Nickel coating on peptide nanotubes by electroless plating

A cyclic tri-β-peptide, cyclo(4-(4-pyridyl)-β-homoalanine)₃, was synthesized. The cyclic peptide was crystallized into μm-sized rods. Electron diffraction analysis revealed that the rod was composed of peptide nanotubes, which were formed by molecular stacking of the cyclic peptides, with nanotube alignment along the long axis of the rod. Ni coating of the rod crystals was carried out by electroless plating. The pyridyl groups at the side chains of the cyclic peptides were used for immobilization of Pd(II) ions on the surface as catalyst for the reduction reaction. The rod crystals were coated with Ni layers, but the electronic conductivity of the Ni-coated rods was found to be low probably due to the grain boundaries between Ni nanocrystals on the μm-sized rod surface.     

化学镀铜法制备纳米Cu-Al2O3复合粉体的研究

采用化学镀方法在超声波辐照下对10－20nm的Al2O3粉末进行化学镀铜，并探讨了镀液组成及工艺条件对纳米Al2O3粉末化学镀铜的影响，利用X射线衍射判断其成分组成，用TEM观察镀覆结果，结果表明：引入超声波并调整镀液组成和工艺条件可以实现室温的纳米Al2O3粉末化学镀铜，使化学镀鲷在低温下保持了镀液的稳定性，同时对纳米粉末进行有效的分散；以EDTA－2Na为络合剂，并加入亚铁氰化钾和2－2联吡碇作为稳定剂，可以有效地消除或减少复合粉末中的Cu2O.通过改变低温超声波化学镀铜时的镀液组成和装载量，可以一次镀覆得到铜含量为5％－90％的Cu-Al2O3复合粉末。     

Fabrication of super-hydrophobic nano-sized copper films by electroless plating

Super-hydrophobic nano-sized copper films were fabricated on smooth glass substrates by an improved electroless plating technology. The copper film deposited for 1 min showed extremely high hydrophobicity with a water contact angle of 138.0^o and super-hydrophobicity with a water contact angle of 152.4^o when it was modified with 1-octadecanethiol (CH3-(CH2)17-SH). Such super-hydrophobicity is attributed to the combined roles of the surface hierarchical structure consisting of the micro-sized island-shaped agglomerates that are composed of the nano-sized copper nodules and the low surface energy formed through the chemical modification.     

Preparation of ceria nanoparticles supported on carbon nanotubes

By chemical reaction of CeCl₃ and NaOH on carbon nanotube solution and subsequent heat treatment, ceria nanoparticles supported on carbon nanotubes were prepared. The processing parameters affecting the size of ceria particles were discussed. The particles were characterized by XRD and TEM. XRD patterns revealed that the particles exhibited CaF₂-type crystal structure. The TEM micrograph showed that the mean sizes of ceria particles were about 6 nm.     

Preparation of Cu nanoparticles on carbon nanotubes by solution infusion method and calcining in ambient atmosphere

Copper nanoparticles were synthesized using carbon nanotubes as a template. The process involved neither pre-purification nor an additional reducing agent. This method was simple and the Cu nanoparticles were uniformly loaded on the carbon nanotubes. TEM, SEM, XRD and EDX were used to examine the morphology of the Cu particles. The diameter of the carbon nanotubes is about 70-90 nm and the size of the nanoparticles is about 50-70 nm.     

Deposition of platinum nanoparticles on carbon nanotubes by supercritical fluid method

Carbon nanotube-supported platinum nanoparticles with a 5-15 nm diameter size range can be synthesized by hydrogen reduction of platinum(ll) acetylacetonate in methanol modified supercritical carbon dioxide. X-ray photoelectron spectroscopy and X-ray diffraction spectra indicate that the carbon nanotubes contain zero-valent platinum metal and high-resolution transmission electron microscopy images show that the visible lattice fringes of platinum nanoparticles are crystallites. Carbon nanotubes synthesized with 25% by weight of platinum nanoparticles exhibit a higher activity for hydrogenation of benzene compared with a commercial carbon black platinum catalyst. The carbon nanotube-supported platinum nanocatalyst can be reused at least six times for the hydrogenation reaction without losing activity. The carbon nanotube-supported platinum nanoparticles are also highly active for electrochemical oxidation of methanol and for reduction of oxygen suggesting their potential use as a new electrocatalyst for proton exchange membrane fuel cell applications.     

