Electroless nickel plating on the surface of carbon fibers

The electroless nickel plating on the surface of carbon fibers was prepared by pretreating the carbon fibers in order to increase their conductivity,and consequently enhance the EMI shielding effectiveness of the composites.The relationship between the performance of depositing coat and pH value,temperature,reaction time and the way of agitation was studied.Results show that the depositing quality is stable under pH between 4.5 and 5.0,temperature between 75 ℃ and 85 ℃,reaction time for 10 min and air agitation.The uniform and compact nickel layer deposited on carbon fibers was proved by XRD and SEM,and the electrical resistivity of carbon fibers with nickel coating was tested.Results indicate that the electrical resistivity of carbon fibers with electroless nickel plating is decreased by an order of magnitude compared with that of carbon fibers.It means that nickel coating can greatly improve the electromagnetic interference shielding properties of carbon fibers.

Surface Modification with Carbon Fiber for the Metallization of Polyether-ether-ketone

The poly-ether-ether-ketone(PEEK)polymer is a semi-crystalline aromatic thermoplastic with outstanding features,such as superior mechanical properties,thermal stability,radiation resistance and excellent chemical and hydrolysis resistance.However,PEEK exhibits a high volume resistivity(1014Ω·m)and surface resistance(1015Ω).This limits its use in the electronics and electromagnetic field.To decrease the resistivity and reduce the thermal expansion of composite materials,this paper modified the PEEK with carbon fiber(CF)and metalized the composites with the electroless Ni-P alloy plating through self-catalyzed deposition,which brings about high conductivity,thermal conductivity,high-temperature weldability resistance and high-low temperature resistance property.The composites and metal coatings were characterized by metallurgical microscope,SEM,and resistance tester.The metal coatings have a uniform surface and low surface resistance less than 10 mΩ~20 mΩ.The thermal shock test at 250°C and the-70°C^100°C high-low temperature environment test were measured.Compared with the electroless plating on unmodified peek,there is no bump and crack,etc.after testing,which shows a good adhesion between the metal coatings and PEEK-CF,high-low temperature resistance as well as high temperature weldability.The researches on the modification of PEEK by carbon fiber and its surface metallization provide technical support for the application of PEEK Composites in radar antenna and other electronic fields.

Electromagnetic Interference Shielding Properties of Electroless Nickel-coated Carbon Fiber Paper Reinforced Epoxy Composites

Carbon fibers（CFs） were coated with a nickel-phosphorus（Ni-P） film using an electroless plating process. The morphology, elemental composition and phases in the coating layer of the CFs were investigated by scanning electron microscopy（SEM）, energy dispersive spectroscopy（EDS） and X-ray diffraction（XRD）, respectively. Wet paper-making method was used to prepare nickle coated carbon fiber paper（NCFP）. Vacuum assisted infusion molding process（VAIMP） was employed to manufacture the NCFP reinforced epoxy composites, and carbon fiber paper（CFP） reinforced epoxy composites were also produced as a comparison. Electromagnetic interference（EMI） shielding properties of the composites were measured in the 3.22-4.9 GHz frequency range using waveguide method. Both NCFP and CFP reinforced epoxy composites of 0.5 mm thickness exhibited high EMI shielding effectiveness（SE） at 8wt% fiber content, 35 d B and 30 d B, respectively, and reflection was the dominant shielding mechanism.

Plasma Modification of Activated Carbon Fibers for Adsorption of SO_2

Viscose-based activated carbon fibers （VACFs） were treated by a dielectric-barrier discharge plasma under the feed gas of N2. The surface functional groups of VACFs were modified to improve the adsorption and catalysis capacity for SO2. The surface properties of the untreated and plasma-treated VACFs were diagnosed by SEM, BET, FTIR, and XPS, and the adsorption capacities of VACFs for SO2 were also compared and discussed. The results show that after the plasma treatment, the external surface of VACFs was etched and became rougher, while the surface area and the total pore volume decreased. FTIR and XPS revealed that nitrogen atoms were introduced onto the VACFs surface and the distribution of functional groups on the VACFs surface was changed remarkably. The adsorption characteristic of SO2 indicates that the plasmatreated VACFs have better adsorption capacity than the original VACFs due to the nitrogen functional groups and new functional groups formed in modification, which is beneficial to the adsorption of SO2.

