共查询到19条相似文献,搜索用时 140 毫秒
1.
硫硒化锌基颜料是在硒化锌中引入硫及掺杂剂而形成的固溶体型颜料。选用化学共沉淀法合成并在真空条件下煅烧而得到颜料样品,利用X-射线衍射分析、差热分析、分光光度计等对试样进行测试。研究了硫引入后颜料的组成、结构和性质的变化。硫硒化锌基颜料中,硫取代硒而占据硒的位置使ZnSe晶格发生畸变,硫引入量较低时,主晶格仍是ZnSe,当硫引入量达到一定值时,主晶格为ZnSe和α-ZnS。硫引入引起结构上的变化,因 相似文献
3.
5.
硫硒化锌颜料制备工艺的研究 总被引:2,自引:0,他引:2
本文研究用化学共沉淀法合成硫硒化锌颜料在真空条件下煅烧,研究煅烧温度、真空度及硫硒化锌组成变化同结构和性质间的关系,确定了制备硫硒化锌颜料合理的、简单易行的生产工艺。 相似文献
6.
7.
8.
聚苯胺是一种非常有前途的导电聚合物。掺杂能提高聚苯胺的导电性、稳定性及其他性能,聚苯胺的掺杂受到了人们的广泛关注,尤其是有机酸的掺杂。有机酸种类众多且性能各异,能够使聚苯胺很多性质发生变化。本文重点综述了分别以单一有机酸、有机酸和金属氧化物、有机酸和无机酸、有机酸和其他无机物为掺杂剂合成聚苯胺的研究现状,详细介绍了各种掺杂态聚苯胺的性能及应用,简要介绍了影响聚苯胺性能的因素,并比较了不同掺杂态聚苯胺的优缺点。分析结果表明:与单一有机酸掺杂的聚苯胺相比,采用两种类型的掺杂剂共掺杂合成的聚苯胺具有更突出的性能及更大的应用前景。提出了采用两种或两种以上不同类型的掺杂剂共掺杂将是聚苯胺今后的主要研究方向。 相似文献
9.
介绍了聚吡咯制备方法及掺杂剂种类,主要综述了使用不同染料作为掺杂剂制备聚吡咯对其形貌和性能的影响,指出了目前染料掺杂聚吡咯复合材料的研究现状,并对其发展进行了展望。 相似文献
10.
《涂料技术与文摘》2016,(2)
正201602037含有导电聚合物和导电颜料的富锌环氧涂料及其防腐性能研究[刊,英]/Kalendova,Andrea等//Progress in Organic Coatings,2015,78.-1~20涉及了一种富锌有机涂料,其中的导电聚合物和导电颜料的性质,以及颜料粒子表面的导电聚合物包覆层影响其防腐蚀性能。本研究先用聚苯胺磷酸盐(PANI)、聚吡咯(PPy)、天然石墨和碳纳米管对导电聚合物防腐性能的影响进行分析。颜料体积浓度(PVC)分别按0.3%,0.5%和1%,同时采用锌粉使颜料的体积浓度/临界颜料体积浓度之比(PVC/CPVC)=0.64,以此 相似文献
11.
The effect of niobium doping on the densification and grain growth of nano-sized α-Al2O3 powders during sintering has been investigated. The dopant concentration added ranged from 0.1 to 0.5 mol%. It was observed that addition of niobium oxide could improve the densification of the pure alumina with a lower sintering temperature, a shorter sintering time. The effect is strengthened by increasing the amount of dopant. It also demonstrated that niobium dopant significantly promotes the grain growth of alumina during sintering and the grain size of alumina increases with increasing the amount of dopant in the added range. 相似文献
12.
Electrochemical assessment of the self-healing properties of Ce-doped silane solutions for the pre-treatment of galvanised steel substrates 总被引:8,自引:0,他引:8
W. Trabelsi P. Cecilio M.G.S. Ferreira M.F. Montemor 《Progress in Organic Coatings》2005,54(4):276-284
The present work aims at assessing the electrochemical behaviour of galvanised steel (GS) substrates pre-treated with bis-[triethoxysilylpropyl] tetrasulfide silane (BTESPT) doped with cerium nitrate. Furthermore, the work aims at evaluating the self-healing properties of the dopant and discussing the possible mechanisms involved in this process. The study was performed by electrochemical impedance spectroscopy (EIS) and by the scanning vibrating electrode technique (SVET), during immersion in NaCl solutions. X-ray photoelectron spectroscopy (XPS) was also used to complement the electrochemical results. The results show that the protective behaviour of the pre-treatments based on Ce-doped silane solutions is dependent on the concentration of the dopant. The results also show that the dopant improves the anti-corrosion performance of the silane coatings formed on galvanised steel substrates. 相似文献
13.
《Journal of the European Ceramic Society》2023,43(14):6260-6271
Flash Sintering has shown tremendous promise in reducing the sintering time and temperature. However, significant heterogeneity in densification and microstructure was observed in the flash-sintered sample due to hotspot formation and electrochemical effects (electrochemical blackening). In this work, we have varied the extent of electrochemical reaction by (0.75–3 mol%) ZnO addition during flash sintering of 3 mol% yttria-stabilized Zirconia (3YSZ). A substantial increase in grain size was observed throughout with an increase in dopant concentration. With the addition of 0.75 mol% ZnO dopant in 3YSZ, a significant improvement in densification and a significant reduction in the presence of cracks were observed. The extent of electrochemical blackening was seen to be increasing with the increase in dopant concentration. The blackened phase was found to be distorted tetragonal Zirconia by Raman analysis. The ZnO doped 3YSZ showed ionic to electronic transition in conduction during flash sintering likely due to electrochemical effects. 相似文献
14.