化学镀制备纳米银-石墨烯复合材料及其电化学性能

以葡萄糖为还原剂,采用化学镀原位合成纳米银-石墨烯复合材料(Ag/GR),通过X射线衍射(XRD)、X射线能量色散谱(EDS)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)和傅里叶红外光谱(FTIR)等方法对材料的结构形态进行表征分析.结果表明,石墨烯表面银的负载形态为预期的单质状态,AgNPs平均粒径约为21 nm.同时,利用循环伏安法(CV)、交流阻抗谱(EIS)、线性伏安扫描法(LSV)和差分脉冲伏安法(DPV)对抗坏血酸(AA)在Ag/GR/GCE电化学传感器上的电化学响应进行研究.电化学测试结果表明,Ag/GR复合材料具有最高的响应电化学信号212.9μA和最低的电荷转移电阻90.5Ω,峰值电流约为石墨烯电极(110μA)的2倍和玻碳电极(42.5μA)的5倍,AgNPs与石墨烯具有良好的协同作用,对AA具有明显的电催化活性.AA的阳极峰电流在5～120μmol/L浓度范围内线性增加.然而,AA的阳极峰电流与浓度范围为50～120μmol/L的自然对数高度相关,检测限为0.06μmol/L.     

化学镀法制备纳米Cu/Al复合粉末

为了改善超细铝粉的表面易氧化问题和微米级铝粉对推进剂的热分解催化作用不明显现象,以对推进剂具有良好催化作用的纳米Cu包覆金属Al表面.采用化学镀铜法对微米级铝粉表面进行镀覆,制备出纳米Cu粒子在超细Al颗粒表面包覆完整的Al-Cu核壳式复合粉末,并利用正交实验优化镀液组分及镀覆工艺条件.利用XRD、SEM、EDX等仪器,对复合粉末的形貌、物相结构及表面成分进行分析,结果表明铝粉表面包覆一层致密的纳米铜层,这种纳米层是由粒度约为18.83nm的晶态析出的纳米铜组成.     

浮动催化法制备竹节状碳纳米管的研究

报道了竹节状碳纳米管的浮动催化法合成,通过对生长因素的控制可以用浮动催化法连续合成竹节状碳纳米管.实验发现关键因素是采用正己烷为碳源,并且详细讨论了影响竹节状碳纳米管生长的其它重要因素.结果表明碳纳米管的形态结构与碳源分子有直接关系.     

Study of a pre-treatment process for electroless copper plating on ceramics

In this paper, a pre-treatment process for electroless copper plating on the ceramics was explored. Due to the catalytic activity of gold nanoparticles, the traditional three-step coarsening-sensitization-activation pre-treatment process has been optimized to a two-step coarsening-activation process. In our study, the following results were observed: electroless copper coating on the ceramics was formed after activating the substrate by gold nanoparticles; a more flat and compact nano-composite coating was also obtained by adding gold nanoparticles to the plating solutions. The mechanisms of pre-treatment and composite plating with gold nanoparticles were discussed.     

A simultaneous annealing effect during high-temperature electroless copper plating using the non-isothermal deposition method

A simultaneous annealing effect on the electroless-plated copper films deposited using the non-isothermal deposition (NITD) method was demonstrated. The Cu films were deposited onto NiMoP/Si substrates and their properties, such as microstructure, resistivity, and crystalline texture, were studied. At a deposition temperature of 400 °C, we found that the resistivity of the as-deposited Cu films was as low as 2.4 μΩ·cm, and X-ray diffraction showed a remarkable (111)/(200) peak ratio of 18.7. It reveals that the NITD system has an excellent capability to deposit and anneal a metal film in one step and does not require any post-annealing process.     

Photo-induced decomposition of platinum metalorganic films for electroless copper plating

Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.     

Study of electroless copper plating on ABS resin surface modified by heterocyclic organosilane self-assembled film

6-(3-triethoxysilylpropyl)amino-1, 3, 5-triazine-2, 4-dithiol monosodium (TES) was used to fabricate self-assembled film on corona pretreated acrylonitrile–butadiene–styrene (ABS) resin surface. The self-assembled film modified ABS resin was treated by electroless copper plating. Orthogonal test was carried out to study optimal condition of the process. The surface appearance, plating rate and thickness of electroless copper films were investigated to determine the optimal time of corona-discharge, self-assembly and electroless copper plating. SEM results indicated that porous morphology appeared on ABS resin surface modified by TES self-assembled film and the surface roughness also increased. The adhesion test showed that the adhesion property between ABS resin and copper was excellent. The surface of electroless copper film had high brightness under the optimal condition of 1 min corona-discharge, 30 min self-assembly and 10 min electroless copper plating. The electroless-copper plating temperature was 55 ～ 60°C and pH was 13 ～ 13·5.     