Preparation and surface modification of PVDF-carbon felt composite bipolar plates for vanadium flow battery

The performance of vanadium flow batteries （VFBs） is closely related to the materials used in the bipo- lar plates. Carbon-based composite bipolar plates are particularly suitable for VFB applications. However. most original preparation methods cannot simultaneously achieve good electrical conductivity and me- chanical performance. In this paper, we propose a novel approach to fabricating bipolar plates with car- bon plastic materials, including four steps, namely coating a poly （vinylidene fluoride） （PVDF） solution onto carbon felt, solvent evaporation, hot-pressing, and surface modification. The resulting bipolar plates showed high conductivity, good mechanical strength, and corrosion resistance. Surface modification by coating with carbon nanotubes （CNTs） removed the PVDF-rich layer from the surface of the carbon fibers. The high surface area of the CNT withdrew PVDF resin from the carbon fiber surface, and promoted the formation of a conductive network. The flexibility and battery charge-discharge cycle measurements showed that the composite bipolar plates can meet requirements for VFB applications.

Electrochemical behavior of Cu-Zn-Al shape memory alloy after surface modification by electroless plated Ni-P

The electrochemical behavior of Cu-Zn-Al shape memory alloy (SMA) with andwithout electroless plated Ni-P was investigated by electrochemical methods, in artificial Tyrode'ssolution. The results showed that Cu-Zn-Al SMA engendered dezincification corrosion in Tyrode'ssolution. The anodic active current densities as well as electrochemical dissolution sensitivity ofthe electroless plated Ni-P Cu-Zn-Al SMA increased with NaCl concentration rising, pH of solutiondecreasing and environmental temperature uprising. X-ray diffraction analysis indicated that aftersurface modification by electroless plated Ni-P, an amorphous plated film formed on the surface ofCu-Zn-Al SMA. This film can effectively isolate matrix metal from corrosion media and significantlyimprove the electrochemical property of Cu-Zn-Al SMA in artificial Tyrode's solution.

Studies on copper coating on carbon fibers

The weak interface bonding of metal matrix reinforced by carbon fibers is the central problem of fabricating such composites. Depositing copper coating on carbon fibers is regarded as a feasible method to solve the problem. In this paper, copper coating has been deposited on the fibers through both electroless deposition and electroplating methods. Two kinds of complexing agents and two stabilizing agents are taken during the electroless plating process. The solution is stable, and little extraneous component is absorbed on the surface. After adding additive agents and increasing the concentration of H2SO4 to the acid cupric sulfate electrolyte, the "black core" during usual electroplating process is avoided. The quality of copper coating is analyzed using SEM and XRD, etc.

Interconnected Ni(OH)_(2)and polyether amine on carbon fiber surface for simultaneously improving interfacial adhesion of epoxy composites and electrochemical properties

Interconnected Ni(OH)_(2)nanoflakes and polyether amine(PEA)were deposited on carbon fiber tows via a facial and effective process of chemical bath deposition and dip coating.Based on this,a win–win benefit of simultaneously improvements in interfacial shear strength(IFSS)of carbon fiber/epoxy composites and the electrochemical activity has been achieved.Compared with CF and CF-Ni(OH)_(2)composites,the IFSS of CF-Ni(OH)_(2)-PEA/epoxy composite respectively increased 7.9%and 45.4%,which was put down to the covalent bonding of Ni(OH)_(2)-PEA coating with fiber and epoxy matrix,as well as the effective stress transfer by the uniform honeycomb structure of Ni(OH)_(2).In aqueous KOH electrolyte,the CF-Ni(OH)_(2)-PEA electrode presented the maximum specific capacitance of 689.98 F·g^(-1)at 5 m V·s^(-1),572.28 F·g^(-1)at a current density of 0.5 A·g^(-1)due to the strong adhesion of carbon fiber with Ni(OH)_(2)by PEA,the reservation of the threedimensional hollow honeycomb structure of Ni(OH)_(2)for easy ion-transport and–NH_(2)functional groups from PEA for providing more active sites.The excellent performance of CF-Ni(OH)_(2)-PEA reinforcement demonstrates its promising potential for application in high performance composites with integrated structure and function,which shows great advantages in various fields of aerospace,energy,electronics,automobile,civil engineering,sports,etc.

