A New Activation Method for Electroless Metal Plating：Palladium Laden via Bonding with Self—Assembly Monolayers

A new activation method has been developed for electroless copper plating on silicon wafer based on palladium chemisorption on SAMs of APTS without SnCl2 sensitization and roughening condition.A closely packed electroless copper film with strong adhesion is successfully formed by AFM observation.XPS study indicates that palladium chemisorption occurred via palladium chloride bonding to the pendant amino group of the SAMs.     

On the formation of the interlayer between Ni-P coating and AZ33 magnesium alloy substrate by means of in situ SEM observation

Pre-treatment process is the key step for electroless plating. Once a suitable pre-treatment film is in place, the desired metals can be plated. In this paper, Ni-P coating was successfully prepared on AZ33 magnesium alloy with Mg（OH）2 pre-treatment film by electroless plating. To investigate the role of MgF2 in Ni-P coating, the deposition procedures between Mg（OH）2 pre-treatment film and Mg（OH）2-MgF2 pre-treatment film （a traditional process） were compared. The surface morphology variations of coatings were observed with scanning electron microscopy and the compositions were analyzed by energy dispersive spectrometry. The results showed that during the plating, both MgF2 and Ni-P deposited at the initial stage, and MgF2 distributed in the bottom of the coating, forming a transitional interlayer with Ni- P. According to the heat quench test, a poor adhesion of the coating mainly occurred between the MgF2 and Ni-P coating.     

Ag活化的p型硅(111)表面化学镀Ag膜表面形貌研究

A method of electroless silver deposition on silver activated p-type silicon（111） wafer was proposed. The silver seed layer was deposited firstly on the wafer in the solution of 0.005 mol/L AgNO3 ＋0.06 mol/L HE Then the silver film was electrolessly deposited on the seed layer in the electroless bath of AgNO3＋NH3＋acetic acid＋NH2NH2 （pH 10.2）. The morphology of the seed layer and the silver films prepared under the condition of the different bath composition was compared by atomic force microscopy. The reflectance of the silver films with different thickness was characterized by Fourier transform infrared spectrometry. The experimental results indicate that the seed layer possesses excellent catalytic activity toward electroless silver deposition and rotating of the silicon wafer during the electroless silver deposition could lead to formation of the smoother silver film.     

Diamond-structured hollow-tube lattice Ni materials via 3D printing

Light-weight and high-strength materials have attracted considerable attention owing to their outstanding properties, such as weight-reducing, acoustic absorption, thermal insulation, shock and vibration damping. Diamond possesses specific stiffness and strength arising from its special crystal structure. In this work, inspired by the diamond crystal structure, hollow-tube nickel materials with the diamond structure were fabricated using a diamond structured polymer template based on the Stereo Lithography Appearance technology. The diamond structured template was coated with Ni-P by electroless plating. Finally, the template was removed by high temperature calcinations. The density of the hollow tube nickel materials is about 20 mg/cm3. The morphology and composition of the resultant materials were characterized by scanning electron microscope, energy-dispersive spectrometry, and X-ray diffraction. The results showed that the surface of the Ni film was uniform with the thickness of 4 μm.The mechanical property was also measured by stress and strain tester. The maximum compression stress can be reached to40.6 KPa.     

Effect of 3-Amino-5-mercapto-1,2,4-triazole on Electroless Nickel Deposition

The effects of organic additive, 3-amino-5-mercapto-1,2,4-triazole （AMTA） on bath stability, deposition rate, reaction activation energy, and Ni-P coating composition in acidic electroless nickel plating were investigated. Polarization curve method and infrared reflection spectroscopy were used to analyze the mechanism of the effect of AMTA on electroless nickel deposition. It was observed that AMTA improved bath stability, decreased the deposition rate, and increased the reaction activation energy. It was also revealed that AMTA decreased the phosphorus content and increased the sulfur content in Ni-P coating. In addition, AMTA inhibited the anodic oxidation of hypophosphite and accelerated the cathodic reduction of Ni^2＋. Infrared reflection spectroscopy result indicates that AMTA was adsorbed on the surface of Ni-P and interacted with Ni^2＋ to form an AMTA-Ni^2＋ compound. On the basis of the results of this study, the mechanism of the effect of AMTA on electroless nickel deposition was deduced.     

