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1.
爆轰法制备碳包覆铁镍合金纳米颗粒及其表征   总被引:2,自引:0,他引:2  
对掺杂硝酸铁和硝酸镍复合炸药前驱体,采用爆轰法合成碳包覆铁镍合金纳米颗粒。通过XRD,TEM,XRF,VSM等方法对合成的碳包覆合金纳米颗粒的形貌特征、结构组成及磁性行为进行了分析表征。结果表明,通过有效调整前驱体中金属源材料比例和碳材料组成,可爆轰合成较为完美的核壳结构碳包覆铁镍纳米颗粒,所得球形的纳米颗粒尺寸主要分布在10~60nm范围内且分散性较好,组成核主要由不同比例的铁镍元素构成,外壳层主要由石墨碳构成;由室温下磁性分析可知,该纳米颗粒表现出良好的超顺磁性。  相似文献   

2.
本文以氢氧混合气体为爆炸源,乙酰丙酮铜(II)为前驱体,采用操作简单、高效的气相爆轰方式合成了类球形的铜纳米晶颗粒。进一步采用XRD、TEM、SAED和EDX对所获得产物的形貌特征、物相组成和微观结构进行了表征和分析。同时为了预测气相爆轰流场中铜纳米颗粒的生长特性,将Kruis模型引入气体爆轰反应程序中。研究结果表明:实验合成的类球型FCC结构纳米铜晶体分散性良好,平均粒径在24 nm左右且纳米铜晶体外包覆了1nm左右的较薄石墨层。基于Kruis模型对球形铜纳米粒子的生长特性预测结果与实验数据吻合较好,为可控合成铜纳米粒子提供了可靠的理论指导。  相似文献   

3.
以氢氧混合气体为爆炸源,乙酰丙酮铜(II)为前驱体,采用操作简单、高效的气相爆轰方式合成了类球形的铜纳米晶颗粒。进一步采用XRD、TEM、SAED和EDX对所获得产物的形貌特征、物相组成和微观结构进行了表征和分析。同时为了预测气相爆轰流场中铜纳米颗粒的生长特性,将Kruis模型引入气体爆轰反应程序中。结果表明:实验合成的类球型fcc结构纳米铜晶体分散性良好,平均粒径在24nm左右且纳米铜晶体外包覆了1nm左右的较薄石墨层。基于Kruis模型对球形铜纳米粒子的生长特性预测结果与实验数据吻合较好,为可控合成铜纳米粒子提供了可靠的理论指导。  相似文献   

4.
以二茂铁为前驱体,氢氧混合气体为爆源,在爆轰管内对碳包覆铁纳米颗粒进行合成。研究了初始反应温度及热处理对产物粒子的影响。通过XRD、TEM及VSM对爆轰产物进行了检验。结果表明,碳包覆纳米颗粒呈球形或椭球形。随着反应温度的升高,碳包覆纳米铁的晶粒尺寸为30~50 nm并且趋于均匀化,说明初始反应温度的高低直接影响生成颗粒的大小。通过不同温度热处理后爆轰产物的磁滞回线分析,饱和磁化强度(Ms)随着热处理温度的升高而降低,磁滞回线为比较“瘦”的形状,但仍然具有较高的磁矫顽力,表明合成的碳包覆纳米材料呈现出硬磁性和顺磁性双重性质。  相似文献   

5.
以二茂铁为前驱体,氢氧混合气体为爆源,在爆轰管内对碳包覆铁纳米颗粒进行合成。研究了初始反应温度及热处理对产物粒子的影响。通过XRD、TEM及VSM对爆轰产物进行了检验。结果表明,碳包覆纳米颗粒呈球形或椭球形。随着反应温度的升高,碳包覆纳米铁的晶粒尺寸为30~50 nm并且趋于均匀化,说明初始反应温度的高低直接影响生成颗粒的大小。通过不同温度热处理后爆轰产物的磁滞回线分析,饱和磁化强度(M s)随着热处理温度的升高而降低,磁滞回线为比较"瘦"的形状,但仍然具有较高的磁矫顽力,表明合成的碳包覆纳米材料呈现出硬磁性和顺磁性双重性质。  相似文献   

