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investigation is to study the effect of deposited titanium dioxide as a flame-retardant for the impartation of flame-retardancy and also as a semiconducting photocatalyst for self-cleaning properties to create photoactive flame-retarded cellulosic fabric. This

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Abstract  

Thermogravimetry-differential thermal analysis, emanation thermal analysis, mass spectrometry detection, Fourier transform infrared and XRD were used to characterize thermal behaviour of titanium dioxide photocatalyst precursors prepared by precipitation at various conditions from peroxotitanic acid sols. The transmission electron microscopy HRTEM technique was used to characterize the surface microstructure. The sols contained TiO2 anatase particles of approximately 10 nm in diameter. During heating of the air dried samples, their chemical degradation took place giving rise to anatase. On further heating, the crystallization of anatase and formation of rutile phase was observed. To test the photocatalytic activity of the samples, the decomposition of 4-chlorophenol (4-CP) under ultraviolet and visible irradiation was monitored. It was shown that photocatalytic activities of the samples are comparable to the Degussa P25 photocatalyst reference material.

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nanoparticles, titanium dioxide (TiO 2 ) nanoparticles are of biggest ecotoxicological concern due to the rapid increase of anthropogenic input of nano-TiO 2 into the environment. Titanium dioxide (TiO 2 ), a widely used mineral oxide in the cosmetics

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Reaction Kinetics, Mechanisms and Catalysis
Authors: Haiying Wang, Yucheng Yang, Jianhong Wei, Ling Le, Yang Liu, Chunxu Pan, Pengfei Fang, Rui Xiong and Jing Shi

-doped TNT samples are in the range of previously reported N-doped titanium dioxide [ 32 , 36 – 40 ]. Typically, the binding energy of NO x molecules is larger than the value of 403 eV, the binding energy of N–H bond or adsorbed NH 3 molecules is lower

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.04.007 . 18. Guo , G , Yu , J , Luo , Z , Qian , ZY , Huang , WX , Tu , MJ 2006 Study on ageing resistance of polyprplylene/nano-scale rutile titanium dioxide/POE polyolefin elastomer composites . Acta Polym Sin 2 : 219

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Modification of the physico-chemical properties of hydrous titanium dioxide (TiO2) was conducted by using binding polyacrylonitrile (PAN) for the preparation of larger size particles having higher granular strength. The thermal behavior of the obtained composite has been studied by thermogravimetric and differential thermal analysis (TG/DTA). Sorption behavior of the TiO2-PAN composite for removal of some hazardous radionuclides has been studied at different conditions such as, pH, contact time, ion concentrations and reaction temperature as well as the drying temperature. The effects of interfering ions as well as some complexing agents on the distribution ratio of the sorption process have been determined. As a result of the obtained data the optimum conditions for the removal of the studied radionuclides were recommended.

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Sorption of chromium radionuclide has been studied in the pH range of 1–10 on titanium dioxide from aqueous solutions. The adsorption isotherm obtained is of the Freundlich type. The kinetic study of adsorption and desorption of tagged chromate ions at different temperatures show that the adsorption process is exothermic innnature. Further, the feasibility of adsorption process is confirmed by calculating the thermodynamic parameters.

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This paper reports a radiochemical study of the kinetics of ion exchange of Na+ and Cs+ with H+ on hydrous titanium dioxide. The experimental conditions are set to favor the particle diffusion mechanism only, and this is confirmed by the Bt versus t plots. On the basis of these studies the various physical parameters such as the effective diffusion coefficients, activation energies and entropies of activation have been evaluated. Tentative explanations are given for these results, from which some conclusions are drawn.

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Distribution coefficients /Kd/ of lanthanide elements on layered hydrous titanium dioxide, H2Ti4O9.nH2O /where n=1.2–1.3/, have been determined as a function of the pH of the aqueous phase. The plots of 1g Kd vs. pH gave straight lines with slopes equal to +3 except for the data for heavier lanthanides, suggesting ideal ion-exchange equilibria between tervalent cations in the aqueous phase and hydrogen ions in the hydrous oxide. Mutual separations of La–Cs and La–Ba have been achieved on a column of this material on the basis of large differences in affinities between the metal ion pairs.

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Ion-exchange selectivities towards oxoanions and halide ions were studied for radio-chemical applications by an amorphous hydrous titanium dioxide (Am-HTDO) as functions of pH and concentration. The selectivity series was found to be Mo(VI)<W(VI)<P(V)<As(V)<Sb(V) for micro-amounts at pH 9 and Br Cl F for macro-amounts. A feasibility was suggested for radiochemical separations of32P by35Cl(n,)32P and77Br by75As(, 2n)77Br, and selective removal of anionic radionuclides.

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