Electrodeposition and characterization of assembly of Sn on Cu nanorods for Li-ion microbattery application

Assembly of Sn on Cu Nanorods as anode for Li-ion microbatteries was prepared by a two-step electrodeposition design. Firstly, Cu nanorods arrays were grown on copper substrate by anodic aluminum oxide template-assisted growth method. Then, Sn was deposited onto Cu nanorods arrays by galvanostatic deposition. X-ray diffraction and scanning electron microscopy measurements reveal that Cu nanorod arrays are covered with Sn. Electrochemical performances of prepared electrodes were evaluated by charge/discharge cycle measurement. The assembly of Sn on Cu nanorods electrode exhibited highly reversible specific capacity and superior capacity retention resulting from the three-dimensionally nano-architectured design, which exhibits a large surface area, shortened Li-ion diffusion distance, Cu?CSn alloying, and can accommodate the volume expansion of Sn during cycling. Deposition time is an important parameter for fabricating the assembly of Sn on Cu nanorods electrode with suitable structure and morphology.     

纳米材料在蛋白质分离中的应用

蛋白质的分离技术不仅在药物检测和制药工程中具有重要意义,而且还是生化工程和蛋白质分析的一个研究热点.纳米材料具有许多与众不同的特性,广泛应用于化工、生物、医药、航天等多个领域,被认为是21世纪最有前途的材料.本文作者从非金属氧化物纳米材料、非金属单质纳米材料、金属氧化物纳米材料、金属单质纳米材料、纳米聚合物、纳米复合材料等方面综述了纳米材料在蛋白质分离方面的应用现状,总结了其在蛋白质分离中的优缺点,并就其在蛋白质固定和分离领域的应用前景进行了展望.     

纳米合金的制备进展*

对纳米合金材料的制备方法和研究进展作了比较全面的综述.对机械合金化法(BM)、还原法、超声波法、脉冲电沉积法、静高压法、激光汽化器控制浓度法(LVCC)、氢等离子体-金属反应法、非晶晶化法等进行了介绍,并对这些方法有关的机理、特点、影响因素以及结果等进行了讨论.     

Temperature effects on the electrochemical behavior of spinel LiMn(2)O(4) in quaternary ammonium-based ionic liquid electrolyte

Temperature dependence of the physiochemical characteristics of a room-temperature ionic liquid consisting of trimethylhexylammonium (TMHA) cation and bis(trifluoromethane) sulfonylimide (TFSI) anion containing different concentrations of LiTFSI salt was examined. Electrochemical properties of a spinel LiMn(2)O(4) electrode in 1 M LiTFSI/TMHA-TFSI ionic electrolyte were investigated at different temperatures by using cyclic voltammetry, galvanostatic measurements, and electrochemical impedance spectroscopy. The Li/ionic electrolyte/LiMn(2)O(4) cell exhibited satisfactory electrochemical properties with a discharge capacity of 108.2 mA h/g and 91.4% coulombic efficiency in the first cycle under room temperature. At decreased temperature, reversible capacity of the cell could not attain a satisfactory value due to the high internal resistance of the cell and the large activation energy for lithium ion transfer through the electrode/electrolyte interface. Anodic electrolyte oxidation results in the decrease of coulombic efficiency with increasing temperature. Irreversible structural conversion of the spinel LiMn(2)O(4) in the ionic electrolyte, possibly associated with the formation of TMHA intercalated compounds and/or Jahn-Teller distortion, was considered to be responsible for the electrochemical decay with increasing cycles.     

铅纳米微粒用作油性润滑的摩擦学性能研究

The solution dispersion method has been successfully used to prepare Pb nanoparticles in a paraffin oilpolyglycol mixed solution by directly dispersing melted Pb granules. In this solution system,paraffin oil was used as reacting media and polyglycol served as an antioxidant to protect Pb nanoparticles from oxidizing. The size and structure of the prepared Pb nanoparticles were characterized by means of the transmission electron microscopy （TEM）and powder X-ray diffraction（XRD）. Their tribological behavior was evaluated with a four-ball tester. The TEM and XRD investigations reveal that the prepared Pb nanoparticles,with the average particle diameter of 70 nm,appear to be of close spherical shape and possess the same crystal structure as the bulk Pb. The tribological results show that the Pb nanoparticles as an oil additive exhibit good friction-reduction and antiwear properties at different additive concentration and applied load. Meanwhile,they can also strikingly improve the load-carrying capacity of the base oil. The rubbed surface was also investigated by the scanning electron microscope（SEM）and energy dispersive spectroscopy（EDS）. However,there was not presence of Pb element on the worn surfaces,which indicated that no chemical reaction occurred between the Pb nanoparticles and the rubbing surfaces. In addition,the tribological mechanism of the formation of the sliding-bearing system was also proposed.     

PS-TiO2 复合纳米微球的表征及摩擦学行为

采用化学法合成了PS-TiO2复合纳米微球,并对其进行了TEM、 FTIR、 TGA及DSC等分析表征。将这种微球用作润滑油添加剂,在四球试验机上研究了它的减摩抗磨性能,同时又对磨斑表面进行了X射线光电子能谱分析(XPS).研究表明：这种添加剂有良好的抗磨性能,并能在摩擦表面形成由TiO2、 Fe2O3以及有机碎片所组成的边界润滑膜。