6.
以铁/钴/镍硝酸盐为金属源,与无水乙醇、尿素、黑索今(RDX)混合制得复合炸药,采用爆轰的方式制备出石墨包覆金属铁、钴、镍(Fe@G,Co@G,Ni@G)纳米颗粒并利用XRD,TEM-EDX,XRF的方法对合成产物组成、形貌和显微结构进行分析;同时将石墨包覆金属纳米颗粒按照一定比例(0%、0.2wt%、0.4wt%、0.6wt%和0.8wt%)分别与基础油(SN150)配制成五种混合润滑油,并采用四球磨擦实验研究其摩擦学性能。结果表明爆轰所得产物为核壳结构,直径在10~50nm左右,核心为单质金属,包覆层主要由石墨构成,厚度大约在3~8nm左右;添加了石墨包覆金属颗粒的润滑油摩擦性能有明显变化,摩擦系数和磨痕直径随着石墨包覆金属的含量呈现先减小后增大的趋势;三种石墨包覆金属中,Ni@G作为润滑油添加剂的摩擦学性能最好。  相似文献   

7.
以铁/钴/镍硝酸盐为金属源,与无水乙醇、尿素、黑索今(RDX)混合制得复合炸药,采用爆轰的方式制备出石墨包覆金属铁、钴、镍(Fe@G,Co@G,Ni@G)纳米颗粒并利用XRD,TEM-EDX,XRF的方法对合成产物组成、形貌和显微结构进行分析;同时将石墨包覆金属纳米颗粒按照一定比例(0%,0.2%,0.4%,0.6%和0.8%,质量分数)分别与基础油(SN150)配制成5种混合润滑油,并采用四球磨擦实验研究其摩擦学性能。结果表明:爆轰所得产物为核壳结构,直径在10~50nm,核心为单质金属,包覆层主要由石墨构成,厚度在3~8 nm;添加了石墨包覆金属颗粒的润滑油摩擦性能有明显变化,摩擦系数和磨痕直径随着石墨包覆金属的含量呈现先减小后增大的趋势;3种石墨包覆金属中,Ni@G作为润滑油添加剂的摩擦学性能最好。  相似文献   

8.
以氢气、氧气和四氯化钛为混合前驱体,通过气液爆轰法合成了多晶纳米二氧化钛.研究了不同摩尔比例的前驱体和初始反应压力对纳米二氧化钛晶相结构的影响.采用X射线衍射及透射电子显微镜对产物的纳米结构、成分、颗粒大小和形态进行了表征.结果 表明:获得的二氧化钛存在纯净的锐钛矿相、纯净的金红石相和混合相,其中混合相的球形或者类球形...  相似文献   

9.
以三种前驱气体(CH4-2O2、H2-0.5O2、C2H2-2.5O2)进行爆轰试验,研究了初始压力对爆轰参数的影响及规律,以测得的预混气爆轰压力、速度、胞格等性能参数表征了预混气爆轰特性。以测得的爆轰参数为依据自主设计了长度2m、内径80mm、壁厚8mm、点火能量为40J的爆轰管道。在自主设计的爆轰管道内采用氢气、氧气和四氯化钛为混合前驱体,通过气液爆轰法合成了纳米二氧化钛,采用TEM对产物进行了表征,结果表明获得的纳米二氧化钛其球形或者类球形颗粒大约为20-150nm。  相似文献   

10.
溶胶-喷雾干燥W-Cu前驱体粉末煅烧过程中的相变   总被引:2,自引:1,他引:1  
采用溶胶-喷雾干燥法制备不同铜含量的W-Cu前驱体粉末,前驱体粉末分别在400、600和800℃各煅烧90min,运用XRD和SEM等手段对煅烧前后复合粉末的相组成和显微形貌进行分析,研究前驱体粉末在煅烧过程中的相变行为。结果表明:前驱体粉末在煅烧过程中发生一系列的分解和化合反应,随着煅烧温度的升高,粉末的相组成、颗粒形貌和尺寸发生明显变化,对W-30%Cu(质量分数)合金,在400℃煅烧后,复合粉末由WO3、CuO和CuWO4组成,粉末颗粒大多呈立方结构,大小为200~400nm;在600℃煅烧后,复合粉末由CuO和CuWO4组成,粉末颗粒大多呈短棒状结构,大小为400~500nm;在800℃煅烧后,复合粉末由CuO、CuWO4和Cu3WO6组成,粉末颗粒大小为3~4μm;前驱体粉末中铜含量对煅烧后复合粉末的相组成也存在较大影响,铜含量越多,越容易生成复合氧化物。  相似文献   

