【作者】 唐浩奎；

【导师】 曹宏；

【作者基本信息】 武汉工程大学 ， 材料学， 2010， 硕士

【摘要】 碳包覆纳米金属粒子属于新型纳米碳材料,具有典型核壳结构,数层~数十层石墨结构层紧密围绕纳米金属核有序排列。这种材料具有独特的核壳结构和奇特的电学、磁学、光学和力学性能,因而有望用作电催化剂、电池材料、电波屏蔽材料和摩擦材料等。目前大多数制备碳包覆金属纳米粒子的方法存在产物中杂质含量高、工艺难以控制、成本高和产量较低等问题。本论文选用蔗糖为碳源,铜、镍的硝酸盐为金属源,采用混合蒸干、碳化退火、酸浸超声等较为温和、简单的工艺制得了具有核/壳结构的碳包覆CuNi合金纳米粒子(Carbon Encapsulated Cu-Ni Alloy Nanoparticles, CECNANPs)。采用EDS、XRD和TEM等测试手段进行成分、物相和结构分析,结果表明所制得的CECNANPs外形呈准球状,单个粒子尺寸分布较为均匀,大约分布在20-30nm,核为fcc-CuNi,而非其碳化物或氧化物。采用热重分析仪进行性能分析,结果说明碳层提高了合金核纳米粒子的抗氧化性能。将CECNANPs作为液体石蜡的添加剂,采用XP试验机研究了不同添加量,不同载荷,不同转速下,CECNANPs的摩擦磨损性能,结果表明0.6wt.%为最佳添加量,此时的摩擦系数略低于空白液体石蜡,磨损量显著低于空白液体石蜡,同时摩擦表面平整度和光滑度提高;将CECNANPs作为醇酸树脂的添加剂,考察了不同添加量对涂料的粘度,漆膜的附着力和硬度等性能的影响,结果说明15wt.%是最佳添加量;将CECNANPs作为研究电极,采用循环伏安法讨论了酸碱体系里不同扫速下对对硝基苯酚和甲醇的电催化活性,结果说明对对硝基苯酚有较好的电化学还原活性,过程主要受扩散控制。相同情况下,CECNANPs对甲醇没有表现出电催化活性。更多还原

【Abstract】 Carbon encapsulated metal nanoparticles (CEMNPs) are new carbon materials. They have the representative core/shell structure, in which graphite layers arrange around the center (filled with nano-metal). Because of their special structures and unique physical and chemical properties, they might be used as electro-catalysts, battery materials, the electro-magnetic waves shield materials and friction materials.For the preparation of CEMNPs, the present techniques show some disadvantages, e.g., the morphology and the structure of the resulting nanoparticles are not easy to control, costly and it is difficult to produce high-purity nanoparticles in large quantities. Carbon encapsulated copper nickel alloy nanoparticles(CECNANPs) with core/shell structure were successfully prepared in nitrogen atmosphere by mixing, evaporation, carbonization, annealing, concentrated nitric acid total immersed, ultrasound purified methods under the simple and mild conditions, in which sucrose functioned as carbon precursor, copper nitrate hydrate and nickel nitrate used for source of the metal nanoparticles. The elements, morphology and structure of the product were characterized via EDS, XRD, HRTEM. The results indicated the shape of product was quasi-spherical, a single particle distributed uniformly with the size about 20-30nm, the core of the as-prepared was fcc-CuNi, rather than that of carbide phases or oxide phases. TG-DTA-DTG measurements suggested that the carbon shell increased antioxygenic property of the copper nickel alloy nanoparticles.The CECNANPs was used as the additive of paraffin, and its tribological properties were investigated by XP tester with various additive amounts, different loads and rotate speeds. The results indicated 0.6wt.% was the best adding concentration and its friction coefficient was slightly lower than that of paraffin, but raised the anti-wear property greatly,the flatness and smoothness of tribological surface was enhanced. The CECNANPs was used as the additive of alkyd resin, the adding concentration of CECNANPs on the viscosity of coating, the adhesive force and the hardness of paint film were inspected, the results concluded 15wt.% was the best adding concentration. The CECNANPs was used as the working electrode to discuss the electro-catalytic activity for PNP and methanol with various scan velocity. The results suggested PNP had good electro-catalytic reduction activity, its process was mainly controlled by diffusion. But it did not show electro-catalytic activity for methanol under the same conditions.更多还原