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1.
Ferrites and chromites of Ni and Co synthesised by solid reaction method are usually used as black colour ceramic pigments. Due to the presence of Co and Ni in their composition they are classified as harmful substances. In this work, Co, Cr and Fe have been partially substituted by harmless Mg and Al ions, and the optimised compositions have also been synthesised by coprecipitation and gel polymeric route. Samples obtained have been characterised by CIEL*a*b colour parameters, XRD, DTA-TG, and SEM-EDAX techniques. Samples obtained by gel polymeric route presents the best reactivity and black colouring results.  相似文献   

2.
以甲苯-2,4-二氨基甲酸甲酯(2,4-TDC)为分子探针模型,构建了一种新的评价金红石二氧化钛颜料紫外屏蔽性能的反应体系,系统地考察了反应条件对分子探针光降解的影响,并对一系列二氧化钛颜料紫外屏蔽性能进行了对比研究。结果表明,金红石二氧化钛作用下,2,4-TDC光降解过程符合一级反应动力学;随着二氧化钛颜料用量的增加,2,4-TDC光降解速率常数呈现指数次下降趋势;紫外光照下表面包覆的金红石二氧化钛颜料不能完全抑制·OH和h+活性物种的产生。根据2,4-TDC的光降解速率常数,能体现一系列工业金红石二氧化钛颜料紫外屏蔽性能差异。该方法具有条件温和、操作简便、实验周期短、结果重现性好等优点,将在二氧化钛颜料的紫外屏蔽性能测试中具有潜在的应用价值。  相似文献   

3.
Using the Pechini method, pigments with spinel structure (Zn7Sb2O12)were synthesized by substitution of the cation Zn2+ by Co2+, in compounds with different concentrations of Sb2O3. The doping resulted in CoxZn(7–x)Sb2O12 phases(x=1–7) that were isomorphs to spinel, denominated as samples A and B. After thermal treatment at 400°C for 1 h, the powders were characterized by thermogravimetry(TG) and differential thermal analysis (DTA). The results indicate a different behavior whena higher amount of Sb2O3 is used, due to the presence of a secondary phase (ilmenite). This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

4.
In this study, Fe x Ti1–2x M x O2 (M=Nb, Ta) rutile solid solutions have been synthesized from gels made from Fe(III) acetylacetonate, NbCl5, TaCl5, Ta(V) ethoxide, TiCl4 and Ti(IV) isopropoxide. The results obtained are compared with those obtained by the ceramic method. The solid solutions synthesized from gels were obtained at lower temperatures than these synthesized by the ceramic method.  相似文献   

5.
A procedure is reported for the preparation of vanadium-doped zircon pigmenting system with different vanadia loadings which enabled their complete formation and further characterization. Vanadium-zircon solid solutions were prepared by gelling mixtures of ZrO2 and V2O5 colloidal sols and tetraethylorthosilicate and studied over the temperature range up to the formation of zircon. The reaction sequence of gels was evaluated by X-ray powder diffraction (XRD) and ultraviolet-visible (UV-Vis) diffuse reflectance. It was found that the first crystalline phase detected was a vanadium-containing tetragonal ZrO2 solid solution where vanadium was stabilized in the reduced V+4 state. The formation of the V-ZrSiO4 solid solution occurred by the reaction between the monoclinic form of V+4-ZrO2 solid solution and the amorphous silica phase. Energy dispersive X-ray microanalysis (SEM/EDX) data, measurements of lattice parameters and UV-Vis diffuse reflectance of V-ZrSiO4 solid solutions revealed that vanadium was dissolved as V+4 replacing Si+4 in tetrahedral sites in the crystal structure of zircon. The solubility limit of vanadium in ZrSiO4 was about 0.01 mole of vanadium per mole of zircon (0.5 wt% as V2O5).  相似文献   

6.
The study was focused on the performance of rutile addition in glaze composition for antibacterial application. Rutile powder in micro size (ξηзm) were added in the glaze composition at different weight percentage (5 wt%, 7 wt%, 9 wt%, 10 wt% and 15 wt%). Glazing was performed by dipping technique for 10 seconds. Glazed tile was then sintered at 1200 °C for 1 hour. Characterizations used to observe the properties of produced tiles were physical observation, scanning electron microscopy (SEM) and modulus of rupture. Results show that cracking occurred in glazed tile which could be related to the viscosity of the glaze mixture during dipping. The relation between viscosity and the occurrence of crack depend on the amount of rutile The amount of crack appearance increases with increasing glaze viscosity. However, modulus of rupture increased when the tile was glazed.  相似文献   

