共查询到20条相似文献,搜索用时 156 毫秒
1.
2.
Fe2O3纳米粒子的醋酸改性对其催化高氯酸铵热分解的影响 总被引:3,自引:0,他引:3
利用表面改性法对Fe2O3纳米粒子进行醋酸改性,用TEM和纳米粒度测试仪对Fe2O3纳米粒子进行了形貌和粒度表征,用FTIR和XPS对改性后的Fe2O3纳米粒子进行了结构表征,用DTA研究了醋酸改性处理对Fe2O3纳米粒子的高氯酸铵(AP)热分解催化性能的影响.结果表明,用凝胶-溶胶法制备了平均粒径为40nm,窄粒度分布的Fe2O3纳米粒子,醋酸改性处理改善了Fe2O3纳米粒子的分散性.FTIR和XPS结果表明,Fe2O3纳米粒子与醋酸分子发生了化学键合.DTA结果表明,Fe2O3纳米粒子的醋酸改性能提高Fe2O3纳米粒子的AP热分解催化性能;随着Fe2O3纳米粒子含量的增加,醋酸改性的效果越明显. 相似文献
3.
以粒度相当、分散性能相似的纳米SiO2、纳米TiO2、纳米Al2O3和纳米ZnO等4种纳米氧化物粒子为填料,采用相同工艺来改善PP-R树脂各项性能,尤其是耐热性能和力学性能.研究结果表明,纳米粒子对PP-R树脂的改性效果顺序是:纳米ZnO>纳米TiO2>纳米Al2O3>纳米SiO2;纳米氧化物粒子的极性对PP-R树脂的性能有显著影响,在排除纳米粒子的粒度、分散性和复合材料制备工艺等因素的影响前提下,纳米粒子的极性越强,改性效果越好. 相似文献
4.
5.
利用相转移法成功地合成了粒径在2~7nm的硫醇表面修饰Au纳米粒子.采用透射电子显微镜、纳米粒度分布仪、红外光谱分析仪等现代测试技术对所合成的Au纳米粒子进行了表征.结果表明,表面为硫醇所修饰的Au纳米粒子,在有机溶剂中具有很好的分散性,表面修饰层的存在不仅有效地阻止Au纳米粒子的团聚,而且使得纳米粒子粒径分布窄,粒径可控. 相似文献
6.
7.
8.
以酒石酸铜为催化剂前驱体,乙炔为碳源,采用化学气相沉积法在石墨基体上制备螺旋纳米碳纤维。通过综合热分析仪、扫描电镜、原子力显微镜和X射线衍射仪等手段对反应产物的分解温度、形貌和物相结构进行表征。结果表明:酒石酸铜热分解铜纳米粒子的初期温度为270~350℃;在450℃热分解获得的铜粒子粒径分布在40~120nm之间,分散性良好。螺旋纳米碳纤维的形貌与合成温度存在相关性,过低或过高的温度都不利于其生长,尤以450℃为最佳。在450℃制得的螺旋规则、形貌均匀,直径分布在40~120nm之间,表明分散性良好的铜催化剂粒子有利于优质螺旋纳米碳纤维的合成。 相似文献
9.
10.
11.
12.
Faiçal Kharchouche Saâd Belkhiat 《Journal of Materials Science: Materials in Electronics》2018,29(19):16238-16247
Conditions for the elaboration of varistors by spark plasma sintering (SPS) are investigated, using 70 nm zinc oxide nano-particles. For this purpose, the system constituted of zinc oxide, bismuth oxide and other metal oxide is used. Material sintering has been performed by SPS at various temperatures and dwell times. Determination of the microstructure and chemical composition of the as-prepared ceramics are characterized by scanning electron microscopy and X-ray diffraction analysis. Micro-structural analysis revealed the presence of ZnO, spinel and bismuth rich phases. ZnO based Varistor samples sintered within climb speeds 100 and 400 °C/min are compared. The nonlinear electrical characteristics, current–voltage, are measured. The breakdown voltage of the varistors strongly depends on grain sizes. The results show that the best varistors are obtained by SPS at sintering temperatures ranging from 900 to 1200 °C. 相似文献
13.
