电沉积非晶态Ni-Fe-P合金屏蔽织物的制备及其表征

在已镀铜涤纶织物表面采用电镀技术制备了一种非晶态Ni-Fe-P合金屏蔽织物。选用8因素3水平的正交试验对制备工艺进行了探讨研究,分析了电镀液组成对镀层沉积速率及组分的影响,借助SEM、EDS和XRD对镀层表面形貌、成分及结构进行了分析,并测试了合金织物的电磁屏蔽效能。结果表明,制备非晶态Ni-Fe-P合金织物的电镀工艺为硫酸镍135 g/L,硫酸亚铁105 g/L,次亚磷酸钠8 g/L,抗坏血酸24 g/L,柠檬酸36 g/L,亚磷酸22 g/L,温度65℃,p H值=1.5,电流密度13 A/dm2,合金织物表面镀层致密均匀,结晶细致,镀层为非晶态结构的Ni-FeP合金,其中P的质量分数为18.67%,在300 k Hz~1.5 GHz频率范围内,合金织物电磁屏蔽效能达到了60.82~73.63 d B。     

锡镍合金柔性电磁屏蔽材料的研制

在已镀铜的涤纶织物上电镀锡镍合金,得到了一种表面致密均匀的柔性电磁屏蔽材料,对制备工艺进行了初步研究与探讨。试验表明,焦磷酸钾150g/L,氯化铵5~10g/L,甘氨酸10g/L,温度25~30℃,电流密度0.67~1A.dm-2时,得到的功能性纺织品色调高雅,光泽柔和,且具有良好的电磁屏蔽性能。锡镍合金镀层无致敏性,从而减少传统的镍镀层材料对人体的危害;减少镍的用量,降低了生产成本,具有明显的现实意义与广阔的应用前景。     

非晶态Ni-Fe-P合金屏蔽织物的工艺优化及耐蚀性研究

通过在已化学镀铜涤纶织物上电沉积非晶态Ni-Fe-P合金,制备出一种镀层致密均匀的柔性金属化屏蔽织物。研究和分析了电流密度、温度和p H值对合金织物方阻值、增重率及屏蔽效能的影响,从而制定出最佳工艺。通过对比腐蚀前后非晶态Ni-Fe-P合金和非晶态Ni-P合金镀层表面形貌、成分和电磁屏蔽效能可以得出,在电流密度为8.7 A/dm2,温度为60℃,p H值=1.5的工艺条件下所制备的非晶态NiFe-P合金织物结晶更加细化、光亮,致密性和均质性都得以明显提高,并具有良好的耐腐蚀性能,且在300 k Hz~1.5 GHz频率范围内的电磁屏蔽效能达到了69.20~80.30 d B。     

多层金属纤维混纺织物的电磁屏蔽效能

金属纤维混纺织物由于具有较好的电磁屏蔽性能得到了广泛应用,但其屏蔽效能受纺织工艺等诸多因素影响,难以建立精确的计算模型。在分析介质平板屏蔽体屏蔽效能的基础上提出等效算法,将金属纤维混纺织物等效为均匀介质平板,以计算多层织物材料的电磁屏蔽效能。通过测试单、双层金属纤维混纺织物的电磁屏蔽效能,验证了等效方法的正确性和可行性,可用于指导复合材料的设计。     

电磁屏蔽织物材料研究进展

目的现代战场电磁环境日益恶化,含有电子元件和电爆装置的高价值、高技术弹药能否在复杂电磁环境中发挥应有效能,已经成为武器装备建设中一个亟须解决的问题。方法利用电磁屏蔽织物材料作为包装内衬或遮蔽篷布,以增强高价值、高技术弹药在复杂电磁环境中的抗电磁干扰能力,对确保弹药的可靠性具有重要意义。结果综述了金属纤维混纺织物、金属化学镀织物、金属真空镀织物和涂层屏蔽织物研究现状,对比分析了各种织物材料制备工艺的优缺点,简要介绍了非晶态合金织物屏蔽效能的研究进展。结论电镀非晶态合金织物是未来电磁屏蔽织物材料发展的重点方向之一。     

宽频电磁屏蔽柔性织物

项目内容:选用特殊化纤织物为基材,使纤维金属化,制造出一种新型的柔性电磁屏蔽织物。采用多层结构设计方案,制备出具有FeNi二元软磁合金膜-铜导电膜-纤维内芯结构的电磁屏蔽材料,使电磁屏蔽织物同时具有屏蔽高频电磁场和低频磁场的特性,是一种宽频电磁屏蔽材料。其综合屏蔽效能达到80dB以上,该指标处国内领先水平,可广泛应用于电磁辐射防护领域。市场分析:未来市场容量约为1.25亿人民币●新型电磁屏蔽室(国内):4万个×1000(个)=0.4亿;采用本项目生产的宽频电磁屏蔽柔性织物建造的新型电磁屏蔽室,具有造价低、质轻、易建造和维修、环境优…     

