114 research outputs found
Process, Mechanism and Applications for Copper Electrodeposition from an Alkaline Citrate Bath
铜镀层具有优良的均匀、柔韧和导电等物理化学性能,被广泛地应用于防渗碳处理、表面处理、电子和信息工业等领域。传统的且目前仍在广泛应用的剧毒氰化镀铜工艺已不能满足环境保护和清洁生产的要求,因而促进了无氰镀铜新工艺的研发。目前已被报道的无氰镀铜工艺多达数十种,但它们均有各自的缺点,难以大面积推广、完全取代氰化镀铜工艺。其中,最主要的缺点是钢铁基体与铜镀层间的结合力较差。其主要原因在于,(1)铁易与铜离子发生置换反应,形成疏松的置换铜层;(2)钢铁件表面极易在空气或水溶液中发生钝化。这意味着要想获得结合力好的镀层,就必须同时解决“置换铜”和“钢铁钝化”这两个问题。 本论文开发了一种新型柠檬酸盐碱性无...Copper electrocoatings have been extensively used in anti-carburizing treatment, surface treatment, electronic and information industry, on account of its excellent physicochemical properties such as uniformity, flexibility and conductivity. The conventional and highly toxic cyanide bath for copper plating, which is still applied in some regions such as strike copper plating, no longer meets the i...学位:工学硕士院系专业:化学化工学院化学系_应用化学学号:2052007115100
Non-cyanide copper plating on steel substrate in alkaline citrate bath
以柠檬酸盐为配位剂,结合胺化合物为辅助配位剂,研究了钢铁基体上无氰镀铜工艺。探索了搅拌方式、温度、PH、铜离子质量浓度和添加剂质量浓度对镀层质量的影响以及该工艺抗fE2+、fE3+、zn2+、Sn4+等杂质的能力。试验结果表明,电流效率在90%左右,并随电流密度、温度和PH的提高而增大;镀液深镀能力达100%。通过极化曲线,解释了配位剂和添加剂的作用。The process of alkaline non-cyanide copper electroplating on steel substrate was studied using citrate as complexing agent and amine compound as assistant complexing agent.The effects of agitation mode, temperature, pH, copper ions concentration and additive content on deposit quality were discussed.The ability of bath to resist impurities such as Fe2+, Fe3+, Zn2+ and Sn4+ was revealed.The test results showed that the current efficiency is about 90% and is increased with increasing current density, temperature and pH.The throwing power of the bath is 100%.The action mechanisms of the complexing agents and additive were explained based on polarization curves.广东省教育部产学研结合专项资金项目(2006D90404019);福建省科技计划重点项目(2008H0086);国家自然科学基金项目(20873114
Electrodeposition of Copper in a Citrate Bath and Its Application to a Micro-Electro-Mechanical System
Corresponding author. Email: [email protected]; Tel: +86-592-2185957; Fax: +86-592-2181436.[中文文摘]研究并讨论了在新型柠檬酸盐体系铜电沉积工艺中电镀工艺参数对镀层形貌和颗粒尺寸的影响;利用X射线衍射(XRD)和X射线光电子能谱(XPS)表征了镀层的结构和组分存在状态;并将柠檬酸盐体系电沉积铜应用于微机电系统(MEMS)加工工艺.结果表明:在6 g.L-1 Cu2+,pH=7.0-8.5,1-2 A.dm-2,45℃,搅拌条件下可得到结晶细小,表面平整的致密铜镀层;镀层为面心立方多晶结构的单质铜,不含其他杂质.利用MEMS工艺成功制得平面电感,其有效的最大品质因数(Q)为12.75,达到了设计要求.[英文文摘]We investigated the effect of plating parameters on the coating morphology and grain size of copper using a novel citrate bath.The structure and deposit were characterized by X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS),respectively.The copper plating bath was applied to a micro-electro-mechanical system(MEMS).Results show that an even and compact copper coating was obtained for the fine grains using plating parameters of 6 g.L-1 Cu2+,pH=7.0-8.5,1-2 A.dm-2,45 ℃,and bath agitation.The deposit consists of pure copper in
a fcc polycrystalline structure. A planar inductor was successfully fabricated by MEMS using this bath and its maximum quality factor was 12.75, which satisfies the design requirements.国家自然科学基金(20873114,20833005); 国家重点基础研究发展规划项目(973)(2009CB930703)资
Application of Copper Electrochemical Deposition for the Metallization of Micropores
