【正文】 , and the titanium After synthesis the template be achieved by thermal treatment (calcination) or In most cases OMMTiO2 materials are pore wall material and the pore system is very important to achieve the desired properties of the pounds. The most important factor is the choice of the calcination temperature, which determines the final degree of order of the OMM and must be chosen in such a way that it is processes in the pore wall material are not destroying the pores. Several approaches to overe these limitations proposed (., the strengthening of the pores by in situ formed carbon12 or approaches like the ″brick and mortar″ strategy13).With regard to the applicability of ordered mesoporous materials (OMM) especially TiO2 based OMMs are promising materials for technical applications due to the photocatalytic properties of the anatase TiO2 It was shown thatthe nanostructuring of TiO2 is able to enhance the photocatalytic efficiency significantly pared to mercially available products (., Degussa P2514,15).The processes taking place in the OMMs during calcination are wellknown qualitatively. The temperature the approach to quantify these effects, and especially the Xray scattering of the disordered pores, is given in a recent The synthesis of OMM TiO2 materials with a defined pore wall material and well developed mesopores is not easily achievable due to the many factors influencing the crystallization of the TiO2 modifications. In the synthesis of bulk samples of TiO2 the phase relationships between brookite, anatase, and rutile are naturally influenced by temperature17 and The presence of different other materials in the sample (like metal cations or oxides19?21) is able to shift the transition temperature for the anataserutile phase transition drastically as well as the presence of different gas atmosphere during synthesis. 22 The mechanisms for the aforementioned influences onthe phase relationship are based mainly on defects in the TiO2 structure, either on the Tisites, by incorporation of other atoms, or in the form of oxygen vacancies, which play an important role if the synthesis or crystallization is carried out under reducing When synthesizing nanosized TiO2 particles the mean particle size is important for the phase relationships: rutile is the thermodynamically favorable phasein bulk materials, but as soon as the particle size is below 10?15 nm anatase is more ?25 Furthermore the presence of brookite is able to enhance the anatase rutile phase transition in As the size of the synthesized particles reaches the nanoscale the energies of the surfaces bee more and more important in relation to the bulk energies and start to determine the materials’ ?29 Ranade et give a short literature review about the possible transformations in the TiO2 system. Kirsch et behavior of anatase in mesoporous titania films and observed that in experiments carried out at different temperatures (400?450 176。C) the crystallization of anatase from the amorphous precursor starts rapidly and the crystallites are growing within a short time up to an upper limit。 at 450 176。C they observed that the crystallite size achieved 90% of its final value after 26 min. However the plex interdependencies in the crystallization processes of TiO2 in OMMs between phase stability and crystallite size (and thus the domination of surface energies) in the pore wall material make a simple prediction of the behavior of the system difficult. The key factor for a plete understanding of the synthetic processes in these materials and theordering of the pore system is to understand the crystallization of the different TiO2 modifications and their equilibriums in nanosized structured particles. Our approach to influence the crystallization of the TiO2 phases. This can impact on the mean crystallite size of the TiO2 phases and by this on the mesoporous system. We show that the application of different gas atmospheres during calcination is a simple method to achieve a desired positionof different TiO2 modifications. The processes taking place during crystallization are examined, and it is shown that by applying inert or reducing atmospheres the mesoporous system can retain a in air.Figure 1. Phase content in the samples as determined by Rietveld refinements of the powder patterns (The error of the calculation is approximately %).2. EXPERIMENTAL SECTIONThe block copolymer surfactants EO106PO70EO106 (F127, EO =?CH2CH2O,PO = ?CH2(CH3)CHO?), MW 12600 gmol) from Sigma, tetrabutyl orthotitanate TBOT), Ti(OC(CH3)3)4, HCl, C2H5OH, and CH3COOH were purchased from SigmaAldrich. The the presence of F127 triblock copolymer as structure directing agent. The molar ratio of each reagent in the starting solution was fixed at TiO2F127C2H5OHHClCH3COOH = 1::50:2:4 molar ratios. g of F127, mL of CH3COOH, and mL of HCl were dissolved in 30 mL of ethanol and then added to mL of TBOT. The mixture was stirred vigorously for 1 and aged for an additional 24 carried out in a Nabertherm tube furnace (R5050012) with temperature controller B170. Because the template was not removed under nonoxidizing atmospheres all these samples additionally with 4 . Small angle scattering data collected with a Bruker AXS D8 Advance diffractometer in transmission geometry. The machine is equipped with a Goebel mirror, fixed slits, and a secondary Nifilter. Measurements were carried out with Cukα1,kα2 radiation from 176。 to 5176。 2Θ with a step width of 176。 and 5 s measurement time per step. To ensure parability between the measurements the samples were prepared on adhesive film, so that all samples contained an equal sample volume. The sample was carried out as described in a previous work16 for the evaluation of the contribution of statistically distributed pores to the scattering. Xray powder diffraction data of the samples collected with a Bruker AXS D4 Endeavor diffractometer. The machine is equipped with fixed slits and a secondary Ni