11.
Preparation and characterization of the YBCO superconducting films by chemical solution route with polyethylene glycol (PEG200) and Cu(NO3)2 as precursors are presented. It was found that PEG200 and sucrose were novel chelates and Cu (NO3)2 was an alternative precursor for the preparation of YBCO superconducting film by chemical solution route. The precursor solution was prepared by mixing yttrium trifluoroacetate, barium trifluoroacetate, and copper nitrate in solvent of methanol with chelates including PE...  相似文献   

12.
Color tunable quantum dots (QDs) based on the Cu, Mn, Ag co-doped ZnInS core and ZnS outer-shell were synthesized by using an eco-friendly method. Core-shell doped QDs with the average size of 3.85 nm were obtained by using a one-pot synthesis followed by a hot injection with n-dodecanethiol (DDT) and oleylamine (OLA) as stabilizers in oil phase. Cu, Mn and Ag ions were introduced as single-dopant or co-dopants during the synthesis, providing an effective means to control the emission color of the QDs. The as-synthesized QDs showed photoluminescence emission ranging from green (530 nm) to near-red (613 nm), adjusted by doping components, dopant concentration, and Zn/In ratio. Importantly, quasi-white emission has been achieved by controlling the concentration of co-doped metal ions (Mn, Cu and Ag). The primary results demonstrated the promising potential of co-doped QDs as alternative materials for future high quality white LED applications.  相似文献   

13.
Conjugate reduction of copper and nitrate from diluted solutions against the background of 3 M phosphoric acid is studied. It is found that copper ions catalyze nitrate reduction. The activation effect is attributed to cuprous ions that form as an intermediate product in the course of electrochemical reduction of cupric cations. The Cu+ ions chemically interact with nitrate yielding active components, which, in contrast to nitrates, can readily discharge at the cathode enhancing the efficiency of total cathodic process and promoting the electrode passivation.  相似文献   

14.
合成了以甲胺/环戊胺为伴随基团,分别以氯离子、1,1-环丁基二羧酸根和草酸根作为离去基团的3种新的铂(II)配合物。以顺-二碘-二环戊胺合铂(II)、硝酸银、甲胺、氯化钾、1,1-环丁基二羧酸钾和草酸钾为原料合成目标化合物。采用元素分析、质谱、核磁共振氢谱和红外光谱分析其组成和结构,利用MTT体外检测法进行了初步的体外活性评价,表明合成的3种化合物结构与理论一致,具有一定的体外肿瘤生长抑制活性。  相似文献   

15.
5V锂离子电池尖晶石正极材料LiM0.5Mn1.5O4的研究评述   总被引:9,自引:0,他引:9  
评述了锂离子电池锰酸锂正极材料的重要性,介绍了3d.过渡金属离子(Cr^3+,Ni^2+,Cu^2+,Fe^3+)掺杂在锰酸锂正极材料中的应用。研究了3d-过渡金属离子掺杂对锰酸锂正极材料结构和电化学性能的影响,并提出了其影响锂离子电池充放电和循环性能的机制。展望了3d-过渡金属离子掺杂在锂离子电池锰酸锂正极材料中的发展前景,并指出LiM0.5Mn1.5O4是非常有应用前景的5V锂离子电池正极材料。  相似文献   

16.
以金属钴盐、铁盐及柠檬酸为原料,采用有机凝胶-热分解法成功制备了尖晶石型的CoFe2O4纤维.通过红外光谱(FTIR)、X射线衍射(XRD)、热重-差热分析(TG-DSC)以及扫描电镜(SEM)等分析手段对凝胶的结构、组成、热分解过程以及热处理产物的形貌进行了表征,并分析了影响凝胶可纺性以及纤维产生缺陷的各种因素.结果表明:在pH值为5.5左右的溶液中金属离子与柠檬酸反应形成具有线性分子结构的[(C6H6O7)4CoFe2]n,由这些线性分子所组成的凝胶显示出良好的可纺性.所制备的尖晶石型CoFe2O4纤维由40~50 nm大小的晶粒组成,纤维直径可小于1 μm,长径比达1×106.通过振动样品磁强计(VSM)测得这种尖晶石型CoFe2O4纤维的饱和磁化强度和矫顽力分别为81.97 A·m2/kg和1041.47×79.6 A/m.  相似文献   