Electroless nickel plated graphite fibers and surface behavior in G_(r(Ni))/6061Al composite

The electroless nickel plated graphite fibers reinforced aluminum matrix composites (Gr(Ni))/Al) were produced by squeeze casting, and the microstructure of Gr(Ni)/Al composite and surface behavior of Ni-P coating were studied. The optimum process of electroless Ni-P plating included: burning to get rid of glue→degreasing→neutralization→acidulating→sensitizing→activation→electroless plating. The surface analysis results show that the electroless nickel plating can diffuse into the graphite fiber surface during the squeeze casting, and the Ni-P coating and aluminum alloys can produce brittle phase NiAl3 or NiAl. The X-ray diffraction(XRD) results indicate that Al4C3 is so little that no Al4C3 peaks are found, and the harmful Al4C3 can be decreased by the electroless plating Ni-P coating. The coating improves the interfacial bonding of continuous graphite fibers reinforced aluminum matrix composites.

Effects of Fiber Surface Pretreatment and Composite Posttreatment on Mechanical Properties of 2D⁃Cf/Phosphate Geopolymer Matrix Composites

Geopolymers are an important class of materials with potential applications because of their heat resistance,flame resistance,environmental friendliness,and possibilities of being transformed into ceramic matrix composites at low cost.However,the low mechanical properties as well as the intrinsic brittleness limit their technological implementations,and it is necessary to enhance the mechanical properties of geopolymers by adopting various kinds of reinforcements.In this work,therefore,two⁃dimensional continuous carbon fiber(Cf)reinforced phosphate⁃based geopolymer composites(Cf/geopolymer)were prepared through ultrasonic⁃assisted impregnation method.Effects of acetone treatment and high⁃temperature treatment on the properties of Cf/geopolymer composites were studied by X⁃ray photoelectron spectroscopy(XPS),X⁃ray diffraction(XRD),and scanning electron microscopy(SEM).Results of the study proved that acetone treatment plays a key role in ameliorating the interfacial interaction between Cf and phosphate matrix,which can thus enhance the mechanical properties of Cf/geopolymer composites.The Cf/geopolymer composites prepared by acetone⁃treated Cf had a flexural strength of 156.1 MPa and an elastic modulus of 39.7 GPa in Y direction.Moreover,an additional Sol⁃SiO2 re⁃impregnation treatment could further enhance the mechanical properties of the acetone⁃treated Cf/geopolymer composites by repairing the cracks and filling the pores.The results in this paper not only provide insights into the surface modification of Cf,but also report a facile and low⁃cost preparation route for Cf/geopolymer composites with potential applications in aerospace and defense technology.

一种集成电路电容适用的碳纤维改性复材制备及性能

为了提升集成电路电容用复合材料的综合性能,对比分析了碳纤维(CF)、Ni(OH)_(2)改性碳纤维CF-Ni(OH)_(2)和聚多巴胺改性碳纤维CF-PNi的表面形貌、化学结构、润湿性能和力学性能。结果表明,原始CF表面存在深度不一的加工沟槽、粗糙度较大,当经过Ni(OH)_(2)和聚多巴胺改性处理后,碳纤维表面沟槽基本消失,表面粗糙度减小。改性CF相较CF与树脂(EP)的接触角都有不同程度减小,与树脂接触角从大至小顺序依次为:CF、CF-Ni(OH)_(2)、CF-PNi;当采用Ni(OH)_(2)对CF进行改性后,CF-Ni(OH)_(2)/EP的弯曲强度F_(s)、弯曲模量F_(m)、层间剪切强度ILSS和横向拉伸强度Hl相较CF有明显提升,采用聚多巴胺进一步对CF-Ni(OH)_(2)进行改性处理后,CF-PNi/EP的F_(s)、F_(m)和Hl会相较CF-Ni(OH)_(2)/EP进一步提升,而ILSS变化幅度不大。

碳纤维表面改性及其对热塑性复合材料界面性能影响的研究进展

基于复合材料界面作用机制,系统总结了碳纤维表面改性方法,分别讨论了不同碳纤维改性处理方法对热塑性复合材料界面性能的影响及相关研究进展。碳纤维表面进行改性处理是增强热塑性复合材料界面结合强度的有效途径。最后对碳纤维表面改性方法的未来发展方向进行了展望。

