Transfer of a Photocatalytically Active TiO Nanotube Array onto Cementitious Materials.

Due to a recent change concerning the risk and hazard regulations of titanium dioxide powders, which possibly leads to restrictions in the use of those materials in photocatalytic applications, an alternative utilization of titanium dioxide is shown in this work. This is achieved by covering surfaces of cement-based materials with a regular-shaped monolayer of photocatalytically active titanium dioxide nanotube arrays which are not affected by the regulation changes due to their shape and size. This study delivers a proposal for the synthesis of TiO nanotubes via anodization and their post-treatment to generate detached crystalline nanotube arrays which can be easily transferred onto material surfaces.

Doping homogeneity in co-doped materials investigated at different length scales.

Doping homogeneity is important for the properties of co-doped phosphors, as it can affect the energy transfer between sensitizer and activator ions. In a case study we apply different methods, that is scanning electron microscopy (SEM) combined with energy dispersive X-ray spectroscopy (EDX) mapping, SEM combined with cathodoluminescence (CL) and solid-state nuclear magnetic resonance (NMR), to study the doping homogeneity of the host system monazite LaPO4 doped with two different lanthanide ions on different length scales. A new criterion for doping heterogeneity in co-doped systems is developed, which is based on the NMR visibility function, which for this purpose is extended to doping with two or more paramagnetic dopants.

Synthesis and characterization of methylammonium phosphates as crystalline approximants for anhydrous, low melting phosphate glasses.

Low-melting methylammonium phosphate glasses are synthesized from crystalline starting agents. To this end crystalline tris(methylammonium) cyclotriphosphate [CHNH]PO, was synthesized by a novel and simple synthesis route from PO and -methylformamide. It, undergoes an irreversible phase transition to methylammonium -polyphosphate [CHNH]PO.