复合柔性屏蔽材料的制备及其应用

利用特殊的加温加压复合方式,将高性能屏蔽织物和铜丝网热复合在一起,制备了新型的复合柔性屏蔽材料,并对其性能进行了检测,对其应用途径进行了分析。结果表明,该屏蔽材料在不同的频段具有较高的屏蔽效能,在300 MHz以上的高频段,屏蔽效能达到60 dB以上,在300 MHz以下的低频段也能达到8～60 dB,尤其在环境适应性、抗撕裂性等方面有明显优势,可以广泛应用于室内外的电磁防护实例中。     

镀银织物双层叠放模式与电磁屏蔽效能增量研究

电磁辐射是四大环境污染之一,通过不同电磁屏蔽体的叠加组合能够有效提高屏蔽效能。研究了镀银织物以紧密叠放、夹空气层和夹角叠放3种模式构造,采用小窗法屏蔽效能测试系统实测了0～18 GHz宽频段内双层织物的电磁屏蔽效能的增量问题。结果表明：镀银织物双层紧密叠加有利于电磁屏蔽效能提升,其屏蔽效能可达70 dB,明显高于单层织物,紧密叠放更有利于双层织物的屏蔽效能;夹空气层双层织物在0～6.5 GHz频段的屏蔽效能有所提高,而在其他频段其屏蔽效能呈下降趋势,尤其不利于高频电磁波的屏蔽;夹角叠放双层织物屏蔽效能均达到60 dB以上,大夹角叠放(90°)时使双层织物的屏蔽效能降低。建立了双层织物电磁屏蔽效能的增量模型,为电磁屏蔽效能分析提供了一个新的视角,通过结构优化方式探索屏蔽体构造的最佳配置,对电磁屏蔽体的设计、生产及使用具有一定的参考价值。     

涤纶织物化学镀银工艺探究

采用聚乙二醇1000优化了化学镀银中的敏化/活化工艺,采用施镀所用还原液对织物还原处理,以氨水、乙二胺和硫代硫酸钠作为复合络合剂,开发了涤纶织物绿色化学镀银技术;并在此基础上开发了双层镀银技术。采用扫描电镜和四探针研究了工艺对银镀层的表面形貌和表面方块电阻的影响,并由上海计量测试技术研究院测得镀银涤纶织物的电磁屏蔽效能。结果表明,得到的镀银层光滑、平整、致密,单层镀银涤纶织物的方块电阻为20 mΩ/□~30 mΩ/□、双层镀银涤纶织物的电阻为9 mΩ/□~15 mΩ/□,在30 MHz~3000 MHz频率范围内,单、双层镀银涤纶织物的电磁屏蔽效能分别为78.05 dB和87.82 dB。     

合成纤维复合夹层屏蔽结构改性及其电磁特性研究

提出具有复合介质夹层屏蔽结构模型的设想,利用铜箔-聚四氟乙烯为原材料,设计了单层屏蔽结构与复合夹层屏蔽结构的对比实验,测试了复合夹层屏蔽结构的电磁屏蔽效能增量,并用Ватолцн多层电磁屏蔽理论公式进行了验证。具有复合夹层屏蔽结构材料的电磁屏蔽效能明显优于单层屏蔽结构材料的电磁屏蔽效能。继而以涤纶无纺布、锦纶合成纤维为研究对象,采用电化学改性的方法,制备了具有复合夹层屏蔽结构的柔性电磁屏蔽材料。结果表明,通过对研究对象的选择和优化电化学改性的工艺,可以制备出1 MHz~1000 MHz入射电磁波频段范围内,满足不同要求的合成纤维复合夹层屏蔽结构改性材料,其SE值最高可达98 dB。     

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.     

Microscopic and macroscopic models of photo-induced volume changes in amorphous selenium

Electroless copper plating of polyester fabrics was demonstrated in the present investigation. The electroless Cu plating process on polyester fabric was modified by replacing the conventional PdCl₂ activator with an AgNO₃ activator to reduce the overall cost of the plating process. Both uncoated and Cu-coated polyester fabrics were characterized by the scanning electron microscope (SEM), energy dispersive spectroscopy (EDX), X-ray diffraction analysis (XRD) and X-ray photoelectron spectroscope (XPS). Relatively uniform and continuous plating was obtained under the given plating conditions. The possible mechanism of electroless copper plating of polyester fabrics utilizing an AgNO₃ activator was suggested. The electromagnetic interference (EMI) shielding effectiveness (SE) was also evaluated to study the shielding behavior of copper-plated polyester fabrics. The results demonstrated that copper-plated polyester fabrics can be applied for EMI shielding.     

