Oxynitride phosphate glasses are a subfield of phosphate-based glasses, where part of the oxygen of the network has been replaced by nitrogen, in a process commonly called nitridation, of the phosphate melt. Because of this, the properties of the glasses are greatly enhanced, notably mechanical and chemical resistance, which has resulted in an important field with applications in glass-to-metal sealing or as electrolytes for solidstate batteries when processed as thin films. Whereas the properties of oxynitride phosphates have been thoroughly researched in view of their prospected applications, the elucidation of their structure remains uncomplete in some aspects, notably in the way that the network building groups are interconnected as well as from the point of view of the role of the modifiers onto the nitrided network structure. In the present work, 1D, 2D, REDOR, and INADEQUATE NMR experiments have been complemented with high-temperature NMR of lithium and sodium oxynitride phosphate glasses to study the structural arrangement of the building units and its evolution with temperature. The results have evidenced that the network organization adopted by the glasses distinctively depends on the nature of the modifier cation. However, the results exclude any significant phase separation or segregation of oxide and oxynitride regions, despite some clustering of nitride species may be occurring, mostly in the lithiumcontaining glasses.

NMR provides detailed structural information and the charge compensation for the Na+. A comprehensive structural characterization of a fluorophosphotellurite glass system.

Seventeen samples of acrylonitrile (AN)-co-methyl acrylate (MA)-polymer (MA content 0-11 mol%) are examined. Several selective isotopic labelings are employed (d 1 -MA, d 2 -MA, 13 CO-MA, CD 3 -MA, d 1 -AN, d 2 -AN, and 15 N-AN).The thermal treatment under inert atmosphere is investigated to gain insight into the chemical transformation mechanisms concerning the MA sub-unit. The volatiles are determined by means of evolved gas analysis (EGA) (Fourier transform infrared [FTIR] and GC/MS). Methanol is found for the first time as one decisive volatile stemming from the MA sub-unit, next to water and carbon dioxide. In addition, methylamines are proven to be formed by reaction of ammonia with the MA sub-unit, while a similar reaction of hydrogen cyanide (HCN) yielding in acetonitrile could be ruled out. Several volatile compounds could even be quantified. The non-volatile polymeric material is characterized by means of simultaneous thermal analysis (differential scanning calorimetry, thermogravimetric analysis), in-situ-FTIR spectroscopy and sophisticated solid-state NMR methods. Selected defined model compounds are synthesized and analyzed for comparison. Detailed reaction mechanisms for the thermal transformation are concluded from the results, pointing in particular to the importance of ammonia for all processes as stoichiometric and/or catalytic reagent.