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纳米二氧化钛具有卓越的物理化学性能,在环境、医学、电子信息等众多领域得到了广泛的应用.然而,随着纳米二氧化钛材料的广泛应用,它给环境及人类健康带来的潜在风险也开始引起人们的关注.相关研究表明,纳米二氧化钛颗粒或含纳米二氧化钛的材料对某些生物具有明显的毒性作用,且在特定条件下这种毒性作用会加强.本文对目前有关纳米二氧化钛应用中有关环境及健康风险的文献进行了综述,在介绍纳米二氧化钛材料在光催化作用等领域应用的基础上,分析了其对环境及人类健康可能带来的潜在风险,并提出了目前研究中存在的不足及进一步研究的建议. 相似文献
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以嵌段共聚物P123为模板剂,采用蒸发诱导自组装法制备了铽负载介孔TiO2光催化剂,并利用XRD、N2吸附解吸和UV-Vis吸收光谱等技术手段对样品进行了表征。 制备的样品为锐钛矿和金红石混合晶相,以罗丹明B为模拟有机降解物,样品显示了良好的可见光催化活性。 研究发现0.7%的铽负载和380 ℃的煅烧温度是较佳的制备条件。 介孔结构所具有的高的比表面积、小的晶粒尺寸、铽负载诱导的电荷分离和可见光吸收增强协同提高了光催化活性。 同时,提出了铽负载二氧化钛诱导增强光催化作用的机理。 相似文献
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红外光谱法研究苯胺和环氧丙烷的共聚机理及共聚物的表征 总被引:1,自引:0,他引:1
采用原位红外光谱技术对苯胺和环氧丙烷的电化学共聚机理进行了研究, 研究结果表明, 环氧丙烷能在苯胺及其低聚物阳离子自由基的催化作用下发生α位开环, 与苯胺发生电化学共聚, 生成了含有芳香-脂肪醚结构的共聚物. 采用显微红外成像技术研究苯胺和环氧丙烷共聚物在电极表面的生长特点发现, 该共聚物能在电极表面从中间向两侧有规律地生长. 相似文献
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The reactions of titanium monoxide and dioxide molecules with carbon dioxide were investigated by matrix isolation infrared spectroscopy. It was found that the titanium monoxide molecule is able to activate carbon dioxide to form the titanium dioxide-carbon monoxide complex upon visible light excitation via a weakly bound TiO(η(1)-OCO) intermediate in solid neon. In contrast, the titanium dioxide molecule reacted with carbon dioxide to form the titanium monoxide-carbonate complex spontaneously on annealing. Theoretical calculations predicted that both activation processes are thermodynamically exothermic and kinetically facile. 相似文献
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A. S. Kraev A. V. Agafonov O. I. Davydova T. A. Nefedova T. A. Trusova A. G. Zakharov 《Colloid Journal》2007,69(5):620-626
Particles of titanium dioxide and titanium dioxide-hydroxypropyl cellulose organic-inorganic composite are synthesized by the sol-gel method. The effects of an electric field on the shear stress, viscosity, tensile and compression stresses of dispersions of titanium dioxide, the hybrid material, and titanium dioxide-hydroxypropyl cellulose mechanical mixture are investigated. It is established that the value of the electrorheological effect observed for hybrid material dispersions is higher than that for dispersions of titanium dioxide and mechanical mixtures of the materials. 相似文献
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K. S. Pramod V. Vijayasundaram N. Krishnakumar PL. RM. Palaniappan 《Journal of Thermal Analysis and Calorimetry》2012,108(1):133-139
This article presents the changes in the thermal properties of the control and titanium dioxide (TiO2), both nano and bulk exposed Zebrafish bones by using thermo analytical techniques. The result shows that the mass loss due
to the thermal decomposition occurs in three distinct steps due to loss of water, organic and inorganic materials. The titanium
dioxide exposed bones present a different thermal behaviour compared to the control bones. The residue masses are found to
be increased due to titanium dioxide exposure. In particular, nano titanium dioxide exposure increases the residue mass level
significantly (three fold) when compared to titanium dioxide bulk exposure. These thermal characteristics can be used as a
qualitative method to check the metal oxide intoxication in biological samples. 相似文献
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Krishna V Noguchi N Koopman B Moudgil B 《Journal of colloid and interface science》2006,304(1):166-171
Fullerenes are known for their unique electronic properties including high electron affinity. Although use of fullerenes for scavenging photo-generated electrons from titanium dioxide particles has been demonstrated, no attempts have been made to utilize the unique properties of fullerenes to increase the efficacy of photocatalysis. The present study has demonstrated that a mixture of water-soluble polyhydroxy fullerenes (PHF) and titanium dioxide (anatase polymorph) enhances photocatalytic degradation of organic dye. The PHF molecules adsorbed to the surface of titanium dioxide due to electrostatic forces, with adsorption density being higher at lower pH values. The surface coverage of titanium dioxide nanoparticles by PHF molecules determined the extent of enhancement, with an optimum dosed weight ratio of PHF to titanium dioxide at 0.001. Hydroxylation and concomitant solubilization of fullerenes allow their unique electronic properties to be harnessed for photocatalysis. 相似文献
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Determination of titanium dioxide in foods using inductively coupled plasma optical emission spectrometry 总被引:4,自引:0,他引:4
Titanium dioxide is a common food additive of increasing interest in dietary intake studies and dietary exclusion studies. Food labelling for titanium dioxide is imprecise so a method was developed for its rapid determination in foods using acid digestion and inductively coupled plasma optical emission spectrometry (ICPOES). Twenty-five foods thought to contain titanium dioxide were obtained. Based on preliminary digestion studies, samples (500 mg) were digested in 18 mol l-1 H2SO4 at 250 degrees C for 1 h and then diluted to 5.9 mol l-1 H2SO4 before determination of titanium by ICPOES at 336.121 nm. Emission intensity was suppressed by H2SO4 so standards were matched for acid concentration. Titanium dioxide embedded in gelatine was used to assess accuracy. A standard reference material of known titanium concentration and six foods of known titanium dioxide content were used as external reference materials. Limits of detection were 2-7.5 ppb, depending on spectral integration times, and the signal was linear up to 5 ppm. Results for all control samples were in good agreement with the expected values. Twelve of the foods contained detectable titanium, ranging from 0.001 to 0.782% by weight, but only eight indicated this on their labels, four being exempt under food labelling regulations. Based on food portion sizes, an individual's daily intake of titanium dioxide could exceed 200 mg from just one of these products. This method may facilitate future studies on titanium dioxide intake, given the present limitations of food labelling. 相似文献
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A. P. Voznyakovskii V. P. Ponimatkin V. V. Timkin 《Russian Journal of General Chemistry》2013,83(13):2651-2662
Finely dispersed titanium dioxide is widely used in modern technologies. Proved reserves of titanium ores in Russia are expected to meet industrial needs. However, the available facilities for the manufacture of titanium dioxide from ores are clearly insufficient, which naturally requires new plants to be put into operation. The technologies used for the production of titanium dioxide were developed as early as 1940s, when ecological aspects of the production process were almost not taken into account. The present survey analyzes environmental problems related to the titanium dioxide production according to the sulfate and chloride technologies in comparison with the fluoride process proposed for industrial implementation. The fluoride process has been examined as applied to ilmenite from the Turan deposit in Tomsk oblast, and some actions directed toward improvement of ecological parameters of this process have been proposed. 相似文献