扰电磁波频率为1~18GHz频段上具有良好的屏蔽性能,当干扰电磁波频率为13.3GHz时,其屏蔽效能为36.7dB。碳纤维可以增强MWCNTs/PVA复合材料的屏蔽性能,MWCNTs质量分数为0.6%的碳纤维增强MWCNTs/PVA复合材料样品,在干扰电磁波频率为1~18GHz频段时,其电磁屏蔽效能大于40dB。     

非织造基网格型碳纤维复合材料的屏蔽性能分析

在PET非织造基材表面,采用等间距排列连续碳纤维的方式制备网格型单层和双层碳纤维复合材料,测试分析具有不同排列间距、重叠层数和重叠角的复合材料,在30 MHz~1.5GHz频段内的电磁屏蔽性能,从而为制备低成本、高性能的电磁屏蔽复合材料提供一定的理论指导。结果表明:对单层网格型复合材料,在碳纤维排列间距为6mm时,其最优屏蔽效能特征峰值为46.66dB,对应频率1.05GHz;对双层网格型复合材料,以0°-0°角重叠、排列间距为6mm时,其屏蔽效能特征峰值达到51.31dB,对应频率1.15GHz;相比于单层复合材料,双层复合材料的屏蔽性能提高了10%,其有效频宽提高了42%。     

Froth floatation integrated into electrodeposition to prepare Ni/short carbon fibers composites with network and sheet structures

A new method of electrodeposition to prepare Ni/short carbon fibers (CFs) composites with network and sheet structures is described. The key point of the electrodeposition process is to obtain a sheet like preform floating on the electrolyte surface by froth flotation. The preform was composed of short homogeneous CFs. During the electrodeposition process, the preform was uniformly coated by nickel and the coating gradually grew from cathode to anode. The electrodeposits retained the network and sheet structures. The coating thickness can be controlled by appropriate electroplating conditions. The composites of epoxy resin reinforced by the electrodeposits were prepared successfully, and its electrical resistivity and electromagnetic shielding properties are reported.     

Nickel-catalyzed deposition of Cu film on PET fabric with supercritical fluid

Polyester fabric was catalyzed with Nickel(II) acetylacetonate (Ni(acac)₂) in supercritical carbon dioxide (scCO₂) prior to electroless copper plating . The nickel activated polyester fibers were then characterized by scanning electron microscopy and X-ray photoelectron spectroscopy. Deposited weight, surface morphology, crystal structure, surface resistance, electromagnetic interference shielding effectiveness and thermal loss of the copper plated polyester fabrics catalyzed with nickel in scCO₂ were investigated. The results indicate that the amount of copper deposited onto polyester fabric catalyzed with Ni(acac)₂ in scCO₂ is much more than that without scCO₂. Deposition rate of copper particles onto polyester fabric increases with increased temperatures of scCO₂. The copper particles are uniformly coated on the polyester fibers. The surface resistance of the copper plated fabric is 50 mΩ/sq when the temperature of scCO₂ is increased to 90?°C. The electromagnetic interference shielding effectiveness of the copper plated polyester fabric is 60–80 dB at frequencies ranging from 2 to 18 GHz. These results suggest that catalysis in scCO₂ for electroless copper plating provides polyester fabric with excellent electrical conductivity, surface resistance and electromagnetic interference shielding effectiveness.     

3D打印制备碳纳米管/环氧树脂电磁屏蔽复合材料

采用3D打印技术制备具有连续通孔的环氧树脂基体,利用浸渍工艺将碳纳米管（CNTs）附着于环氧树脂基体孔壁,获得具有优异电性能和电磁屏蔽功能的CNTs/环氧树脂复合材料。研究结果表明,CNTs含量仅为2.86vol%时,CNTs/环氧树脂复合材料电导率高达35 S/m,总电磁屏蔽效能高达39.2 dB（厚度为2.0 mm）。研究表明,CNTs/环氧树脂复合材料对进入其内部电磁波的吸收占总屏蔽效能的98%,表现出吸收屏蔽为主导的电磁屏蔽机制。CNTs/环氧树脂复合材料的弯曲强度和弯曲模量相比环氧树脂基体也有一定的提高。该研究为具有优异电磁屏蔽性能的高分子基复合材料制备提供了新思路和方法。      

镀金属炭毡/树脂复合材料的电磁屏蔽性能

采用镀金属炭毡与环氧树脂、聚丙烯（PP）、ABS、聚苯乙烯（PS）、聚乙烯（PE）复合制备电磁屏蔽（EMS）复合材料,镀金属炭毡复合材料在1－1000MHz范围内的屏蔽效率可达40dB以上,不同的树脂体系对复合材料的屏蔽效率无显著影响,在炭毡纤维表面镀不同的金属对复合材料的屏蔽效率有较大的影响。     

