Fabrication of patterned polyaniline microstructure through microcontact printing and electrochemistry

Polyaniline (PANI) microstructures on ITO glass surface were achieved by microcontact printing of self-assembled film and electrochemical polymerization in an aqueous monoaniline solution. The patterned microstructures of PANI were easily transferred to an adhesive tape surface, which could be applied in the area of plastic circuit application. Optical microscope, atomic force microscopy (AFM), lateral force microscopy (LFM) and X-ray photoelectron spectroscopy (XPS) were used to examine the topography and properties of patterned PANI films. Optical microscope and AFM results showed that the PANI microstructure has regular pattern and clear boundary, while LFM and XPS results implied that this microstructure was completely covered by PANI. The data suggested that the interfacial properties of the surface control the rate of electrochemical polymerization, and the polymerization rate on the modified ITO surface is higher than that on the bare ITO area. In our experiments, cyclic voltammetric method, potentiostatic method and chronopotentiometry method were employed to deposited patterned PANI films on octadecyltrichorosilane modified ITO substrate.     

Fabrication and electrical properties of metal-coated acrylate rubber microspheres by electroless plating

Electroless copper plating on micron-scale acrylate rubber (ACM) microspheres was studied. The core-shell structured Cu-coated ACM microspheres with high conductivity and low density were fabricated by introducing a reaction control method. Via multi-times activating treatment, the acrylate rubber (ACM) microspheres were implanted with more Ag catalytic active centers on the surfaces to promote the formation of coatings. The surface-coating structures and the electrical properties of Cu-coated ACM microspheres were investigated. It was found that the Cu-coated ACM microspheres were a kind of elastic particles. The different coating structures could be produced by controlling the extent of plating reaction. The coated microspheres with different coating structures were conductive, and their volume resistivities decreased remarkably with the increasing of applied pressure and varied with the temperature according to their surface coating structures.     

磁性ICF玻璃靶丸的化学镀工艺

 采用化学镀工艺在ICF玻璃靶丸表面包覆了一层磁性的Ni-P合金镀层,制备出磁性ICF玻璃靶丸。研究了化学镀主盐质量浓度、还原剂质量浓度、络合剂质量浓度、施镀温度及镀液pH值对沉积速率与镀液稳定性的影响,获得了化学镀制备磁性ICF玻璃靶丸的最佳工艺为：主盐硫酸镍30 g/L,还原剂次亚磷酸钠30 g/L,络合剂柠檬酸钠50 g/L,pH值10,温度(40±2) ℃。     

Low-phosporous nickel-coated carbon microcoils: Controlling microstructure through an electroless plating process

Carbon microcoils (CMCs) have been coated with a nickel-phosphorus (Ni-P) film using an electroless plating process, with sodium hypophosphite as a reducing agent in an alkaline bath. CMC composites have potential applications as microwave absorption materials. The morphology, elemental composition and phases in the coating layer of the CMCs and Ni-coated CMCs were investigated by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The effects of process parameters such as pH, temperature and coating time of the plating bath on the phosphorus content and deposition rate of the electroless Ni-P coating were studied. The results revealed that a continuous, uniform and low-phosphorous nickel coating was deposited on the surface of the CMCs for 20 min at pH 9.0, plating bath temperature 70 °C. The as-deposited coatings with approximately 4.5 wt.% phosphorus were found to consist of a mix of nano- and microcrystalline phases. The mean particle size of Ni-P nanoparticles on the outer surface of the CMCs was around 11.9 nm. The deposition rate was found to moderately increase with increasing pH, whereas, the phosphorous content of the deposit exhibited a significant decrease. Moreover, the material of the coating underwent a phase transition between an amorphous and a crystalline structure. The thickness of the deposit and the deposition rate may be controlled through careful variation of the coating time and plating bath temperature.     

