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纳米氧化锌制备方法比较 总被引:12,自引:0,他引:12
介绍以不同方法制备纳米ZnO,采用XRD,TEM等测试手段对纳米级的粉体结构和形貌进行的研究,重点探讨了不同方法对合成纳米晶粒大小的影响。实验表明:尿素均匀沉淀法、草酸和碳酸钠直接沉淀法、室温固相法均可得到纳米氧化锌,但以尿素沉淀法产品平均粒径最小,碳酸钠沉淀法次之;并且这两种方法易于工业化生产。 相似文献
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以硫酸锌和草酸为原料,采用超声波沉淀法,研究了不同粒径的纳米氧化锌的制备,讨论了不同工艺条件对粒径的影响规律。实验结果表明,采用超声波沉淀法可以制备出平均粒径为21~47nm的纳米氧化锌;反应条件对纳米氧化锌的粒径有显著影响:纳米氧化锌的粒径随草酸与硫酸锌配比的增大而增大,而随反应温度的升高而减小;并且沉淀剂的加入方式对所制备的纳米氧化锌的粒度也有较大影响:一次性将草酸沉淀剂倾倒入锌盐溶液比缓慢滴加所得微粒的粒径较小。 相似文献
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在浸没循环撞击流反应器中,以纯碱与硝酸锌反应-沉淀制得前驱体,经煅烧后得到纳米氧化锌产品。通过正交设计实验研究了Zn(NO3)2浓度、反应温度、反应时间、Na2CO3与Zn(NO3)2摩尔比等因素对产品收率的影响。初步确定了制备纳米氧化锌的最优工艺条件:Zn(NO3)2浓度1.5 mol/L,反应温度60℃,反应时间1 h,Na2CO3与Zn(NO3)2摩尔比1.3∶1;该条件下锌收率可达94%。制得的氧化锌产品经XRD表征,其纯度较高;经TEM表征,其形貌为球形或接近球形;在最优工艺条件下制取的产品平均粒径为20 nm。建立了相关工艺条件与产品收率的数学关系式。 相似文献
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Erjun Tang Baoyong Tian Erli Zheng Cuiyan Fu Guoxiang Cheng 《Chemical Engineering Communications》2013,200(5):479-491
Zinc oxide nanoparticles were prepared by uniform precipitation using urea hydrolysis. The ZnO precursor was slowly deposited from aqueous solution. Anionic surfactant was added into solution to block ZnO crystal growth and its agglomeration. Then ZnO nanoparticles were synthesized by the calcination of the precursor at high temperature. Transmission electron microscope (TEM) observation and particle size analyzer demonstrated that the ZnO nanoparticle exhibited nearly spheric shape with 10–40 nm particle size. The surface of the ZnO nanoparticle was modified by methacryloxypropyltrimethoxysilane (MPS). FT-IR (Fourier transform-infrared spectrophotometry) and XPS (X-ray photoelectron spectrophotometry) revealed that MPS was grafted onto the zinc oxide nanoparticle. XRD (X-ray diffraction) showed that the ZnO nanoparticle was a hexagonal crystal with a perfect crystalline structure, and its crystalline morphology was not altered through surface modification. The activation index (AI) of the modified ZnO nanoparticle was measured. It was found that the surface of the ZnO nanoparticle was changed from hydrophilicity into hydrophobicity via surface modification, implying the enhancement of its compatibility with organic polymers. FE-SEM (field scanning electron microscopy) showed that the modified ZnO nanoparticles were homogeneously dispersed in PVC matrices. Consequently, ZnO nanoparticles were integrated with PVC matrices by the grafting organic molecule. 相似文献
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Erjun Tang Baoyong Tian Erli Zheng Cuiyan Fu Guoxiang Cheng 《Chemical Engineering Communications》2008,195(5):479-491
