Thermal behavior of layered alpha-titanium phosphates: from the titanium(IV) bis(hydrogenphosphate) monohydrate to an europium(III)-phase via propylamine intercalation

Polycrystalline layered alpha-titanium phosphate, alpha-Ti(HPO4)(2)center dot H2O, has been obtained under H3PO4(aq) reflux conditions, and its intercalation compound with propylamine, alpha-Ti(HPO4)(2)center dot 2C(3)H(7)NH(2)center dot H2O, was used for trapping luminescent Eu-centers in two-dimensional confined space. All materials were characterized by X-ray powder diffraction, scanning electron microscopy, solid-state nuclear magnetic resonance (SS-NMR, P-31 MAS and C-13 CPMAS) and thermogravimetric analysis coupled with mass spectrometry. Moreover, the activation energy of thermal decomposition has been calculated as a function of the extent of conversion, applying both a modified Friedman method developed in our laboratory and the advanced nonlinear method proposed by Vyazovkin.