According to established routes for the microporous metallization of printed circuit boards (PCB), electroless copper plating using glyoxylic acid as a reducing agent and copper electroplating in a citrate bath were used for microporous metallization with PCB distributing micropores as a template. The results show that electroless copper plating using glyoxylic acid as a reducing agent and copper electroplating in a citrate bath can be successfully applied to the microporous metallization of PCB. After an electric conducting treatment of the micropores by electroless copper plating the copper deposited as fine grains and attached to the inner walls of the micropores. The copper deposit was also found in the loose grain arrangement and the leak plating area. Immediately after thickening treatment by copper electroplating, the resistance toward the copper coating of the inner wall decreased notably. The ratio of the copper electroplating rates at the inner and outer micropores was found to be 0.8:1.0. The copper electrodeposit fully covered the surface of the inner wall including the leak plating area, which means that the electroplated copper grains have a certain sideway growing ability. The copper coating on the inner wall was continuous, compact, and adhesive. This coating highly enhanced the conductivity of the interconnected PCB.National Natural Science Foundation of China[20873114, 20833005, 21021002]; National Key Basic Research Program of China[2009CB930703
与南海西边界流有关的区域海洋学进展
从动力学角度,回顾了与南海西部主流系及其涡旋研究有关的南海物理海洋学的进展.主要内容涉及南海西边界流漂流浮标观测、西边界流源区涡旋遥感观测、西边界流源区跨陆架交换、涡流相互作用、西边界流年际变化、西边界流区海气相互作用、南海贯穿流等方面的进展.西边界流是一个强流系,其与季节和年际变化相关的结构特征、变率及跟某些动力过程的关联有待研究.在西边界流变率、涡旋环流相互作用、海气过程以及南海贯穿流取得了以下成果:(1)利用漂流浮标观测样本对南海西边界环流进行分析,指出南海西边界表层环流在到达越南中部沿岸后伴随着流幅变窄的同时流速加强;探讨了南海北部环流变化机理,定量诊断南海西边界流北支冬季逆风流产生的动力机制;利用航次数据对18°n断面的经向地转流进行诊断,表明南海西边界流的经向输送年际变化明显;(2)结合航次观测数据,对2003/2004年冬季南海北部2个反气旋涡旋和2007年夏季18°n附近的3个反气旋涡旋进行研究,指出冬季2个涡旋产生后以罗斯贝(rOSSby)波速度(约0.1M/S)沿北部陆坡向西南方向传播,并初步揭示了南海西边界环流与夏季3个涡旋的相互作用;南海北部陆架区涡旋西南向传播最大(最大为0.09M/S),而越南以东海域涡动能(EkE)最大,这都说明涡旋活动与南海西边界流存在强的相互作用;(3)发现南海西边界流附近海表面温度(SST)强的季节内振荡特征,进一步研究表明此区域冬季SST季节内变化会使潜热季节内信号减弱20%;(4)探讨了南海贯穿流的长期变化特征以及与整个太平洋环流系统的相互关联.国家自然科学基金重点项目(40830851); 国家重点基础研究发展计划(2011CB403504); 中国科学院近海海洋观测研究网络——西沙南沙海洋观测研究站建设项目(KZCX2-EW-Y040)资
Raman and AFM Characterization of Au and Cu Nanorod and Nanowire Arrays
通过电化学氧化法制备具有不同孔径氧化铝模板 ,利用交流电镀的方法在模板中沉积金属 ,再用酸溶解模板可以得到相应尺度的金属纳米线或纳米棒的阵列 .本文利用原子力显微镜和表面增强拉曼技术分别表征了金和铜两种金属纳米线阵列 .研究结果表明 ,作为探针分子的硫氰(SCN )在金属纳米线上的碳氮三键的振动频率随纳米线直径的增大而蓝移 .这一现象可能是因为尺寸效应对纳米线的费米能级造成影响 ,使不同直径的金属纳米线电子结构存在微小的差别 .Recently metal nanowires (nanorods) have aroused tremendous interest because of their novel properties and potential applications in wide fields [1] . Many two?dimensional nanowire arrays of semiconductors and metals with different diameter and length have been made by using template synthesis method. To characterize the novel optical, electronic and magnetic properties of these materials, UV?Vis and fluorescence spectroscopies are two of the most wildly used methods [2, 3] . Raman spectroscopy has, however, only been applied to the characterizing of semiconductor nanowires and carbon nanotubes [4,5] . Important and meaningful information can be obtained in these cases, as some forbidden Raman modes in the bulk materials become Raman active [4, 5] . Raman spectroscopy is apparently not suitable to study metal nanowires since it can only detect the mechanical vibration bands located in the extremely low frequency region. Consequently, an alternative way has to be established to study the metal nano?wires (?rods) with Raman spectroscopy. In the present work, we have taken the probe molecule strategy and used surface?enhanced Raman spectroscopy (SERS) to characterize metal nanorods (nanowires). It is well known that for a molecule which interacts strongly