超细钴粉的制备与表征(英文)

以自制Co(OH)2为原料,乙二醇为溶剂和还原剂,十二烷基苯磺酸钠为分散剂,液相中还原制备超细钴粉。研究分散剂SDBS浓度对钴粉粒度、比表面积与磁性能的影响。利用比表面积测定、X射线衍射、傅里叶变换红外光谱、扫描电子显微镜、磁强计等测试手段对钴粉进行表征。结果表明:钴粉的比表面积随SDBS浓度的增加而增加。当分散剂用量为7.5g/L,制备的钴粉比表面积为8.1235m2/g,晶粒尺寸0.5-0.6μm。钴粉颗粒粒径比较均匀,近似球形,没有发生团聚现象,其物相呈面心立方与密排六方结构,以面心立方为主。分散剂用量为7.5g/L,制备钴粉比饱和磁化强度为39.52A·m2/kg,剩余磁化强度为3.16A·m2/kg,矫顽力为15302A/m;未加入分散剂钴粉比饱和磁化强度为132.93A·m2/kg,剩余磁化强度为21.32A·m2/kg,矫顽力为23347A/m。     

气体雾化法制备锌粉及其性能研究

探讨了锌粉雾化的基本原理,以及雾化喷嘴结构、喷射顶角、锌液温度和气体压力等对锌粉粒度的影响,并运用激光粒度分析仪、比表面积测试仪和蔡司显微镜等对制备的雾化锌粉的粒度分布、比表面积大小及锌粉形貌进行分析。研究的锌液温度为(620±10)℃,雾化压力为1.6 MPa;结果表明:适当提高锌液温度及提高喷枪入口的气流速度或压力均有利于锌粉的细化;雾化法制得的锌粉呈近球形,锌粉的D_(50)≤20μm;随锌粉的平均粒径减小,比表面积呈逐渐增大的趋势,锌粉粒径为-100~-325目时,比表面积从0.1367 m~2/g增大到0.2233 m~2/g。     

共沉淀法制备LiNi0.8Co0.1Mn0.1O2过程中加料速度对其性能的影响

采用共沉淀法制备Ni0.8Co0.1Mn0.1(OH)2前驱体,与LiOH.H2O混合后在氧气气氛中焙烧得到LiNi0.8Co0.1Mn0.1O2正极材料,探讨共沉淀反应过程中快速加料和慢速加料制度对前驱体形貌和LiNi0.8Co0.1Mn0.1O2正极材料性能的影响。通过X射线衍射(XRD)、扫描电镜(SEM)和电化学测试对样品进行表征。结果表明:慢速加料法减小了材料的粒径,合成了平均粒径在0.5μm左右的球形Ni0.8Co0.1Mn0.1(OH)2前驱体,且粒径分布比较集中;所合成LiNi0.8Co0.1-Mn0.1O2正极材料具有良好的层状结构,且无杂相存在;缓慢加料法得到的样品的电化学性能有很大提高,在0.1 C、0.5 C和1 C下首次放电比容量分别达到223.5、194.3和190.7 mA.h/g,循环30次后,容量保持率为80.09%、80.80%和85.84%。     

从废旧锂离子电池中回收制备超细Co3O4

用湿化学法从废旧锂离子电池中回收并制备出了Co3O4粉体.研究了过程参数对粉体性能的影响,测定了Co3O4粉体的比表面积和红外光谱,观察了粉体的微观形貌.结果表明,制备的粉体比表面积大,其值都在100m2/g左右,颗粒粒径分布在10nm～20nm之间,颗粒形貌呈球形结构,其红外特征峰与市售Co3O4的特征峰相比发生了一定的红移.     

等离子体制备银纳米粉末的研究

采用阳极弧放电等离子体制备银纳米粉末，并利用X射线衍射(XRD)、透射电子显微镜(TEM)、X射线能谱仪(XEDS)和BET吸附等测试手段对样品的成分、形貌、晶体结构、粒度及其分布、比表面积等进行性能表征。结果表明：本法所制备的银纳米粉末纯度高，分散性好，呈类球形均匀分布；晶体结构与相应的块体材料基本相同，为fcc结构，其平均粒径为24nm，粒径范围在10～50nm，比表面积为23．81m^2／g。     

化学包裹粉工艺制备粗晶粒WC-Co硬质合金

以费氏粒度为8.06μm的WC粉与Co(NO3)2·6H2O为原料,采用N(CH2CH2OH)3(TEA)为还原剂制备WC-12%Co(质量分数)包裹粉,以包裹粉为原料制备WC-12%Co硬质合金。采用扫描电镜观察包裹粉与合金中WC晶粒的立体形貌,采用X射线衍射仪分析粉末的物相组成,采用比表面积分析仪分析TEA还原产物多孔泡沫Co的比表面积,采用金相显微镜观察合金的组织结构。结果表明:包裹粉中Co为纯fcc高温相结构,呈多孔泡沫状纳米组装结构形式包裹在WC粉末表面;WC-12%Co合金组织结构均匀,平均晶粒度为4.8μm,WC晶粒结晶完整、呈规则多面体形状。     

