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ZrO2和Al2O3在金红石型TiO2表面的包覆研究 总被引:3,自引:0,他引:3
以(NaPO3)6为分散剂,用化学沉积法对金红石型TiO2进行了锆、铝氧化物包膜。研究了包覆过程中,TiO2的分散、ZrO2和Al2O3用量、反应pH值以及时间对二氧化钛的亨特白度(Wh)和光泽度(L)的影响,并采用扫描电镜(SEM)、透射电镜(TEM)、X光电子能谱(XPS)和沉降性试验对包覆前后的二氧化钛进行了表征,得到包锆、包铝氧化物的优化工艺条件。研究了二氧化钛表面包锆、铝氧化物的包覆机理和表面结构。经过其表面包膜处理,二氧化钛的颜料性能得到明显改善。 相似文献
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聚合物结构对包膜缓释肥缓释性能的影响 总被引:2,自引:0,他引:2
研发和使用缓控释肥能有效解决普通肥料利用率低以及由于化肥使用过量而引起的环境问题。聚合物包膜型缓控释肥是缓控释肥中的一种,影响其缓释性能的因素如环境因素、包膜厚度、加工工艺等,前人已研究较多。聚合物结构对于缓释性能的影响也很重要,而这方面研究较少。本文主要讨论了聚合物结晶性、分子亲疏水性、分子链柔顺性、交联等结构因素对缓释性能的影响。深入研究聚合物结构对缓释性能的影响有助于缓控释材料的创新;能为聚合物包膜材料的设计、聚合物缓控释肥的研发及生产提供一定的理论依据。 相似文献
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对利用硫铁矿烧渣制备氧化铁黄和氧化铁红进行了研究。考察了影响硫铁矿烧渣还原、酸溶、中和、氧化等过程的各种因素。结果表明,在适宜的条件下,利用烧渣可以制备出用做颜料的氧化铁黄和氧化铁红。 相似文献
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盐酸曲马多药物树脂制备技术的研究 总被引:3,自引:0,他引:3
采用静态法和动态法和工艺制备盐酸曲马多药物树脂,并对制备过程中体系温度,反应时间,药物溶液浓度,溶液流速等影响因素进行了研究;以正交设计对工艺进行优化。 相似文献
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盐酸曲马多药物树脂制备技术的研究 总被引:1,自引:0,他引:1
采用静态法和动态法两种工艺制备盐酸曲马多药物树脂,并对制备过程中体系温度、反应时间、药物溶液浓度、溶液流速等影响因素进行了研究;以正交设计对工艺进行优化。 相似文献
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M. V. Vasekha 《Russian Journal of Applied Chemistry》2012,85(6):888-891
Possibility was examined of using spent solutions of sulfur dioxide gas sorbents, together with sodium sulfite and pyrosulfite, for conversion of iron hydrate wastes produced by copper-nickel industries to red iron oxide pigment. 相似文献
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采用浸泡实验, 电化学测试和表面分析技术研究了硫酸根离子浓度对铁在稀碳酸氢钠溶液中开路状态和阳极极化行为的影响. 在无硫酸根离子及含有少量硫酸根离子的碳酸氢钠溶液中, 铁的开路电位约为(-0.225±0.005) V, 并呈现钝化状态, 其电化学阻抗很大, 腐蚀速率较低. 在含有较高浓度硫酸根离子的碳酸氢钠溶液中, 铁的开路电位为(-0.790±0.010) V并呈现活性溶解状态, 其电化学阻抗较小, 腐蚀速率较高, 同时阳极极化曲线上能观察到活化-钝化转变现象. 由于铁在含有较高浓度硫酸根离子的碳酸氢钠溶液中处于活化状态, 阳极极化曲线上存在数个电流峰. 足够高的硫酸根离子浓度会导致铁表面预先形成或转变而成的氧化膜失效. 相比于自然曝氧状态, 在除氧条件下较低的硫酸根离子浓度即可引起铁在碳酸氢钠溶液中由钝态向活性溶解态的转变. 相似文献
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New method for controlling the physicochemical properties and morphology of iron oxide is suggested. The methods of transmission and scanning electron microscopy and X-ray phase and thermal analysis were used to study the structure and properties of highly dispersed iron oxides formed under exposure of the reaction mixture to an external electric field. The effect of synthesis conditions on the formation of structure and morphology of particles of iron oxide, a compound that finds practical application as a pigment or catalyst base, was examined. 相似文献
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The technique of Raman microscopy has been used to identify and characterise the pigments used in red shards of medieval and earlier items of pottery which have been found in various archaeological sites in the South of Italy. The research has led to the identification, on the basis of their characteristic Raman/resonance Raman spectra, of the red pigments as iron(III) oxide (e.g. Indian Red, Red Ochre or Venetian Red) and the yellow pigments as hydrated iron(III) oxyhydroxide (e.g. Yellow Ochre and Mars Yellow). X-ray powder diffraction experiments confirm the conclusions drawn above. 相似文献
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Effect of Calcium Oxide Additive on Sorbent for High-Temperature the Performance of Iron Oxide Coal Gas Desulfurization 总被引:1,自引:0,他引:1
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Huiling Fan Kechang Xie Ju Shangguan Fang Shen Chunhu Li 《天然气化学杂志》2007,16(4):404-408
The effect of calcium oxide additive in iron oxide sorbent for hot gas desulfurization was investigated by XRD and TPR techniques. XRD characterization showed that CaO was highly dispersed after the calcination of sorbents. Calcium sulfate formed in the desulfurization was decomposed and regenerated to CaO by reacting with CO before the next sulfidation process. Calcium participated in every sulfidation/regeneration cycle and contributed to the enhancement of sulfur capacity. The TPR results showed that the reduction temperature of the sorbent increased with the increase of the content of calcium. Calcium played a role of retarding reduction. Therefore, the addition of calcium oxide additive will benefit the utilization of iron oxide sorbent in strongly reducing atmospheres. 相似文献
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Effect of Calcium Oxide Additive on the Performance of Iron Oxide Sorbent for High-Temperature Coal Gas Desulfurization
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Huiling Fan Kechang Xie Ju Shangguan Fang Shen Chunhu Li Key Laboratory for Coal Science Technology of Ministry of Education Shanxi Province Taiyuan University of Technology Taiyuan Shanxi China 《天然气化学杂志》2007,16(4)
The effect of calcium oxide additive in iron oxide sorbent for hot gas desulfurization was investigated by XRD and TPR techniques.XRD characterization showed that CaO was highly dispersed after the calcination of sorbents.Calcium sulfate formed in the desulfurization was decomposed and regenerated to CaO by reacting with CO before the next sulfidation process.Calcium participated in every sulfidation/regeneration cycle and contributed to the enhancement of sulfur capacity.The TPR results showed that the reduction temperature of the sorbent increased with the increase of the content of calcium.Calcium played a role of retarding reduction.Therefore,the addition of calcium oxide additive will benefit the utilization of iron oxide sorbent in strongly reducing atmospheres. 相似文献