A gel was formed when a mixture of TiOCl2 and tartaric acid was heated on a water bath. Ultrafine powders of TiO2 in the anatase phase were formed, when the gel was decomposed at 623 K and the mole ratio of tartaric acid to titanium was
2. The anatase phase was converted into rutile phase on annealing at higher temperatures, > 773 K. When initial ratio of titanium
to tartaric acid was < 2, the decomposition of gel leads to the formation of mixed phases of rutile and anatase. However,
pure rutile phase was not formed by the decomposition of gel for any ratio of tartaric acid and titanium. These powders were
characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and surface area measurements. The average
particle size obtained for anatase phase was 3 nm whereas it was 30 nm for rutile phase. Raman scattering experiments were
also performed to confirm both anatase and rutile phases. 相似文献
14.
研究一种以溶胶-凝胶作为前躯体制备纳米La2O2CO3粉体的新方法,以柠檬酸和硝酸镧为原料,采用凝胶自蔓延燃烧法制备纳米La2O2CO3粉体,并利用X射线衍射、差热分析、透射电镜等手段对合成产物进行表征,确定最佳的工艺条件。结果表明:在前驱溶液的pH值为2,烘干温度为400℃,煅烧温度为600℃时,可以制备出平均晶粒尺寸为30 nm的La2O2CO3颗粒,且粉体的粒径均匀,粒径分布狭窄。 相似文献
15.
火焰CVD法制备纳米TiO_2颗粒材料的尺寸特征 总被引:3,自引:0,他引:3
用TEM图像颗粒计数的方法,研究了工业丙烷/空气火焰CVD法制备纳米TiO_2颗粒材料的尺寸特征,得到了O_2/C_3H_8摩尔比在2.5~9之间,TiCl_4质量流量在0.06~0.135g/min之间的不同操作条件下16个工况的颗粒频率尺寸分布和累积尺寸分布。测量结果表明,工业丙烷/空气火焰CVD法制备的纳米TiO_2颗粒的尺寸分布接近正态分布,平均粒径(d_(50))在15~50 nm之间、相对尺寸分布宽度在0.2~0.6之间。对平均粒径的分析结果表明,工业丙烷/空气火焰CVD法制备的纳米TiO_2颗粒的平均尺寸,和CO/O_2火焰CVD法制备的纳米TiO_2和纳米SiO_2颗粒的平均粒径与颗粒长大准数可关联为d_(50)=1.35(1十N_(grw))~(1/3)。 相似文献
16.
《Materials Letters》2005,59(29-30):4013-4015
A novel approach was employed in the fabrication of silica nanocubes with controlled size and shape. The silica nanocubes were highly dispersed with width of about 30 nm and product with high purity. A small amount of tartaric acid was introduced in the TEOS hydrolysis process. In this work tartaric acid as the organic template, was formed on the surface of hydrous silica colloidal particles. The organic template ordered by carboxyl, led to the self-assembly of amorphous silica sol encapsulated into cubic matrixes, and the organic template was packed into 3D structure. 相似文献
17.
18.
Fu B Shen Q Qian W Zeng Y Sun X Hannig M 《Journal of materials science. Materials in medicine》2005,16(9):827-831
The purpose of this study was to investigate the interfacial interaction of tartaric acid with hydroxyapatite and enamel. Hydroxyapatite particles were mixed with 15% (w/v) alcohol-aqueous (1:1) solution of tartaric acid for 72 h. After the mixture, the filtrate was separated from the solid. The filtrate, the solid, hydroxyapatite, and tartaric acid were dried for FTIR and XRD analysis. Enamel disks etched with tartaric acid for 60 s were analyzed by attenuated total reflectance (ATR). Enamel disks etched with 15% tartaric acid for 15, 30, 60, 120 s were analyzed by SEM. FTIR spectra showed carboxylate in the solid and in subtraction spectra. ATR spectra revealed carboxylate on the enamel surfaces. XRD data indicated the formation of calcium tartrate and calcium hydrogen phosphate after the reaction of tartaric acid with hydroxyapatite. SEM observations revealed typical decalcification of the periphery of the enamel rods due tartaric acid etching. It is concluded that tartaric acid can decalcify and chemisorb onto HA simultaneously, hence, tartaric acid could be used as etchant and ingredient of self-etching primers in adhesive dentistry. 相似文献
19.