17.
Polypyrrole (PPy) films doped with anions of various size, charge and chemical nature (inorganic, surfactant, with aromatic ring) were electrochemically synthesized and investigated by low-temperature N2 sorption experiments at −196 °C. The specific surface area, total pore volume, average pore radius, pore size distribution and other parameters for oxidized PPy films using dodecylsulfate, 2-naphthalene sulfonate, 1,5-naphthalene disulfonate, poly(4-styrenesulfonate), tosylate, perchlorate, nitrate and chloride as dopant ions, were calculated. The obtained data show that although the average pore radius of investigated mesoporous PPy films (17–19 Å) is practically independent of the dopant anion used, however the latter determines the total pore volume and specific surface area values in different PPy materials investigated. As the total pore volumes for PPy films doped with large amphiphilic anions show the smallest values, the corresponding values for PPy/small inorganic anions, are up to 2 times higher.  相似文献   

18.
以偏钨酸铵和硝酸铜为原料,采用EDTA-柠檬酸法制备了含有0~0.8wt.%稀土氧化物( Ce0.8Sm0.2O1.9, SDC)的W-20Cu复合粉体,所制备的复合粉体经压制成型、1250°C烧结2h后获得SDC/W-20Cu复合材料烧结体。对所制备复合粉体进行物相、形貌的表征;研究稀土氧化物的添加对SDC/W-20Cu烧结体的密度、组织结构和物理力学性能的影响。实验结果表明:所制备的W-Cu复合粉体平均粒度为100~200nm;同时,SDC的添加对烧结体的密度和电导率会有轻微的影响,但能够抑制晶粒的长大并明显改善烧结体的力学性能。经1250°C烧结后,SDC/W-20Cu烧结体的相对密度均高于97%;当SDC的添加量为0.6%时,具有最大的抗弯强度和显微硬度,分别是1128MPa和258HV;此外,在室温和600°C的测试条件下,其最大的抗拉强度可以达到580MPa和258MPa。  相似文献   

19.
Copper ions-loaded polyelectrolyte multilayer films (PEMs) of poly(acrylic acid), coded as PAA, and poly(diallyldimethylammonium chloride), coded as PDDA, were constructed on silicon substrate via layer-by-layer (LBL) self-assembly, using CuCl2 blended in the electrolyte solution as the source of Cu2+. Cu(OH)2 nanoparticles were then in-situ synthesized in the multilayer films by immersion of the copper ions-loaded PEMs into 0.1 M NaOH solution. The Cu2+-loaded PAA/PDDA multilayer films and those doped with in-situ Cu(OH)2 nanoparticles were characterized by means of ultraviolet-visible light (UV-vis) absorption spectrometry, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The friction and wear behaviors of the multilayer films sliding against 440C stainless steel counterparts were evaluated using a UMT-2 multifunctional micro tribometer. Results indicate that the Cu2+-loaded PAA/PDDA multilayers with a bilayer number of 2-8 show similar UV-vis absorbance features, and no noticeable accumulation in the amount of Cu2+ occurs during the fabrication of the multilayers, possibly owing to a weak bonding between Cu2+ and -COO. The blue-shift of the absorption peak of -COO-Cu2+ band, observed for PAA/PDDA multiplayer films, becomes more obvious after being doped with in-situ Cu(OH)2 nanoparticles. The final Cu(OH)2 nanoparticles-doped PAA/PDDA multilayer films have excellent friction-reducing and antiwear abilities, possibly owing to the modification and refining of their morphology and microstructure by the in-situ doped Cu(OH)2 nanoparticles. The present approach could be extended to incorporate nanoparticles of other types of metal ions into the final PEMs to realize multifunctionalization.  相似文献   

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