Co粉制取工艺对粉末松装密度的影响

以两种不同形貌的碳酸钴为原料，通过氢气还原工艺制得钴粉。采用扫描电子显微镜、激光粒度分析仪、费氏粒度分析仪和松装密度仪表征相应的粉末特征，研究了钴粉制取工艺对粉末松装密度的影响。结果表明：钴粉制取过程中的还原温度、碳酸钴原料的粒度和形貌、钴粉的粒度分布是影响粉末松装密度的直接因素。还原温度越高制得钴粉松装密度越大，碳酸钴原料粒度越大、形貌越接近于球形制得钴粉松装密度越大，费氏粒度1.03μm和5.28μm碳酸钴在620℃下还原制得的钴粉松装密度分别为2.40、2.71 g/cm³，均大于400℃还原制得的钴粉；均匀混合粗细不同的钴粉可提高粉末松装密度，将质量分数为20%、费氏粒度1.50μm、松装密度1.45 g/cm³的钴粉和质量分数为80%、费氏粒度5.40μm、松装密度2.71 g/cm³钴粉充分混合，混合后的钴粉松装密度为2.93 g/cm³。     

粒径可控高振实密度球银的制备工艺研究

以硝酸银为原料,对苯二酚(C6H4(OH)2)为还原剂,链烷醇胺A为分散剂,用液相化学还原法制备高振实密度超细银粉。用激光粒度分布仪测试银粉的粒度分布与平均粒径,用扫描电子显微镜(SEM)和透射电子显微镜(TEM)分析银粉的形貌、粒径和团聚状态,用多晶X射线衍射(XRD)仪检测粉体的晶相。结果表明：通过调节硝酸银的浓度、硝酸银与还原剂的配比以及分散剂的用量等,可以实现对所制备球银粒径的控制;制备的超细银粉为面心立方晶体结构,呈规则球形,振实密度可达4.0 g/cm3。     

阳极弧等离子体制备镍纳米粉的性能表征

采用阳极弧放电等离子体方法成功制备了高纯镍纳米粉末;利用X射线衍射（XRD）、透射电子显微镜（TEM）和选区电子衍射（SAED）、BET吸附法测试手段对试样的成分、形貌、晶体结构、比表面积、粒度及其分布进行性能表征,并采用元素分析仪测定C,H,N含量,采用X射线能量色散分析谱仪（EDS）测定试样所含的元素及其相对含量,用红外吸收光谱（FT-1R）对结构组成进行定性分析.实验结果表明：本法所制备的镍纳米粉末的晶体结构与相应的块体材料基本相同,为fcc结构的晶态,平均粒径为47 nm,粒度范围分布在20 nm～70 nm,呈规则的球形链状分布,比表面积为14.23 m2/g,试样纯度高且具有很强吸附性.     

约束弧等离子体制备碳包覆铁纳米颗粒的性能

采用约束弧等离子体技术制备碳包覆铁纳米颗粒,利用X射线衍射、透射电子显微镜、高分辨透射电子显微镜、X射线能量色散分析谱仪和N2吸附等测试手段对样品的化学成分、形貌、微观结构、比表面积和粒度等特征进行表征分析。结果表明：采用约束弧等离子体技术制备的碳包覆纳米金属颗粒具有明显的核？壳结构,内核金属为体心立方结构的铁,外壳为无定形碳。颗粒大多呈球形和椭球形,粒径分布在15～40nm范围内,平均粒径为30nm,内核粒径为18nm,外层碳的厚度为6～8nm,比表面积为24m2/g。     

Preparation and particle size characterization of Cu nanopartides prepared by anodic arc plasma

Copper nanoparticles were successfully prepared in large scale by means of anodic arc discharging plasma method in inert atmosphere. The particle size, specific surface area, crystal structure, and morphology of the samples were characterized by X-ray diffraction （XRD）, BET equation, transmission electron microscopy （TEM）, and the corresponding selected area electron diffraction （SAED）. The experimental results indicate that the crystal structure of the samples is fcc structure the same as that of the bulk materials. The specific surface area is 11 m^2/g, the particle size distribution is 30 to 90 nm, and the average particle size is about 67 nm obtained from TEM and confirmed from XRD and BET results. The nanoparticles with uniform size, high purity, narrow size distribution and spherical shape can be prepared by this convenient and effective method.     

