共查询到19条相似文献,搜索用时 46 毫秒
1.
2.
3.
用共沉淀法制备掺杂复合稳定剂CeO2-Y2O3纳米四方多晶氧化锆粉体,并讨论了pH,煅烧温度以及稳定剂的含量对所制备的粉体的组成情况和晶粒尺寸。用XRD、BET和热分析的结果表明pH≥9.5,煅烧温度为700℃左右可以获得细晶、稳定的TZP粉体。 相似文献
4.
本文利用形成纳米ZrO2粉体的前驱体的化学结构特征设计合成一种能与之发生螯合作用的新型分散剂(简称为D1),能够有效地减小颗粒尺寸,提高分散效果.采用螯合分散剂制备纳米氧化锆的最佳工艺条件为ZrOCl2·8H2O浓度1.0 mol/L,D1分散剂用量1%(ω),沉淀pH值10.0,陈化时间12 h,锻烧温度750℃,锻烧时间1 h.以稀土元素Y作晶型稳定剂,成功制备粒径超细(5~8 nm),均匀分散的四方纳米ZrO2粉体(3Y-TZP).螯合分散剂同十六烷基三甲基氯化铵,TritonX-100等常用分散剂相比,对纳米ZrO2的分散性能和颗粒尺寸的改善效果最为显著,明显优于其它几种分散剂.结果表明根据纳米粉体的化学结构设计特定的分散剂是解决纳米颗粒团聚问题的重要途径. 相似文献
5.
有机物对低温超强碱法制备纳米四方多晶氧化锆粉体性能的影响 总被引:2,自引:0,他引:2
利用低温超强碱法制备出了纳米四方多晶氧化锆粉体。为改善该粉体分散性较差、氧化钠含量较高的缺点 ,用有机物对粉体进行了表面改性处理 ,采用X射线荧光光谱、X射线衍射、透射电镜等对粉体性能进行了分析。结果表明 ,采用无水乙醇和柠檬酸铵对粉体进行改性处理 ,使得粉体粒度均匀、分布变窄 ,形态近球形 ,其中柠檬酸铵的处理效果尤为显著 ,使粉体平均粒径从 0 .6 9μm减小到 0 .5 4μm ;进一步的高分辨像分析结果表明 ,粉体颗粒多由 2~ 3个大小为 2 0~ 30nm的单晶组成 ,较大的团聚体较少 ,因此有机物对粉体的表面改性处理有利于获得分散性好、粒度均匀的高质量纳米氧化锆粉体。 相似文献
6.
7.
低温超强碱法制备引入有机添加剂的纳米四方多晶氧化锆粉体及其性能 总被引:1,自引:1,他引:0
采用引入有机添加剂的低温超强碱法,控制适当的工艺条件,得到了室温稳定的纳米四方/立方多晶氧化锆粉体。采用X射线荧光光谱、X射线衍射、透射电镜、粒度分析仪等手段对粉体性能进行了表征。实验结果表明:该粉体在室温和小于873K热处理时,均以稳定的立方或四方相存在,粉体粒径为9nm左右。在1123K处理的粉体分散性好、粒度小、粒度分布较窄,粉体颗粒的平均粒径为0.46μm。所制备的粉体具有纯度高、氯离子等杂质少等特点。与其它湿化学法相比,加入有机添加剂的低温超强碱法具有工艺操作简单、节约资源和环境污染小的优点。 相似文献
8.
9.
10.
纳米TiO2粉体的分散性研究 总被引:6,自引:0,他引:6
综述了自2000年以来纳米TiO2粉体在制备及分散性方面的研究及进展,比较了不同制备方法、分散剂及分散设备对粉体分散性的影响。本文的主要目的是通过对影响分散的各个因素做系统的比较总结,找出合适的分散条件,为TiO2改性等工作做好准备,得出水热合成法和微乳液法、无机与有机高分子聚电解质复合型分散体系,表面改性是最好的合成工艺过程。提出未来纳米TiO2分散的研究方向。 相似文献
11.