脉冲激光改性碳纤维复合材料及其金属化研究

目的选择性地实现碳纤维复合材料(Carbon fiber reinforced plastic,CFRP)表面良好的导电性,满足它在共形天线上的应用。方法采用波长为1064 nm的纳秒脉冲激光器对惰性极高的CFRP表面进行表面改性处理,并结合化学镀铜技术,制备激光改性碳纤维复合材料表面金属层。利用扫描电镜、X射线光电子能谱仪对改性后的材料表面进行表征,利用焊点拉脱方法表征金属层结合力。结果研究表明,激光能量密度越高,则CFRP基材表面树脂被去除得越多;激光搭接率越大,则碳纤维束表面越粗糙;在适当的激光能量密度(60 J/cm^(2))和横/纵向搭接率(50%)下,会产生大量的极性化学基团。当激光能量密度为10~100 J/cm^(2)、激光搭接率为0%时,CFRP表面镀铜层的结合强度为0.57~3.16 MPa,且激光能量密度与镀层结合强度呈正相关。当激光能量密度为60 J/cm^(2)、激光搭接率为−100%~90%时,CFRP表面镀铜层的结合强度为0.19~3.24 MPa,且激光搭接率与镀层结合强度呈正相关。结论脉冲红外纳秒激光在一定能量密度和搭接率的条件下,可改变碳纤维表面形貌、化学成分,实现金属层的制备。

高分散水性碳纤维的制备

本研究以壳聚糖盐酸盐(CHI)和十二烷基磺酸钠(SDS)制备改性剂(CHI&SDS),采用浸渍法对BHM3碳纤维进行表面改性,以提升BMH3碳纤维在水中的分散能力。系统研究了CHI/SDS质量比、CHI&SDS改性剂质量分数及纤维长度对改性BMH3碳纤维在水中分散性的影响,并通过X射线光电子能谱仪和动态接触角测试仪,对改性BMH3碳纤维化学结构和表面润湿性进行了表征。结果表明,BMH3碳纤维经过质量分数0.15%,CHI/SDS质量比=25∶1的CHI&SDS改性剂改性后,纤维长度5 mm的改性BMH3碳纤维在水中的分散率可达96.2%,相较于未改性碳纤维提升了87.5个百分点。改性BMH3碳纤维表面含氧官能团数量显著提升,水接触角明显降低,这是BMH3碳纤维分散性能改善的原因,也是成功实现高分散水性碳纤维制备的基础。

紫外辐照与壳聚糖接枝联合处理对ABS表面改性效果的影响

聚丙烯腈-丁二烯-苯乙烯(ABS)是一种应用广泛的工程塑料。将绿色环保的紫外光辐照表面修饰技术与壳聚糖接枝处理技术相结合对ABS基板表面进行改性处理,探究了紫外光辐照条件、壳聚糖醋酸溶液的浓度、改性温度和改性时间对ABS基板表面形貌、表面粗糙度、表面亲水性和表面化学性质的影响。首先使用2 g/L的二氧化钛(TiO_(2))作为光催化剂在300 W下对ABS进行光辐照处理30 min,然后利用0.75 g/L的壳聚糖醋酸溶液在70℃下改性处理30 min,通过扫描电镜(SEM)、原子力显微镜(AFM)观察ABS基板表面形貌变化,并利用表面接触角测量仪和X射线光电子能谱(XPS)分析ABS基板表面亲水性能的变化。结果表明,经过紫外光辐照和壳聚糖接枝改性处理后,ABS基板处理后表面形成少量微小孔洞,表面粗糙度较小,但是ABS基板表面亲水基团的浓度大幅增加,表面亲水性明显增强,化学镀铜层光滑平整,颜色粉红,具有金属光泽。