空腔铜靶的化学镀制研究

 介绍了在预处理芯轴(聚甲基丙烯酸甲酯)表面采用化学镀的方法制备铜空腔的技术,研究了镀液中硫酸铜含量、甲醛含量,镀液pH值、温度等对化学镀铜沉积速率和溶液稳定性的影响。根据实验确定了适宜的化学镀铜工艺规范：硫酸铜质量浓度10~20 g/L,TART·K·Na质量浓度10~30 g/L,EDTA·2Na质量浓度10~28 g/L,甲醛体积浓度10~25 mL/L,添加剂质量浓度10 mg/L,pH值12~13,温度35~65 ℃。通过该工艺制备出的镀层厚度达到10～25 μm,均匀性达到95%,表面无砂眼、裂纹等缺陷,刻蚀芯轴后空腔能自持。该方法为ICF研究制备金属或合金材料靶提供了新的途径。     

磁性ICF靶丸的化学镀工艺制备与表征

 采用化学镀工艺在ICF聚苯乙烯靶丸表面包覆了一层磁性的Ni-P合金镀层,并分别用扫描电子显微镜、能谱仪、X射线衍射仪以及振动样品磁强计对其形貌、组成、结构和磁性能进行了表征。结果表明：通过化学镀工艺制备的Ni-P合金镀层厚度约为4 μm,且为非晶结构,并具有一定的磁性;该磁性ICF靶丸可望用来进行磁悬浮实验研究。最后,对聚苯乙烯靶丸表面磁性涂层的制备机理进行了讨论。     

Characteristics and electrochemical performance of Ni-coated ZnO prepared by an electroless plating process

ZnO was coated homogeneously with amorphous Ni film by an electroless plating process. After electroless Ni plating, transmission electron microscope (TEM) images and energy dispersive spectrometry spectra (EDS) of ZnO clearly indicated that Ni was coated on the surface of ZnO, the coatings and ZnO contacted enough. X-ray diffraction and high-resolution TEM showed that the Ni film on ZnO was amorphous. Electrochemical performance of Ni-coated ZnO was investigated by the galvanostatic charge/discharge cycling test. Compared to that of uncoated ZnO, the charging–discharging performance of Ni-coated ZnO was obviously improved, e.g. the average discharge capacity of the Ni-coated ZnO increased 71.5% at the stage of stable cycling test.     

Microwave-assisted activation for electroless nickel plating on PMMA microspheres

A novel microwave-assisted activation method for electroless plating on PMMA microspheres is presented in this study. When the microwave irradiation was applied during the activation step, the amount of the Pd species adsorbed on PMMA surfaces was much higher than that of sample pretreated with a conventional activation process without microwave irradiation. With this activation method, it was also shown that the adsorbed Pd species with a size of 4-6 nm were uniformly distributed on the surfaces of the PMMA microspheres, thus a smooth and uniform nickel-phosphorus coating on the PMMA microspheres was obtained by subsequent electroless plating. The samples after each step were characterized by XPS, TEM, ICP and SEM.     

Incorporation of nano zinc oxide for improvement of electroless nickel plating

The advantages of electroless nickel plating (EN) include excellent corrosion resistance, wear resistance, solderability, low porosity and uniform thickness even on complex parts and ability to plate on nonconductors. In the present study nano ZnO particles were synthesized by using an electrochemical technique and incorporated the particles into Ni-P plates. An alkaline bath was selected and used for nano zinc oxide incorporation. The electrochemical and metallurgical properties of the Ni-nano ZnO-P plates were evaluated and compared with that of the un-reinforced Ni-P plates. The incorporation of the nano ZnO particles resulted in improvement of metallurgical and corrosion resistance characteristics of the plates.     

Influence of surface treatment on the electroless nickel plating of textile fabric

The present study is performed with an objective to acquire a deeper understanding of the properties of nickel-plated polyester fabric after conducing low temperature plasma treatment. Low temperature plasma treatment with oxygen and argon gases was employed to render a hydrophilic property of woven polyester fabrics and facilitate the absorption of a palladium catalyst in order to provide a catalytic surface for electroless nickel plating. The properties of plasma-induced electroless nickel-plated polyester fabrics were evaluated by various standard testing methods in terms of both physical and chemical performances.     