Microstructure and electromagnetic interference shielding effectiveness of electroless Ni–P plated polyester fabric

Microstructure and electromagnetic interference shielding effectiveness of electroless Ni–P deposits obtained from an alkaline hypophosphite reducing electroless nickel bath was studied. The effects of plating temperature on the deposition rate, surface morphology, chemical composition and structure of the electroless Ni–P deposits were investigated. Surface resistance and electromagnetic interference (EMI) shielding effectiveness (SE) of Ni–P plated polyester fabric were also evaluated. The results demonstrated electroless Ni–P plated polyester fabric present useful EMI shielding materials.     

导电涤纶织物的制备及其性能研究

采用化学镀的方法制备镀铜和镍导电涤纶织物.分别用四探针法和双轴传输线法测量了导电涤纶织物的表面电阻和电磁屏蔽效能.采用扫描电镜(SEM)分析了不同的粗化时间对织物表面粗糙度的影响和化镀铜和镍过程中的表面形态变化.采用自主设计的"透明胶带法"测量金属与织物纤维的结合力.采用条样法测定织物镀金属前后的断裂强力和断裂延伸率.     

磁控溅射法制备电磁屏蔽织物的研究

本文采用直流磁控溅射在无纺布基底上溅射沉积金属铜来制备电磁屏蔽织物。通过原子力显微镜观察发现,工艺参数对溅射沉积速率以及膜层的表面形貌都有较大的影响。在一定范围内,溅射功率越大,沉积速率越大,膜层颗粒分布越均匀致密。溅射压力一般选取0.9 Pa左右为宜,在此压力下,溅射沉积速率最大。经测试膜层与基底结合牢度较好,溅射沉积铜后透气性变化较小。频谱分析仪测试结果表明织物的屏蔽性能十分优良。     

Electrical and impact properties of the hybrid knitted inlaid fabric reinforced polypropylene composites

A range of conductive knitted fabric reinforced polypropylene composites have been developed and their electromagnetic shielding effectiveness (EMSE), electrostatic discharge (ESD) and impact properties have been investigated. Carbon and aramid fibers are used as the reinforcement phase in the composites, while copper and stainless steel wires are incorporated as conductive fillers to provide the ESD and EMSE properties of the composite materials. The hollow spindle spinning system has been used to make SS/PP, Cu/PP, SS/C/PP, Cu/C/PP and Cu/K/PP uncommingled yarns. The double plain knitted fabric and its inlaid fabrics were fabricated from the yarns using a 5G traverse knitted machine. Changing the yarn composition, fabric knit structure, and stitch density varies the amount of copper and stainless steel conductive fillers in the composites. 4 layer cross-ply laminates were laid-up by hand, then formed into 3-mm thick conductive thermoplastic composites using a compression molding. It was observed that the EMSE and ESD of the composites increase with increasing the incident frequency, especially at higher frequency range. The effects of inlaid ends, materials and yarn constitutions on the EMSE of the conductive thermoplastic composites were investigated. The results indicate that the composites can be used for the purpose of electromagnetic shielding and ESD attenuation, as well as for some microwave applications.     

多功能聚吡咯/聚酰亚胺电磁屏蔽复合膜的制备与性能研究

目的 开发具有优异屏蔽效率、轻质且热稳定性良好的电磁屏蔽材料。方法 以聚酰亚胺(PI)为聚合物基体,聚吡咯(PPy)为添加相,采用静电纺丝-低温原位聚合技术制备PPy/PI电磁屏蔽复合膜。通过在薄膜内部的多孔结构中构建致密的导电网络,赋予复合膜优异的导电性和高效的电磁屏蔽效能。结果 在聚合PPy浓度为0.1 mol/L时,复合膜的电导率和电磁屏蔽效能分别为2.23 S/cm和26.04 dB,且其单位厚度电磁屏蔽效能可达到110.81 dB/mm,展现出优异的电磁屏蔽性能。结论 PPy/PI复合纤维膜表现出良好的力学性能(拉伸强度为11.73 MPa)、优异的热稳定性(>400 ℃)和力学传感性能,具备在恶劣环境下广泛应用的潜力。