化学镀铁镍碳纤维制备及其电磁屏蔽性能

为提高碳纤维(CF)的屏蔽性能和实现宽频化应用,本文通过化学镀方法分别在CF表面沉积Ni、FeNi金属层,制备了碳纤维杂化材料(CF@Ni、CF@FeNi)。其次以水性聚氨酯(WPU)为基体,依次以CF、CF@Ni和CF@FeNi为填料,制备了轻质、柔性的复合材料。同时测试了复合材料在30~3000MHz的电磁屏蔽性能和10~100kHz的磁屏蔽性能。结果表明,成功地在碳纤维表面镀覆了一层致密、均匀的金属层,其中CF@FeNi的饱和磁化强度(Ms)、剩余磁化强度(Br)和矫顽力(Hc)分别达到了10.02emu/g、0.76emu/g和26.06Oe。金属镀层改善了碳纤维的电磁屏蔽性能,并有效提高了其在低频段的磁屏蔽性能。当添加量为9%时,WPU@CF@FeNi在30~3000MHz与10~100kHz的屏蔽效能峰值分别达到26.9dB和18.0dB。

碳纤维表面改性提高其树脂基复合材料电磁屏蔽性能的研究进展

随着大数据、物联网和新能源汽车等新兴产业的快速发展,相关电子设备与元器件向高性能化、高集成化、轻量化、精密化等方向迈进。随之产生的电磁干扰会威胁人体健康、信息安全以及各种电子设备的正常工作,因此迫切需要高性能的电磁屏蔽材料。碳纤维具有优异的力学性能和良好的导电性,其树脂基复合材料更是兼具质量轻、比强度/模量高、耐疲劳性好、可设计性强以及良好的电磁屏蔽性能等优势。但与传统的金属材料相比,碳纤维复合材料的电磁屏蔽性能较低,为了进一步提高其电磁屏蔽性能,通常需要对碳纤维进行表面改性。本文介绍了碳纤维复合材料的电磁屏蔽机理,综述了不同的碳纤维表面改性方法以及对碳纤维增强树脂基复合材料的电磁屏蔽性能的影响,分析了各种碳纤维表面改性方法的优缺点,进一步对碳纤维增强树脂基电磁屏蔽复合材料的发展趋势进行了展望。

碳纤维材料表面改性技术的研究进展

碳纤维增强材料具有优异的力学性能和质量比,是先进复合材料的首选材料。由于碳的疏水性和化学惰性以及碳纤维生产过程中高温、碳化和石墨化等工序,造成碳纤维表面与聚合物分子之间界面附着力较差,这是长期存在且需要克服的问题。碳纤维表面改性技术分为化学法和物理法两类,介绍了近年来国内外在碳纤维表面改性方面的研究进展。比较了酸处理法、电化学法、碳纳米管接枝法、涂层法、等离子处理法及高能辐射法等处理方法对碳纤维表面改性的效果,并结合实际生产指出了各种方法所存在的不足。

碳纤维表面改性技术研究进展及发展趋势

综述了近几年国内外碳纤维表面改性处理技术的研究进展,分别介绍了涂层改性、氧化改性、表面接枝改性、等离子体改性的改性原理及效果。现有碳纤维表面改性技术仅对表面产生物理或化学的改性,单独一种改性技术在连续化生产中难以实现有效控制,而多种改性技术的组合式应用技术可以相互融合各种改性技术的优点,适合在各个碳纤维生产流程中进行表面改性设计具有更高的研究价值。碳纤维组合式表面改性技术将是未来提升碳纤维连续化生产的发展趋势。

基于铑活化环氧树脂基板表面化学镀铜技术探究

环氧树脂基板被广泛应用于印制电路板生产中,由于基材本身惰性和较低表面能,不利于化学镀铜层的沉积,因而通常需要进行改性处理。本文提供了一种新型的环氧树脂基板化学镀铜工艺方法,将有机金属化合物Rh(C_(5)H_(7)O_(2))(CO)(PPh_(3))与双酚A型环氧树脂混合作为基材表面催化化学镀铜的活化改性层,再利用1 mol/L的硼氢化钠溶液进行40 min还原处理,最后进行化学镀铜。通过基板间剪切强度测试,发现得到的改性层与基板之间结合力较好,可满足PCB实际生产需求。利用粗糙度测试以及SEM测试分析,经过还原处理后的基材表面Ra=6.72 nm相较于未经过还原处理的基材改性层表面的Ra=5.43 nm有明显提升,从金相显微镜图和SEM测试图中可看出该技术制备的化学镀镀层表面的铜晶粒分布均匀且结晶致密,说明该化学镀铜工艺可得到表面平整光滑、厚度均匀的镀铜层。