M. Kumar Mohinder Singh Chauhan M. Shaheer Akhtar Ahmad Umar 《Ceramics International》2021,47(3):3089-3098
Nanostructured ZnO doped with different Ce precursor concentrations (1, 5 and 10 mol%) has been prepared via co-precipitation method and tested for their photocatalytic and chemical sensing performances toward methyl orange (MO) and picric acid (PA) chemicals, respectively. After addition of Ce dopant, the spherical morphology of ZnO particles changed to a cone-like structure and exhibited the single-phase wurtzite structure, except for the 10 mol % dopant concentration. Blue-shift was detected in 5 mol% Ce doping, and this was found to be the optimum concentration for achieving the maximum dye degradation and sensing performances. The 5 mol% Ce doped ZnO expressed the complete MO degradation under UV light illumination, but the decrease in MO degradation with 10 mol% Ce doped ZnO was suggested to suppress the Ce3+ character in the sample. Facile redox couple Ce3+/Ce4+ appeared to improve the charge separation of Ce-doped ZnO upon UV illumination, forming the basis for release of O2, leading to increased catalytic and PA sensing performances. 相似文献
15.
主要研究不同的矿化剂对Cr-Sn红陶瓷颜料呈色、性质及制备工艺的影响,讨论矿化剂对Cr-Sn红颜料的作用机理,确定比较适合Cr-Sn红陶瓷颜料的矿化剂种类及用量。 相似文献
16.
Ulf Betke Daniel Schrake Michael Scheffler 《International Journal of Applied Ceramic Technology》2022,19(1):188-199
Open cellular ceramic foams were manufactured from plain and chromia-doped alumina, with a chromium concentration ranging between 1.25 mol% and 5.0 mol%. The (AlCr)2O3 starting powders were prepared by precipitation of a chromia precursor onto the surface of an alumina powder and subsequent calcination. Characterization of the starting powders as well as the foam samples made therefrom were carried out with respect to the chromium concentration in the alumina phase and the influence of the dopant on the cellular structure and sintering behavior of the doped material. While no positive effect on the compressive strength of the ceramic foams was found, the dopant influences the sintering behavior resulting in an increased shrinkage and in a reduction of total porosity. 相似文献
17.
《Ceramics International》2017,43(9):6677-6683
A grain growth model to describe dopant effects on nanocrystalline ceramics is proposed by incorporating the dopant-segregation-dependent grain boundary (GB) energy and the GB mobility subjected to intrinsic drag and pore drag (both affected by dopant segregation) into the parabolic growth formula. The model addresses the common case of residual porosity in grain growth behavior. Taking near-fully dense nanocrystalline lanthanum doped Yttria stabilized Zirconia (La doped YSZ) as the system of study, the grain growth behavior was explored using the model. The substantially suppressed grain growth in La doped YSZ as compared to La-free YSZ could be attributed to the combined effect of thermodynamically reduced GB energy and kinetically reduced GB mobility. Contrary to previous assumptions, the model suggests that, relative to the GB energy overall effect, the effect of the dopant on the GB mobility plays a more significant role in reducing coarsening. Furthermore, model calculation shows that both intrinsic drag and pore drag makes certain contribution to the evolution of GB mobility during the grain growth. 相似文献
18.
Chunjie Wang Yue Wang Wenzhi Huang Binglin Zou Zuhair Subhani Khan Yu Zhao Jili Yang Xueqiang Cao 《Ceramics International》2012,38(3):2087-2094
Nanopowders with cubic fluorite-type structure as well as uniform distribution in particle size were synthesized by hydrothermal method in the ternary oxide zirconia–yttria–ceria system with ceria content of 0–25 mol%. X-ray diffraction (XRD), thermogravimetric analysis/differential scanning calorimeter (TG/DSC), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (Raman), specific surface area (SBET) and high resolution transmission electron microscopy (HRTEM) were applied to characterize the structure, thermal decomposition, morphological characteristic and crystal growth of the produced powders. Qualitative analyses indicate that the as-synthesized nanoparticles are single-phase crystallites with an average particle size of 4–9 nm. The specific surface area, lattice parameter and microstrain are closely related to Ce4+ concentration. Moreover, activation energy of crystal growth is significantly dependent on the dopant (CeO2) concentration. It firstly increased and then decreased with increasing dopant concentration, and the maximum value was observed at the dopant concentration of 5 mol%. 相似文献
19.
Hung C. Ling Man F. Yan Warren W. Rhodes 《Journal of the American Ceramic Society》1991,74(2):287-289
The aging behavior of a series of lead perovskite dielectrics with the compositions x Pb(Fe2/3 W1/3 )O3 ·(1 – x )Pb(Fe1/2 -Nb1/2 )O3 , where 0 ≤ x ≤ 1, and the effect of dopants were studied. Below the Curie temperature ( T c ), the capacitance and the dissipation factor (tan δ) decrease approximately linearly with logarithmic time. The aging rate depends on the temperature difference, Δ T , between the aging temperature and T c , and on the dopant concentration, but is independent of the measurement frequency between 1 and 1000 kHz. The maximum aging rate is about 3% per decade of time for capacitance and 5% per decade for tan δ at 1 mol% dopant concentration, and increases to 6.3% for capacitance and 8.5% for tan δ at 0.7 mol% dopant concentration. These results are consistent with an aging mechanism caused by changing ferroelectric domain structure with time, as proposed for BaTiO3 . 相似文献