7.
化学镀镍-高磷合金的微观结构及晶化行为研究   总被引:8,自引:0,他引:8  
分别以SnCl2.2H2O和SnCl2.5H2O为锡源,采用胶溶晶核法,经沉淀和胶溶过程,在液相中一步合成了金红石型TiO2。详细考察了各种胶溶条件对产物结构的影响,并通过两种锡源实验结果的比较对异相晶核法中两种锡源的成晶机理进行了分析,所合成的金红石型TiO2晶粒度为20-50nm,两种方法获得完全红金石型TiO2所需引入SnO2的最低物质的量的分数分别为10%和8%。  相似文献   

8.
微乳液法低温制备纳米金红石型二氧化钛的研究   总被引:1,自引:0,他引:1  
以TiCl4为原料、在十六烷基三甲基溴化铵/正己醇/水组成的微乳液体系中、在较低温度下,制备了球形、花状、捆绑丝和星形的金红石型二氧化钛纳米颗粒。研究了w值(水与CTAB物质的量之比)、反应物浓度、反应温度以及P值(正己醇与CTAB的物质的量之比)等因素对产品形貌的影响,并用TEM、XRD对产品进行了表征。  相似文献   

9.
分别以SnCl2·2H2O和SnCl4·5H2O为锡源,采用胶溶晶核法,经沉淀和胶溶过程,在液相中一步合成了金红石型TiO2.详细考察了各种胶溶条件对产物结构的影响,并通过两种锡源实验结果的比较对异相晶核法中两种锡源的成晶机理进行了分析.所合成的金红石型TiO2晶粒度为20~50nm,两种方法获得完全金红石型TiO2所需引入SnO2的最低物质的量的分数分别为10%和8%.  相似文献   

10.
Thephotoconductivepr0pertiesofazocomPoundswerereportedasearlyasl969byR..'wh00bservedphotocurrentsfromthinlayersofl-phenylazonaPhthol.Fromthenon,thousandsofpigmelltsofavarietyofstrUctufeshavebeensynthesisedandstudied.'ThepigmentswhichabsorbandphotorespondinthevisibleregionarenotusableinthexerograPhicprintersWhichusethelongwavelengthilluIninat0rs,suchaslight-eIinttingdiodes(660-7OOnm)andsolidstatediodelasers(7OO-85OIUn.Sotheneedforlaseraddressablephotoconductorsis0bviousandthevariousstrUct…  相似文献   

11.
双偶氮染料光致增色性质及光电导性研究   总被引:7,自引:0,他引:7  
自Rau[1]首次报道偶氮染料具有光电导性质以来,偶氮染料一直被作为有应用价值的光电导材料而受到人们的重视[2].特别是近年来发现,偶氮染料具有优良的光存储性能,引起了人们的极大兴趣[3].但由于一般的偶氮染料吸收波长较短,难与目前普遍使用的激光器波长响应相匹配,从而限制了其使用.因此,如何从分子设计的角度使偶氮染料的吸收向长波方向移动,是目前国际上研究的热点[4,5].Law等[5]合成了一些二氨基芴酮与萘酚偶合的双偶氮染料,研究了扩大萘酚萘环共轭体系时其吸收的变化情况.本文合成了几个新的双偶氮染料,研究了茶酚酸…  相似文献   

12.
制备具有光催化活性的金红石相纳米氧化钛粉体   总被引:25,自引:1,他引:25  
孙静  高濂  张青红 《化学学报》2003,61(1):74-77
以TiCl4为原料,通过控制盐浓度和水解温度可以在温和条件下制备出晶粒尺 寸为6nm的金红石相氧化钛粉体,比表面积为175m^2/g。测定了粉体的X衍射、红外 和拉曼光谱。TEM照片显示粉体呈放射状颗粒,其粒径尺寸在200-400nm。苯酚的 光催化降解实验表明它比具有相同比表面积的锐钛矿粉体有更高的光催化活性。其 较大的团聚颗粒尺寸有利于光催化反应后的分离。  相似文献   

13.
利用合成色素随pH变化的人分布分数曲线和吸收光谱构成两维波谱信息,建立了灰色体系中色素的定量分析方法。约束背景双线性分解法(CBBL)结合数值遗传算法(NGA)用于两维矩阵的数据处理。推导了型体总数与两维矩阵的有效秩之间的关系。吸光度矩阵的主成分数根据残余矩阵的残差平方和噪声水平相比较 确定,对标准样品及模拟灰色体系样品的研究表明该法确定的主成分数与理论值一致。对胭脂红、日落黄和柠檬黄的模拟灰色休  相似文献   