Preparation and particle size characterization of Cu nanoparticles prepared by anodic arc plasma

1. Introduction Metal nanoparticles exhibit novel physical and chemical properties owing to the small size effect, surface effect, quantum size effect, and quanta tun-nel effect [1-4]. In recent years, the research and de-velopment for metal nanoparticles have attracted significant interest and is still the subject of intense investigation owing to their intriguing properties and various potential applications [5-7]. Because the properties depend strongly on the details of particle size, speci…     

PARTICLE SIZE AND MICROSTRUCTURE OF Ni NANOPOWDERS PREPARED BY ANODIC ARC PLASMA

Pure Ni nanopowders were successfully prepared by the method of anodic arc discharged plasma with homemade experimental apparatus. The particle size, mircostructure and morphology of the particles by this process were characterized via X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED); The specific surface area and pore parameters were investigated by multi-point full analysis of nitrogen adsorption-desorption isotherms at 77K by BrunauerEmmett-Teller (BET) surface area analyzer; The chemical composition were determined by X-ray energy dispersive spectrometry (XEDS) equipped in SEM and element analyze instrument. The experiment results indicate that the samples by this method with high purity, the crystal structure of the particles is as same as the bulk material, is fcc structure, with average particle sizes about 47nm, ranging from 20 to 70nm, and distributed uniformly in spherical chain shapes, the specific surface areavis 14.23m^2/g, pore volume of pore is 0.09cm^3/g and average pore diameter is 23nm.     

Growth mechanism of Cu nanopowders prepared by anodic arc plasma

1 Introduction In recent years, the research and development for metal nanopowders has attracted significant interest and it is still the subject of intense investigation owing to their intriguing properties and extensive prospects [1-5]. Metal nanopowder…     

Preparation and characterization of Ni nanopowders prepared by anodic arc plasma

Ni nanopowders were successfully prepared in large quantities by anodic arc discharged plasma method with homemade experimental apparatus in inert gas. The particle size, microstructure and morphology of the particles were characterized via X-ray diffractometry (XRD), transmission electron microscopy (TEM) and the corresponding selected area electron diffractometry(SAED). The specific surface area and pore parameters were investigated by nitrogen sorption isotherms at 77 K with Brunauer-Emmett-Teller(BET) equation and Barrett-Joyner-Halenda (BJH) method. The chemical compositions were determined by X-ray energy dispersive spectrometry(XEDS) and element analysis. The experimental results indicate that this method is convenient and effective, and the nanopowders with uniform size, higher purity, weakly agglomerated and spherical chain shape are gotten. The crystal structure of the samples is FCC structure as the bulk materials, the particle size distribution ranges from 20 to 70 nm, and the average particle size is about 46 nm obtained by TEM and confirmed by XRD and BET results. The specific surface area is 14.23 m^2/g, specific pore volume is 0.09 cm^3/g and average pore diameter is 23 nm.     

Synthesis, Characterization, and Optimization of Co2SnO4 Nanoparticles via Co-precipitation Method

Nano-structured pure Co₂SnO₄ powders have been synthesized using the co-precipitation method in the presence of oleic acid (OA) as a capping agent. The Taguchi L₄ statistical design was used to investigate the effect of the main parameters (i.e., OA concentration, calcination time, and calcination temperature) on Co₂SnO₄ formation, crystallite size, and morphology. Co₂SnO₄ particles were characterized by powder x-ray diffraction (XRD), energy-dispersive x-ray spectroscopy, scanning electron microscopy (SEM), Fourier transform of infrared spectroscopy (FT-IR), dynamic light scattering (DLS), and Brunauer-Emmett-Teller (BET) surface area measurements. The formation of small and well-crystalline particles, on the order of 41.12-90.60 nm in crystal size, has been determined from XRD patterns and confirmed by SEM and DLS. The specific surface area was measured by a BET method to be 25.43 m²/g. The particle size of the product was observed by DLS to be in the range of 40-105 nm. The results indicated that calcination temperature has the most significant effect on the produced cobalt stannate crystal size.     

真空感应熔炼气雾化法制备高强度PH13-8Mo钢粉末的特性表征

采用真空感应熔炼气雾化(VIGA)法制备出球形高强度PH13-8Mo钢粉末,通过不同目数的筛网对粉末进行筛分,得到120~212μm,53~120μm,15~53μm和<15μm不同粒度区间的高强度PH13-8Mo钢粉末。利用氧氮分析仪、扫描电镜(SEM)、激光粒度分布仪和智能粉体特性测试仪等分析手段研究了不同粒径区间的PH13-8Mo钢粉末的氧含量、表面形貌、表面及内部微观组织、流动性和松装密度。结果表明:随着粉末粒度区间减小,PH13-8Mo钢粉末的比表面积从0.017 m^2/g显著增大到0.243 m^2/g,粉末中的O含量从0.017%增大到0.033%;当PH13-8Mo钢粉末粒径的范围为15~53μm区间时,粉末中的O含量相对较低,冷却速率较大,卫星球颗粒少,表面和内部组织主要由胞状晶和微晶组成,且该粒度范围的PH13-8Mo钢粉末的松装密度和流动性指数高。