纳米镍颗粒填充碳纳米管的制备与磁性能

采用自制的实验装置, 通过阳极弧放电等离子体技术成功制备了Ni纳米颗粒填充的碳纳米管, 利用高分辨透射电子显微镜(HRTEM)、 XRD、 TEM、 X射线能量色散分析谱仪(XEDS)和振动样品磁强计(VSM)等测试手段对样品的化学成分、 形态、 微观结构和磁性能进行了表征。实验结果表明, 采用本文中实验方法能获得大量被纳米金属颗粒填充的碳纳米管, 其内部填充物为面心立方(FCC)结构的纳米Ni颗粒, 外围薄层为石墨碳层。碳纳米管的外径为30~40 nm, 壁厚5~8 nm, 内部填充的纳米颗粒呈球形和椭球形, 粒径均匀, 在管腔内不连续分布。产物具有顺磁特性, 矫顽力是78 Oe, 饱和磁化强度是33 enu/g。     

化学镀法制备核壳型银-铜双金属粉

为改善超细铜粉的高温抗氧化性能,通过热力学数据理论上分析了液相还原反应取代置换反应的可行性,并以水合肼作还原剂,银以稳定性适中的银氨络合物存在,采用化学镀法制备银包覆超细铜粉的新技术,利用SEM、XRD等手段对双金属粉的形貌和晶相组成进行了分析.研究表明,一次包覆铜粉基体表面银的包覆率为40.22%,二次包覆银的包覆率可达94.98%,在铜粉表面形成了连续的银膜,可以认为是表面包覆结构,拓展了超细铜粉的应用领域.     

Preparation of Co-plated WC powders by a non-precious-Co-activation triggered electroless plating strategy

In this study, Co nanoparticles were mixed with WC powders by electroless plating with a new non-precious-Co-activation strategy. By soaking WC powders in a mixed solution of cobalt sulfate heptahydrate and sodium hypophosphite and then heat treated at 220 °C, Co active sites were seeded on WC powders to activate the following electroless plating of Co. The effects of reaction conditions on the weight gain and plating rate during electroless plating process were systematically investigated. As is evidenced by results, when the temperature, concentration of CoSO₄ and NaH₂PO₂·H₂O, and pH were 80 °C, 50 g/L, 45 g/L and 11 respectively, WC was evenly coated with Co. Notably, the XPS characterization indicated the content of zero-valence Co was elevated obviously after the plating process due to the effective reduction from two-valence Co.     

Fabrication of carbon nanotubes field emission cathode by composite plating

Carbon nanotubes (CNTs) have high aspect ratio and have great potential to be applied as the field emission cathode because of its large field enhancement factor. In this work, a high performance carbon nanotube field emission cathode (CNTFC) was fabricated by using a composite plating method. The CNTs were purified by acid solutions and then dispersed in electrobath with nickel ions at temperatures of 60, 70, or 80 degrees C for the electroless plating process on glass substrate. The resulting CNT-Ni composite film has strong adhesion on the glass substrate. The degree of graphitization and the microstructure of the CNTFCs were studied by Raman spectroscopy and scanning electron microscopy. The field emission properties of the CNTFCs show a low turn-on electric field E(on) of about 1.2 V/microm, and a low threshold electric field E(th) of about 1.9 V/microm. Such a composite plating method could be applied to the fabrication of large area CNT field-emission displays.     

碳纳米管的化学镀银

碳纳米管因其优异的力学、物理性能，是一种理想的复合材料增强体。通过化学镀可在碳纳米管表面镀上一层连续的银镀层，以增强碳纳米管与金属基体的界面结合力．本文研究了在碳纳来管上化学沉积银的工艺及其影响因素．SEM、TEM观察表明：氧化、活化及镀是影响镀层质量的最重要因素．尽可能多的活化点以及尽可能慢的镀速将大大改善镀层质量。