14.
The preparation of rutile type solid solutions in (TiO2)x -(RuO2)1−x system in the 0≤x ≤0.7 concentration range is described. The single phase solid solutions are formed by controlled nanocrystallization of amorphous gels prepared by the sol-gel method. The kinetics of this crystallization process has been analyzed. It was found that the crystallization does not correspond to the Johnson-Mehl-Avrami model and it can be described by the two-parameter Šesták-Berggren kinetic model. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

15.
均相水解法制备金红石含量可控的纳米TiO2   总被引:6,自引:0,他引:6  
刘威  陈爱平  林嘉平  戴智明  邱炜  刘伟  朱孟钦  臼田昭司 《化学学报》2004,62(12):1148-1152,MJ04
用均相水解法通过调节对甲苯磺酸的添加量制备了金红石含量线性可控的纳米TiO2粒子,相同条件下,没有加入对甲苯磺酸时,制备的TiO02颗粒为纯锐钛矿晶型.制备的纳米TiO2颗粒,其单晶尺寸为19.5mm(金红石),13.5mm(锐钛矿),比表面积72.7m^2/g,通过公式计算得到了制备的TiO2纳米颗粒带隙能为2.83eV,比P25和纯锐钛矿纳米TiO2颗粒的带隙能均低.  相似文献   

16.
The synthesis of new compounds based on CeO2 is investigated in our laboratory. The main attention is directed to the preparation of these compounds which can be used as pigments for colouring of ceramic glazes. The synthesis of these compounds is based on high-temperature calcination of starting oxides. The optimum conditions for the syntheses of compounds have been estimated and the pigments prepared have been evaluated from the standpoint of their structure. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

17.
为了提高 BaTiO3的室温介电常数和减少介电损失,目前工业上在电子元器件的制造过程中,采用固相掺杂方法,于 BaTiO3粉体中掺入适量锶、锆、锡和一些稀土元素的氧化物,以改善其性能。但由于固相掺杂的不均匀性,使得元器件的各项参数改善并不理想 [1]。近几年国外虽有用 Sol Gel法对 BaTiO3进行掺杂改性的研究 [2],但却因为原材料价格昂贵而无法在我国生产。为此,本文率先用湿化学合成方法,在 100℃以下水溶液中对 BaTiO3进行了掺杂改性,使掺杂离子均匀进入母体晶格,合成了一系列 BaTiO3基固溶体纳米粉末,并对其介电特性进…  相似文献   

18.
新型SiBNC陶瓷先驱体——聚硼硅氮烷的合成与表征   总被引:5,自引:1,他引:5  
唐云  王军  李效东  李文华  王浩  谢征芳 《化学学报》2008,66(11):1371-1376
以甲基氢二氯硅烷、三氯化硼、六甲基二硅氮烷为起始原料, 采用共缩合的方法合成了一种新型的可溶可熔的SiBNC陶瓷先驱体--聚硼硅氮烷(PBSZ). 该法合成工艺简单, 且合成收率约为91% (w%). 采用元素分析、傅立叶红外光谱、核磁共振波谱、X射线光电子能谱、动态热机械分析、热重分析等对PBSZ的组成、结构和性能进行了表征. 结果表明, 先驱体的主要骨架为-Si-N-B-, 其中, B, N以硼氮六环形式存在, 而C则以Si-CH3形式存在. 该先驱体熔点为69 ℃, 数均分子量为10802, 分子量分散系数为1.50. 此外, 所合成的先驱体具有优良的成型性, 在80 ℃的N2气氛中可纺丝得到15~20 μm的有机纤维, 1000 ℃时相应陶瓷产率约为63% (w%).  相似文献   

19.
Ceramic ultrafiltration and nanofiltration membranes (TiO2) are prepared by sol-gel route using a special arrangement which allows the reaction of the reactants directly in the pores of a tubular Al2O3 support or on its surface, respectively. By this direct synthesis the number of technological steps can be reduced which is the main advantage of the method. The produced layers are well joined with the Al2O3 support and the reaction can be adjusted by various technological parameters. The dried and sintered coatings are characterized by X-Ray diffraction, FESEM and AFM. In addition, pore size distribution and filtration properties are investigated and discussed.  相似文献   

20.
含脱氢松香酸骨架的吖啶染料的合成及其理化性质研究   总被引:1,自引:0,他引:1  
以脱氢松香酸为原料,经甲酯化、硝化、还原、关环和水解等多步合成了三个松香基吖啶酮化合物7a~7c.通过1HNMR,13C NMR,MS和IR等表征手段对产物结构进行了表征,并采用紫外-可见分光光度法对化介物的理化性质进行研究.  相似文献   

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