中间相沥青基碳纤维镀镍制备吸波材料

为制备中间相沥青基镀镍碳纤维,本文对比研究了电磁搅拌法和超声波法两种镀镍工艺,结果表明,两种工艺均可制备出表面镍含量较高的碳纤维,但超声波法制备的镀镍碳纤维的连续性优于电磁搅拌法,适合后续结构型吸波复合材料的制备。对镀镍碳纤维的电磁性能的研究发现,镀镍后碳纤维的电损耗参数下降,磁导率提高,利于低频带吸收。利用中间相沥青基镀镍碳纤维制备出树脂基复合材料,对其吸波性能进行测试,研究结果发现:以镀镍纤维层间全平行排布铺层制备的复合材料与未加镀镍碳纤维的相比,同时提高了在低频带和高频带的吸波效果,在14.88GHz吸收峰峰值为-27.62dB,低于-5dB的累积频宽约为14GHz,低于-10dB的累积频宽约为6.5GHz,吸波效果明显。     

镀Ni-P和Ni-N合金碳纳米管的磁性能及其复合材料的微波吸收性能

用竖式炉流动法,以二茂铁为催化剂,噻吩为助催化剂,苯为碳源通过催化裂解反应在1100~1200℃制备了直线形碳纳米管,外径为20~50 nm,内径10~30 nm,长度50~1000 μm。用化学镀工艺在碳纳米管表面均匀包覆了Ni-P和Ni-N合金,研究了它们的磁性能及其环氧树脂基复合材料在2~18 GHz的微波吸收性能。与纯碳纳米管相比,镀Ni-P合金碳纳米管复合材料的吸收峰向高频移动,镀Ni-P和Ni-N合金碳纳米管经热处理后,复合材料的吸收峰向低频移动。镀Ni-P合金碳纳米管以及镀Ni-P和Ni-N合金经热处理碳纳米管的矫顽力分别为304.34 Oe、 81.65 Oe、 183.85 Oe。随着矫顽力的增加,在2~18 GHz,复合材料的微波吸收峰向高频移动。在复合材料中,碳纳米管以及镀Ni-P和Ni-N合金的碳纳米管作为偶极子吸收微波。      

High electrical conductivity and high corrosion resistance fibers with high modulus and high strength prepared by electroless plating of gold on the surface of poly (<Emphasis Type="Italic">p</Emphasis>-phenylene benzobisoxazole) (PBO)

In an attempt to produce glittering gold fibers with high modulus and high strength, gold plating on the surface of poly(p-phenylene benzobisoxazole) (PBO) fibers was carried out by using an electroless plating method. Due to the difficulty in plating gold directly on organic and inorganic fibers, gold plating was carried out on the surface of copper-plated and nickel-plated fibers; for the latter the nickel was plated on the copper-plated fibers. Namely, composite fibers, termed PBO/Cu/Au and PBO/Cu/Ni/Au, were prepared. The morphology of plated fibers was studied by X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy and electrochemical polarization measurements. It was found that gold was uniformly plated on the PBO fiber, and the gold-plated fibers have good corrosion resistance. The electrical conductivities of the two kinds of gold-plated fibers were higher than 4 × 10⁴ S/cm, and their tensile strengths and Young’s moduli were greater than 1.9 GPa and 130 GPa, respectively, when estimated in terms of a single composite fiber.     

Mechanical and electrical properties of carbon fiber composites with incorporation of graphene nanoplatelets at the fiber–matrix interphase

In this study, carbon fibers (CFs) were coated with graphene nanoplatelets (GnP), using a robust and continuous coating process. CFs were directly immersed in a stable GnP suspension and the coating conditions were optimized in order to obtain a high density of homogeneously and well-dispersed GnP. GnP coated CFs/epoxy composites were manufactured by a prepreg and lay-up method, and the mechanical properties and electrical conductivity of the composites were assessed. The GnP coated CFs/epoxy composites showed 52%, 7%, and 19% of increase in comparison with non-coated CFs/epoxy composites, for 90° flexural strength, 0° flexural strength and interlaminar shear strength, respectively. Meanwhile, incorporating GnP in the CF/epoxy interphase significantly improved the electrical conductivity through the thickness direction by creating a conductive path between the fibers.     

激光改性纤维对其增强环氧树脂复合材料力学性能的影响

利用激光对玻璃纤维、玄武岩纤维和碳纤维进行表面改性后,以环氧树脂为基体,分别制备三种纤维增强环氧树脂复合材料。利用SEM和万能试验机对表面改性前后的碳纤维形态、力学性能及三种纤维/环氧树脂复合材料的力学性能和断面形貌进行表征,研究了纤维激光表面改性对三种纤维及其增强环氧树脂复合材料力学性能的影响。结果表明:激光表面改性对碳纤维/环氧树脂复合材料的力学性能提升最高,其拉伸强度最大提高了77.06%,冲击强度最大提高了31.25%,玄武岩纤维/环氧树脂复合材料的力学性能提升次之,而玻璃纤维/环氧树脂复合材料的力学性能有所下降。因此,激光进行表面改性适用于碳纤维和玄武岩纤维。