THE SYNTHESIS AND STUDIES ON PALLADIUM CATALYSTS ANCHORED ON CHELATE RESIN

A chelate resin with 8-aminoquinoline group attached to a styrene-divinybenzene copolymer matrix was reacted with PdCl_2, forminga polymeric palladium complex, which was reduced with different reducing agents, such as hydrogen, stannous chloride, sodium borohydride, lithium aluminum hydride, hydrazine and basic aqueous methanolic solution and thus the polymer-supported palladium (Ⅱ) complex, colloidal palladium and palladium complex with different valence states were obtained. The hydrogenation of n-hexene in methanol at 40℃ under atmospheric hydrogen pressure and the selective hydrogenation of 1,5,9-cyclododecatriene at 100℃ under 20 kg/cm~2 hydrogen pressure were studied. The results showed that the palladium complexes With different valence states prepared with hydrazine or methanol-water (pH=11) were effective catalysts for the hydrogenation of olefins. The loss of palladium on catalysts was correlated to the palladium dispersion and valence states. It was found thst the loss of palladium decreas     

Pd nanoparticles on boron doped graphene catalyst for electrochemical detection of hydrogen peroxide prepared by electroless deposition methodEI北大核心CSCD

Taking advantage of large conjugated structure and reductivity of boron-doped graphenethe palladium nanoparticles/boron-doped graphene catalyst was prepared by electroless deposition method using boron-doped graphene as reductant and stabilizer. The average size of palladium nanoparticles highly dispersed on the surface of boron-doped graphene was about 6.5 nm. The electrochemical sensor was prepared by modifying the as-formed catalyst on the surface of glassy carbon electrode. The obtained electrochemical sensor exhibited an excellent electrochemical catalytic activity for H2 O2 . It exhibited high sensitivity with the detection limit as low as 830 nmol/L and good linearity in the range of 2.5-300 μµmol/L for detection of H2 O2 . It could be utilized for the determination of H2 O2 in milk samples. © 2022, Youke Publishing Co.,Ltd. All rights reserved.     

Suzuki Reaction of Aryl Bromides Using a Phosphine-Free Magnetic Nanoparticle-Supported Palladium Catalyst

A palladium catalyst immobilized on superparaganetic nanoparticles was prepared with a palladium loading of 0.30 mmol/g. The catalyst was characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, thermogravimetric analysis, Fourier transform infrared, atomic absorption spectrophotometry, and nitrogen adsorption. The immobilized palladium catalyst was an efficient catalyst without added phosphine ligands for the Suzuki cross-coupling reaction of several aryl bromides with phenylboronic acid. The recovery of catalyst was simply by magnetic decantation in the presence of a magnet. The immobilized palladium catalyst can be reused many times without significant degradation in catalytic activity. No leaching of active palladium species into the reaction solution was detected.     

Electroless Nickel Plating and Electroplating on FBG Temperature Sensor

Metal-coated fiber Bragg grating（FBG）temperature sensors were prepared via electroless nickel（EN）plating and tin electroplating methods on the surface of normal bare FBG.The surface morphologies of the metal-coated layers were observed under a metallographic microscope.The effects of pretreatment sequence,pH value of EN plating solution and current density of electroplating on the performance of the metal-coated layers were analyzed.Meanwhile, the Bragg wavelength shift induced by temperature was monitored by an optical spectrum analyzer.Sensitivity of the metal-coated FBG（MFBG）sensor was almost two times that of normal bare FBG sensor.The measuring temperature of the MFBG sensor could be up to 280℃,which was much better than that of conventional FBG sensor.     

乙二胺功能化树脂负载Pd(0)配合物：可重复使用的高活性Heck芳基化催化剂

The ethylenediamine-functionalized resin-supported Pd(0)complex was prepared from PdCl_2 and ethylenedia-mine-functionalized chloromethylated polystyrene,followed by reduction with KBH_4.The complex was character-ized by FT-IR,XRD,BET,SEM and EDS.The resin-supported catalyst exhibited high catalytic activity in theHeck reaction and could be reused up to 17 times in NMP or 16 times in DMF at 90 ℃ in the Heck reaction of io-dobenzene with acrylic acid.The leaching investigation disclosed that the palladium leaching was caused by the in-teraction of iodobenzene with the metal Pd(0)on supported catalyst.The leached palladium species in filtrate wasvery stable and could be reused five times after the solid catalyst was filtered off.A cross-transfer test in recyclingin the presence of additional carbon disclosed that the soluble leached palladium species had much higher catalyticactivity than supported and/or adsorbed palladium in solid-solution heterogeneous Heck reaction.     

Repair of Pd/α-Al2O3 composite membrane with defects

A palladium composite membrane with a large number of defects was repaired using the electroless plating combined with the technique of osmosis. The loose structure of palladium film prepared by the conventional electroless plating was densified. Defects were repaired. Hydrogen selectivity was thus significantly increased without significantly increasing palladium film thickness and reducing hydrogen permeability. Project supported by the Chinese Academy of Sciences (Grant No. KJ951-A1-508) and the National Natural Science Foundation of China (Grant No. 29392003).     

