共查询到20条相似文献,搜索用时 15 毫秒
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以嵌段聚合物羟基化SBS(SBS-OH)为模板,乙酸锌和硫化钠为前驱物,制备了ZnS纳米粒子。采用紫外-可见吸收光谱(UV-Vis)、荧光光谱(PL)、广角X射线衍射(WAXD)及透射电子显微镜(TEM)对ZnS纳米粒子进行了表征。结果表明,SBS-OH可以在ZnS纳米粒子的生长过程中,起到较好的模板作用,随SBS-O... 相似文献
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V. P. Isupov L. E. Chupakhina R. P. Mitrofanova 《Journal of Materials Synthesis and Processing》2000,8(3-4):251-253
It has been demonstrated that the formation of magnesium-aluminium double hydroxides [Mg(1 – X)Al
X
(OH)2]
X+(A
n–
X/n
) m H2O, (A–Cl–, NO–
3, SO2–
4) occurs during mechanical activation of the mixture of magnesium hydroxide (brucite) with aluminium chloride, nitrate and sulphate in high-energy planetary-type activators. The effect of activation time on the formation of the double hydroxide has been investigated. Thermal decomposition of the chloride form of the double hydroxide has been studied. 相似文献
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氧化铝高能球磨时机构力化学效应研究 总被引:8,自引:0,他引:8
研究了氧化铝在高能球磨过程中机械力化学效应的变化,机械力化学效应因子随球磨时间的变化可分为三个阶段;第一阶段主要是晶粒尺寸减小和显微应变增加同时进行;第二阶段主要是有效温度系数的增加;第三阶段主要是点阵膨胀至饱和。用溶解法比较了球磨前后氧化铝的活性,发现经球磨后,氧化铝在盐酸中的溶解活化能由18kJ/mol降至4kJ/mol,表面活化层增厚。 相似文献
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Chaikina M. V. Sadykov V. A. Pavlova S. N. Zabolotnaya G. N. Maximovskaya R. I. Kriventsov V. V. Kochubey D. I. Burgina E. B. Roy R. Agrawal D. K. 《Journal of Materials Synthesis and Processing》2000,8(5-6):279-286
Cation- and anion-substituted zirconium phosphates of X
kZr
m
(PO4)
n–y
Y composition, where X = Na+, La3+, NH4
+, Y = F–, WO4
2–, 1/3 < k < 2, 2 < m < 4, 3 < n < 6 were synthesized by the procedure, including mechanical activation of the starting salts mixture followed by annealing at 300–900°C. The interaction between components was studied by XRD, EXAFS, FT–IR, [31P-MAS] NMR. The possibility of synthesizing nonstoichiometric compounds is demonstrated and prospects for application of the mechanochemical method for synthesis of complex zirconium phosphates are outlined. 相似文献
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核壳型复合半导体纳米粒子,作为复合半导体纳米粒子材料的一个重要分支,凭借其优异的性质,受到了广泛关注.本文主要介绍了有机/无机和无机/无机核壳型复合半导体纳米微粒及其光学性质、分类、制备方法和应用.并对其发展做了展望. 相似文献
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两亲性嵌段聚合物在选择性溶剂中的自组装行为导致其在纳米材料制备过程中具有非常好的应用前景。文中以两亲性嵌段聚合物的基本结构特点及自组装行为为出发点,概述了用于制备半导体纳米材料的两亲性嵌段聚合物的种类及特点,重点介绍了以两亲性嵌段聚合物为模板制备半导体纳米粒子的基本方法及在各种条件下半导体纳米粒子的不同生长机制,并对两亲性嵌段聚合物在制备功能化纳米材料方面的应用进行了展望。 相似文献
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通过机械化学合成方法制备了矫顽力分别为2.95×106、2.83×106和8.60×105 A/m的分散的单晶纳米Sm2Co7、SmCo5和Sm2Co17硬磁颗粒。研究了球磨时间、原料配比和退火工艺等对所制备的纳米永磁颗粒的微观组织、结构和磁性能的影响。结果表明,机械化学球磨时间至少是4h或更长时间才能获得Sm-Co硬磁合金粉末。原料经过高能球磨后、未退火时,由于大部分颗粒为非晶结构,矫顽力较低,随着退火温度的上升,矫顽力增大,当退火温度为600℃时,达到最大值为2.83×106 A/m,然后,随着退火温度的进一步升高,矫顽力减小。Sm-Co纳米颗粒的粒径随着退火温度的降低而明显减小。 相似文献
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高岭土和氢氧化铝共司粉磨时的机械力化学效应研究 总被引:4,自引:0,他引:4
罗驹华 《材料科学与工程学报》2003,21(2):266-269
本文通过SEM、XRD、DTA、FT-IR等测试手段对高岭土和氢氧化铝的高能球磨过程进行了研究。结果表明,高能球磨可以使该混合物发生明显的机械力化学变化,粉磨后颗粒形貌改变,粒径变小,晶体变成无定形态,部分化学键出现断裂。这为莫来石的低温煅烧提供了理论基础。 相似文献
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采用机械化学法制备了MnO2粉体,研究了不同高锰酸钾与乙酸锰配比对产物结构与性能的影响.用X射线衍射、红外光谱、扫描电镜、BET等方法研究了产物的结构及形貌;用恒电流充放电方法考察了MnO2超级电容器在6 mol/L KOH电解液中的电容性能.结果表明,原料中乙酸锰含量增多,产物结晶度增大,颗粒粒径变小,但电极比电容却从504F/g减小到388 F/g;当高锰酸钾:乙酸锰摩尔配比为2:2和2:3时,所得产物超级电容器在200 mA/g电流,0~1 V范围,电极放电容量分别达到了504 F/g和516 F/g.放电过程中,MnO2超级电容器在不同电压范围表现出不同的电容特性:在1~0.67 V和0.4~0 V范围内主要为双电层电容,在0.67~0.4 V范围内主要是法拉第假电容. 相似文献
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In the present study,morphology,size distribution,structure,biocompatibility and magnetic properties of potassium ferrite nanoparticles(KFeO_2 NPs),synthesized by conventional sol—gel method have been reported.The formation of spherical nanoparticles with orthorhombic structure has been confirmed by scanning electron microscopy and X-ray diffraction.The particle size,as obtained by transmission electron microscopy has been found to be in the range of 4—7 nm.Further,the size distribution has been scrutinized using Analyse-it software,where a platykurtic feature in the size distribution was observed.Fourier transform-infrared spectroscopy and thermogravimetric analysis showed the formation of metal(Fe,K) bonds at Neel temperature of 337℃.Vibrating sample magnetometer analysis revealed the superparamagnetic behaviour of the synthesized KFeO_2NPs,with saturation magnetization of 25.72 emu/g.In vitro cytotoxicity test,using MTT assay,on T cell lines(Jurkat cells) showed that KFeO_2 NPs are biocompatible at a particle concentration of 100 |j.g/ml. 相似文献
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P. Butyagin 《Journal of Materials Synthesis and Processing》2000,8(3-4):205-211
The mechanochemical synthesis was analyzed as the heterogenous solid-phase reaction, caused by the action of external mechanical forces. The efficiency of the process is controlled by two factors: chemical, G
0, and mechanical, A
S. A
s, J/m2, which expresses the work required for the contact area formation, is sensitive to the mechanical strength of the reagents and of the intermediate products formed on the intergrain boundaries. The G
0 term, mol/J(m2/g), relates to the reaction probability at the contact zones and, all other factors being equal, depends on the size ratio: the smaller the size of the guest atom in the lattice of the host component, the larger the G
0 value. 相似文献