共查询到19条相似文献,搜索用时 93 毫秒
1.
2.
微波干燥制备Al2O3纳米粉体的研究 总被引:1,自引:0,他引:1
以AlCl3和NH3·H2O为原料,采用沉淀法制备Al2O3纳米粉体,利用XRD、TEM、DTA等分析测试手段对所得Al2O3粉体的晶相组成、粒径分布等性质进行了研究,发现微波处理10分钟后在550℃加热30分钟即可得到平均粒径小于35纳米的Al2O3纳米粉体。 相似文献
3.
4.
以Ti(SO4)2水溶液为前驱物,尿素为沉淀剂,采用水热沉淀法制备TiO2纳米粉体.利用XRD、TEM、DTA等分析测试手段对所得TiO2粉体的晶相组成、晶体形貌等性质进行了研究,讨论了晶粒尺寸与前驱物摩尔比、反应温度、保温时间之间的关系.结果表明,前驱物摩尔比为1∶2~1∶4,在140~200℃保温2~6h的水热条件下,可制得粒径为十几纳米的锐钛矿型TiO2晶体.实验得出,随着前驱物摩尔比减少、反应温度升高、保温时间延长,晶体粒径增大. 相似文献
5.
6.
7.
8.
利用微波介电加热和微波干燥水解法制备TiO2微粒 总被引:4,自引:0,他引:4
利用微波介电加热和微波干燥条件下TiCl4直接水解的方法制备出平均尺寸为40m,粒径分布窄,均为球形且形态均一,团聚较少,金红石型的TiO2纳米粒子,其内部品粒平均大小为17nm。而传统加热和干燥条件下形成的纳米微粒平均为60nm,粒经大小不均一,形态较不规则,团聚严重。微波加热和干燥方法具有清洁、快速均匀高效、环境友好的优点,推广前景良好。TiCl4水解法经济便利,适于工业化生产。 相似文献
9.
本文用超临界二氧化碳萃取(干燥)法制备TiO2气凝胶,并有XRD,FT-IR对制备的气凝胶粒子进行表征,所得粒子粒径为3.3nm,干燥过程时间为5h。 相似文献
10.
11.
12.
撞击流反应-沉淀法制取纳米二氧化钛影响因素的实验研究 总被引:2,自引:0,他引:2
采用浸没循环撞击流反应(SCISR),通过四氯化钛快速水解沉淀法制备了纳米二氧化钛,研究了浓度、温度、转速、中和时间、煅烧温度以及煅烧时间等因素对纳米二氧化钛粒径的影响。 相似文献
13.
反胶团法制备氧化钛超滤膜的研究 总被引:2,自引:0,他引:2
采用新型的反胶团法制备了氧化钛超滤膜。实验以钛酸丁脂、水、环己烷、异戊醇及表面活性剂Span-80等为原料,通过控制水量制得三种粒径分布的氧化钛反胶团微乳液。TEM照片表明,TiO2反胶团粒子随着[H2O]/[Span-80]由13.9增加到55.5而增大,但当[H2O]/[Span-80]增加到110.9时TiO2反胶团粒子反而减小。BET法结果与TEM照片一致,而且表明[H2O]/[Span-80]为110.9的TiO2反胶团微乳液所制得的无支撑膜孔径分布最窄、最可几孔径约为4.5nm。采用该种微乳液所制得的氧化钛支撑膜的最可几孔径约为16nm, 纯水渗透率为1.57×10-4m3(m2sMPa)-1;常温下N2、H2渗透率分别为4.3mol (m2sMPa)-1和14.1mol(m2sMPa)-1,表明所得TiO2分离层较完整。 相似文献
14.
15.
Initial Sintering of Submicrometer Titania Anatase Powder 总被引:1,自引:0,他引:1
Jean-Luc Hébrard Patrice Nortier Michèle Pijolat Michel Soustelle 《Journal of the American Ceramic Society》1990,73(1):79-84
Measurements of surface area reduction of TiO2 anatase powder (of initially 100 m2 · g−1 ) were carried out for various partial pressures of water and oxygen at 823 K. The kinetic equation obtained for the experimental rates has the formulation r = k[P H2O ]1/α [ P O2 ]1/β where α and β are equal to 2 and -12, respectively. A mechanistic model involving six consecutive elementary steps was developed, in which hydroxyl species play a dominant role. No geometrical assumption is required. The general expression of the deduced theoretical rates has the same form as previously given. The comparison between the experimental and the predicted rates points out that the rate-limiting step is the surface diffusion of hydroxyl species. This model can easily be used for any other compounds, for particle growth, and for porosity elimination. 相似文献
16.
17.
以乙炔炭黑和硅粉为原料,采用微波烧结技术合成制备了粒度不同的碳化硅粉体.研究了反应温度和保温时间对碳化硅粉体产率和粒度的影响.结果表明:在900℃反应30 min,所得产物的主要物相为β-SiC和仍残余少量金属Si.随着反应温度的升高,产物中SiC的含量不断增加,残余金属Si的含量则明显下降.当反应温度升高至1100℃以上时,则得到单相的β-SiC.在1200℃下反应5min,产物中主要物相为SiC,存在着少量未反应的金属Si,当反应时间延长到15 min时,即得到单相的β-SiC. 相似文献
18.
Highly crystalline TiO2 nanostructures were prepared through a facile inorganic acid-assisted hydrothermal treatment of hexagonal-structured assemblies of nanocrystalline titiania templated by cetyltrimethylammonium bromide (Hex-ncTiO2/CTAB Nanoskeleton) as starting materials. All samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The influence of hydrochloric acid concentration on the morphology, crystalline and the formation of the nanostructures were investigated. We found that the morphology and crystalline phase strongly depended on the hydrochloric acid concentrations. More importantly, crystalline phase was closely related to the morphology of TiO2 nanostructure. Nanoparticles were polycrystalline anatase phase, and aligned nanorods were single crystalline rutile phase. Possible formation mechanisms of TiO2 nanostructures with various crystalline phases and morphologies were proposed. 相似文献