Sitian Zang Ningxiang He Xiaoting Sun Mingyue Sun Weiwei Wu Huazhe Yang 《Ceramics International》2019,45(1):394-400
A comprehensive study on the influence of typical additives on zirconia (ZrO2) crystallization was presented. Zirconium nitrate pentahydrate (Zr(NO3)4·5H2O) and cerium(III) nitrate hexahydrate (Ce(NO3)3·6H2O) were employed as reagents, ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) or glycerol were adopted as additives, and ammonia water was adopted as pH regulator. The ZrO2 powders were prepared by hydrothermal method. The crystal phase purity, grain size and micro morphology of the ZrO2 powders were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS) to investigate the influence of EDTA-2Na, glycerol and Ce4+ content on the purity of tetragonal phase and the grain size of ceria-stabilized tetragonal zirconia polycrystals (Ce-TZP). It was found that EDTA-2Na could decrease the purity of tetragonal phase and alter the grain size of Ce-TZP nonlinearly, while glycerol could not decrease the purity of tetragonal phase and the grain size of Ce-TZP, and the grain size was not linear with the amount of glycerol; Doping Ce4+ could increase the purity of tetragonal phase of zirconia but could not decrease the grain size, and the grain size was not linear with the Ce4+ content; In addition, it was indicated that EDTA-2Na and glycerol could not improve the distribution uniformity of Ce4+. This study is expected to have provided a novel path to achieve tailored ZrO2 crystals with reduced low-temperature degradation. 相似文献
12.
Cubic phase spherical zirconia nano-powderwas prepared by a direct template route in the lamellar liquid crystal formed by polyoxyethylene tert-octylphenyl ether (Triton X-100)/sodium dodecyl sulfate (SDS)/H2O. The precursor powder and zirconia powder were characterized by XRD, FT-IR, TG/DSC, TEM, and SEM methods. Results show that the stability of the lamellar liquid crystal is controlled by NH3 · H2O concentration. The size of nanoparticles is greatly affected by NH3·H2Oand ZrOCl2 · 8H2O concentrations. The zirconia nanoparticles shownarrow particle size distribution of 10-30 nm. 相似文献
13.
刚玉-尖晶石-铝酸钙悬浮液流变特性的研究 总被引:2,自引:1,他引:1
用NXS-11型旋转粘度计对刚玉-尖晶石-铝酸钙粉体与水组成的悬浮液流变特性进行了研究。试验结果表明:在适当的铝酸钙水泥加入量下,超细粉(<2μm)/细粉(<0.088mm)重量比为0.43时,采用聚磷酸盐分散剂并控制其加入量,可使刚玉-尖晶石质浇注料的基质具有最佳的流变特性。 相似文献
14.
15.
16.
《Ceramics International》2020,46(6):7161-7169
Zirconia ceramics are promising restorative materials that are being extensively used in clinical dental prosthodontics such as inlays, implant crowns and fixed bridges due to their high strength, high toughness, high corrosion resistance and excellent esthetical effects. However, in addition to the superior mechanical and physical properties, the biocompatibility is a more important index to evaluate the performance of the ceramic implant dentures. The aim of the current work is to improve the biocompatibility of zirconia ceramic implants by surface modification. To achieve this goal, a bionic design method was used to imitate the natural human perikymata structure and a series of microtextures were fabricated on the zirconia surfaces by the picosecond laser processing. The effectiveness of the microtextures on the biocompatibility of zirconia ceramics was quantified in terms of the contact angle, the friction coefficient and the surface wear signatures. The results indicate that the laser texturing has a significant effect on the wettability and the tribological behavior of zirconia ceramic dental implants. To improve the biocompatibility of the zirconia ceramic implants, a smaller groove width with an appropriate groove depth is favorable. 相似文献
17.
氮化硅粉体水基悬浮液电动特性的研究 总被引:1,自引:0,他引:1
通过测量氮化硅粉体在水溶液中的Zeta电位和颗粒大小j研究了不同条件下氮化硅水基悬浮液的电动特性。结果表明,溶液的pH值以及引入的聚合电解质不同均会使氮化硅颗粒表面的荷电状态发生变化,进而导致粉体在水溶液中的分散状况发生改变.在碱性条件下添加适量的阴离子聚电解质有利于氮化硅水基悬浮液的稳定分散。 相似文献
18.