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An attenuated total reflectance Fourier transform infrared spectroscopy technique has been developed utilizing an oxide coated internal reflection element to quantitatively evaluate the concentrations of three inorganic oxoanions, arsenate, sulfate, and selenate, at environmentally significant levels. Two iron oxide coatings, goethite and an iron sol-gel, were used and compared to an uncoated internal reflection element which typically has a limit of detection around 1.0 mM. The goethite coating improved the limits of detection by factors of 45.6 and 137.0 for arsenate and sulfate as compared to an uncoated cell. The iron sol coating improved the limits of detection by factors of 481.2, 156.2, and 114.0 for arsenate, sulfate, and selenate, respectively. 相似文献
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Casula MF Corrias A Arosio P Lascialfari A Sen T Floris P Bruce IJ 《Journal of colloid and interface science》2011,357(1):50-55
We report the synthesis, characterization and relaxometric study of ferrofluids based on iron oxide, with potential for use as magnetic resonance imaging (MRI) contrast agents (CAs). The effect of different cost-effective, water-based surface modification approaches which can be easily scaled-up for the large scale synthesis of the ferrofluids has been investigated. Surface modification was achieved by silanization, and/or coating with non-toxic commercial dispersants (a lauric polysorbate and a block copolymer with pigment affinic groups, namely Tween 20 and Disperbyk 190) which were added after or during iron oxide nanoparticle synthesis. It was observed that all the materials synthesized functioned as negative contrast agents at physiological temperature and at frequencies covered by clinical imagers. The relaxometric properties of the magnetic nanoparticles were significantly improved after surface coating with stabilizers compared to the original iron oxide nanoparticles, with particular reference to the silica-coated magnetic nanoparticles. The results indicate that the optimization of the preparation of colloidal magnetic ferrofluids by surface modification is effective in the design of novel contrast agents for MRI by enabling better or more effective interaction between the coated iron oxide nanoparticles and protons present in their aqueous environment. 相似文献
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An important issue in the aqueous coating process is dispersion stability. An unstable dispersion results in aggregation of the colloidal particles, thereby affecting the film coating process. In the coating suspension containing pigment, a latex for aqueous film coating might interact with pigment, resulting in unstable dispersion. We therefore conducted a stability investigation in a mixed dispersion including latexes, EudragitL30D-55 (A-latex), EudragitRL30D (C-latex) and EudragitNE30D (N-latex) and pigments, titanium dioxide and iron oxide yellow. An aggregation of the dispersion containing A-latex was observed at pH 2. Regarding the dispersions with C-latex and N-latex, no aggregation was observed in the range pH 2-11. We calculated total interaction energy between latex-latex particles, pigment-pigment particles and latex-pigment particles based on DLVO theory. The calculated results explained two mechanisms of the stable mixed dispersion. The first was that the individual latex particle and the pigment particle dispersed without aggregation in the mixed dispersion because of the electrostatic interaction. The next was that the latexes adsorbed onto the surface of the pigments, making electrostatically stable heterocoaggregates. We also calculated the binding constant of iron oxide yellow for C-latex at pH 10. The value of the constant was determined to be 1.1 x 10(-2). 相似文献
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Inductively coupled plasma atomic emission spectrometry (ICP-AES) was applied to the determination of lead, arsenic, nickel and cobalt in high-purity iron oxide pigment. Samples were dissolved with hydrochloric acid and hydrogen peroxide. The digest was passed through a column, which was packed with a polymer resin containing a neutral organophosphorus extractant, tri-n-butylphosphate. Iron was sorbed selectively on the resin and the analytes of interest passed through the column, allowing the effective separation of them from the iron matrix. Conditions of separation were optimized. The detection limits (3σ) in solution were 10, 40, 7 and 5 μg L−1, and in pigment were 0.2, 0.8, 0.14 and 0.1 mg kg−1 for lead, arsenic, cobalt and nickel, respectively. The recoveries ranged from 95% to 107% when sample digests were spiked with 5 μg of the analytes of interest, and relative standard deviations (n = 6) were 1.5-17.6% for the determination of the spiked samples. The method was successfully applied to the determination of trace amounts of these elements in high-purity iron oxide pigment samples. 相似文献