机械合金化制备负载型非晶态Ni－Nb纳米粒子催化材料

用机械合金化法制备了负载型非晶态Ｎｉ－Ｎｂ／ＳｉＯ２纳米粒子，粒径约为１０ｎｍ，硅胶的加入不仅大大加速了金属合金化的过程，而且使金属粒子比较均匀地分散在ＳｉＯ２中。这种材料比之单纯的纳米粒子更适合于作为催化剂。     

Synthesis and electrochemical characteristics of Al2O3-coated LiNi1/3Co1/3Mn1/3O2 cathode materials for lithium ion batteries

LiNi_1/3Co_1/3Mn_1/3O₂ cathode materials have been coated with Al₂O₃ nano-particles using sol-gel processing to improve its electrochemical properties. The X-ray diffraction (XRD) pattern of the as-prepared Al₂O₃ nano-particles was indexed to the cubic structure of the γ-Al₂O₃ phase and had an average size of ∼4 nm. The XRD showed that the structure of LiNi_1/3Co_1/3Mn_1/3O₂ was not affected by the Al₂O₃ coating. However, the Al₂O₃ coatings on LiNi_1/3Co_1/3Mn_1/3O₂ improved the cyclic life performance and rate capability without decreasing its initial discharge capacity. These electrochemical properties were also compared with those of LiAlO₂-coated LiNi_1/3Co_1/3Mn_1/3O₂ cathode material. The electrochemical impedance spectroscopy (EIS) was studied to understand the enhanced electrochemical properties of the Al₂O₃-coated LiNi_1/3Co_1/3Mn_1/3O₂ compared to uncoated LiNi_1/3Co_1/3Mn_1/3O₂.     

PP/弹性体/无机纳米粒子复合材料的研究进展

概述了目前PP 弹性体 无机纳米粒子三元复合体系的研究进展情况,包括:基体树脂的选择与改性、弹性体尤其是新型聚烯烃弹性体(POE)的应用、无机纳米粒子对复合体系的影响、增韧增强机理的研究等。     

纳米颗粒对镍刷镀层组织及性能的影响

应用纳米复合电刷镀技术制备了纳米氧化铝/镍复合镀层,采用透射电镜、XPS等现代分析技术和性能评价手段研究了纳米颗粒对镍刷镀层组织和性能的影响.结果表明:纳米颗粒在复合刷镀层中弥散分布、粒度均匀,与基质镍金属以化学键结合;纳米颗粒增加了基质金属的成核率,细化了镀层组织,显著提高了刷镀层的硬度和耐磨性.与镍金属刷镀层相比,复合刷镀层硬度和耐磨性分别提高0.5倍和1.5倍以上.复合刷镀层的组织特征合理地解释了纳米颗粒对其性能影响的机理.     

Deformation and failure mechanism of nano-composite coatings under nano-indentation

Two nano-composite coatings based on nc-TiC particles in an a-C:H matrix are deposited via closed-field unbalanced reactive magnetron sputtering. The compositions of the coatings are varied by changing the acetylene gas flow during the depositions. A Cr/Cr–Ti/Ti–TiC graded interlayer is introduced between substrate and coating. Electron probe micro-analyses (EPMA) show that the Ti content of the coatings varies between 31.7 and 11.5 at.%. The coatings exhibit a hardness (H) of 20.0 and 15.7 GPa, and a Young's modulus (E) of 229.4 and 136.6 GPa, respectively, as measured through nano-indentations. Cube corner indentations are performed to probe the fracture toughness of the coatings through the determination of critical indentation loads (L_r) at which radial cracks start to propagate. Transmission electron microscopy (TEM) observations and energy-filtered TEM are employed to characterize the coatings nanostructures. The variation in Ti content is accompanied by a variation in TiC particle size and volumetric fraction, as well as a change in the columnar structure of the coatings. A focus ion beam (FIB) slicing technique is employed to prepare samples from nano-indented locations of coated Silicon and stainless steel (SS) substrates. TEM inspection of the FIB sliced samples determines that the most brittle phase in the coating is the C-enriched columnar boundary, and identifies the location of failure within the interlayer. As a consequence of the different nanostructure, the coatings exhibit different elastic recovery properties and toughness.     

