Thermoanalytical investigation of layered titanium salts

The investigated materials have similar routes of thermal decomposition; i.e. they lose their crystal water first, then at a higher temperature their structural one. At least the result TiP₂O₇ goes through a phase change at about 1000 K. The amorphous titanium phosphate lost its crystal and structural water at higher temperature than those of crystalline forms. Both α- and γ-titanium phosphates and also their transition metal containing forms have layered structure. In case of α- and γ-forms after the loss of crystal water a phase change occurs which is followed by the decomposition of the molecule. Various transition metals containing γ-titanium phosphates lose their crystal water at the same temperature, with the exception of Ni containing ones. The process is finished in this case at temperature 90 K higher than that of the others. This revised version was published online in July 2006 with corrections to the Cover Date.     

Photografting of vinyl polymers onto ultrafine inorganic particles: Photopolymerization of vinyl monomers initiated by AZO groups introduced onto these surfaces

The photografting of polymers onto ultrafine inorganic particles, such as silica and titanium oxide, initiated by azo groups introduced onto these surfaces was investigated. The introduction of azo groups onto the particles was achieved by the reaction of 4,4′-azobis(4-cyanopentanoic acid) with surface isocyanate groups, which were introduced by the treatment with tolylene 2,4-diisocyanate. It was found that the photopolymerization of vinyl monomers, such as methyl methacrylate (MMA), styrene, and N-vinylcarbazole, is initiated by ultrafine particles having azo groups. The corresponding polymers were effectively grafted onto these surfaces through the propagation of the polymer from the surface radicals formed by the photodecomposition of the azo groups: e.g., the percentage of grafting of PMMA and polystyrene onto silica was reached to 112 and 176%, respectively. The percentage of grafting onto silica in the graft polymerization initiated by photodecomposition of surface azo groups was much larger than that initiated by thermal decomposition. Polymer-grafted ultrafine particles thus obtained gave a stable colloidal dispersion in good solvents for the grafted chain. © 1994 John Wiley & Sons, Inc.     

石英晶体微天平技术研究纳米TiO_2表面Cu(Ⅱ)吸附与光化学还原过程

环境中排放的重金属离子Cu!对水生和陆生生物有强的毒害性。饮用水中Cu!的浓度高于1.0mg·L-1时,将会导致人畜得血色沉着病和胃肠粘膜病[1]。Cu!无法进行生物降解,除去废水中Cu!的常见方法有离子交换、置换、化学沉淀等[2],然而这些方法需要消耗大量的化学试剂,成本高。近来,研     

铝钛合金溴化物对直链烷烃异构化反应的催化作用

首次研究了铝铁合金溴化物的合成及其对直链烷烃异构化反应的催化作用,讨论了正戊烷的异构化反应,得到其动力学方程为1nC/C_0=-0.50t,表观活化能为26.3 kJ/moJ,测定了正己烷、正庚烷、正辛烷在不同溶剂中、不同温度下催化异构化反应的动力学曲线,为铝铁合金溴化物的工业应用提供了理论依据。     

对环氧化反应具有高催化活性的钛硅介孔分子筛的制备

 使用短链二元羧酸（包括草酸、戊二酸、柠檬酸和酒石酸）为模板剂，采用溶胶－凝胶法合成了具有大比表面积，孔径在3～7nm的钛硅介孔分子筛．EDX和紫外可见漫反射光谱的研究结果表明，所合成的钛硅介孔分子筛中钛的分布均匀，钛物种以孤立态四面体构型为主．本方法所合成的钛硅介孔分子筛对环己烯环氧化反应具有很高的催化活性和选择性．     

Adsorption, diffusion and desorption of chlorine on and from rutile TiO2{110}: a theoretical investigation.

The adsorption, diffusion and desorption of chlorine on and from stoichiometric, reduced and partially reduced (defective) rutile TiO2{110} are investigated using ab initio density functional theory (DFT) calculations. Theoretical results are compared with experimental investigations, and microkinetic simulations based on DFT values are then used to verify the diffusion mechanisms assumed in the experimental investigations.     

Preparation and characterization of nitrogen-doped TiO2 photocatalyst in different acid environments

Nitrogen-doped TiO₂ powders were successfully prepared by a wet method, i.e., a micro-emulsion-hydrothermal method, in different acid environments. Several characterization techniques, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-visible diffuse reflectance spectra, were combined to determine the crystal phase, concentration and chemical states of the nitrogen doped in TiO₂. The high photocatalytic activity of the nitrogen-doped TiO₂ was evaluated through the decomposition of rhodanmine B under visible light irradiation. It was suggested that the doped nitrogen formed oxynitride (NO) and produced impurity states at higher above the valence band of TiO₂. Therefore, the nitrogen doping could enhance the response of photocatalyst to the visible light and improve the photocatalytic activity because of the narrowing of band gap of TiO₂.     

用钐和四氯化钛体系一锅法合成咪唑烷衍生物

在四氢呋喃溶液中,用Sm/TiCl4体系还原亚胺合成了咪唑烷衍生物.发现当没有促进剂1,2-二溴乙烷时,咪唑烷衍生物的产率小于20%,加入1,2-二溴乙烷后,产率大大提高.产物的结构通过IR,1HNMR和MS光谱确证.根据实验结果提出了一个可能的反应机理.