Qualitative electroless Ni/Au plating considerations for the solder mask on top of sequential build-up layers

Advanced printed circuit boards (PCBs) with sequential build-up (SBU) layers require alternating dielectric and copper layers on top of a core substrate. This can be achieved by lamination of resin coated copper (RCC) or by coating of dielectric polymers followed by copper deposition. The plating of electroless Ni/Au used as a solderability preservative on top of sequential build-up layers is investigated. For this application a solder mask polymer has to be applied in order to separate solder pads. Experiments showed that on parts of the underlying build-up layer exposed to the electroless Ni plating solution electroless Ni can grow. This overplating is caused by the remains of colloidal Pd/Sn catalyst on top of the build-up layer from preceding electroless Cu deposition. At very small features skipping of the plating can also take place. The overplating and skipping phenomena are influenced by a number of parameters, such as the temperature, the concentration of the stabilizer and pH. The dimensions of features on the board and the thickness of the solder-mask polymer also influence skipping. Based on qualitative analyses of the skipping and overplating phenomena rules of thumb for the solder mask design based on the plating conditions are proposed.     

Improvement of copper plating adhesion on silane modified PET film by ultrasonic-assisted electroless deposition

Copper thin film on silane modified poly(ethylene terephthalate) (PET) substrate was fabricated by ultrasonic-assisted electroless deposition. The composition and topography of copper plating PET films were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. Peel adhesion strength, as high as 16.7 N/cm, was achieved for the planting copper layer to the modified PET substrate with ultrasonic-assisted deposition; however, a relative low value as 11.9 N/cm was obtained for the sample without ultrasonic vibration by the same measurement. The electrical conductivity of Cu film was changed from 7.9 × 10⁴ to 2.1 × 10⁵ S/cm by using ultrasonic technique. Ultrasonic operation has the significant merits of fast deposition and formation of good membranes for electroless deposition of Cu on PET film.     

A novel process for electroless nickel plating on anodized magnesium alloy

In this paper, a novel palladium-free activation electroless nickel (EN) plating process, by which a TiB₂ powders contained intermediate film was used as catalyst, was introduced for anodized magnesium alloy AZ91D. The corrosion behavior of AZ91D without and with coating was compared and the bonding strength of the EN plating to the substrate was also measured. The results showed that the EN plating could easily take place on the intermediate catalytic layer, directly on which a smooth and compact Ni–P alloy layer without obvious flaws, about 20 μm thickness, was successfully deposited. The catalytic function was principally from TiB₂ powder. The adhesive tensile test indicated a good bonding strength of about 11 MPa between the substrate and the catalytic layer. An obvious passivation range and higher E_corr (−0.323 V) for the EN plating during anodic polarization in 3.5 wt.% NaCl solution, implied a typical character of a compact Ni–P alloy layer, with an effective protection for the substrate.     

Room-temperature deposition of crystalline patterned ZnO films by confined dewetting lithography

In this work patterned ZnO films were prepared at room-temperature by deposition of ∼5 nm size ZnO nanoparticles using confined dewetting lithography, a process which induces their assembly, by drying a drop of ZnO colloidal dispersion between a floating template and the substrate. Crystalline ZnO nanoparticles exhibit a strong visible (525 nm) light emission upon UV excitation (λ = 350 nm). The resulting films were characterized by scanning electron microscopy (SEM) and atomic force microscope (AFM). The method described herein presents a simple and low cost method to prepare crystalline ZnO films with geometric patterns without additional annealing. Such transparent conducting films are attractive for applications like light emitting diodes (LEDs). As the process is carried out at room temperature, the patterned crystalline ZnO films can even be deposited on flexible substrates.     

Fabrication of patterned gold electrodes with spin-coated-and-fired Au(1 1 1) film by the soft lithography

We prepared high quality Au(1 1 1) film on Si wafer through the spin coating and thermal decomposition of a gold ink, spin-coated-and-fired (SCAF) Au film. The X-ray measurements, XRD and pole-figure analysis, showed that the SCAF Au film has a (1 1 1) out-of-plane orientation with a random in-plane orientation. In order to confirm the chemical activity of the SCAF Au film, we demonstrate the formation of patterned structures with the film by using soft lithography technique. The chemical activities of this physically stable SCAF Au film to the alkanethiols were at least equivalent those of physically deposited the Au films. The possibility of the mass production of micro patterned structure with the SCAF Au film was also demonstrated over the wide region on Si wafer by the microcontact lithography. These suggest that the Au film will help the easy fabrication of various nanosized devices on Si wafer and other substrates.     