强磁场对锰锌铁氧体前驱体纳米颗粒形貌的影响

在共沉淀制备非铁磁性锰锌铁氧体前驱体纳米颗粒的过程中,分别施加零磁场、弱磁场(0.1～0.7 T)和强磁场(10 T),探讨磁场对非铁磁性锰锌铁氧体前驱体纳米颗粒形貌的影响规律.结果表明,当磁感应强度超过某一临界值时,非铁磁性纳米颗粒由球形颗粒向链状颗粒,然后向棒状或者纤维状颗粒转变.在10 T的强磁场下,纳米颗粒长成长径比很大的纤维状,能谱分析结果表明,纤维状颗粒主要为复合铁氧体,而非单一的沉淀产物.随着反应温度增加、溶液滴加时间延长将使纤维直径降低.     

适用于鱼肉中氯霉素检测的抗体包被金磁纳米微粒修饰安培免疫传感器研究

研制了基于氯霉素抗体包被Fe3O4/Au金磁纳米微粒(GMP)和三乙撑四胺铜(II)(CuL)共固定修饰平面热解石墨电极的安培免疫传感器(PRG|CuL / anti CAP-GMP),用于测定鱼肉中CAP含量.该免疫传感器是利用外加磁场,将anti CAP-GMP吸引到CuL修饰的PRG电极(PRG|CuL)表面制备而成.CuL对H2O2还原具有良好的电催化能力,当该传感器在含CAP样品液中温育后,CAP与电极表面的anti CAP的免疫结合物导致CuL对H2O2的催化还原电流(I)降低,电流下降值(△I)和CAP浓度成正比,可用于CAP定量测定.在25℃的pH=6.5磷酸盐缓冲液(PBS)中温育30 min,该传感器对CAP的检测线性范围为0.6~110 ng/mL,检出下限为0.092 ng/mL(3σ法).应用于鱼肉中CAP检测并与传统的液相色谱法(HPLC)比较,结果一致,其添加回收率在97%~104%之间.该免疫传感器集分离、富集为一体,电极表面可更新,检测灵敏快速,对于水产品中痕量氯霉素分析提供了一种新颖的方法.     

咔唑衍生物及8-羟基喹啉与ZnS纳米粒子复合及光学性能研究

采用微乳液的方法制备了平均粒径为85 nm的ZnS纳米粉体。主要测试了咔唑衍生物及8-羟基喹啉与ZnS纳米粒子复合后在四氢呋喃、N,N-二甲基甲酰胺中的单/双光子荧光特性。研究发现咔唑衍生物的双光子荧光强度较未加入纳米ZnS时只有提高不足20%,而8-羟基喹啉与纳米ZnS复合后得到了一种新的发光体系,其荧光强度可提高2~4倍,同时荧光发射峰出现了较大程度的红移,其红移达116 nm。     

应用超临界流体技术制备纳米材料的研究进展

超临界流体以其粘度低、密度大、较好的传质、传热和溶解性等特性，在许多领域都有广阔的应用前景。纳米微粒材料在磁性材料、电子材料、光学材料等方面极具应用价值．故其制备技术已成为化学工程研究的一个新兴领域。本文主要介绍超临界流体技术在纳米材料制备中的应用与发展。     

SiO2纳米粒子对铜导电胶连接强度的影响

以环氧树脂为基体，间苯二胺和二氨基二苯甲烷的低融点混合物为固化荆，铜粉为导电填料，制备了热固化各向同性导电胶。研究了固化温度、固化时间及固化荆、纳米SiO2粒子添加量对连接性能的影响。在固化温度为145℃．固化时间为2h时．导电胶连接强度达到20MPa。体系中添加适量的纳米SiO2粒子，连接强度提高到25MPa。SiO2粒子均匀地分散在环氧树脂基体的三维立体网状大分子链中，起到分散应力，吸收冲击能．阻止裂纹扩展的作用。