Preparation of Pd/ceramic composite membrane 1. Improvement of the conventional preparation technique

The Pd/ceramic composite membrane made is reported in this paper. The thin palladium film was deposited on the surface of a porous ceramic substrate by the conventional and improved electroless plating technique, respectively. The rate of palladium deposition increases and especially the sensitization and activation steps in the conventional electroless plating process has been omitted by an improved technique.     

Unsupported palladium alloy foil membranes fabricated by electroless plating

It is desirable to create thin (<25 μm), unsupported, defect-free palladium and palladium alloy foils in a cost-effective manner in order to study intrinsic material properties exclusive of support effects. We have developed a novel technique for producing unsupported palladium films by electroless plating upon mirror-finished stainless steel supports followed by mechanical removal. High quality pure palladium films as thin as 7.2 μm were produced. Single gas steady state permeation experiments were performed using hydrogen and nitrogen to examine permeability and selectivity. The pure palladium membranes showed hydrogen permeabilities comparable to cold-rolled unsupported foils, and high H₂/N₂ selectivity. Palladium-copper membranes were prepared by sequential electroless plating of copper onto palladium foils followed by in situ annealing. The annealing process produces films of desired composition with permeabilities comparable to those in the literature. The annealing process does not appear to produce defects in the film, and the membranes thus produced have performed 15 days without increased leak rates.     

Area-selective microscale metallization on porous anodic oxide film of aluminium

A new method for micropatterning of metallic patterns on porous anodic oxide film of aluminium is described. The porous anodic oxide film was impregnated with organic dye and palladium ions before the hydrothermal pore-sealing. The surface layers formed during the pore-sealing, i.e. outer acicular hydroxide layer and a compact intermediate sub-layer trap the palladium ion underneath the layers. Exposing the palladium enriched area by the help of laser beam followed by electroless nickel deposition results the deposition of nickel on the laser-exposed part. Thickness of the deposits can be up to about 2–3 μm, after about the 20 min of immersion in electroless nickel plating bath. The metallic micropatterns, formed by the method are crack free, smooth and uniform over extended length.     

Preparation of palladium composite membranes by modified electroless plating procedure

A thin palladium composite membrane was produced by modified electroless plating procedure. Compared with the conventional electroless plating procedure, the modified electroless plating procedure consists of the activation of a ceramic substrate by the sol–gel process of a Pd(II)-modified boehmite sol. Additionally, the infiltration of an electroless plating solution to a porous substrate during the deposition of palladium was employed with the filter device to improve adherence of a palladium layer to a substrate. The resulting membrane with a thickness of about 1 μm has a high compactness. The membrane shows a hydrogen selectivity of 20–130 for H₂/N₂, and a hydrogen flux of 1.8–87 m³/m²·h, depending on operation conditions.     

陶瓷表面无敏化活化法微细化学镀铜

本文提出一种新的化学镀铜工艺,与激光微细刻蚀技术相结合可在Al2O3基底上实现无敏化活化化学镀铜,获得光亮致密、分辨率较高(40μm),导电性良好的化学镀层.     

氯化钯掺杂的羧基丁苯胶乳薄膜的制备及用于化学镀铜性能

利用羧基丁苯胶乳优良的成膜性能,并通过氯化钯掺杂使薄膜具备催化化学镀的活性,在其表面进行化学镀铜研究,选用次亚磷酸钠和硼氢化钠为还原剂,将硫酸铜还原成单质铜。 采用扫描电子显微镜（SEM）、能量色散谱（EDS）和X射线衍射（XRD）等对其形貌、成分进行表征。 测试了胶膜的增重率、表面金属及沉积层的结合牢度。 结果表明,薄膜的表面形成均匀致密、导电性优良和结合力良好的铜层。 该方法可应用于平面非金属材料如聚酯透明材料、装饰板材等,获得了良好导电表面,形成具有电磁屏蔽功能的面型材,具有广阔应用前景。     

超薄铜膜包覆的金刚石纳米复合粉体制备与表征

在氯化亚锡敏化、氯化钯活化的条件下,通过化学镀方法,成功地在纳米金刚石粉体表面制备了超薄铜膜.用X射线粉末衍射(XRD)和傅立叶红外吸收光谱(FTIR)表征了该Cu-金刚石纳米复合材料.此种复合材料在无水乙醇中超声分散5 min后的溶胶可稳定存放半年之久而不见沉降.     

碳纳米管表面的无钯活化化学镀镍研究

本文提出碳纳米管表面无钯活化的化学镀镍方法.碳纳米管经硝酸氧化和碱中和后表面生成羧基,利用羧基吸附镍离子,之后吸附的镍离子被化学还原为镍的纳米微粒并成为化学镀镍的催化活性中心.红外吸收光谱和电子显微镜观察等证实了上述活化过程的机理.实验表明,新的活化方法对碳纳米管表面化学镀是切实可行的,文中同时对化学沉积层的不同形貌进行讨论.