with a surface, its vibrational band frequency and shape are very sensitive to the electronic property, the chemical environment and the morphology of the surface. Hence Raman spectroscopy has long been used to analyze the atomic structures and the electronic properties of the surface indirectly through assessing carefully the spectral changes of the adsorbate known as a probe molecule. On that account, it is of great interest to diagnose the electronic structures of the metal nanorods with the vibrational spectrum of a probe molecule. We have examined the changes in the electronic properties of the nanorods through analyzing the spectral changes of the probe molecule. For this purpose a typical SERS molecule of SCN - was employed. The nanorod arrays of Au and Cu with different diameter from about 15 nm to 130 nm were fabricated electrochemically by means of the anodic aluminum oxide (AAO) templates. To partially expose metal nanowires with various lengths, the AAO template was chemically etched off to a certain extent by an aqueous solution of phosphoric acid or sodium hydroxide as shown in Fig. 1. After the template was etched off, the nanowires can be characterized by TEM, see Fig. 2. The tapping mode AFM image was obtained on a scanning probe microscope (Nanoscope IIIa). SERS measurements were performed on a confocal microprobe Raman system (LabRam I).作者联系地址:厦门大学固体表面物理化学国家重点实验室!化学系福建厦门361005,厦门大学固体表面物理化学国家重点实验室!化学系福建厦门361005,南京师范大学化学系!江苏南京,210097,厦门大学固体表面物理化学国家重点实验室!化学系福建厦门361005,厦门大学固体表面物理化学国家重点实验室!Author's Address: State Key Lab.for Phys.Chem.of Solid Surf.,Xiamen Univ.,Xiamen 361005, China; 1 Dept. of Chem., Nanjing Norm
氧化铁表面沉积热解炭及气化
以丙烯作为碳源,堇青石作为沉积基体,采用自行设计的化学气相沉积炉研究了在不同温度下引入不同分压的氢气对化学气相沉积炭/炭复合材料过程速率的影响;用气相色谱对反应过程的尾气进行了详细分析,以了解氢气对反应机理的影响;分别用偏光显微镜和扫描电子显微镜考察了沉积炭的组织结构和微观结构。研究表明:氢气的引入抑制了芳香化合物的气相成核, 从而降低热解炭在表面的化学气相沉积速度并最终缩短炭/炭复合材料的生产周期;氢气的引入也改变了化学气相沉积的反应机理
In-situ STM study of Sn UPD on Cu(111)electrode
本文用现场扫描隧道显微镜 (in situSTM)研究Sn在Cu( 1 1 1 )上的欠电位沉积 (underpotentialdepositionUPD)过程。实验结果表明 ,Sn原子在Cu( 1 1 1 )表面上的UPD首先在晶面的边缘处发生 ,随后向晶面的其余地方发展并取代吸附在表面的SO2 -4 ,这一过程伴随着显著的台阶轮廓的变化。在Sn的UPD层溶出过程中 ,台阶边缘形状发生了更剧烈的变化 ,并且观察到凹洞的出现 ,表明Sn与Cu( 1 1 1 )基底形成了表面合金The underpotential deposition(UPD)of Sn on Cu(111)has been investigated in H 2SO 4 solution using in situ scanning tunneling microscopy(STM). The experimental results indicated that UPD of Sn initializes at the edge of the terraces following the nucleation and growth model and grew towards to the center of the terraces until a submonolayer of Sn was formed. This process was accompanied by the change of the profile of the steps. Pits were observed at the surface after the dissolution of the UPD Sn indicating that the surface alloy has been formed between Cu and UPD Sn.国家自然科学基金资助项目 (No .2 98330 6 0 ,2 99730 34)~
应用TG-FTIR研究鹤岗烟煤的热解特性
采用TG-FTIR联用技术研究了鹤岗烟煤的热解过程。研究表明,在升温速率为30℃/min时,该煤的热解过程可以分为4个阶段,其中在430~650℃区间发生剧烈热解反应,DTG曲线在489℃时出现最大值。热解气体的逸出情况由FTIR进行实时检测,并且定性分析了CH4、CO2、CO和焦油的析出情况。通过比较TG/DTG曲线和FTIR数据,发现TG和FTIR的分析结果是一致的。假定煤热解反应为一级反应模型,分不同的温度区间采用Coats-Redfern法求解煤热解反应动力学参数,计算结果与实验符合较好
镍/石墨复合粉体及其热喷涂涂层新材料
以中间相碳微球为芯材,采用水溶液加压氢气还原方法制备了镍包覆石墨(Ni/C)复合粉体材料.对比研究了该粉体及其热喷涂涂层与以普通人造石墨为芯材的Ni/C粉体及涂层的性能差异.通过研究球形Ni/C涂层的热稳定性能,找到了在涂层工作温度下涂层硬度和质量随时间的变化规律.另外通过对比研究镍与石墨及其混合粉末的氧化失重,探讨了400℃下镍对石墨氧化的催化作用.火焰喷涂实验发现,球形Ni/C粉体在较低能耗条件下即能制备出合格的涂层,且喷涂工艺参数易于控制,涂层性能更加稳定,涂层硬度的波动范围比普通Ni/C涂层缩小了70%.在400℃的大气气氛中,涂层硬度大约在20h左右出现最大值,然后减小并趋于稳定.氧化实验发现,镍与石墨的混合粉末在25~28h之间出现增重最大值(0.25%),这与假设镍对石墨的氧化无催化作用时粉末持续增重的情况不同
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