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超细空心粉末制备及其应用的研究进展 总被引:2,自引:0,他引:2
超细空心粉末由于其特殊的结构和性质在国内外引起了研究者的极大兴趣.本文介绍了超细空心粉末的制备方法的最新研究进展.制备方法一般可分为雾化热分解法、置换反应法和模板法,并简单介绍了由本实验室提出的利用自催化还原反应制备空心镍粉的方法,这种方法的进一步研究正在本实验室开展.同时对超细空心粉末在化工、生物制药、军事工业和光学等领域的应用进行了概述. 相似文献
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据报道,中科院化冶所最近研发成功了一种碱式碳酸镍水浆加压氢还原制备超细镍粉的新工艺。该工艺采用纯水作为分散介质与一定组分的碱式碳酸镍制浆进行加压氢还原,可以在比较温和的条件下制得0.1~0.5u不同粒度的镍粉,镍粉粒度均匀、颗粒呈圆球形。 相似文献
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研究了乙二醇体系中,在超声场条件下,制备得到的纳米镍粉的性能.采用XRD进行了成分分析,SEM、TEM进行了微观形貌表征,对镍粉压制而成的电极进行了循环伏安测试.结果表明:与不加超声场条件相比,有超声场时制备得到的镍粉颗粒直径更小,颗粒分散度更好.超声场条件下制备的镍粉压制而成的电极在含有乙醇的1mol/L KOH溶液中进行循环伏安测试,与没有乙醇时相比,镍粉电极的氧化峰值电流密度增大,还原峰值电流密度相应地减小,表明对于乙醇的氧化还原反应来说超声场条件下制备的镍粉是一种有效的催化剂.同时与高纯镍块电极相比,在对乙醇的氧化方面纳米镍粉电极表现更高的电化学活性. 相似文献
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《中国粉体技术》2017,(6):32-35
以抗坏血酸为还原剂,硝酸银为反应前驱体,通过对液相体系分时间段取样研究液相还原法制备超细球形银粉的生长机理。借助扫描电子显微镜(SEM)、透射电子显微镜(TEM)、能谱(EDS)仪、X射线衍射(XRD)仪、紫外吸收光谱(UV-Vis)仪和颗粒图像分析仪对银粉进行表征和分析。结果表明,以抗坏血酸还原硝酸银制得了平均粒度为0.543μm,球形度为0.926,分散良好的超细球形银粉;该氧化还原反应可自发进行,使被还原的银原子达到过饱浓度形成银原子团簇和细小的银晶核,银晶核主要以原子扩散控制生长和晶核聚集两种方式长大,最终获得表面自由能较小、粒度分布均匀的球形银粉。 相似文献
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运用透射电子显微镜对超细粉的形貌和粒径进行了研究、分析,比较了液相法和气相法民得超细粉的性能,得出了液相和气相法是制备纯度高、粒度小、粒径分布范围窄的超细粉的较佳方法。 相似文献
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两步还原法制备MLCC电极用超细铜粉 总被引:1,自引:0,他引:1
为了制备MLCC电极用超细铜粉,克服CuSO4直接水合肼还原法制备的铜粉存在粒度分布不均匀、振实密度小的问题,提出了两步液相还原新工艺,即以CuSO4溶液为原料,首先采用NaOH沉淀-葡萄糖预还原制备Cu2O,然后用水合肼还原Cu2O制备超细铜粉.针对实现铜晶体的成核与长大过程的分离,研究了水合肼加入方式对铜粉性能的影响,发现较慢的水合肼滴加速度和将水合肼还原Cu2O阶段分为升温均匀成核与水合肼连续滴加长大两个过程有利于得到粒度均匀的铜粉.在最佳试验条件下制得的铜粉呈类球形,粒度分布均匀,分散性好,平均粒径为1.8μm,振实密度达4.2g/ml. 相似文献
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《Advanced Powder Technology》2020,31(8):3433-3439
This paper explored a solid-phase reduction method to prepare ultrafine nickel powder under different conditions. The effect of a NaCl separator agent on the morphology, primary particle size and specific surface area of the prepared nickel powder is discussed. The results show that direct contact among primary Ni particles can be effectively inhibited during the reduction of nickel oxalate due to the presence of the NaCl separator agent. An ultrafine nickel powder with a primary particle size of between 80 and 150 nm can be prepared with NaCl as the separator agent at temperatures from 400 °C to 460 °C. The powder reduced at 430 °C has a uniform particle distribution and a decreased amount of agglomeration. 相似文献
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Dai Changhong Zhang Xianpeng Zhang Jinsong Yang Yongjin Cao Lihua Xia Fei 《Journal of Materials Science》1997,32(9):2469-2472
Ultrafine powders of silicon carbide synthesized by microwave and conventional heating are described. Silicon carbide powders
with diameters in the nanometer range were formed by reducing SiO2 with various forms of carbon in a nitrogen atmosphere. Ultrafine SiO2 powder, phenolformaldehyde resin and ultrafine carbon black were used as starting materials. The properties of the powders
were determined by means of X-ray diffraction, TEM, etc. The results showed that the technique and conditions for preparing
samples, as well as the temperature and type of heating, had obvious effects on the powders characteristics.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
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《Materials Letters》2007,61(4-5):1125-1129
The preparation of ultrafine copper powder with chemical reduction method was investigated. Ascorbic acid was employed as reducing agent. Reaction of CuSO4·5H2O with ascorbic acid at 70 °C gives polyhedron monodispersed ultrafine copper powder. The copper powder having excellent dispersibility was prepared when the pH value was controlled at 6 with aqueous ammonia. Influences of reaction temperature on the efficiency of copper powders were also studied. TG/DTG/DTA of copper powder was discussed with thermal analyzer. As-prepared copper powder was applied in BME-MLCC. The micro-structures of end termination and interface were discussed with SEM and polarized light microscope. The copper end termination has high adhesion force, excellent solderibility behavior and resistance behavior to soldering. 相似文献
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平均粒径大小及磁性能不同的Fe3O4超微粉的制取 总被引:9,自引:0,他引:9
本文研究了以共沉淀法和沉淀氧化法获得平均粒径大小及磁性能不同的Fe_3O_4超微粉的可能性。实验表明:以不同的共沉淀反应条件所制取的Fe_3O_4超微粉平均粒径及磁性能变化不大,而由改变沉淀氧化反应条件则可制取平均粒径及磁性能显著不同的各种Fe_3O_4超微粉。 相似文献