磁性ICF靶丸的化学镀工艺制备与表征

采用化学镀工艺在ICF聚苯乙烯靶丸表面包覆了一层磁性的Ni-P合金镀层,并分别用扫描电子显微镜、能谱仪、X射线衍射仪以及振动样品磁强计对其形貌、组成、结构和磁性能进行了表征。结果表明：通过化学镀工艺制备的Ni-P合金镀层厚度约为4 μm,且为非晶结构,并具有一定的磁性;该磁性ICF靶丸可望用来进行磁悬浮实验研究。最后,对聚苯乙烯靶丸表面磁性涂层的制备机理进行了讨论。     

Microstructure and electromagnetic characteristics of BaTiO3/Ni hybrid particles prepared by electroless plating

To improve the microwave absorption ability, hybrid particles containing both dielectric loss of BaTiO₃ and magnetic loss of Ni were fabricated via electroless Ni plating on BaTiO₃ particles. A continuous Ni coating was successfully covered on the surface of the BaTiO₃. The effect of the Ni content on complex permittivity, complex permeability, and microwave absorption properties of BaTiO₃/Ni hybrid particles was investigated. The real (?′) and imaginary (?″) parts of complex permittivity as well as imaginary part of complex permeability (μ″) were found to increase with an increase in Ni content, while the variation of the real part of complex permeability (μ′) with Ni content was non-linear. The microwave absorption performances could readily be tuned base on the changing Ni content of the hybrid particles. The optimal absorption performances were attained when the content of Ni reached 38.9 wt% in hybrid particles.     

空腔铜靶的化学镀制研究

介绍了在预处理芯轴(聚甲基丙烯酸甲酯)表面采用化学镀的方法制备铜空腔的技术,研究了镀液中硫酸铜含量、甲醛含量,镀液pH值、温度等对化学镀铜沉积速率和溶液稳定性的影响。根据实验确定了适宜的化学镀铜工艺规范：硫酸铜质量浓度10~20 g/L,TART·K·Na质量浓度10~30 g/L,EDTA·2Na质量浓度10~28 g/L,甲醛体积浓度10~25 mL/L,添加剂质量浓度10 mg/L,pH值12~13,温度35~65 ℃。通过该工艺制备出的镀层厚度达到10～25 μm,均匀性达到95%,表面无砂眼、裂纹等缺陷,刻蚀芯轴后空腔能自持。该方法为ICF研究制备金属或合金材料靶提供了新的途径。     

Fabrication of Ni-P/palygorskite core-shell linear powder via electroless deposition

Palygorskite is a kind of hydrated magnesium aluminium silicate clay mineral. A novel linear core-shell structured Ni-P coated micro-fiber palygorskite (MFP) was fabricated via an electroless (EL) plating process in an alkaline bath. The composition, morphology and structure of the as-prepared products were characterized by the techniques such as powder X-ray diffraction (XRD), energy-dispersive X-ray spectrum (EDS), scanning electron microscopy (SEM) and transmission electron microscope (TEM). It was observed that the size and morphology of Ni-P coated MFPs were altered by depositing temperature and time. The as-prepared Ni-P coated MFPs showed good conductivity. To the best of our knowledge, the Ni-P coated MFPs have not been reported before. And this fabrication process might also apply in preparing other metal coated MFPs such as silver, copper and palladium.     

Preparation and microwave absorption properties of electroless Co-P-coated nickel hollow spheres

Co-P-coated nickel hollow spheres (NHSs) were prepared by electroless plating technology. The morphology and component content of Co-P coating varies with the change of sodium citrate concentration in elctroless plating solution. And as phosphorus content increases in coatings, resulting in smaller grain, coercivity of microspheres decreases. The microwave absorption properties of spheres-wax composite were investigated in the range of 2-18 GHz. Both permittivity and permeability increase with an increase of cobalt content in coatings. For composite layer, a minimal reflection loss (RL, −36.9 dB) of was predicted at 8.1 GHz with a thickness of 3 mm.