Zinc oxide nanoparticles were prepared by uniform precipitation using urea hydrolysis. The ZnO precursor was slowly deposited from aqueous solution. Anionic surfactant was added into solution to block ZnO crystal growth and its agglomeration. Then ZnO nanoparticles were synthesized by the calcination of the precursor at high temperature. Transmission electron microscope (TEM) observation and particle size analyzer demonstrated that the ZnO nanoparticle exhibited nearly spheric shape with 10-40 nm particle size. The surface of the ZnO nanoparticle was modified by methacryloxypropyltrimethoxysilane (MPS). FT-IR (Fourier transform-infrared spectrophotometry) and XPS (X-ray photoelectron spectrophotometry) revealed that MPS was grafted onto the zinc oxide nanoparticle. XRD (X-ray diffraction) showed that the ZnO nanoparticle was a hexagonal crystal with a perfect crystalline structure, and its crystalline morphology was not altered through surface modification. The activation index (AI) of the modified ZnO nanoparticle was measured. It was found that the surface of the ZnO nanoparticle was changed from hydrophilicity into hydrophobicity via surface modification, implying the enhancement of its compatibility with organic polymers. FE-SEM (field scanning electron microscopy) showed that the modified ZnO nanoparticles were homogeneously dispersed in PVC matrices. Consequently, ZnO nanoparticles were integrated with PVC matrices by the grafting organic molecule. 相似文献
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高分子网络凝胶法制备纳米氧化锌的工艺控制 总被引:1,自引:0,他引:1
以乙酸锌[Zn(Ac)2]为原料,丙烯酰胺(AM)为单体,N,'N'-亚甲基双丙烯酰胺(MABM)为网络剂,采用高分子网络凝胶法制备了纳米ZnO粉体,研究了其制备过程中反应物浓度、引发剂(NH4)2S2O8含量、溶液的pH值及备反应条件对纳米ZnO晶粒尺寸的影响.X射线衍射分析结果表明:纳米ZnO颗粒的平均晶粒大小随Zn2+起始浓度引发剂含量的增加而增加,随溶液pH值的增加而减小.确定了用高分子网络凝胶法制备纳米ZnO粉体的最佳工艺参数为:反应温度80℃;反应时间2h:干燥温度100℃:干燥时间4h. 相似文献
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燃烧法合成高纯β-SiC超细粉的工艺参数 总被引:1,自引:0,他引:1
以硅粉、碳黑、活性炭为原料,以聚四氟乙烯为添加剂,在氮气中分别用直接燃烧合成和预热燃烧合成工艺制备了高纯β-SiC微粉.用扫描电镜测得产物呈等轴球形,平均粒径为100 nm.添加剂聚四氟乙烯的质量分数(下同)为5%以上时,均可以直接点燃合成高纯度亚微米级的β-SiC,2%的添加剂就可以使理论预热温度由1 023 K降到673 K,降低了成本.另外,以活性炭代替碳黑为原料,对比了硅和碳的摩尔比为1:1和1:1.25的2个配方对产物物相的影响,说明用足够纯净的活性炭为原料代替碳黑制备β-SiC是可行的.将预热法、氮气助燃法以及化学活化法成功的进行了结合,布料方式由以往的压块改为直接粉状布料,且在60L燃烧合成反应器中单炉装料1 kg条件下,合成了高纯度的户sic粉体,适应了中试生产的需要. 相似文献
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氨浸法从含砷粗氧化锌制活性氧化锌研究 总被引:2,自引:2,他引:2
在碱性氨浸法处理含有砷、铅的低级氧化锌制取活性氧化锌的工艺中,引入铁盐除砷方法,解决了氨浸法生产活性氧化锌中除砷的问题,对于含砷1%~2%的原料,产品中的砷含量可降低至0.0005以下,本方法还为含砷的铜、镍、钴废料的利用提供了参考途径。 相似文献
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为了研究ZnO压敏电阻组成中非化学配比氧化物对ZnO压敏电阻导电性能的影响,采用在不同氧分压条件下烧结样品以研究其烧结行为。结果表明:ZnO晶粒的电导率对数与氧分压对数成线性关系;斜率为-1/4;间隙Zn原子以一价电离Zni形式存在。由于CoO,MnO和NiO阳离子空位氧化物多偏析于晶界,晶界处氧的增加有利于降低压敏电阻漏电流,烧结时间从2h延长到8h,漏电流从5μA/cm^2降到3.6μA/cm^2。波谱分析表明:掺杂氧化物在晶界处都有偏析,ZnO晶粒中掺杂原子混溶比例不完全与掺杂阳离子半径相关。 相似文献